ppeesstt mmaannaaggeemmeenntt …ipmcenters.org/pmsp/pdf/srtomato.pdf · ppeesstt...

PPPEEESSSTTT MMMAAANNNAAAGGGEEEMMMEEENNNTTT SSSTTTRRRAAATTTEEEGGGIIICCC PPPLLLAAANNN FFFOOORRR TTTOOOMMMAAATTTOOO

IIINNN VVVIIIRRRGGGIIINNNIIIAAA,,, NNNOOORRRTTTHHH CCCAAARRROOOLLLIIINNNAAA,,,

AAANNNDDD DDDEEELLLAAAWWWAAARRREEE

WWWOOORRRKKKSSSHHHOOOPPP DDDAAATTTEEE::: AAAPPPRRRIIILLL 444,,, 222000000555 PPPMMMSSSPPP CCCOOOMMMPPPLLLEEETTTEEEDDD::: JJJUUUNNNEEE 222000000666

SSSSSS oooooo uuuuuu tttttt hhhhhh eeeeee rrrrrr nnnnnn RRRRRR eeeeee gggggg iiiiii oooooo nnnnnn IIIIII PPPPPP MMMMMM CCCCCC eeeeee nnnnnn tttttt eeeeee rrrrrr

VVVVVV iiiiii rrrrrr gggggg iiiiii nnnnnn iiiiii aaaaaa TTTTTT eeeeee cccccc hhhhhh

NNNNNN oooooo rrrrrr tttttt hhhhhh CCCCCC aaaaaa rrrrrr oooooo llllll iiiiii nnnnnn aaaaaa SSSSSS tttttt aaaaaa tttttt eeeeee UUUUUU nnnnnn iiiiii vvvvvv eeeeee rrrrrr ssssss iiiiii tttttt yyyyyy

UUUUUU nnnnnn iiiiii vvvvvv eeeeee rrrrrr ssssss iiiiii tttttt yyyyyy oooooo ffffff DDDDDD eeeeee llllll aaaaaa wwwwww aaaaaa rrrrrr eeeeee

222222 000000 000000777777

Tomato Pest Management Strategic Plan – Virginia, North Carolina, Delaware 2

TABLE OF CONTENTS

WORKSHOP PARTICIPANTS AND STATE CONTACTS.................. 3

EXECUTIVE SUMMARY........................................................... 7

PRIORITIES FOR TOMATO IN VA, NC, AND DE ......................... 8

PRODUCTION and CULTURAL PRACTICES ...............................10

ARTHROPOD PESTS .............................................................12

Other Tomato Insect Pests ...................................................21

TOMATO DISEASES .............................................................27

TOMATO NEMATODES..........................................................43

EFFICACY TABLES AND TOMATO ACTIVITIES TIMELINE ...........49

ACKNOWLEDGEMENTS.........................................................57

ABBREVIATIONS .................................................................57

REFERENCES ......................................................................58


WORKSHOP PARTICIPANTS AND STATE CONTACTS

Name Email Organization/Address

Jim Belote [email protected] Extension Agent/Unit Coordinator Accomack Co. Extension P.O. Box 60 Accomac, VA 23301-0060 Billy Hall Grower, Kuzzens Tomatoes 3769 Grapeland Circle

Exmore, VA 23350 Katie Jennings [email protected] Dept. of Horticultural Science North Carolina State University 124 Kilgore Hall, Box 7609 Raleigh, NC 27695-7609 Thomas Kuhar [email protected] Dept. of Entomology Virginia Tech Eastern Shore-AREC (0512) 33446 Research Drive Painter, VA 23420-2827 David Monks [email protected] Dept. of Horticultural Science North Carolina State University 128 Kilgore Hall, Box 7609 Raleigh, NC 27695-7609 Mike Paglia UAP Cooperative

5253 Newman Lane Eastville, VA 23347

Therese Schooley [email protected] Virginia Tech Pesticide Programs (former Program Manager) 34 Agnew Hall – 0409

Blacksburg, VA 24061 Bill Shockley [email protected] Extension Agent/Unit Coordinator Northampton Co. Extension 5432-A Bayside Road Exmore, VA 23350 Jack Speese [email protected] Dept. of Entomology Virginia Tech Eastern Shore-AREC (0512) 33446 Research Drive Painter, VA 23420-2827


Rikki Sterrett [email protected] 4-H Youth Development Agent (former Horticulturalist-Eastern Shore AREC) Northampton Co. Extension 5432-A Bayside Road Exmore, VA 23420-2827 Christine Waldenmaier [email protected] Dept. of Plant Pathology (PPWS) Virginia Tech Eastern Shore-AREC (0512) 33446 Research Drive Painter, VA 23420-2827 Henry Wilson [email protected] Dept. of Weed Science (PPWS) Virginia Tech Eastern Shore-AREC (0512) 33446 Research Drive Painter, VA 23420-2827 Primary Contacts: Steve Toth [email protected] Associate Director Southern IPM Center 3318 Gardner Hall, Box 7613 Raleigh, NC 27695-7613 919-515-8879 Mike Weaver [email protected] Professor and Director

Virginia Tech Pesticide Programs Dept. of Entomology 34 Agnew Hall, MC 0409 Blacksburg, VA 24061 540-231-6543

Susan Whitney King [email protected] Extension Specialist Department of Entomology/ Wildlife Ecology University of Delaware 252 Townsend Hall Newark, DE 19716 302-831-8886 Written and Developed By: Holly Gatton [email protected] Project Manager Virginia Tech Pesticide Programs

Dept. of Entomology 34 Agnew Hall, MC 0409 Blacksburg, VA 24061


Edited By: Susan Nessler [email protected] Editor Virginia Tech Pesticide Programs Dept. of Entomology 34 Agnew Hall Blacksburg, VA 24061 540-231-8715 Contributing Authors: Thomas Kuhar [email protected] Dept. of Entomology Virginia Tech Eastern Shore-AREC (0512) 33446 Research Drive Painter, VA 23420-2827 Katie Jennings [email protected] Dept. of Horticultural Science North Carolina State University 124 Kilgore Hall, Box 7609 Raleigh, NC 27695-7609 Susan Whitney King [email protected] Extension Specialist Department of Entomology/ Wildlife Ecology University of Delaware 252 Townsend Hall Newark, DE 19716 302-831-8886 David Monks [email protected] Dept. of Horticultural Science North Carolina State University 128 Kilgore Hall, Box 7609 Raleigh, NC 27695-7609 Steve Rideout [email protected] Dept. of Plant Pathology (PPWS) Virginia Tech Eastern Shore-AREC (0512) 33446 Research Dr. Painter, VA 23420-2827

Steve Toth [email protected] Associate Director Southern IPM Center 3318 Gardner Hall, Box 7613 Raleigh, NC 27695-7613 919-515-8879


Christine Waldenmaier [email protected] Dept. of Plant Pathology (PPWS) Virginia Tech Eastern Shore-AREC (0512) 33446 Research Drive Painter, VA 23420-2827 Mike Weaver [email protected] Professor and Director Virginia Tech Pesticide Programs Dept. of Entomology 34 Agnew Hall, MC 0409 Blacksburg, VA 24061 540-231-6543

Henry Wilson [email protected] Dept. of Weed Science (PPWS) Virginia Tech Eastern Shore-AREC (0512) 33446 Research Drive Painter, VA 23420-2827


EXECUTIVE SUMMARY With the passage of the Food Quality Protection Act, an urgent need has developed to address current pest management issues and embrace alternative or “reduced risk” pest control options for various commodities. A workshop was held on April 5, 2005, in Exmore, VA, to solicit input from tomato growers, Extension agents, researchers, and specialists from Virginia, North Carolina, and Delaware in order to identify critical pest management needs in the fresh market tomato industry. The following Pest Management Strategic Plan outlines the cultural practices used in fresh tomato production along with the pests and diseases that are of greatest concern to growers. Specialists in the areas of entomology, weed science, and plant pathology have assembled data tables to demonstrate the efficacy of currently available chemical and nonchemical control methods. The critical needs outlined on the following pages must be addressed in order to ensure the success of future tomato production in the mid-Atlantic states. NOTE: Please refer to “Abbreviations” at the end of this report for a list of abbreviations and acronyms used for organizations and other terms discussed below.


PRIORITIES FOR TOMATO IN VA, NC, AND DE

RESEARCH PRIORITIES

EDUCATIONAL PRIORITIES

REGULATORY PRIORITIES

• Identify alternatives to methyl bromide.

• Develop and offer methods of methyl bromide rate reductions with plasticulture (VIF-type plastics such as solid metal and heat trap).

• Continue testing new pesticides.

• Find viable materials that are effective, yet acceptable to community (i.e., reduced-risk and IPM-friendly pesticides).

• Breed TSWV-resistant tomato varieties.

• Manage weeds: sedges (yellow, purple, and annual), common purslane, morningglory, nightshade, groundcherry, and other broadleaf weeds.

• Do research on insects (e.g., stink bugs, thrips, and spider mites).

• Do research on diseases (e.g., TSWV,

• Disseminate most current pest management information.

• Keep growers up to date on management programs including new chemistry, alternatives, and related technology.

• Maintain up-to-date, grower-friendly field and pest management guides on paper and on the web. May want to maintain guides with basic pictures and information that have a long shelf life. Out-of-print guides need to be reprinted with some new information.

• Adopt grower-friendly technology to ensure timely and efficient transfer of pest management information to growers.

• Provide publications and tools for growers.

• Develop topic-specific one- to two-page fact

• Continue to retain viable methyl bromide use under CUE.

• Make EPA aware that VIF-type plastics may be a viable solution to methyl bromide problem by reducing methyl bromide rates while retaining material.

• Need viable materials that are effective, yet acceptable to community (i.e., low-risk pesticides).

• Maintain the registration of older broad-spectrum pesticides that are viable and safe as a rotational tool for resistance management.

• Adopt Special Local Need (Section 24C) and Emergency Use Exemption (Section 18) labels in a timely and realistic manner with respect to grower needs.

• Inform EPA of the need to establish


bacterial speck, bacterial spot, botrytis, fruit rots, fusarium/verticillium wilts, and nematodes).

• Investigate threshold/damage relationships and evaluation/prediction tools for insects, diseases, and weeds.

• Manage pesticide resistance of insect, disease, and weed pests.

• Develop clear and understandable enclosed-cab safety standards.

sheets.

• Continue to retain viable methyl bromide use under CUE.

• Develop pesticide resistance management education programs to control insects, diseases, and weeds.

clear and understandable label standards for enclosed cabs.


PRODUCTION and CULTURAL PRACTICES PRODUCTION FACTS AND FIGURES

A total of 209 million lbs. of tomatoes worth nearly $96 million were produced in Virginia in 2004. Of the 5,700 acres of tomatoes planted, 5,500 acres were harvested, most of which were destined for the fresh market. Tomato production averaged 380 cwt./acre in Virginia. Much of the eastern U.S. tomato crop was lost due to hurricane damage, which caused tomato prices to jump to $45.90 per hundredweight. Virginia ranked 3rd in the nation in tomato production in 2004, producing 5.8% of the nation’s total. North Carolina ranked 9th in tomato production in 2004, producing 62 million lbs. worth $17,980,000. Delaware produced 800,000 lbs. on 60 acres (135 cwt./A) in 2001 worth $284,000.

PRODUCTION REGIONS Most of the tomatoes grown in Virginia are produced on the Eastern Shore in Accomack and Northampton counties. Tomatoes are also produced in Hanover and Westmoreland counties. The sandy loam soil that is found in these areas is excellent for tomato production. In North Carolina, tomatoes are produced mainly in the western (Henderson, Buncombe, Haywood, Macon, Polk, and Rutherford counties), Piedmont (Rowan, Cleveland, and Lincoln counties), and Coastal Plain (Sampson County) regions. Tomatoes are grown in all three of Delaware’s counties: New Castle, Kent, and Sussex.

TOMATO VARIETIES Tomato varieties suitable for Virginia’s climate include: Sunshine, Sunbeam, Sunbrite, Sun Leaper, Mountain Fresh, Mountain Bell, Florida 47, Florida 91, Plum Crimson, Plum Dandy, Carolina Gold, Mini Charm, and Juliete. All these varieties are recommended for planting in Delaware except Sun Leaper, Mini Charm, and Mountain Fresh. Additional Delaware varieties include Amelia, Floralina, Cupid, Santa, TSH4, H-9704, and H-9997. Most tomatoes grown in North Carolina are of the “Mountain” series, which were developed at NCSU. Specific tomato varieties grown in North Carolina include Amelia VR, BHN 446, BHN 640, Carolina Gold, Celebrity, Floralina, Florida 47, Mountain Crest, Mountain Fresh, Mountain Spring, Solar Set, Sun Chaser, Sun Leaper, Sunbeam, Sunrise, Cherry Grande, Mountain Belle, Sun Gold, Elfin, Jolly Elf, Navidad, Rosa, Santa Claus, Saint Nick, BHN 410, Spectrum 882, and Plum Crimson. Different tomato varieties have varying levels of resistance to certain diseases. For example, Mini Charm is resistant to verticillium wilt, fusarium wilt, and tobacco mosaic virus. However, Sunbrite, Sunbeam, Mountain Fresh, Mountain Bell, Florida 91, Sunleaper, Plum Crimson, and Plum Dandy are resistant only to verticillium and fusarium wilt. The North Carolina varieties Amelia VR and BHN 640 are resistant to TSWV.


CULTURAL PRACTICES

Tomatoes grow in a variety of soil types within Virginia, but mostly sandy loam soils. In North Carolina, tomatoes are also grown on all kinds of soil, from silty loam to Piedmont red clay. The recommended soil pH for tomato production is 6.5. However, you can add lime to raise the pH if it is less than 6.0. Apply nitrogen, potassium, and phosphorus at a rate of 40 to 50 lbs./A at four different times: 1) just before laying plastic mulch, 2) after the seedlings are planted, 3) when the fruit is first set, and 4) when the fruit begins to ripen. If soil analyses indicate deficiencies in other micronutrients, they may need to be supplemented. For example, calcium is one of the more important micronutrients, especially for the prevention of blossom-end rot.

