dhriti floriculture
TRANSCRIPT
The role of nutrient solution composition on the uptake of nutrients,
growth and vase life of tulips grown hydroponically under South African
conditionsGeline Derbyshire, Eleanor W Hoffman and Estelle Kempen
South African Journal of Plant and Soil 2015, 32(3): 129–137
01-Feb-201701-Feb-2017
- Dhriti SatyaProf. Dr. agr. sc. Margarethe Serek
2
Introduction :
South Africa : Warm production region (≠ Tulip production)
Marketing!
Advantages-InfrastructureLaborAbundance natural resourcesEstablish export market through fynbos sector
Difficult to produce cut-tulip-Climatic conditionsExpensive climate controlProducers dependent on imported bulb
Tulip bulbs are importedSome are planted first in season => Early-forced bulb
and others are stored dry to plant later in season => Late-forced bulb
3
Introduction :
Tulip bulb force to grow hydroponically
Soilless culture => Control root-zone environment (Nutrient management)
Assume to increase the tulip’s vase life, healthy scape and leaves and also flowering
Flowering depends on - Bulb fertility - Composition of growing medium - Use of supplementary nutrients
4
Plant material
Standard Steiner solution(South Africa)
2 Bulb maturities4 commercial tulip cultivar
Belgium (Europe)
Amended solution(Europe + NH4+)
‘Leen van der Mark’ ‘Jan van Nes’, ‘Royal Virgin’ Ile de France
10-12cm
Materials and methods: :Nutrient solutions
5
Plant material
60cm
40cm 10cm
X (12 forcing trays)
3 bulbs per cultivar per tray were randomly labeled.
48 bulbs were planted randomly in 12 forcing trays to represent 12 bulbs of each cultivar in a split-plot design.
Prior to harvest so as to eliminate bias - • Growth measurements• Postharvest evaluations• Nutrient analysis.
unlabelled, marketable plants were to be used in the vase-life studies
Materials and methods:
6
TreatmentsIn glasshouse
1st -: In October 2012Performed immediately after arrival of the bulbs in South Africa (thus termed the early-forcing bulbs)
2nd -: In March 2013Bulbs stored dry for > 6 months were used (late forcing bulbs). These bulbs subsequently differed in their physiological age prior to rooting and forcing.
•EC of 1.6–1.8 mS/cm•pH 5.5–7.0• Replaced weekly
Four nutrient solutions
Current SA Standard Steiner Europe Europe + NH4+
+ micronutrients + micronutrients + micronutrients-
Materials and methods: :
7
Rooting
Immediately after removal from storage
bulbs were rooted in forcing trays in a dark room at 3–4 °C
Nutrient flow
Bulb roots 3–5 cm in length; attained within3 weeks for early-forcing bulbs &1 week for late-forcing bulbs
Sensor
The EC and pH of the nutrient solutions were monitored throughout the rooting period and maintained. The nutrient solution was replaced weekly to prevent salinisation or depletion of nutrients
Materials and methods:
8
Vegetative growth phase
The growth and development (expressedas plant height in mm) of three plants per cultivar per tray was recorded twice a week.
Rooted bulbs
Glasshouse(temperature 20 ± 2 °C,
relative humidity 55–65%)
Materials and methods:
9
Harvest
Min 300mm + Color change
dry mass of eachplant (g) was recorded
stems were evaluated forstem length (mm),leaf area (cm2) andplant fresh mass (g)
X (10 bunches)of 8 flowers each per nutrient solution
vase-life testsRetail simulation
Materials and methods:
10
Vase life
Evaluation of vase-life duration of each stem• degree of wilting• color loss of the tepals• toppling of the stem and• yellowing of the foliage. The day of first flower removal + 50% flower removal was recorded. Vase life was terminated when >60% of tepals on a particular flower were withered or a stem had toppled.
Materials and methods:
11
Figure 1: Effect of various cultivars and bulb age on the first 11 d of scape growth (mm) of hydroponically forced cut tulips grown under warm climatic conditions
Significant cultivar growth differencesScape growth
With later harvest,• Cultivar emerge early• Rate of stem elongation increase• Sprouting increase• More response to vernalisation treatment
Results and discussion:
Scape length & Plant height non significant to different nutrient solutions.
12Figure 2: Effect of bulb age and cultivar on postharvest stem length (mm).
Stem length
Results and discussion:
21.7%longer More responsive to vernalisation
35%longer
Longer production † stem elongation
Stem length non significant to different nutrient solutions.
Post harvest parameters
13
Treatment Leaf area (cm2)
Current SA 224.10
Standard Steiner
251.92
Europe 237.70
Europe + NH4+
230.72
F-value 3.07
p-value 0.03
Significance *
* p < 0.05
Results and discussion:
Table: Effect of (a) nutrient solution on leaf area of cut tulips grown hydroponically under warm climatic conditions.
Produced the largest leaf area
Post harvest parameters
N content of leaves Regulate photosynthesis
and stimulate leaf expansion
(b) CultivarsTwo cultivar had largest leaf area whereas two had smallest. Different cultivar respond differently to environmental factors
(c) BulbsEarly-forced bulb = 333.5 cm2
Late-forced bulb = 138.6 cm2 (also shorter stem)Leaf formation Initially by reserves in bulb, later by assimilates from leaves.Increases until senescence
14
Figure: Interactions between (a) nutrient solution and bulb age (b) cultivar and bulb age on the fresh mass of cut tulips that were forced hydroponically under warm climatic conditions
lower Fresh Mass of late-forced bulbs Î t ∝to anthesis for the early-forced bulbs, and thus longer exposure to nutrition and the production of photosynthates. late-forced bulbs that were stored for alonger period than early-forced bulbs continue to respire at low rate during storage. Thus they have fewer reserves available for initial growth and emergence of leaves, which may have resulted in a smaller leaf area and thus less assimilates available for further growth of new organs. In turn this may have resulted in thedecreased FM for late-forced bulbs.
Results and discussion:
15Figure 4: Interactions between cultivar and bulb age on the dry mass of cut tulips grown hydroponically under warm climate conditions
Results and discussion:
Dry mass CHO (photosynthesis) 90% DM
*
*
*
Difference less expected Genetic cultivar differences
Early forced bulbs increased DM –longer time to flower (23 d w LFB 11d) bulbs Nutrients accumulation + CHO production over a longer period. duration of bulb chilling received
The DM - not significantly affected by the nutrient solution composition
16
Figure: Interactions between (a) cultivar and bulb age and (b) nutrient solution and bulb age on the vase life of cut tulips grown hydroponically under warm climatic conditions
Vase life
Results and discussion:
Water stress terminate vase life EFB have higher transpiration rate
17
Scape growth was not significantly influenced by applied nutrientsTulip bulb contains sufficient reserves.
Nutrition solution affected the leaf area of flowering stems Marketability
Nutrient solutions (Standard solution & Europe) Highest quality cut flower & longest vase life for all cultivar.
Leen van der Mark – longest stem Preferred for cut flower
Leen van der Mark should be promoted under warm conditions.
Early-forced bulb Longer stem, sig. leaf area, increased fresh and dry weight.Late-forced bulb Scape grew rapidly, longest vase life Quality
Optimized nutrient solution produce quality cut tulips, depending on the cultivar and physiological bulb age.
Conclusions:
18
Geline Derbyshire, Eleanor W Hoffman and Estelle Kempen, 2015. The role of nutrient solution composition on the uptake of nutrients, growth and vase life of tulips grown hydroponically under South African conditions. South African Journal of Plant and Soil 2015, 32(3): 129–137.
Reference:
19
Thank you for your attention!