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Manganese Status in Vine Leaf on Calcareous Soils After Manganese foliar

fertilizationM. Herak usti1, D. Gluhi2, M. Petek1, L. oga1, S. Slunjski1, B. Lackovi3

1Department of Plant Nutrition, Faculty of Agriculture, University of Zagreb, Svetoimunska cesta 25, HR-10000 Zagreb, Croatia. E-mail: mcustic@agr.hr

2Institute for Agriculture and Tourism, Karla Huguesa 8, HR-52440 Pore3Faculty of Agriculture, University of Zagreb

KeyWords:chlorosis, active lime, grapevine, microelement, Sanvignon

AbstractGrapevine chlorosis often occur on alkaline soils and are commonly associated with microelement deficiency, notably that of iron and/ormanganese. As most soils in the Pleivica wine-growing region are of marked alkaline reaction, chlorosis of the variety Sauvignon Blanc(planted on SO4 rootstock) is a usual occurrence immediately before flowering. Trials were therefore set up to investigate Mn foliarapplication in 4 vineyards with different levels of physiologically active lime in soil. Although differences in leaf Mn contents wererecorded between locations (97.44-134.38 mg kg-1), they are not results of soil lime contents but of a series of other factors such as ionantagonism and agroecological factors. This is corroborated by almost identical Mn values in healthy and chlorotic vine plants (114.40-114.71 mg kg-1). Significant differences were determined, depending on Mn fertilization (73.60-155.51 mg kg -1) and sampling time(61.06-190.50 mg kg-1). Investigations are continuing.

Introduction

Incidence of leaf chlorosis is frequent in grapevine productionon calcareous soils. The main problem encountered oncalcareous soils is the large amount of HCO3

- ions in soilaqueous solution, buffering pH in a range 7.5-8.5. This has astrong influence on cation uptake from the soil, indirectlyinstigating occurrence of chlorosis due to lack or imbalance of

particular cations in vine leaf. As agricultural potentials ofchanging the amount of HCO3

- ions in soil are very restricted(soil aeration, increase of organic matter content, use of

physiologically acid fertilizers, etc.), foliar fertilization is oftenapplied. Although foliar fertilization should be an efficacious

solution, its expected effect often fails to appear in practice.Besides selection of particular biogenic elements to be applied,it is very important to know the amount of cations in leaf and itsratio to other cations, as well as the application date.Manganese foliar fertilization should be applied if leafmanganese is lower than 20 mg kg-1 (Fregoni, 1998). The upperthreshold of leaf manganese is 150 (Christensen, 1984) or 200mg kg-1 (Fregoni, 1998). Leaf manganese content isundoubtedly also dependent on the time of vine leaf sampling.The research objective was to find out whether the amount of

physiologically active lime (CaO) in soil, Mn fertilization andleaf sampling time affect the leaf Mn content and occurrence ofchlorosis.

Materials and Methods

Investigations were conducted in 4 production vineyards in thePleivica wine-growing region (central Croatia) on the varietySauvignon Blanc. According to the active lime contents, thesoils were divided into three groups; 25% CaO(locations Veselnica and Boricka). Manganese was applied inthree treatments with a total of 750 g ha -1 yr-1 of Mn. Leafsamples for chemical analysis were taken 4 times during thegrowing period; leaf manganese was determined by the AASmethod (AOAC, 1995).

Results and DiscussionResults of statistical data processing (Table 1) indicate that eachof the listed sources of variability has a strong influence on the

leaf manganese content. There are significant interactionsbetween discrete sources of variability and hence no source ofvariability can be independently considered. Average leafcontent of manganese in the growing period was 114.56 mg kg -1, which, according to the results of other authors (Christensen,1984; Fregoni, 1998), is a satisfactory supply for grapevine.

Although a significant difference in leaf manganese content onsoils with different CaO contents was expected (Herak usti etal., 2008), this could not be confirmed in this research (Table2). Soil with the lowest Ca content (location Sipkovica; < 20%CaO) and location with the highest CaO content (Veselnica;

30% CaO) had almost equal amounts of leaf Mn.

Foliar application of Mn during the vine growing period (threetreatments) resulted in a marked increase of leaf Mn (Table 3),reaching the upper threshold of optimal manganese sufficiencyas reported by some authors. Further foliar fertilization (long-term investigations) might result in manganese phytotoxicity.

Table 1 Effect of the source of variability on leafmanganese content.

Source of variability SignificanceLocation (A) ***Fertilization (B) ***Time of sampling (C) ***Interaction

A x B ***A x C ***B x C ***A x B x C ***Mean 114.56C.V. 16.08 %

As Mn is a biogenic element important to grapevine, but also aheavy metal, its multiple application in the growing period islikely to result in Mn accumulation in leaves. The results givenin Table 4 show a trend of Mn accumulation in leaves duringthe growing period. From the initial lower values (61.06 mg kg-1), the leaf Mn content rose after harvest to the high 190.50 mgkg-1. As the 4th leaf sampling was carried out after the harvest,

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possible manganese phytotoxicity is not likely to be manifestedon vine plants, but accumulated Mn will remain in leaves, fallto the ground and enter the process of organic matterdecomposition.

Table 2 Comparison of mean values for the factorlocation.

Treatment Mn (mg kg-1)

Sipkovica 134. 38 aVeselnica 122.34 aKlemenka 104.07 bBoricka 97.44 bSignificance ***LSD (0.05) 13.28

Table 3 Comparison of mean values for the factorfertilization.

Treatment Mn (mg kg-1

)

Control 73.60 bFertilization 155.51 aSignificance ***LSD (0.05) 9.39

Table 4 Comparison of mean values for the factorsampling.

Treatment Mn (mg kg-1)

1st sampling 61.06 c2nd sampling 106.88 b3rd sampling 99.78 b4th sampling 190.50 aSignificance ***LSD (0.05) 13.28

According to the data given in Table 5, in the growing period of2006 there was no statistically significant difference inmanganese content between healthy and chlorotic vine plants

Table 5 Difference in Mn content in leaves from healthy andchlorotic vine plants

Vineyards Mn (mg kg-1)Healthy vineyard 114.40Chlorotic vineyard 114.71Sig. n.s.

ConclusionAccording to the research results of 2006, there was nodifference in Mn content between healthy and diseased vine

plants. Grapevine chlorosis in the studied vineyards was notcaused by excess or deficit of leaf manganese, but probably bya whole series of agroecological factors and ion interactions.Investigations are therefore continuing.

References

AOAC. 1995. Officinal method of analysis of AOACInternational, 16th Edition, Vol. I, Arlington, USA.

Christensen L.P. 1984. Nutrient level comparisons of leaf petioles and blades in twenty six grape cultivars over threeyears. Am. J. Enol. Vitic. 35:124-133.

Fregoni M. 1998. Viticoltura di qualita. In: La nutrizioneminerale della vite. 493-579.

Herak usti M., D. Gluhi, L. oga, M. Petek, and I. Goak.

2008. Vine plant chlorosis on unstructured calcareous soils andleaf Ca, Mg and K content. Cereal Research Communications36:1.439-442.