Treat tomato seeds with chlorine to prevent the development of bacterial canker, bacterial spot, and bacterial speck. This treatment can be done either by the seed company or by the producer. Typically, tomato seedlings are hardened before they are planted in order to improve their success rate once placed in the field. In Virginia this is done by withholding nitrogen and water while allowing plants to wilt slightly between bouts of light irrigation. North Carolina recommendations call for withholding water but not fertilizer. Both states discourage hardening seedlings by exposing them to cool temperatures because this causes “catfacing.”

Transplant tomato seedlings in the spring from mid-April through May. Space the raised, dome-shaped rows about 4 to 6 ft. apart. Plant individual tomato seedlings 15 to 36 inches apart within the row, depending on whether they are determinate or indeterminate varieties. Eastern Shore tomatoes are grown mainly on top of black plastic mulch with overhead or drip irrigation. Tomato plants are then pruned, staked, and tied with string to improve productivity and facilitate harvesting. Tomatoes are grown in a similar fashion in other areas of Virginia and North Carolina. However, some bare-ground fields without irrigation or stakes can also be found.

Mature tomatoes are harvested beginning in mid-June while they are still green and more tolerant of handling, shipping, and storage. Although tomato harvests peak in mid-July to early August, producers often stagger plantings throughout the season so the fruit can be gathered until the first killing frost of the fall. All Virginia tomatoes are harvested by hand three to six times per season. Most North Carolina tomatoes are vine ripened, hand harvested, or field packed.


ARTHROPOD PESTS Stink bugs and thrips are the most common pests of early-season tomatoes in Virginia. Tomato fruitworms and aphids, however, can be very damaging to the late-season crop. Colorado potato beetles have been problematic in the Northern Neck region as a result of their adaptation to tomato. Nonetheless, they have not been major pests of this crop on the Eastern Shore. This is most likely due to the abundance of their preferred host (potato) as well as the widespread use of Admire™. This pesticide has greatly reduced the CPB population. In addition, spider mites (Tetranychus urticae), beet armyworms (Spodoptera exigua), fall armyworms (Spodoptera frugiperda), cabbage loopers (Trichoplusia ni), and fruit flies (Drosophila melanogaster) may cause problems under unusual conditions resulting from weather or seasonal variations throughout the state. Spider mites, for example, are particularly devastating in dry years. Tomato pinworms (Keiferia lycopersicella) and vegetable leafminers (Liriomyza sativae), which were once serious problems due to insecticide resistance, may also occur during dry years. Recent chemical developments have put several effective insecticides on the market to control these pests. Changes in cultural practices (e.g., growing transplants locally instead of bringing them up from Florida and discontinuing cull piles) have also played a role in the reduction of these two pests. European corn borers (Ostrinia nubilalis), flea beetles (Family: Chrysomelidae), tomato hornworms (Manduca quinquemaculata), tobacco hornworms (Manduca sexta), true armyworms (Pseudaletia unipuncta) and whiteflies (Family: Aleyrodidae) also occur in Virginia tomato fields. These pests, however, are not difficult to control given the current availability of labeled insecticides.

INSECTS

Green Peach Aphid, Myzus persicae Potato Aphid, Macrosiphum euphorbiae

In a survey of Virginia tomato growers, 75% of respondents expressed concern about the impact of aphids on production. Both species listed above are common pests of tomatoes in Virginia, although the potato aphid is more prevalent than the green peach aphid. Typically, aphids feed on the underside of leaves, causing severe curling and reduced photosynthate potential. The feeding of large aphid populations results in the excretion of large amounts of honeydew, which supports the growth of secondary fungal diseases. Aphids may also function as vectors of certain viral diseases of tomato. Virginia aphid populations begin increasing from May through June and again in mid-September through October. Even so, aphids tend to be only a low to moderate pest concern to tomato growers. This is because plant viruses are often managed by varietal resistance and because these


insects are easily killed by natural enemies. Aphids also succumb to insecticides used for other pests.

MONITORING: Scout the tomato plants. Make an insecticide application if you see at least one aphid on 25% or more of the fully expanded compound leaves.

CHEMICAL CONTROL: The potato aphid is easily controlled with broad-spectrum insecticides, and supplemental sprays are rarely warranted. Green peach aphids are harder to kill using pyrethroids, but they are not as troublesome in the DELMARVA region. Pesticides used to treat thrips will also control aphid populations. Neonicotinoids applied through the canopy will also control aphids.

• cyfluthrin (Baythroid 2E) – Pyrethroid. PHI = 0 days. Apply at a rate of 0.025 – 0.044 lb. a.i./A for control of ECB, CPB, potato aphids, stink bugs, tomato fruitworms, and tomato hornworms. For control of cabbage loopers, tomato pinworms, variegated cutworms, and 1st or 2nd instars of SAW, BAW, and YAW, use 0.033-0.044 lb. a.i./A. Use 0.044 lb. a.i./A for control of flea beetles. Do not exceed 0.26 lb. a.i./A/season. REI = 24 hours. RESTRICTED USE PESTICIDE.

• dimethoate (Dimethoate 4EC) – Organophosphate. PHI = 7 days. Apply at a rate of 0.25 – 0.50 lb. a.i./A for control of aphids. REI = 48 hours.

• endosulfan (Thiodan) – Organochlorine. PHI = 2 days. Apply at a rate of 0.50 – 1.00 lb. a.i./A for control of aphids and stink bugs (higher rate). REI = 48 hours.

• imidacloprid (Admire 2F, Provado 1.6 F) – Neonicotinoid. PHI = 21 days (Admire 2F) and 0 days (Provado 1.6F). Apply Admire at a rate of 0.25 – 0.38 lb. a.i./A and Provado at a rate of 0.05 lb. a.i./A for control of thrips and aphids. Admire is a soil insecticide, whereas Provado is a foliar insecticide. Do not exceed 0.50 lb. a.i./A/season, regardless of application method or formulation. REI = 12 hours.

• methamidophos (Monitor 4EC) – Organophosphate. PHI = 7 days. Apply at a rate of 0.75 – 1.00 lb. a.i./A for control of aphids, stink bugs, thrips, and tomato fruitworms. REI = 48 hours. SECTION 24C (SLN) PESTICIDE.

• thiamethoxam (Platinum 21.6SC) – Neonicotinoid. PHI = 30 days. Apply at a rate of 0.078 – 0.125 lb. a.i./A for control of aphids, flea beetles, CPB, and whiteflies. REI = 12 hours.


BIOLOGICAL CONTROL: Natural aphid predators (e.g., lady beetles and parasitic wasps) will help to control population size. The preservation of these natural enemies should be considered when making chemical control decisions.

CULTURAL CONTROL: No effective commercial controls are available.

TO DO: None

Colorado Potato Beetle, Leptinotarsa decemlineata

Colorado potato beetle (CPB) adults and larvae can defoliate tomato plants. Adults migrate to tomato fields in early summer after emerging from spring potato fields.

MONITORING: Inspect plants for adults, eggs, or larvae beginning in mid-June.

CHEMICAL CONTROL: Neonicotinoid insecticides applied as a transplant drench, irrigation injection, or foliar spray provide excellent control.

• abamectin (Agri-Mek 0.15EC) – Avermectin. PHI = 7 days. Apply 0.01 – 0.02 lb. a.i. /A. REI = 12 hours. Used in early-season infestations because of long REI. RESTRICTED USE PESTICIDE.

• cryolite (Kryocide 96WP, Prokil 96WP) – Inorganic fluorine. PHI = 0 days. Apply Kryocide at a rate of 14.40 – 28.80 lbs. a.i./A and Prokil at a rate of 24 – 48 lbs. a.i./A for control of tomato fruitworms. REI = 12 hours.

• cyfluthrin (Baythroid 2E) – Pyrethroid. PHI = 0 days. Apply at a rate of 0.025 – 0.044 lb. a.i./A for control of ECB, CPB, potato aphids, stink bugs, tomato fruitworms, and tomato hornworms. For control of cabbage loopers, tomato pinworms, variegated cutworms, and 1st or 2nd instars of SAW, BAW, and YAW, use 0.033 – 0.044 lb. a.i./A. Use 0.044 lb. a.i./A for control of flea beetles. Do not exceed 0.26 lb. a.i./A/season. REI = 24 hours. RESTRICTED USE PESTICIDE.

• cyromazine (Trigard 75WP) – Triazine. PHI = 0 days. For the control of CPB and leafminers, apply 0.124 lb. a.i./A. A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Trigard from 2003 to 2004.

• imidacloprid (Admire 2F, Provado 1.6F) – Neonicotinoid. PHI = 21 days (Admire 2F) and 0 days (Provado 1.6F). Apply Admire at a rate of 0.25 – 0.38 lb. a.i./A and Provado at a rate of 0.05 lb. a.i./A for control of thrips and aphids. Admire is a soil insecticide, whereas Provado is a foliar insecticide. Do not exceed 0.50 lb. a.i./A/season, regardless of application method or formulation. REI = 12 hours.


• spinosad (SpinTor 2SC) – Spinosyn. PHI = 1 day. Apply at a rate of 0.06 – 0.13 lb. a.i./A for control of FAW, thrips, and tomato fruitworms. Do not exceed 0.45 lb. a.i./A/season. REI = 48 hours.

• thiamethoxam (Platinum 22SC, Actara 25WDG) – Neonicotinoid. PHI = 30 days. Apply Platinum at a rate of 0.078 – 0.125 lb. a.i./A for control of aphids, flea beetles, CPB, and whiteflies. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 50% of farmers used Platinum and 25% of farmers used Actara from 2003 to 2004.

BIOLOGICAL CONTROL: No effective commercial controls are available.

CULTURAL CONTROL: No effective cultural controls are available, but stink bugs tend to move into tomato crops from weeds located in surrounding fields.

TO DO: • Conduct research on new insecticide chemistries and residual efficacy of existing products. • Continue to research neonicotinoids as alternatives to current pesticides. • Refine scouting methods and conduct research on the use of pheromone traps for monitoring.

Lepidopteran Pests

Tomato Fruitworm, Helicoverpa zea Beet Armyworm, Spodoptera exigua

Southern Armyworm, S. eridania True Armyworm, Pseudaletia unipuncta

Fall Armyworm, S. frugiperda Yellow-Striped Armyworm, S. ornithogalli

The tomato fruitworm, also known as the corn earworm, soybean podworm, or the cotton bollworm, is generally a problem from mid-July to late August on late-planted tomatoes. This pest is a major problem on fall tomato crops in the DELMARVA region, but it is only a nuisance on spring crops. Once nighttime temperatures become cooler in the early fall, the fruitworm populations begin to decrease. Fruitworms feed on leaf tissue, causing tomatoes to look ragged. They also feed directly on the fruit, rendering them completely unmarketable. Given the high value of tomatoes, Virginia producers do not tolerate such damage. Beet armyworms are a sporadic pest of tomatoes in northern regions, but every few years they can be a big problem in Virginia (usually in late August). In southern regions, armyworms are an annual pest. Armyworms feed on both tomato foliage and fruit, whereas fruitworms consume only the tomatoes themselves. Beet armyworms are notorious for their high fertility rate and resistance to


several types of pesticides. Now, however, new insecticides are helping to manage their populations. True armyworms, fall armyworms, and beet armyworms may occur in Virginia, while southern armyworms, yellow-striped armyworms, and beet armyworms can be found in North Carolina. True armyworms are not considered pests of commercial tomatoes. In a survey of Virginia tomato growers, 75% of respondents expressed concern about the impact of armyworms on production. Only 25% of growers were concerned about tomato fruitworms. MONITORING: Blacklight and pheromone traps can monitor moth flight and alert producers of peak moth activity. Treatment is recommended if fruitworm moth catches in local blacklight traps average ≥ 20 per night once most corn in the area has matured. However, since the damage threshold is so low due to the high value of tomatoes, pesticide applications are sometimes made as soon as the pest is observed. CHEMICAL CONTROL: Insecticides for control of fruitworms should be applied every 5 – 7 days following the initial spray at the threshold recommended above. Pyrethroids are frequently used to control fruitworms. However, recent tests have indicated that more chemicals are needed to kill these pests, so insecticide resistance could soon be an issue. Reducing the number of sprays and thresholds can be risky due to a decrease in marketable fruit. Although it may be possible to reduce the number of pesticide applications based on research data, it would be difficult to implement this change. Fresh market fruit is ruined by minor damage and cannot be sold. Reducing the number of sprays by extending the time interval between applications could make tomato fruit vulnerable to a great deal of damage.

• cryolite (Kryocide 96WP, Prokil 96WP) – Inorganic fluorine. PHI = 0 days. Apply Kryocide at a rate of 14.40 – 28.80 lbs. a.i./A and Prokil at a rate of 24 – 48 lbs. a.i./A for control of tomato fruitworms. REI = 12 hours.


• lambda-cyhalothrin (Warrior) – Pyrethroid. PHI = 5 days. Apply at a rate of 0.02 – 0.03 lb. a.i./A for control of fruitworms, pinworms, armyworms, ECB, CPB, leafminers, flea beetles, aphids, whiteflies, stink bugs, mites, and thrips. For control of cabbage loopers,


cutworms, and hornworms, apply 0.015 – 0.025 lb. a.i./A. Do not exceed 0.36 lb. a.i./A/season. REI = 24 hours. RESTRICTED USE PESTICIDE.

• esfenvalerate (Asana XL) – Pyrethroid. PHI = 1 day. Apply at a rate of 0.015 – 0.05 lb. a.i./A for control of tomato fruitworms, hornworms, armyworms, cabbage loopers, CPB, cutworms, flea beetles, potato aphids, tomato pinworms, whiteflies, and leafminers. Do not exceed 0.50 lb. a.i./A/season. REI = 12 hours. RESTRICTED USE PESTICIDE.

• fenpropathrin (Danitol 2.4EC) – Pyrethroid. PHI = 3 days. Apply at a rate of 0.15 – 0.20 lb. a.i./A for control of tomato fruitworms, stink bugs, hornworms, spider mites, armyworms, whiteflies, thrips, cabbage loopers, and tomato pinworms. Do not exceed 0.80 lb. a.i./A/season. REI = 24 hours. RESTRICTED USE PESTICIDE.


• methomyl (Lannate LV) – Carbamate. PHI = 1 day. Apply at a rate of 0.45 lb. a.i./A for control of aphids, 0.60 lb. a.i./A for control of FAW and a rate of 0.45 – 0.90 lb. /A for control of tomato fruitworms. REI = 48 hours. Methomyl is used to treat fruitworms that are 4th instar or larger. It is an important tool used as part of the pesticide rotation recommended for resistance management. However, methomyl has undesirable qualities in that it kills beneficial insects and has a long REI.


• tebufenozide (Confirm 2F) – Diacylhydrazine. PHI = 7 days. Apply at a rate of 0.13 – 0.25 lb. a.i./A for control of FAW. Do not apply more than 1.00 lb. a.i./A/season. REI = 12 hours.

BIOLOGICAL CONTROL: Various hymenopteran parasitoids as well as generalist predators such as ladybird beetles and predatory bugs play an important role in killing eggs and small larvae of most of the lepidopteran species. Applications of biologically based insecticides such as Bacillus thuringiensis subsp. kurstaki (Javelin), azadirachtin, or nuclear polyhedrosis viruses (Gem-Star or Spod-X) provide moderate to good levels of control depending on pest species.


CULTURAL CONTROL: Late-planted tomatoes are at a higher risk of fruitworm infestation than those planted early because populations are often generated from infestations in nearby corn. Weeds serve as oviposition sites for armyworms. Control weeds both within the tomato field and in surrounding areas.

TO DO: • Administer educational programs on resistance management, especially all broad-spectrum insecticides. • Research new pesticides to deal with potential insecticide resistance in beet armyworm and fruitworms.

Green Stink Bug, Acrosternum hilare Brown Stink Bug, Euschistus servus

Both green and brown stink bugs are high-priority pests in tomato fields in Virginia, particularly of developing fruit during the spring. In a survey of Virginia tomato growers, all the respondents expressed concern about the impact of stink bugs on production. Stink bug feeding causes minute puncture marks in the fruit surrounded by a yellow halo, which greatly reduces market value. The ability to hide and move quickly makes stink bugs hard to monitor and treat. MONITORING: Monitor fields, particularly the outer edges, for stink bugs on a weekly basis. However, scouting for stink bugs is difficult because they drop from the plant when disturbed. This behavior makes it hard to establish a treatment threshold. For best results, make an insecticide application once stink bugs are spotted in a field and two to three areas in the field show fruit damage. CHEMICAL CONTROL: Insecticides provide the only effective form of stink bug control. Brown stink bugs remain harder to kill than green stink bugs. Pyrethroids are the most common class of chemicals used to treat stink bugs.

• cyfluthrin (Baythroid 2E) – Pyrethroid. PHI = 0 days. Apply at a rate of 0.025 – 0.044 lb. a.i./A for control of ECB, CPB, potato aphids, stink bugs, tomato fruitworms, and tomato hornworms. For control of cabbage loopers, tomato pinworms, variegated cutworms, and first or second instars of SAW, BAW, and YAW, use 0.033 – 0.044 lb. a.i./A. Use 0.044 lb. a.i./A for control of flea beetles. Do not exceed 0.26 lb. a.i./A/season. REI = 24 hours. RESTRICTED USE PESTICIDE.

• lambda-cyhalothrin (Warrior) – Pyrethroid. PHI = 5 days. Apply at a rate of 0.02 – 0.03 lb. a.i./A for control of fruitworms, pinworms,


armyworms, ECB, CPB, leafminers, flea beetles, aphids, whiteflies, stink bugs, mites, and thrips. For control of cabbage loopers, cutworms, and hornworms, apply 0.015 – 0.025 lb. a.i./A. Do not exceed 0.36 lb. a.i./A/season. REI = 24 hours.

• endosulfan (Thiodan) – Organochlorine. PHI = 2 days. Apply at a rate of 0.50 – 1.00 lb. a.i./A for control of aphids and stink bugs (higher rate). REI = 48 hours. Use of endosulfan is discouraged due to water pollution issues.

• methamidophos (Monitor 4EC) – Organophosphate. PHI = 7 days. Apply at a rate of 0.75 – 1.00 lb. a.i./A for control of aphids, stink bugs, thrips, and tomato fruitworms. REI = 48 hours. SECTION 24C (SLN) PESTICIDE. Use of methamidophos is discouraged due to its unpleasant smell.

BIOLOGICAL CONTROL: No effective commercial controls are available. CULTURAL CONTROL: No effective cultural controls are available, but stink bugs tend to move into tomato crops from weeds located in surrounding fields. TO DO: • Conduct research on new insecticide chemistries and residual efficacy of existing products. • Continue to research neonicotinoids as alternatives to current pesticides. • Refine scouting methods and conduct research on the use of pheromone traps for monitoring.

Tobacco Thrips, Frankliniella fusca

Western Flower Thrips, F. occidentalis Thrips are tiny, spindle-shaped insects that feed on the leaves of seedling tomato plants, in the blossoms, and on the developing fruit. This feeding may cause leaf crinkling, reduced photosynthetic potential, plant stunting, and virus transmission. Thrips are the most important insect pest of crops in Virginia. In a survey of Virginia tomato growers, 75% of respondents expressed concern about the impact of thrips on production. Two species of thrips, Frankliniella fusca and F. occidentalis, can transmit the devastating disease known as tomato spotted wilt virus. As these insects feed, the virus moves from their bodies through their mouthparts into the plant. Thrips may also damage tomato crops when they lay their eggs in small developing fruit. This activity leaves scars and reduces the marketability of the tomatoes. Thrips can complete several generations per season in Virginia under favorable conditions, although cold winters will kill them. It is


important to note that greenhouse infestations can be transferred when tomato seedlings are replanted outdoors. MONITORING: Scouting should begin at plant emergence or immediately after transplant and continue for approximately six weeks after planting. Thrips are attracted to things that are yellow, including the flowers of nearby plants. If you find thrips, you should apply insecticides. CHEMICAL CONTROL: Apply insecticides at planting to help prevent thrips infestation in fields or areas with a history of their presence. You may also use insecticides for control when thrips are first observed in the field. You can achieve good control by planting resistant tomato varieties, using silver reflective mulch, and applying a neonicotinoid through the canopy.


• lambda-cyhalothrin (Warrior) – Pyrethroid. PHI = 5 days. Apply at a rate of 0.02 – 0.03 lb. a.i./A for control of fruitworms, pinworms, armyworms, ECB, CPB, leafminers, flea beetles, aphids, whiteflies, stink bugs, mites, and thrips. For control of cabbage loopers, cutworms, and hornworms, apply 0.015 – 0.025 lb. a.i./A. Do not exceed 0.36 lb. a.i./A/season. REI = 24 hours. RESTRICTED USE PESTICIDE.


• imidacloprid (Admire 2F, Provado 1.6F) – Neonicotinoid. PHI = 21 days (Admire 2F) and 0 days (Provado 1.6F). Apply Admire at a rate of 0.25 – 0.38 lb. a.i./A and Provado at a rate of 0.05 lb. a.i./A for control of thrips and aphids. Admire is a soil insecticide, whereas Provado is a foliar insecticide. Do not exceed 0.50 lb. a.i./A/season, regardless of application method or formulation. REI = 12 hours.

• methamidophos (Monitor 4EC) – Organophosphate. PHI = 7 days. Apply at a rate of 0.75 – 1.00 lb. a.i./A for control of aphids, stink


bugs, thrips, and tomato fruitworms. REI = 48 hours. SECTION 24C (SLN) PESTICIDE.


BIOLOGICAL CONTROL: No effective commercial controls are available. CULTURAL CONTROL: Planting tomatoes later often helps to reduce thrips pressure because they are not generally a problem late in the growing season. Use aluminum silver mulch instead of black plastic to repel thrips. Overwintering weeds must be controlled because they serve as a food source for thrips. Plant resistant varieties of tomatoes. TO DO: • Continue to incorporate current research into educational programs. • Educate growers on the use of reflective mulch and resistant varieties to control tomato spotted wilt virus. • Research and monitor populations south of Virginia. • Evaluate the benefit of growing tomato transplants in state vs. shipping them in from the southern United States. • Research the use of high barrier plastic, which results in lower fumigation rates and better gas retention.

Other Tomato Insect Pests Other minor tomato insect pests include cabbage loopers, tomato pinworms, vegetable leafminers, and fruit flies. These insects may cause problems under unusual conditions, often due to seasonal variations. In a survey of Virginia tomato growers, 75% of respondents expressed concern about the impact of leafminers on production. Cutworms, European corn borers, flea beetles, tomato hornworms, tobacco hornworms, true armyworms, and whiteflies are also pests of tomatoes in Virginia. However, they are sporadic and/or easily controlled with currently labeled insecticides. In a survey of Virginia tomato growers, 75% of respondents expressed concern about the impact of flea beetles on production.


MITES

Two-Spotted Spider Mite, Tetranychus urticae Broad Mite, Polyphagotarsonemus latus Carmine Spider Mite, T. cinnabarinus

Spider mites, particularly the two-spotted spider mite, have become a serious pest in tomato crops. In a survey of Virginia tomato growers, 100% of respondents expressed concern about the impact of mites on production. Mites overwinter on weeds or certain winter crops and move onto adjacent tomato plots in the spring as the weeds die. They feed on tomato foliage, causing a reduction in yield due to reduced photosynthate potential. Spider mite feeding may also contribute to the fruit discoloration known as gold fleck. Spider mite populations become more obvious during hot, dry weather, particularly in July when wheat is harvested. MONITORING: Sample ten terminal leaflets from the upper 1/3 of the plant with a minimum of five sample sites per field. If more than two mites per leaflet are found, apply a miticide. CHEMICAL CONTROL: Pyrethroids and neonicotinoids can worsen mite problems. Two-spotted spider mite is notorious for developing resistance to miticides quickly, so it is extremely important to rotate chemicals with different modes of action.

• abamectin (Agri-Mek 0.15EC) – Avermectin. PHI = 7 days. Apply 0.01 – 0.02 lb. a.i. /A. REI = 12 hours. RESTRICTED USE PESTICIDE.

• bifenazate (Acramite 50WS) – Diphenyl. PHI = 3 days. Used near harvest time for mite control. Apply 0.375 – 0.5 lb. a.i./A. REI = 12 hours.

• dicofol (Kelthane MF 42EC) – Organochlorine. PHI = 2 days. Apply 0.315 – 0.63 lb. a.i./A. Used, but resistance has reduced effectiveness. REI = 12 hours.


• oxamyl (Vydate 24SC) – Carbamate. Used on mites, but resistance has reduced effectiveness. A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Vydate from 2003 to 2004. RESTRICTED USE PESTICIDE.


BIOLOGICAL CONTROL: No effective commercial controls are available. CULTURAL CONTROL: Horticultural oils can be used to prevent mite infestations. TO DO: • Need good, proven controls. • Need research on potential causes of outbreaks (effects on beneficials), evaluation of efficacy of chemicals (including new chemistry), and insecticide resistance. • Need products that can be applied in combination to reduce the number of applications. This includes fungicides and miticides. • Need to reduce the number of pesticide applications if possible.

SUMMARY - CHEMICAL ARTHROPOD CONTROL The most recent pesticide use survey for tomatoes grown in Virginia was completed in 1992. According to this report, insecticides were used by 75.8% of tomato producers on 20,854 of the treatment acres. However, this information is rather outdated. Currently, tomato producers in Virginia average one to two insecticide applications per week from the time seedlings are transplanted until harvest. It is estimated that 100% of the tomato acreage in the state is treated with insecticides, even organically grown tomatoes, which are treated with Bacillus thuringiensis for worm control. The list of chemicals below is representative of the 2000 insecticide recommendations for commercially grown tomatoes. However, the most frequently used insecticides include Baythroid 2E, Warrior T, Danitol 2.4EC, Admire 2F, Provado 1.6F, and SpinTor 2SC.

• abamectin (Agri-Mek 0.15EC) – Avermectin. PHI = 7 days. For control of CPB, leafminers, mites, and tomato pinworm adults, apply 0.01 – 0.02 lb. a.i. /A. REI = 12 hours. Used in early-season infestations because of long REI. RESTRICTED USE PESTICIDE.

• bifenazate (Acramite 50WS) – Diphenyl. PHI = 3 days. Used near harvest time for mite control. Apply 0.375 – 0.5 lb. a.i./A. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 50% of farmers used Acramite from 2003 to 2004.

• Bacillus thuringiensis - A survey of tomato growers conducted in February 2005 indicated that 75% of farmers used Bt from 2003 to 2004.

• cryolite (Kryocide 96WP) – Inorganic fluorine. PHI = 14 days. Apply Kryocide at a rate of 8 – 16 lbs. a.i./A for control of tomato


fruitworms, CPB larvae, hornworms, flea beetles, cabbage loopers, and pinworms. REI = 12 hours.

• cyfluthrin (Baythroid 2E) – Pyrethroid. PHI = 0 days. Apply at a rate of 0.025 – 0.044 lb. a.i./A for control of ECB, CPB, potato aphids, stink bugs, tomato fruitworms, thrips, and tomato hornworms. For control of cabbage loopers, tomato pinworms, variegated cutworms, and 1st or 2nd instars of SAW, BAW, and YAW, use 0.033 – 0.044 lb. a.i./A. Use 0.044 lb. a.i./A for control of flea beetles. Do not exceed 0.26 lb. a.i./A/season. REI = 12 hours. RESTRICTED USE PESTICIDE. A survey of tomato growers conducted in February 2005 indicated that 50% of farmers used Baythroid from 2003 to 2004.

• lambda-cyhalothrin (Warrior) – Pyrethroid. PHI = 5 days. Apply at a rate of 0.02 – 0.03 lb. a.i./A for control of fruitworms, pinworms, armyworms, ECB, CPB, leafminers, flea beetles, aphids, whiteflies, stink bugs, mites, and thrips. For control of cabbage loopers, cutworms, and hornworms, apply 0.015 – 0.025 lb. a.i./A. Do not exceed 0.36 lb. a.i./A/season. REI = 24 hours. A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used Warrior from 2003 to 2004. RESTRICTED USE PESTICIDE.

• zeta-cypermethrin (Mustang Max 10EC) - A survey of tomato growers conducted in February 2005 indicated that 50% of farmers used Mustang Max from 2003 to 2004. RESTRICTED USE PESTICIDE.

• cyromazine (Trigard 75WP) – Triazine. PHI = 0 days. For the control of CPB and leafminers, apply 0.124 lb. a.i./A. A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Trigard from 2003 to 2004.

• dicofol (Kelthane MF 42EC) – Organochlorine. PHI = 2 days. For the control of mites, apply 0.315 – 0.63 lb. a.i./A. Used, but resistance has reduced effectiveness. REI = 12 hours.

• dimethoate (Dimethoate 4EC) – Organophosphate. PHI = 7 days. Apply at a rate of 0.25 – 0.50 lb. a.i./A for control of aphids. REI = 48 hours. A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Dimethoate from 2003 to 2004.

• emamectin benzoate (Proclaim 5WDG) - A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Proclaim from 2003 to 2004. RESTRICTED USE PESTICIDE.

• endosulfan (Thiodan) – Organochlorine. PHI = 2 days. Apply at a rate of 0.50 – 1.00 lb. a.i./A for control of aphids and stink bugs (higher rate). REI = 48 hours.


• esfenvalerate (Asana XL) – Pyrethroid. PHI = 1 day. Apply at a rate of 0.015 – 0.05 lb. a.i./A for control of tomato fruitworms, hornworms, armyworms, cabbage loopers, CPB, cutworms, flea beetles, potato aphids, tomato pinworms, whiteflies, and leafminers. Do not exceed 0.50 lb. a.i./A/season. REI = 12 hours. RESTRICTED USE PESTICIDE. A survey of tomato growers conducted in February 2005 indicated that 50% of farmers used Asana from 2003 to 2004.

• fenpropathrin (Danitol 2.4EC) – Pyrethroid. PHI = 3 days. Apply at a rate of 0.15 – 0.20 lb. a.i./A for control of tomato fruitworms, stink bugs, hornworms, spider mites, armyworms, whiteflies, thrips, cabbage loopers, and tomato pinworms. Do not exceed 0.80 lb. a.i./A/season. REI = 24 hours. RESTRICTED USE PESTICIDE. A survey of tomato growers conducted in February 2005 indicated that 50% of farmers used Danitol from 2003 to 2004.

• imidacloprid (Admire 2F, Provado 1.6 F) – Neonicotinoid. PHI = 21 days (Admire 2F) and 0 days (Provado 1.6F). Apply Admire at a rate of 0.22 – 0.32 lb. a.i./A for control of thrips, aphids, and CPB, and Provado at a rate of 0.05 lb. a.i./A for control of thrips and aphids. Admire is a soil insecticide, whereas Provado is a foliar insecticide. Do not exceed 0.50 lb. a.i./A/season, regardless of application method or formulation. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used Admire from 2003 to 2004.

• indoxacarb (Avaunt 30WDG) – A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used Avaunt from 2003 to 2004.

• malathion (Malathion 57EC) – A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Malathion from 2003 to 2004.


• methomyl (Lannate LV) – Carbamate. PHI = 1 day. Apply at a rate of 0.45 lb. a.i./A for control of aphids, 0.60 lb. a.i./A for control of FAW, and 0.45 – 0.90 lb. a.i./A for control of tomato fruitworms. REI = 48 hours. A survey of tomato growers conducted in February 2005 indicated that 50% of farmers used Lannate from 2003 to 2004.

• oxamyl (Vydate 2L) – Carbamate. PHI = 1 day. Apply at a rate of 0.50 – 1.00 lb. a.i./A for control of aphids. REI = 48 hours. (Vydate 24SC) – Used on mites, but resistance has reduced effectiveness.


RESTRICTED USE PESTICIDE. A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Vydate from 2003 to 2004.

• pymetrozine (Fulfill 50WDG) – A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Fulfill from 2003 to 2004.

• spinosad (SpinTor 2SC) – Spinosyn. PHI = 1 day. Apply at a rate of 0.02 – 0.12 lb. a.i./A for control of armyworms, thrips, CPB larvae, leafminers, ECB, hornworms, and tomato fruitworms. Do not exceed 0.45 lb. a.i./A/season. REI = 48 hours. A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used SpinTor from 2003 to 2004.

• tebufenazide (Confirm 2F) – Diacylhydrazine. PHI = 7 days. Apply at a rate of 0.13 – 0.25 lb. a.i./A for control of FAW. Do not apply more than 1.00 lb. a.i./A/season. REI = 12 hours.

• thiamethoxam (Platinum 22SC, Actara 25WDG) – Neonicotinoid. PHI = 30 days. Apply Platinum at a rate of 0.078 – 0.125 lb. a.i./A for control of aphids, flea beetles, CPB, and whiteflies. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 50% of farmers used Platinum and 25% of farmers used Actara from 2003 to 2004.


TOMATO DISEASES Disease control is often the most important, yet challenging, aspect of tomato production in Virginia. This is due primarily to the large number of diseases that infect tomatoes, but also to the limited availability of control options. In particular, early blight, Septoria leaf spot, and bacterial leaf spot are common problems in Virginia. In addition, bacterial and fungal wilts can infect large sections of the field and kill the plants by season’s end. Other diseases often found on tomatoes include botrytis rot (gray mold), southern blight (Sclerotium), timber rot (Sclerotinia), and fruit rots.

BACTERIAL DISEASES

Bacterial Canker, Clavibacter michiganensis subsp. michiganensis Bacterial Speck, Pseudomonas syringae pv. tomato

Bacterial Spot, Xanthomonas campestris pv. vesicatoria Bacterial Wilt, Ralstonia solanacearum

The causal agents of bacterial canker, speck, and spot can be seed borne, which makes obtaining pathogen-free seeds and transplants important. Once present, these diseases are devastating and hard to control. The types of damage they cause are reflected in their individual names: bacterial canker causes plant necrotic cankers, blighting, and wilt during wet conditions; bacterial speck develops under cool, early-season temperatures and results in leaf and/or fruit spotting; and bacterial spot not only produces spots on leaves and tomatoes, rendering them unmarketable, but also causes extreme blighting and defoliation under suitable weather conditions. Bacterial wilt, on the other hand, is soil-borne. It infects plant roots, resulting in wilting and the eventual collapse of the tomato plant. Warm, moist soil conditions are highly favorable for the development of this disease. In a 2005 survey of Virginia tomato growers, 100% of respondents expressed concern about the impact of bacterial disease on production.

MONITORING: Field monitoring by scouts is important to identify emerging bacterial diseases before they become widespread. However, no economic thresholds have been established at present. Treatment is recommended immediately after a disease has been detected. CHEMICAL CONTROL: Actigard is the most effective product for controlling bacterial spot and speck diseases on tomato. Be sure to use it in conjunction with copper to avoid fruit rot problems. Although copper-resistant infections have been found on the Eastern Shore, copper is still an important tool that should be used on a rotational basis, especially to prevent soft rots. Generally, bacterial diseases are difficult to control with the limited chemicals available.


• acibenzolar-S-methyl (Actigard 50WG) – Triazole. PHI = 14 days. Apply at a rate of 0.01 – 0.02 lb. a.i./A at 7-day intervals for control of bacterial spot and speck. Do not apply more than 6 times per crop per season. REI = 12 hours. SECTION 24C (SLN) PESTICIDE for control of bacterial diseases in tomatoes.

• chloropicrin (Telone C-35) – For the control of bacterial wilt, apply 13 – 36 gal./A. REI = 5 days. RESTRICTED USE PESTICIDE.

• copper, fixed (various formulations) – Inorganic. Apply at a rate of 1.00 lb. a.i./A in combination with a half rate of mancozeb for control of bacterial spot and speck shortly after transplanting and repeat every 7 days. REI = 24 hours.

• famoxadone + cymoxanil (Tanos 50WDG) – Oxazolidinedione + Acetimide. PHI = 3 days. Apply at a rate of 4 oz. a.i./A in combination with a full rate of fixed copper for suppression of bacterial speck, spot, and canker. REI = 12 hours.

• hydrogen pyroxide (OxiDate 27SC) – Inorganic. Apply 0.68 – 2.16 lbs. a.i./A every 5 – 7 days for control of alternaria, anthracnose, cladosporium mold, early blight, late blight, powdery mildew, bacterial speck, and bacterial leaf spot. REI = 0 hours. Some Virginia growers will not use it at all because of poor results. OxiDate is also very expensive.

• manganese EBDC (Maneb 75DF) – Carbamate. PHI = 5 days. Apply at a rate of 1.13 – 2.25 lbs. a.i./A at 7- to 10-day intervals for control of bacterial diseases. Do not exceed 16.8 lbs. a.i./A/crop. REI = 24 hours.

• mancozeb + copper hydroxide (ManKocide, Cuprofix MZ) – Carbamate + Inorganic. PHI = 5 days. Apply at a rate of 1.59 – 3.23 lbs. a.i./A for control of bacterial spot and speck. REI = 48 hours.

• methyl bromide (Bro-mean C-33) – For the control of bacterial wilt, apply 270 – 355 lbs./A for 24 – 48 hours. REI = 48 hours.

BIOLOGICAL/VIRAL CONTROL:

• Bacillus subtilis (Serenade 14.6WP) – PHI = 0 days. Apply at a rate of 0.146 – 0.438 lb. a.i./A at 7-day intervals in combination with a full rate of fixed copper as soon as bacterial spot or speck is detected.

• Bacteriophages (Agriphage) – PHI = 0 days. Bacteriophages are viruses that selectively destroy bacteria. More research is needed before Agriphage is commercially acceptable for the control of bacterial diseases. Apply at a rate of 1 – 2 pints a.i./A at 7-day intervals for the prevention of bacterial diseases. REI = 0 hours.


CULTURAL CONTROL: The use of certified plants is critical for control of bacterial diseases, especially in areas where a disease is not yet established. Use locally grown transplants whenever possible to avoid spreading diseases from other locations. If a disease is present or anticipated, do not work in fields when plant surfaces are wet. For staked tomatoes, stakes from bacterial canker-infested fields should be dipped into a chlorine solution before use. A crop rotation of two to three years between tomato plantings may help manage infestations of the causal agents of bacterial canker, speck, and spot. However, rotation is not effective in controlling bacterial wilt, especially given its persistence in the soil. In this case, producers should avoid infested sites. Bacterial wilt can be prevented in part by ensuring the soil is properly drained and minimizing wounding. TO DO: • Create management programs that are effective for all bacterial diseases. • Increase educational efforts regarding bactericide resistance management. • Look at alternatives and additional control options for bacterial wilt. • Research effects of irrigation and transmission of bacterial diseases through handling.

Tomato Pith Necrosis, Pseudomonas corrugata

Tomato pith necrosis is caused by soil-dwelling bacteria, which may infect tomato plants when humidity is high and nighttime temperatures are low. This disease seems to develop most often when there is rapid growth following applications of too much nitrogen and water. Pith necrosis occurs sporadically, either during or following the time of fruit-set. A survey of tomato growers indicated that 25% of respondents were concerned about tomato pith necrosis. MONITORING: Symptoms include wilting, stem collapse, brown or black cankers, and dark, necrotic piths. CHEMICAL CONTROL: No effective commercial controls are recommended. BIOLOGICAL CONTROL: No biological controls are recommended. CULTURAL CONTROL: Avoid overfertilizing or overwatering tomato plants. TO DO: None


FUNGAL DISEASES

Timber Rot, Sclerotinia sclerotiorum

Timber rot is a stem rot disease of tomato and tends to reoccur in soil where it was observed previously. This rot has a wide host range and occurs on many plants besides tomatoes. In a survey of Virginia tomato growers, 50% of respondents expressed concern about the impact of timber rot on their production. Stems rotting near the base may become girdled, which leads to wilting and death of tissue above. No resistant cultivars of tomato are available.

MONITORING: Injured spots or parts of the stem near the ground or at branch points appear water soaked. White, fluffy mycelia cover and fill the stem, along with hard, black sclerotia that resemble peas. Infected tomato fruits become soft and watery.

CHEMICAL CONTROL: No effective commercial controls are recommended.

BIOLOGICAL CONTROL: No biological controls are recommended.

CULTURAL CONTROL: Grow plants in well-drained soil, and rotate with resistant vegetables.

TO DO: None

Late Blight, Phytophthora infestans

Late blight may cause early-season leaf blighting and late-season fruit rot. This disease prevails in cool, wet conditions and can be devastating if preventive control measures are not taken. Complicating control efforts further, new metalaxyl-resistant strains of this fungus are present in the mid-Atlantic region and are particularly aggressive on tomatoes. Late blight is not a major disease problem on the Eastern Shore, but it can be more troublesome in northern areas where there are cool, wet conditions.

MONITORING: Blight forecasting systems (e.g., Blitecast) can be very effective in identifying proper timing of fungicide sprays.

CHEMICAL CONTROL: If cool, wet conditions prevail, a preventive fungicide application is recommended every 7 days. Given the known resistance of late blight to metalaxyl (Ridomil), the use of alternative chemistries is recommended.

• azoxystrobin (Amistar 80WDG) – Methoxyacrylate. PHI = 0 days. REI = 4 hours. Apply at a rate of 0.10 lb. a.i./A for late blight at 5- to 7-day intervals. Amistar is not very effective for late blight but is easy to measure out.

• chlorothalonil (Bravo, Terranil) – Nitrile. PHI = 0 days. Apply at a rate of 0.75 – 2.25 lbs. a.i./A for control of leaf spot diseases, fruit


rots, and late blight (lower rate). When disease pressure increases, mix and alternate chlorothalonil with Tanos, Previcur Flex, Gavel, or Cabrio. REI = 12 hours.

• dimethomorph (Acrobat 50WP) – Cinnamic acid derivative. PHI = 4 days. Apply at a rate of 0.2 lb. a.i./A every 5 – 10 days for control of late blight. REI = 12 hours. May not work as well as Tanos, Gavel, or Cabrio.

• famoxadone + cymoxanil (Tanos 50WDG) – Oxazolidinedione + Acetimide. PHI = 3 days. Apply at a rate of 4 oz. a.i./A in combination with chlorothalonil or mancozeb at labeled rates. Alternate with a fungicide that has a different mode of action such as Gavel or Previcur Flex. REI = 12 hours. Tanos provides good control but is hard to measure and mix.

• mancozeb (Dithane Rainshield NT, Manex II, Penncozeb 80WP) – Carbamate. PHI = 5 days. Apply at a rate of 2.4 lbs. a.i./A for control of leaf spot diseases and late blight. If applied early in the season, mancozeb works well against the foliar blighting phase of late blight. When disease pressure increases, mix and alternate mancozeb with Tanos, Previcur Flex, Gavel, or Cabrio. REI = 24 hours.

• mancozeb + zoxamide (Gavel 75DF) – Carbamate + Amide. PHI = 5 days. Apply at a rate of 1.125 – 1.5 lbs. a.i./A every 7 days. REI = 48 hours.

• propamocarb hydrochloride (Previcur Flex 6F) – Carbamate. PHI = 5 days. Apply at a rate of 1.33 lbs. a.i./A in combination with chlorothalonil or mancozeb at labeled rates. Alternate Previcur Flex with a contact fungicide (chlorothalonil or mancozeb) every 5 days during periods of high disease pressure. REI = 12 hours.

• pyraclostrobin (Cabrio 20EG) – Strobilurin. PHI = 0 days. Apply at a rate of 1.6 – 3.2 oz. a.i./A. Alternate every 5 – 7 days, depending upon disease pressure, with a fungicide that has a different mode of action (e.g., Gavel or Previcur Flex). REI = 12 hours.



TO DO: • Continue research efforts to evaluate fungicide efficacy. • Work to maintain labeling for products that are most effective (Tanos,

Cabrio, Ridomil Gold, Acrobat). • Educate growers in resistance management techniques to protect

existing products.


Leaf Spots Early Blight, Alternaria solani

Septoria Leaf Spot, Septoria lycopersici Gray Leaf Spot, Stemphylium solani

Leaf spots can be devastating, especially during periods of wet weather. They first appear as lesions or blotches on lower plant leaves and stems, and progress up the plant as the disease develops. Leaf spot fungi are seed borne but can also become established on tomato stakes and crop debris. Of the leaf spot diseases, early blight is by far the most injurious in Virginia, particularly in fields with continuous tomato production. In addition, Septoria leaf spot can be very hard to control in susceptible plant varieties. In a survey of Virginia tomato growers, 25% of respondents expressed concern about the impact of leaf spot diseases on production. MONITORING: Early blight forecasting systems (e.g., Tomcast) can be very effective in identifying proper timing of fungicide sprays. No economic thresholds have been established at present. CHEMICAL CONTROL: Preventive fungicide applications are the best way to control leaf spot diseases. Protectant fungicides such as chlorothalonil or mancozeb are effective for low levels of disease pressure. When disease pressure increases, alternate a strobilurin fungicide such as azoxystrobin, famoxadone + cymoxanil, or pyraclostrobin with other types of fungicide applications.

• azoxystrobin (Quadris 2F, Amistar 80WDG) – Methoxyacrylate. PHI = 0 days. Apply at a rate of 0.78 – 0.97 lb. a.i./A for excellent control of leaf spot diseases. Resistance management is important when using this chemical. Quadris should be tank-mixed and alternated with a chemical with a different mode of action. REI = 12 hours.

• chlorothalonil (Bravo, Terranil) – Nitrile. PHI = 0 days. Apply at a rate of 0.75 – 2.25 lbs. a.i./A for control of leaf spot diseases, fruit rots, and late blight. REI = 12 hours.

• famoxadone + cymoxanil (Tanos 50WDG) – Oxazolidinedione + Acetimide. PHI = 3 days. Apply at a rate of 4 oz. a.i./A in combination with chlorothalonil or mancozeb at labeled rates. Alternate with a fungicide that has a different mode of action (e.g., Gavel or Previcur Flex). REI = 12 hours.

• mancozeb (Dithane Rainshield NT, Manex II, Penncozeb 80WP) – Carbamate. PHI = 5 days. Apply at a rate of 2.4 lbs. a.i./A for control of leaf spot diseases and late blight. REI = 24 hours.




• pyraclostrobin (Cabrio 20EG) – Strobilurin. PHI = 0 days. Apply at a rate of 1.6 – 3.2 oz. a.i./A. Alternate every 5 – 7 days, depending upon disease pressure, with a fungicide that has a different mode of action (e.g., Gavel or Previcur Flex). REI = 12 hours.


CULTURAL CONTROL: Use resistant varieties and certified seed whenever possible. Implement good sanitation practices, and avoid previously diseased fields. Rotate crops every 2 to 3 years, and conduct field operations at the proper time to prevent leaf spot diseases.

TO DO: None

Wilts

Fusarium Wilt, Fusarium oxysporium Verticillium Wilt, Verticillium dahliae

Fusarium wilt and verticillium wilt are both soil-borne diseases that can infect tomato fields in Virginia. Some fields and certain tomato varieties appear more susceptible than others to these fungal diseases. Symptoms of fusarium wilt include chlorotic, stunted plants that turn distinctively yellow on one side of the plant. The plants may wilt only during the hottest part of the day but appear to revive overnight. Verticillium wilt causes the appearance of brown, “V”-shaped lesions with chlorotic margins that extend inward from the leaf margins or tips. Infected plants often have discolored vascular systems, appear wilted, and eventually die. Wilts can be transmitted by way of seed, transplants, soil, tomato stakes, and equipment. In a survey of Virginia tomato growers, 50% of respondents expressed concern about the impact of wilt diseases on production.

MONITORING: No economic thresholds are currently established. CHEMICAL CONTROL: No effective commercial controls are recommended. BIOLOGICAL CONTROL: No biological controls are recommended.


CULTURAL CONTROL: Wilt-resistant tomato cultivars are available and should be used in areas where these diseases are troublesome. However, new races of both pathogens have been identified that can overcome the resistance in many popular tomato varieties. Good sanitation and the use of resistant tomato cultivars should be used if the disease has previously been a problem. Crop rotations are usually not very effective given the persistence of the fungi in the soil. However, do not crop fields consecutively for more than three years in a row to avoid losses from these soil fungi. Overwatering early in the season can increase the incidence of fungal wilt diseases. Fusarium wilt develops more quickly in sandy soils that are high in nitrogen and low in potassium.

TO DO: • Research how soil characteristics and field conditions affect disease

severity. • Evaluate fusarium and verticillium wilt control offered by alternatives to

methyl bromide. • Research soil treatments to control fungus. • Research and identify effective chemical controls. • Research whether “plasticulture” environments can be used to grow

antagonists. • Identify ways to reduce inoculum in the field (e.g., with fumigants). • Determine which cover crops are most effective at suppressing wilt

levels.

Southern Blight, Sclerotium rolfsii

Currently, this disease is controlled with methyl bromide. Infection levels are low and scattered when fumigation is used and Terrachlor is added to the transplant water. In nonfumigated soils, it can be a serious problem once the plants start fruiting and soil temperatures are high. Crop rotations with small grains and corn may reduce disease occurrence. In a survey of Virginia tomato growers, 25% of respondents expressed concern about the impact of southern blight on their crop production.

MONITORING: No economic thresholds have been established at present.

CHEMICAL CONTROL: In fields with a history of southern blight, use:

• pentachloronitrobenzene (Terraclor 75WP) – Chlorinated hydrocarbon. Apply during transplant at a rate of 2.25 lbs. a.i./100 gal. of water by adding to the transplant water (0.5 pint/plant).



TO DO: None


Fruit Rots

Staked-tomato production has greatly reduced the incidence of fruit rot by increasing airflow around the fruit and keeping contaminated soil from contacting the tomatoes. However, during seasons that are wet due to heavy rains, even staked tomatoes are more vulnerable to fruit rot. This is especially true when infected soil splashes onto the tomatoes, or when the tomato skin ruptures resulting from excessive water intake.

Botrytis Fruit Rot, Botrytis cinerea

Botrytis fruit rot, or gray mold, causes blighting or fruit rot. In a survey of Virginia tomato growers, 75% of respondents expressed concern about the impact of botrytis on their crop production. Botrytis has a wide host range, affecting over 200 plants. It occurs sporadically in the mountains of North Carolina but is rare in other regions. Cool, moist weather conditions must be present for the disease to develop on plants with dense foliage. It is a major cause of postharvest fruit rot, during harvest or in storage. MONITORING: Botrytis fruit rot symptoms include gray, velvety spores that cover dying flowers and fruit calyces. CHEMICAL CONTROL: No effective commercial controls are recommended. BIOLOGICAL CONTROL: No effective commercial controls are recommended. CULTURAL CONTROL: No effective cultural controls are recommended. TO DO: None

Buckeye Rot, Phytophthora parasitica

This fungus causes grayish brown, circular lesions with light and dark banding, especially on green fruit. Buckeye rot is prevalent during periods of heavy rainfall in poorly drained areas. In a survey of Virginia tomato growers, 50% of respondents expressed concern about the impact of buckeye rot on their crop production. MONITORING: Protect your fields before disease incidence, and check for diseased fruit after heavy rainfall. CHEMICAL CONTROL: Preventive fungicide applications are the best means of control. In locations where buckeye rot is a common problem, start with the following.


• mefenoxam + chlorothalonil (Ridomil Gold Bravo 76WP) – Acylalanine + Nitrile. PHI = 14 days. Apply at a rate of 1.52 lbs. a.i./A when crown fruit is one-third full size, and repeat every 14 days up to a total of three times. REI = 48 hours.

• mefenoxam + copper (Ridomil Gold/Copper 65WP) – Acylalanine + Inorganic. PHI = 14 days. Apply at a rate of 1.3 lbs. a.i./A combined with mancozeb 0.75 lb. a.i./A when crown fruit is one-third full size, and repeat every 14 days up to a total of three times. REI = 48 hours.

Alternate the mefenoxam (Ridomil) combinations with:


• famoxadone + cymoxanil (Tanos 50WDG) – Oxazolidinedione + Acetimide. PHI = 3 days. Apply at a rate of 4 oz. a.i./A in combination with chlorothalonil or mancozeb at labeled rates. REI = 12 hours.

CULTURAL CONTROL: Improve drainage, and stake plants securely so that fruit does not touch the soil.


TO DO: None

Anthracnose, Colletotrichum coccodes Alternaria Fruit Rot, Alternaria alternata

These fungal infections often show up on vine-ripened tomatoes after they turn red and cause fruit rot, which reduces the quality and yield of tomatoes. Anthracnose initially causes small, circular, slightly sunken lesions to appear on the surface of ripening fruits. The spots quickly enlarge, become deeply depressed, and develop a dark center or dark fruiting bodies of the fungus. Alternaria fruit rot typically causes larger lesions accompanied by a velvety black mold. Infection occurs when spore-contaminated soil splashes onto the ripening tomatoes.

MONITORING: No economic thresholds have been established at present. The disease forecaster Tomcast can be used to determine when weather conditions favor disease development.

CHEMICAL CONTROL: Fungicides used to control leaf spots caused by Septoria and Alternaria solani are also effective in controlling these fruit rots. Apply registered fungicides according to product label instructions when weather conditions are above 65°F and the foliage is likely to remain wet for more than 6 hours. Applications on tomatoes should begin when the first fruit is larger than a walnut. Protectant fungicides such as chlorothalonil or mancozeb are effective for low levels of disease pressure. However, when


disease pressure increases, a strobilurin fungicide such as azoxystrobin, famoxadone + cymoxanil, or pyraclostrobin should be added to every other fungicide application.

• azoxystrobin (Quadris 2F, Amistar 80WDG) – Methoxyacrylate. PHI = 0 days. Apply at a rate of 0.78 – 0.97 lb. a.i./A for excellent control of leaf spot diseases. Resistance management is important when using this chemical. Quadris should be tank-mixed and alternated with a chemical with a different mode of action. REI = 12 hours.

• chlorothalonil (Bravo, Terranil) – Nitrile. PHI = 0 days. Apply at a rate of 0.75 – 2.25 lbs. a.i./A for control of leaf spot diseases, fruit rots, and late blight. REI = 12 hours.

• famoxadone + cymoxanil (Tanos 50WDG) – Oxazolidinedione + Acetimide. PHI = 3 days. Apply at a rate of 4 oz. a.i./A in combination with chlorothalonil or mancozeb at labeled rates. Alternate with a fungicide that has a different mode of action (e.g., Gavel or Previcur Flex). REI = 12 hours.

• mancozeb (Dithane Rainshield NT, Manex II, Penncozeb 80WP) – Carbamate. PHI = 5 days. Apply at a rate of 2.4 lbs. a.i./A for control of leaf spot diseases and late blight. REI = 24 hours.



• pyraclostrobin (Cabrio 20EG) – Strobilurin. PHI = 0 days. Apply at a rate of 1.6 – 3.2 oz. a.i./acre. Alternate every 5 – 7 days, depending on disease pressure, with a fungicide that has a different mode of action (e.g., Gavel or Previcur Flex). REI = 12 hours.


CULTURAL CONTROL: Avoid planting tomatoes in fields that were diseased during the previous season. Rotate crops for two to three years. Deep plow or till tomato debris into the soil after the last fall harvest. Use stakes and plastic mulch to prevent fungal spores from splashing onto the fruit.

TO DO: None


Postharvest Fruit Rots Soft Rot, Erwinia carotovora, Leuconostoc spp., and Lactobacillus spp.

Sour Rot, Geotrichum candidum Rhizopus Rot, Rhizopus stolonifer

Black Mold, Alternaria and Stemphyllium spp.

Postharvest fruit rots are generally caused by opportunistic pathogens that cannot directly infect fruit tissues unless they are damaged. Mechanical injuries (e.g., bruises, cuts, and punctures) incurred during postharvest handling create an opportunity for decay because they provide protected sites in which pathogens can develop. A decay pathogen can eventually engulf the entire tomato and spread to adjacent fruit.

MONITORING: No specific monitoring protocol recommended.

CHEMICAL CONTROL: No effective commercial controls are available.


CULTURAL CONTROL: Sanitation is key to controlling fruit rots. All containers carrying fruit require frequent sanitizing. Monitor dump tanks regularly for proper levels of free chlorine or bromine, correct water temperature, and optimal pH. Grading belts must have clean brushes and be free of edges, which can puncture fruit. Monitor storage temperatures and adjust as necessary. Picking fruit when it is dry helps to reduce the spread of inoculum. Fruit picked just after heavy rainfall should be graded carefully. Grading out fruit with abrasions or porous stem scars keeps disease from spreading in storage. Limiting the time in dump tanks to less than 2 minutes will reduce the potential for microbial infiltration of tomatoes. Heating dump tank water 10°F (about 5°C) above the incoming tomato pulp temperature also helps to eliminate microbial infiltration.

TO DO:

• Ensure copper is retained as a fungicidal tool, or have a viable replacement for fruit rots.

• Educate growers on resistance management techniques and ensure compliance.

• Educate packinghouse workers on disease prevention (e.g., handling, treatments, pH, surface tension, temperature, depth, and inoculum reduction).

• Identify tomato varieties that are more susceptible to rot.


VIRAL DISEASES

Tomato Spotted Wilt Virus

TSWV is vectored by at least seven different kinds of thrips, including tobacco thrips and western flower thrips. It takes only 15 minutes of feeding for a tomato plant to become infected, and once TSWV is acquired, there is no cure. TSWV management is difficult because the insect vectors have broad host ranges. In a survey of Virginia tomato growers, 75% of respondents expressed concern about the impact of TSWV on their crop production. MONITORING: Thrips move into tomato fields from surrounding vegetation. Monitor fields at least weekly. Early symptoms are hard to detect but may include leaf cupping and off-colored or bronze foliage. Later, the main stem develops brown or black streaks. The top of the tomato plants may turn yellow and wilt. White or yellow rings approximately 1/2 inch wide will appear on the skin of young fruit. Tomatoes appear bumpy because the skin within the ring becomes raised. Mature fruit are marked by bright yellow rings. CHEMICAL CONTROL: Actigard helps tomato plants to stay healthy. Weekly sprays may be necessary to manage thrips. Admire has residual activity and will control thrips for up to 60 days. Western flower thrips tend to be harder to control than tobacco thrips. BIOLOGICAL CONTROL: None CULTURAL CONTROL: Plant TSWV-resistant tomato varieties. Cull infected plants, and destroy them to prevent viral spread. Control weeds around the tomato plots. Eliminate thrips in greenhouses so they, along with TSWV, are not spread to the field when seedlings are transplanted. TO DO: • Develop resistant varieties that are well suited for commercial

production. Current varieties (e.g., Amelia) do not work well. • Continue to research TSWV and the biology of thrips vectors. • Increase grower awareness of the TSWV incubation period and the

need to control thrips in transplants before sending them out to the field.

• Arrange research and Extension activities to teach growers about economic thresholds and at what point the infected tomato crop should be destroyed.


SUMMARY - CHEMICAL DISEASE CONTROL The most recent pesticide use survey for tomatoes grown in Virginia was completed in 1992. According to this report, fungicides were used by 63.6% of tomato producers on 10,600 of the treatment acres. The fungicides reported at the time of the survey included mancozeb, used by 12.1% of producers on 10,027 treatment acres; chlorothalonil, used by 48.5% on 348 acres; metalaxyl, used by 18.2% on 213 acres; copper sulfate, used by 3% on 9 acres; benomyl, used by 3% on 3 acres; maneb, used by 3% on 0.5 acre; and copper hydroxide, used by 3% on an unspecified number of acres. As mentioned in the Chemical Disease Control section, this survey information is rather dated and may not be representative of current fungicide usage patterns. Anecdotal data was used in the case of the more commonly applied fungicides to provide a better idea of present practices. The list of chemicals below is representative of the 2005 fungicide recommendations for tomatoes grown commercially.

• acibenzolar-S-methyl (Actigard 50WG) – PHI = 14 days. Apply at a rate of 0.01 – 0.02 lb. a.i./A at 7-day intervals following the initial spray for control of bacterial spot and speck. Do not apply more than 6 times per crop per season. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used Actigard from 2003 to 2004. SECTION 24C (SLN) PESTICIDE for control of bacterial diseases in tomatoes.

• azoxystrobin (Amistar 80WDG, Quadris 2F) – Methoxyacrylate. PHI = 0 days. Apply at a rate of 0.78 – 0.97 lb. a.i./A for excellent control of leaf spot diseases, fruit rots, and late blight. The highest rate should be used for optimum late blight control. Azoxystrobin controls some of the diseases missed by chlorothalonil and is therefore a highly effective tool. Resistance management is important when using this chemical, given the recent introduction of Quadris 2F. Following two sequential applications of Quadris 2F, rotate to a chemical with a different mode of action. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used Quadris/Amistar from 2003 to 2004.

• chloropicrin (Telone C-35) – For the control of bacterial wilt, apply 13 – 36 gal./A. REI = 5 days. RESTRICTED USE PESTICIDE.

• chlorothalonil (Bravo) – Nitrile. PHI = 0 days. Apply at a rate of 0.75 – 2.25 lbs. a.i./A for control of leaf spot diseases, fruit rots, and late blight (lower rate). If applied later in the season, chlorothalonil works well on the fruit rot phase of late blight. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that


100% of farmers used Bravo/chlorothalonil, and 50% of farmers used Ridomil Gold Bravo (chlorothalonil/mefenoxam) from 2003 to 2004.

• copper, fixed (various formulations) – Inorganic. Apply at a rate of 1.00 lb. a.i./A in combination with a half rate of mancozeb for control of bacterial speck and bacterial spot shortly after transplanting and repeat every 7 days. REI = 24 hours. A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used fixed copper from 2003 to 2004.

• dimethomorph (Acrobat 50WP) – Cinnamic acid derivative. PHI = 4 days. Apply at a rate of 0.2 lb. a.i./A every 5 – 10 days for control of late blight. REI = 12 hours. May not work as well as Tanos, Gavel, or Cabrio.

• famoxadone + cymoxanil (Tanos 50WDG) – Oxazolidinedione + Acetimide. PHI = 3 days. Apply at a rate of 4 oz. a.i./A in combination with a full rate of fixed copper for suppression of bacterial speck, spot, and canker. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used Tanos from 2003 to 2004.

• hydrogen pyroxide (OxiDate 27SC) – Inorganic. Apply 0.68 – 2.16 lbs. a.i./A every 5 – 7 days for control of alternaria, anthracnose, cladosporium mold, early blight, late blight, powdery mildew, bacterial speck, and bacterial leaf spot. REI = 0 hours. Some Virginia growers will not use it at all because of poor results. OxiDate is also very expensive.

• mancozeb (Dithane Rainshield NT, Manex II, Penncozeb 80WP) – Carbamate. PHI = 5 days. Apply at a rate of 2.4 lbs. a.i./A for control of leaf spot diseases and late blight. If applied early in the season, mancozeb works well against the foliar blighting phase of late blight. REI = 24 hours. A survey of tomato growers conducted in February 2005 indicated that 75% of farmers used mancozeb from 2003 to 2004.

• mancozeb + copper hydroxide (ManKocide) – Carbamate + Inorganic. PHI = 5 days. Apply at a rate of 1.59 – 3.23 lbs. a.i./A for control of bacterial speck and bacterial spot. REI = 48 hours.

• manganese EBDC (Maneb 75DF) – Carbamate. PHI = 5 days. Apply at a rate of 1.13 – 2.25 lbs. a.i./A at 7- to 10-day intervals for control of bacterial diseases. Do not exceed 16.8 lbs. a.i./A/crop. REI = 24 hours.

• mefenoxam (Ridomil Gold EC) – Acylalanine. PHI = 30 days. Recommended at a rate of 1.30 lbs. a.i/A for control of fruit rots caused by Pythium and Phytophthora. REI = 48 hours. A survey of tomato


growers conducted in February 2005 indicated that 100% of farmers used Ridomil Gold EC/fluoronil from 2003 to 2004.

• methyl bromide (Bro-mean C-33) For the control of bacterial wilt, apply 270 – 355 lbs./A for 24 – 48 hours. REI = 48 hours.

• pentachloronitrobenzene (Terraclor 75WP) – Chlorinated hydrocarbon. Apply during transplant at a rate of 2.25 lbs. a.i./100 gal. of water by adding to the transplant water (0.5 pint/plant).


• pyraclostrobin (Cabrio 20EG) – Strobilurin. PHI = 0 days. Apply at a rate of 1.6 – 3.2 oz. a.i./A. Alternate every 5 – 7 days, depending upon disease pressure, with a fungicide that has a different mode of action (e.g., Gavel or Previcur Flex). REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 50% of farmers used Cabrio from 2003 to 2004.

• thiophanate methyl (Topsin M) – Section 18 Exemption for use on white mold.


TOMATO NEMATODES Root knot (Meloidogyne hapla) and lesion (Pratylenchus penetrans) nematodes are the most common species found in tomato fields and often pose the greatest threat to production in Virginia. Nematode infestations generally reduce productivity by inhibiting the plant’s ability to absorb water and nutrients. Populations are especially high in fields where tomatoes are consistently being rotated with other host crops, such as melons or peppers. However, irrigation capabilities and land restrictions usually limit rotations to nonhost crops. MONITORING: Both diagnostic and predictive nematode assay programs in Virginia provide data to producers on the numbers and kinds of nematodes in soil along with recommendations for control. Soil samples for diagnostic assays are processed without charge to determine the cause of production problems during the growing season. Predictive nematode assays are done on samples collected after harvest. These samples are processed at a cost of $11 per sample and must be collected in the fall no later than November 20. CHEMICAL CONTROL: Fumigants: (to treat preventively for the next year, fumigate after the last harvest to control active nematodes)

• chloropicrin (Metapicrin)

• dichloropropene (Telone C-17)

• ethoprop (Mocap)

• metam sodium (Busan, Nemasol, Vapam HL)

• methyl bromide (Terr-O-Gas 67, MC-33)

• metam potassium (K-Pam HL)

Nematicides:

• oxamyl (Vydate L) – Carbamate. PHI = 3 days. REI = 48 hours. For the control of nematodes, apply 2 – 8 pints/A. Reapply every 1 – 2 weeks as necessary, but not to exceed 32 pints/A/season. RESTRICTED USE PESTICIDE.

BIOLOGICAL CONTROL: No effective commercial controls are available. CULTURAL CONTROL: Rotate tomatoes with nonhost crops to lower nematode populations.


TO DO: • Research natural nematicides and inhibitors (e.g., isothiocyanates,

which are a breakdown product of Brassica cover crops). • Disseminate information to growers on nematode field counts done by

Lynn Gayle. • Use chloropicrin with heavier plastics to fill the gap left by methyl

bromide. • Combine alternatives with natural cover crops to improve efficacy. • Research the efficacy of plastics used in tandem with fumigants.

SUMMARY - CHEMICAL NEMATODE CONTROL

Several chemicals are currently available for nematode control, although this may change in the next few years. Currently, the soil fumigants chloropicrin, dichloropropene (Telone C-17), metam sodium (Busan, Nemasol, and Vapam HL), and methyl bromide (Terr-O-Gas 67 and MC-33) are recommended for use in Virginia. In addition, the nematicide oxamyl (Vydate L) is also recommended. Typically, chemical controls are used only when cultural practices cannot provide adequate control. However, these chemicals are still important tools when other methods of control have failed.


TOMATO WEEDS In the past, most tomato producers fumigated plant beds with methyl bromide for weed control. Typically, this chemical was applied to the row beds, which were covered immediately with black plastic mulch. Given the recent legislation to reduce and restrict methyl bromide use along with the rising costs of the chemical, producers are looking for other ways to manage weed problems in tomatoes. Currently, however, many producers are continuing to use black plastic mulch with methyl bromide in lieu of effective alternatives. Yellow nutsedge is becoming an increasingly difficult weed to control in Virginia tomato fields, especially because of the limited herbicide options available. Other problematic weeds include broadleaf signalgrass, goosegrass, fall panicum, johnsongrass, common cocklebur, hairy galinsoga, Pennsylvania smartweed, sicklepod, velvetleaf, purple nutsedge, annual nutsedge, Florida pusley, groundcherry, nightshade, morningglory, common lambsquarters, crabgrass, mustards, pigweed, jimsonweed, ragweed, and barnyardgrass. If left uncontrolled, weeds will compete with tomato plants for essential nutrients, light, and water. Weeds tend to flourish later in the year when there is plenty of water and warm weather. Extended periods of rain can lead to weed problems in row middles.

MONITORING: Proper identification is an important part of effective weed control. Note weeds observed in previous crops within a given field to aid in future management decisions. Scout each field and keep records of the weed species present as well as their location and population density. CHEMICAL CONTROL: See the Chemical Weed Control section below for more information. Herbicides are valuable tools for weed management, but cultural practices such as the use of black plastic mulch over plant beds have become increasingly important as methyl bromide and other fumigants are being phased out. Herbicides may be applied to row middles or over the top. Paraquat will burn tomatoes, so it is preferable to use other herbicides that are less likely to have this effect. To control nightshade, use methyl bromide or better plastics. BIOLOGICAL CONTROL: No effective commercial controls are available. CULTURAL CONTROL: Black plastic is used for control of fall annual weeds, which would normally grow directly around the plant. Morningglory can be weeded by hand after applying herbicide. Hand weeding is not a suitable alternative in Delaware if critical herbicides are lost. In Virginia, workers are paid minimum wage to weed tomato fields by hand.


TO DO: • Develop viable alternatives to methyl bromide. Identify fumigants and

herbicides to supplement alternatives.

• Expand labels to fit use. Some label language does not fit methods.

• Research the application of different herbicides.

• Research new chemistry to fit cultural methods. Chemistry is limited to research on formed beds.

• Develop a viable replacement for Sencor, if lost, because it is a very important tool in tomato weed control.

• Need research into the use of high barrier plastic, which has been studied in Europe but not in the United States. This plastic may control weeds with lower rates of gas because more gas is retained.

• Encourage growers to use mulch along with herbicides. Using silver mulch reduces the amount of methyl bromide used. However, as oil prices rise, mulch costs also rise.

• Get better control of all pests, including weeds.

• Make regulators aware that if methyl bromide is lost, tomato growers will have more problems with nutsedges and broadleaf weeds.

• Make farmers and growers aware that by using heavier plastics, less methyl bromide would need to be used in the United States.

• Increase regulator awareness that methyl bromide’s CUE is complicated and its status is confusing.

SUMMARY - CHEMICAL WEED CONTROL

The list below contains all of the fully labeled products available to producers for weed control in tomatoes. Use estimates from 2003-2004 are also included based on anecdotal data collected in a 2005 survey. Table 3a lists the effectiveness of these herbicides on a variety of weed species. Herbicide performance is affected by weather, soil types, application rate, weed pressure, and other factors. These ratings indicate ONLY relative effectiveness in tests conducted by the University of Delaware; the University of Maryland System; The Pennsylvania State University; Rutgers, The State University of New Jersey; and Virginia Polytechnic Institute and State University (Virginia Tech). Actual performance may be better or worse than indicated in the chart.


• clethodim (Select 2EC) – Oxime. PHI = 20 days. Apply at a rate of 0.094 – 0.125 lb. a.i./A for postemergence control of annual grasses and certain perennial grasses, including barnyardgrass. Repeated applications may be needed to control certain perennial grasses. DOES NOT CONTROL yellow nutsedge, wild onion, and broadleaf weeds. Used on less than 5% of the tomato acreage in Virginia. REI = 24 hours. A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Select.

• halosulfuron-methyl (Sandea 75EC) – Sulfonylurea. PHI = 30 days. Apply 0.023 – 0.047 lb. a.i./A for control of broadleaf weeds and nutsedge. Do not apply more than 0.094 lb. a.i./A per year. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used Sandea.

• metribuzin (Lexone/Sencor) – Triazine. PHI = 7 days. Incorporate at a rate of 0.25 lb. a.i./A before transplanting. Application will provide control of broadleaf weeds. An additional postemergence application of metribuzin may be necessary. Do not apply within 24 hours of treatment with other pesticides. Used on approximately 90% –100% of the tomato acreage for control of weeds in the row middles (not under plastic). REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used Sencor.

• napropamide (Devrinol 50DF) – Propionamide. Apply at a rate of 1.0 – 2.0 lbs. a.i./A before seeding or transplanting and incorporate the same day as application. Controls annual grasses and certain annual broadleaf weeds. Use of napropamide may reduce the stand and yield of fall-planted small grains. Moldboard plowing will reduce the injury to small-grain cover crops. Applied to roughly 5% –10% of the tomato acreage in Virginia. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Devrinol.

• oxyfluorfen (Goal 2XL 22.3EC) – Diphenyl ether. PHI = 30 – 120 days. Apply at a rate of 0.25 – 0.5 lb. a.i./A for control of common groundsel, henbit, wild mustard, burning nettle, annual sowthistle, shepherdspurse, London rocket, redmaids, minerslettuce, filaree, cheeseweed, and coast fiddleneck in fallow tomato beds. REI = 24 hours. Used in Delaware.

• paraquat (Gramoxone Extra 2.5SC) – PHI = 30 days. Apply as a directed spray at a rate of 0.5 lb. a.i./A for postemergence control of weeds growing between beds. Injury could result if paraquat contacts crop plants. This chemical is used on approximately 50% of the tomato acreage for weed control in the row middles. Application of paraquat in this manner allows for burn-down of weeds and crop debris and also


helps prevent disease. In this respect, the chemical is probably used on all of the tomato acres under plastic. REI = 12 hours. RESTRICTED USE PESTICIDE. A survey of tomato growers conducted in February 2005 indicated that 75% of farmers used Paraquat.

• pebulate (Tillam 6E) – Thiocarbamate. PHI = 8 days. Incorporated into the soil immediately after application at a rate of 3.0 – 4.0 lbs. a.i./A for control of annual grasses and yellow nutsedge. If used in combination with metribuzin, the spectrum of broadleaf weed control may be improved. Also recommended for postemergence control of the same type of weeds when applied over transplants (up to fruit formation) at the same rate. Currently used on only 1% – 2% of the tomato acreage. Research is being completed at present to assess this chemical as a methyl bromide alternative. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that 25% of farmers used Tillam.

• rimsulfuron (Matrix 25WDG) – Sulfonylurea. PHI = 45 days. For the control of certain broadleaf weeds and grasses, apply 0.0015 – 0.003 lb. a.i./A. Reapply after 7 – 14 days, but do not exceed 0.006 lb./A per season. REI = 4 hours. A survey of tomato growers conducted in February 2005 indicated that 50% of farmers used Matrix.

• sethoxydim (Poast) – Oxime. PHI = 30 days. Postemergence herbicide used at a rate of 0.2 – 0.4 lb. a.i./A for control of annual grasses and certain perennial grasses. Repeat applications may be necessary for additional control of tough perennial grasses. Do not apply more than 5.0 pints of product per acre in one season. Used on less than 10% of the tomato acreage in Virginia. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that no farmers used Poast.

• s-metolachlor (Dual Magnum 83.7EC) – Acetamide. PHI = 90 days. Apply 0.84 – 1.4 lbs. a.i./A for control of annual grasses and certain broadleaf weeds. REI = 24 hours. A survey of tomato growers conducted in February 2005 indicated that 100% of farmers used Dual Magnum.

• trifluralin (Treflan 4EC) – Dinitroanaline. Incorporate into the soil 8 hours after application at a rate of 0.5 –1.0 lb. a.i./A. Primarily controls annual grasses and certain broadleaf weeds. DOES NOT CONTROL ragweed, jimsonweed, or morningglory. Typically used only by those producers not using black plastic mulch on 2% – 3% of the nonmulched acres. REI = 12 hours. A survey of tomato growers conducted in February 2005 indicated that no farmers used Treflan.


EFFICACY TABLES

AND

TOMATO ACTIVITIES TIMELINE


Gre

en P

each A

phid

s

Pota

to A

phid

s

Beet A

rmyw

orm

s

Cabbage L

oopers

Colo

rado P

ota

to

Be

etle

s

Cutw

orm

s

Euro

pean C

orn

Bore

rs

Fall

Arm

yw

orm

s

Fle

a B

eetles

Horn

worm

s

Leafm

iners

Mites

Pin

worm

s

Stink B

ugs

Thrips

Tom

ato

Fru

itw

orm

s

Whiteflie

s

abamectin (Agri-Mek) NU NU NU NU E NU NU NU NU NU E E E NU NU NU NU

acetamiprid (Assail) E E P P E P P P E P ? P P ? G P E

azadirachtin (Aza-direct, Neemix, others) P P F F G F N F P F N P N P P F P

Bacillus thuringiensis N N G G N G P G N G N N P N N G N

bifenazate (Acramite) NU NU NU NU NU NU NU NU NU NU NU E NU NU NU NU NU

bifenthrin (Capture; Bifenture) P G F G F E G F E E N G? P G? G E NU

carbaryl (Sevin) NU NU NU NU NU G NU NU NU NU NU NU NU NU NU NU NU

cryolite (Kryocide, Prokil) NU NU NU NU G NU NU NU NU NU NU NU NU NU NU NU NU

zeta-cypermethrin (Fury, Mustang Max) P G F G F E G F E E N F P G? G E NUcyfluthrin (Baythroid) P G F G F E G F E E N F P G? G E NUlambda-cyhalothrin (Warrior, Lambda T) P G F G F E G F E E N F P G? G E NU

cyromazine (Trigard) NU NU NU NU G NU NU NU NU NU G NU NU NU NU NU NU

dicofol (Kelthane) NU NU NU NU NU NU NU NU NU NU NU F-G NU NU NU NU NU

dimethoate (Dimethoate) P G NU NU NU NU NU NU NU NU NU NU NU NU G NU NU

dinotefuron (Venom) G E P P E P P P E P ? P P ? G P E

emamectin benzoate (Proclaim) NU NU G E NU E G G NU E G NU G NU NU E NU

endosulfan (Thionex) ? G NU NU P NU NU NU G NU P P NU G? NU NU G

esfenvalerate (Asana XL) P G P G P E G F E E N F P G? G E NU

etoxazole (Zeal) NU NU NU NU NU NU NU NU NU NU NU E NU NU NU NU NU

fenpropathrin (Danitol) P G P G P E G F E E N G? P G? G E NU

imidacloprid (Admire, Provado, others) E E P P E P P P E P ? P P ? G P E

indoxacarb (Avaunt) NU NU E E F E E E NU E NU NU ? NU NU E NU

malathion (Malathion) P G P F P P P P F F P F P F G P F

methamidophos (Monitor) P G P F P F G F G G P ? P G? G? F NU

methomyl (Lannate) F G G G P G F G G G P NU NU G? F F NU

methoxyfenozide (Intrepid) NU NU E E NU E E E NU E NU NU ? NU NU E NU

oxamyl (Vydate L)1 G G NU NU ? NU NU NU NU NU NU ? NU NU NU NU ?

pymetrozine (Fulfill) E E NU NU NU NU NU NU NU NU NU NU NU NU NU NU E

pyriproxyfen (Knack) * * NU NU NU NU NU NU NU NU NU NU NU NU NU NU G

spinosad (SpinTor, Entrust) P NU G E G E E E ? E ? NU ? ? G E NU

spiromesifen (Oberon) NU NU NU NU NU NU NU NU NU NU NU E NU NU NU NU E

tebufenazide (Confirm) NU NU E E NU E E E NU E NU NU ? NU NU E NU

thiamethoxam (Actara, Platinum) E E P P E P P P E P ? P P ? G P E

Novaluron (Rimon) ? ? ? ? G ? ? ? ? ? ?

Pyridalyl NU NU E E F E E E NU E NU NU ? NU G? E NU

Flonicamid G G ? ? ? ? ? ? ? ? ? ? ? ? ? ? G1 Primarily used as a nematicide.

Pest Management Tools

Table 1a. Efficacy ratings for various pest management tools against tomato insects. Rating scale: E = excellent; G = good; F = fair; P = poor; N = no control; ? = research

needed; NU = not used; * = used, but not a stand alone tool.

Tomato Insect Pests

Registered Insecticides & Miticides

Unregistered/New Insecticides


Gre

en P

each A

phid

s

Pota

to A

phid

s

Beet A

rmyw

orm

s

Cabbage L

oopers

Colo

rado P

ota

to

Beetles

Cutw

orm

s

Euro

pean C

orn

Bore

rs

Fall

Arm

yw

orm

s

Fle

a B

eetles

Horn

worm

s

Leafm

iners

Mites

Pin

worm

s

Stink B

ugs

Thrips

Tom

ato

Fru

itw

orm

s

Whiteflie

s

Postharvest destruction to deny food and

overwintering sites to insects ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

Destroying unused plants in greenhouses or

plant beds to avoid insect breeding sites ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

Sanitation in greenhouses to avoid insects ? ? ? ? ? ? ? ? ? ? G G G ? G ? G

Early planting to minimize insects ? ? G ? ? ? ? G ? ? ? ? G ? ? G ?

Late planting to minimize insects ? ? ? ? G ? ? ? ? ? ? ? ? G G ? ?

Do not exceed recommended nitrogen

fertilization rates to reduce attractiveness of

crop to insects F F ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

Use good production practices to keep tomato

plants healthy and harvest earlier ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

Keep fields and field borders free of weeds and

trash which can harbor insects G G G G G

Conservation of beneficial insects G G F ? ? ? ? ? ? G ? G ? ? ? F F


Table 1b. Efficacy ratings for various pest management tools against tomato insects. Rating scale: E = excellent; G = good; F = fair; P = poor; N = no control; ? = research

needed; NU = not used; * = used, but not a stand alone tool.

Cultural/Non-Chemical Pest Management Practices

Biological Controls

Tomato Insect Pests


Ba

cte

ria

l C

an

ke

r

Ba

cte

ria

l S

pe

ck

Ba

cte

ria

l S

po

t

Ba

cte

ria

l W

ilt

Da

mp

ing

-off

Fru

it R

ot

(Alte

rna

ria

,

An

thra

cn

ose

,

Rhiz

octo

nia

)

Fru

it R

ot (P

yth

ium

&

Ph

yto

ph

tho

ra)

Bo

trytis F

ruit R

ot

(G

ray

Mo

ld)

Fu

sa

riu

m W

ilt

Ve

rtic

illiu

m W

ilt

La

te B

ligh

t

Ea

rly B

ligh

t

Se

pto

ria

Le

af

Sp

ot

Gra

y L

ea

f S

po

t

Po

wd

ery

Mild

ew

To

ma

to S

po

tte

d W

ilt

Vir

us

Tim

be

r R

ot

(Scle

rotin

ia)

So

uth

ern

Blig

ht

(Scle

rotiu

m)

Le

sio

n N

em

ato

de

s

Ro

ot-

Kn

ot

Ne

ma

tod

es

Po

st-

Ha

rve

st

Dis

ea

se

s

acibenzolar-S-methyl (Actigard) ? G G N N N N N N N N N N N N G* N N NU NU ?

azoxystrobin (Amistar, Quadris) N N N N N G F F N N F G G G F NU F G NU NU ?

boscalid (Endura) N N N N N G N E N N P F F F N NU E NU NU NU ?

chlorothalonil (Bravo, Echo, Equus) N N N N N G P F N N G* G G G ? NU P P NU NU ?

copper, fixed G F F N P P P P N N P P P P ? NU P P NU NU ?

cymoxanil & famoxadone (Tanos) N F* F* N NU G G NU N N E G G G ? NU NU NU NU NU ?

dimethomorph (Acrobat) N N N N F P G NU N N G F F F ? NU NU NU NU NU N

manganese EBDC (Maneb or Manex) N F* F* N NU G P F N N F G G G NU NU NU NU NU NU N

mancozeb (Dithane, Penncozeb or Manzate) N F* F* N NU G P F N N F G G G NU NU NU NU NU NU N

mancozeb + zoxamide (Gavel) N F* F* N NU G G F N N F G G G NU NU NU NU NU NU N

mancozeb + copper (Mankocide or Cuprofix

MZ) G F F N N F F NU N N F G G G NU NU NU NU NU NU N

mefenoxam (Ridomil Gold, Ultra Flourish) N N N N E N E P N N F NU NU NU NU NU NU NU NU NU N

mefenoxam + chlorothalonil (Ridomil

Gold/Bravo, Flouronil) N N N N G F G F N N G** F F F NU NU NU NU NU NU N

mefenoxam + copper hydroxide (Ridomil

Gold Copper) ? F F N G F G P N N F P P P NU NU NU NU NU NU N

myclobutanil (Nova) N N N N N N N N N N N N N N G NU NU NU NU NU N

pentachloronitrobenzene (Terraclor) N N N N N F N N N N N N N N N NU ? G NU NU N

Propamocarb hydrochloride (Previcur Flex) N N N N G F G NU NU NU G F F F NU NU NU NU NU NU N

pyraclostrobin (Cabrio) N F* F* N NU E G NU N N F E E E F NU NU F-G N N ?

pyrimethanil (Scala) NU NU NU NU NU G NU G NU NU ? G ? ? NU NU NU NU NU NU N

trifloxystrobin (Flint) NU NU NU NU NU G NU F NU NU G G G G NU NU NU F-G NU NU ?

thiophanate-methyl (Topsin M) NU NU NU NU NU G-18 P G-18 NU NU P F F F G-18 NU G-18 ? NU NU ?

oxamyl (Vydate L) NU NU NU NU NU NU NU NU NU NU NU NU NU NU NU NU NU NU G G N

chloropicrin N N N G G N F N G G N N N N NU NU F F P P N

dichloropropene (Telone II) N N N ? G N F N F F N N N N NU NU F F E E N

dichloropropene+chloropicrin (Telone C-17,

Telone C-35) N N N G G N F N G G N N N N N NU F F E E N

metam-sodium (Vapam HL) N N N G G N F N G G N N N N N NU F G E E N

metam-potassium (K-Pam HL) N N N G G N F N G G N N N N N NU G G E E N

methyl bromide (Terr-O-Gas 67, MC-33) N N N G G N F N G G N N N N N NU G G F F N

Tomato Diseases & Nematode Pests

Registered Fungicides & Nematicides

Unregistered/New Fungicides & Nematicides

Table 2a. Efficacy ratings for various pest management tools against tomato diseases and nematode pests. Rating scale: E = excellent; G = good; F = fair; P = poor; N = no control; ? = research needed; NU

= not used; * = used, but not a stand alone tool; 18 = Section 18 Emergency Exemption in VA.



Bacte

rial C

anker

Bacte

rial S

peck

Bacte

rial S

pot

Bacte

rial W

ilt

Dam

pin

g-O

ff

Fru

it R

ot (A

ltern

aria,

An

thra

cn

ose

,

Rhiz

octo

nia

)

Fru

it R

ot (P

yth

ium

&

Ph

yto

ph

tho

ra)

Botr

ytis F

ruit R

ot (

Gra

y

Mo

ld)

Fusarium

wilt

Vert

icill

ium

wilt

Late

Blig

ht

Early B

light

Septo

ria

Leaf S

pot

Gra

y L

eaf S

pot

Pow

dery

Mild

ew

Tom

ato

Spotted W

ilt

Vir

us

Tim

ber

Rot (S

cle

rotinia

)

South

ern

B

light

( Scle

rotium

)

Lesio

n N

em

ato

des

Root-

Knot N

em

ato

des

Post-

Harv

est F

ruit R

ots

Crop rotation G G G G F F F F G F G F F F F P F F G G F

Good sanitation practices E E E F G G G G F G G G G G G G F F F F E

Planting resistant varieties G ? ? F N G N F G G G G G G N G* N N G G N

Postharvest plant & root destruction E E E E F G G G F G G G G G G F F F G G F

Proper fertilization (balanced) G G G G G G G G G G F G G G G G P P G G E

Proper spacing of tomato plants G G G F G G G G G F F F F F F F G G F F G

Proper field drainage F G G E E F E G G F G F F F F F F F F F E

Serenade (Bacillus subtilis) ? N F* N N P N ? ? ? F* F* F* ? F N F ? NU NU ?

Sonata ? N F* N N P N F ? ? F* F* F* ? F N F ? NU NU F

Contans WG NU NU NU NU NU NU NU NU NU NU NU NU NU NU NU NU G NU NU NU NU


Biological Controls

Table 2b. Efficacy ratings for various pest management tools against tomato diseases and nematode pests. Rating scale: E = excellent; G = good; F = fair; P = poor; N = no control; ? = research needed; NU

= not used; * = used, but not a stand alone tool. ** resistant pathogens have become established in some areas


Tomato Diseases & Nematode Pests


Barn

yard

gra

ss

Berm

udagra

ss

Bro

adle

af S

ignalg

rass

Cra

bgra

ss,

Larg

e/S

mooth

Foxta

ils

Goosegra

ss

Johnsongra

ss

(se

ed

ling

)

Panic

um

, F

all

Panic

um

, T

exas

Nuts

edge, P

urp

le

Nuts

edge, Y

ello

w

Carp

etw

eed

Cockle

bur,

Com

mon

Galin

soga, H

airy

Jim

sonw

eed

Lam

bsquart

ers

,

Com

mon

Morn

ingglo

ries

1,2

Nig

hts

hade, E

aste

rn

Bla

ck

Pig

weed,

Sm

ooth

/Redro

ot

Prickly

Sid

a

Purs

lane, C

om

mon

2,3

Ragw

eed, C

om

mon

Sic

kle

pod

2

Sm

art

weed,

Pe

nn

sylv

an

ia

DCPA (Dacthal) F-G N F G G F-G F F - N N P N N N G N N F P G N N N

EPTC (Eptam) G G G G G G G G G P N P F F F-G G - G P N P

glyphosate (Roundup) G G G G G G G G F F G G G G G F G G G F G F-G

s-metolachlor (Dual Magnum) G G G G G G G G P N F F N F-G P-F P-F N F G N-P F-G N N P

paraquat (Gramoxone Max) F-G P F-G F-G F-G F-G F F-G F F-G F-G G G G G F-G F-G G G F F G G F

pendimethalin (Prowl) G G G G G G G G G N N N N N P N-P P F-G N N N N P-F

trifluralin (Treflan) G G G G G G G G N N N N N F-G P-F P F N N N P-F

clomazone (Command) G G G G G G G G N N N-F F G G-E P - N-P

halosulfuron (Sandea) N N N N N N N N N N F N-P F-G G F-G F N E P F G N F

metribuzin (Sencor) F F F F F F N F P N N G F G F-G G P-F P G N-P F F-G F G

napropamide (Devrinol) G G G G G G G G N N-P G N P-F N F-G N N F-G G P-F N P

rimsulfuron (Matrix) G N P-F G P F-G P F F-G G P-F F F P G F P F-G P-F

sethoxydim (Poast) G F G G G G G G G N N N N N N N N N N N N N N N

trifluralin (Treflan) G N G G G G G G G N N G N N N F-G P-F P F-G N F N N P

oxyfluorfen, (Goal) P P P P P P P P P N N F-G - F - F - - G G F -

carfentrazone (Aim) N N N N N N N N N N N G P P G F G G F

1Including ivyleaf, entireleaf, pitted, and tall.2Morningglories, sicklepod, and purslane (common and pink) will continuously emerge throughout the growing season.3Increasing in Virginia and North Carolina.

Unregistered/New Herbicides


Registered Herbicides

Table 3a. Efficacy ratings for various pest management tools against grass and broadleaf weed pests of tomato . Rating scale: E = excellent; G = good; F = fair; P = poor; N = no control; ? = research needed; NU = not used; * =

used, but not a stand alone tool.

Grass & Broadleaf Weed Pests of Tomato


Ba

rnya

rdg

rass

Be

rmu

da

gra

ss

Bro

ad

lea

f S

ign

alg

rass

Cra

bg

rass,

La

rge

/Sm

oo

th

Fo

xta

ils

Go

ose

gra

ss

Jo

hn

so

ng

rass

(se

ed

ling

)

Pa

nic

um

, F

all

Pa

nic

um

, T

exa

s

Nu

tse

dg

e,

Pu

rple

Nu

tse

dg

e,

Ye

llow

Ca

rpe

twe

ed

Co

ckle

bu

r

Ha

iry g

alin

so

ga

Jim

so

nw

ee

d

La

mb

sq

ua

rte

rs,

Com

mon

Mo

rnin

gg

lorie

s

Nig

hts

ha

de

, E

aste

rn

Bla

ck

Pig

we

ed

,

Sm

oo

th/R

ed

roo

t

Prickly

Sid

a

Pu

rsla

ne

, C

om

mo

n

Ra

gw

ee

d,

Co

mm

on

Sic

kle

po

d

Sm

art

we

ed

,

Pe

nn

sylv

an

ia

Black plastic mulch1 G G G G G G G G G P P G G G G G G G G G G G G G

Cover crops F F F F F F F F F F F F F F F F F F F F F F F F

Crop rotation F F F F F F F F F F F F F F F F F F F F F F F F

Cultivation2 G P-F G G G G G G G P-F P-F G G G G G F-G G G G G G G G

1Ratings do not reflect control of those weeds growing from crop hole that are in close proximity of crop. Weeds establishing in close proximity with crop are often yield reducing. 2Not used in plasticulture.


Biological Controls

Table 3b. Efficacy ratings for various pest management tools against grass and broadleaf weed pests of tomato. Rating scale: E = excellent; G = good; F = fair; P = poor; N = no control; ? = research needed; NU = not used; * =

used, but not a stand alone tool.


Grass & Broadleaf Weed Pestsof Tomato


Table 4. Timeline of tomato production in VA, NC, and DE.

Bed Preparation

Transplanting

Pruning

Fertilization

Irrigation

Cultivation

Harvest

Soil Sampling

Insecticide Application

Herbicide Application

Fungicide Application

Insect Monitoring

Disease Monitoring

Table 5. Timeline of tomato pests and diseases in VA, NC, and DE.

Aphids (Green Peach/Potato)

Cutworms

Colorado Potato Beetle

Flea Beetles

Tomato Fruitworm

Armyworms

Vegetable Leafminers

Stinkbugs

Thrips

Mites

Cabbage Loopers

Fruit Flies

European Corn Borer

Hornworms

Whiteflies

Bacterial Speck

Bacterial Spot

Bacterial Wilt

Bacterial Canker

Buckeye Rot

Damping-Off

Early Blight

Fruit Rots (Anthracnose/Alternaria)

Fruit Rot (Botrytis)

Fruit Rots (Pythium/Phytophthora)

Fruit Rots (Postharvest)

Late Blight

Leaf Spots (Septoria/Gray)

Nematodes

Powdery Mildew

Southern Blight

Timber Rot

TSWV

Wilts (Fusarium/Verticillium)

Barnyardgrass

Bermudagrass

Broadleaf Signalgrass

Carpetweed

Cocklebur, Common

Crabgrass, Large/Smooth

Foxtails

Galinsoga, Hairy

Goosegrass

Jimsonweed

Johnsongrass

Lamsquarters, Common

Morningglory

Mustards

Nightshade, Eastern Black

Nutsedge, Yellow

Nutsedge, Purple

Panicum, Fall

Panicum, Texas

Purslane (Florida Pusley)

Ragweed, Common

Sicklepod

Smartweed, Pennsylvania

Weeds

Aug. Sep. Oct.Insects/Mites Jan. Feb. Mar. Nov.Apr. May Jun. Jul

IPM Activities

Worker Activities

Dec.

Diseases

Jan. Feb. Mar. Apr. May Jun. Nov. Dec.Jul Aug. Sep. Oct.


ACKNOWLEDGEMENTS

Workshop Sponsors: Southern Region IPM Center, North Carolina State University, University of Delaware, Virginia Tech, USDA Office of Pest Management Policy, Eastern Shore Agricultural Research and Extension Center (Virginia Tech), Virginia Cooperative Extension, North Carolina Cooperative Extension Service, Delaware Cooperative Extension Service, and the Colleges of Agriculture at UD, NCSU, and VT.

ABBREVIATIONS The following are the abbreviations used for organizations, pests, and other terms discussed in this document. BAW - beet armyworm Bt - Bacillus thuringiensis CPB - Colorado potato beetle CUE - Critical Use Exemption DELMARVA - The Eastern Shore (Peninsula) of Delaware, Maryland, and Virginia EBDC - ethylene-bis-dithiocarbamate ECB – European corn borer EPA - Environmental Protection Agency FAW - fall armyworm IPM - integrated pest management NCSU - North Carolina State University

PHI - pre-harvest interval REI - re-entry interval SLN - Special Local Need SAW - southern armyworm TAW - true armyworm TSWV - tomato spotted wilt virus UD - University of Delaware USDA - United States Department of Agriculture VIF - virtually impermeable (plastic) film VT - Virginia Tech YAW - yellow-striped armyworm


REFERENCES Alabama Cooperative Extension. Tomato Pith Necrosis. Pub. No. ANR-864. http://www.aces.edu/pubs/docs/A/ANR-0864/ANR-0864.pdf. Hansen, M.A. 2000. Timber Rot of Tomato. Virginia Cooperative Extension, Pub. No. 450-712. Kuhar, T. 2002. Tomato Spotted Wilt Virus. Virginia Cooperative Extension, Virginia Vegetable, Small Fruit and Specialty Crops, Vol. 1, Issue 6. http://www.ext.vt.edu/news/periodicals/commhort/2002-06/2002-06-02.html. Relf, D., A. McDaniel, and R.D. Morse. 2004. Tomatoes. Virginia Cooperative Extension, Pub. No. 426-418. Tuckey, D.M. 2001. Crop Profile for Tomatoes in Virginia. http://www.ipmcenters.org/cropprofiles/docs/VAtomato.html. Tuckey, D.M. 2001. Commercial Tomato IPM. Virginia Cooperative Extension, Pub. No. 444-121W. http://www.ext.vt.edu/pubs/ipmfs/444-121/444-121.html. Virginia Agricultural Statistics Service. 2004. Rankings of Principal Crops and Livestock, 2004. http://www.nass.usda.gov/va. Virginia Agricultural Statistics Service. 2004. Selected Vegetables For Fresh Market 2004. http://www.nass.usda.gov/va. Virginia Agricultural Statistics Service. 2004. Vegetable Planting and Harvesting Dates and Principal Producing Counties. http://www.nass.usda.gov/va. Walgenbach, J.F., K.L. Ivors, J.M. Davis, D.M. Monks, and S.J. Toth, Jr. 2005. Crop Profile for Tomatoes in North Carolina. http://www.ipmcenters.org/cropprofiles/docs/nctomatoes.html. Zitter, T.A. 1986. Botrytis Gray Mold of Greenhouse & Field Tomato. Cornell University Cooperative Extension. http://vegetablemdonline.ppath.cornell.edu/factsheets/Tomato_Botrytis.htm.

ppeesstt mmaannaaggeemmeenntt …ipmcenters.org/pmsp/pdf/srtomato.pdf · ppeesstt...

Documents