Plant tissue analysis for testing nutrients deficiency in grape

Plant tissue analysis for testing nutrients deficiency in grape


It is used to distinguish between two nutrients which cause similar deficiency /toxicity symptoms.

Tissue nutrient analysis can be used to develop a nutrient guide for recommendation of manures and fertilizers for economic optimum yield under integrated nutrient management.

We can also use it as diagnostic tool in case of simultaneous multiple nutrients deficiency.

Leaf analysis has much usefulness over soil analysis particularly in perennial crops like grapes.

It is used to an aid to understand the internal functions of the nutrients in the plant.

Introduction

The nutritional needs of established vineyards are best determined by utilizing several things: soil testing, tissue analysis, observations of vine growth and fruiting, and past experience.

Tissue analysis indicates the level of nutrients in the entire plant.

Plant Tissue analysis is done for two reasons:

1. To monitor nutrient levels within the plant to detect a nutritional problem before it negatively impacts yield and quality

2. Troubleshooting to confirm or deny a suspected nutrient problem within a plant

Hence for correcting deficiency of a particular nutrient, it is important to analyse leaf tissues at right stage and right time.


Objective

After completing this lesson, you will be able to :

Explain optimum level of nutrients, factor affecting leaf nutrients analysis, time and methods of leaf sampling in

grape.


Factors influencing nutrient content of the soil

Type of vegetation cover; e.g. with legume cover there could be higher N, etc.,

Application of manures and fertilizers.

Application of soil amendments

Inheriting status of soil


Factors influencing nutrient content of the leaf

Fertilizers input

Type of vegetation cover; e.g. with legume cover there could be higher N, etc.,

Factors inherent in the cultivar, rootstock; genetic make-up, age of crop, time of sampling; seasonal variation, age of leaves, position of leaves, yield of crop etc.


Leaf Samples

Leaf analysis is an important tool to estimate nutritional requirement of fruit trees. Leaf nutrient content can be obtained by analysing leaf tissues at proper growth stage. Thereafter, nutrient requirement of fruit trees can be calculated based on optimum norms of tissue nutrient in grapevine.


When to sample:

1) At full bloom:Full bloom is considered to be when about two-thirds of the flower caps have been shed. Since nutrient element concentration changes throughout the growing season,Sampling at full bloom may provide a more accurate reflection of the nitrogen status of the vine and is early enough to allow amendments to the fertility program to be made during the same growing season.

2) At veraison:Sampling at veraison may provide a more accurate assessment of the status of other elements. Due to the timing, adjustments to be made to the fertility program will be applicable to the next growing season.


Plant tissues sampling guideline for grape

5th petiole from base

Bud differentiation stage for yield forecast.

Petiole opposite to bloom time for quality


Optimum norms

Nutrient Nutrient Thompson SLThompson SL Ana-e-ShahiAna-e-Shahi

N (%) 0.87-1.61 0.50-1.25

P (%) 0.29-0.65 0.46-.068

K (%) 2.0-3.0 1.16-2.42

Ca (%) 0.98-1.36 1.40-2.07

Mg (%) 0.63-1.10 0.24-0.58

S (%) 0.09-.13 0.08-0.18


Optimum norms

Nutrient Nutrient Thompson SLThompson SL Anab-e-ShahiAnab-e-Shahi

Fe (ppm) 54-80 38-107

Mn(ppm) 42-209 18-86

Zn (ppm) 30-88 29-94

Cu(ppm) 5-10 10-30


Procedure for collecting the sample

To obtain the best analytical results, certain steps need to be taken in sample collection as follows

Sample areas displaying different growing patterns separately.

Collect only one variety/rootstock combination per sample from vines of approximately the same age.


Procedure for collecting the sampleSelect petioles from leaves that are well-exposed to sunlight and free from injury and disease

Collect petioles from the same approximate locations in the canopy.

a. Take petioles from the most recently matured leaves (usually five to seven leaves from the shoot tip and opposite from a fruit cluster).

b. Collect samples from shoots occupying approximately the same position on vines.


Factors affecting leaf analysis results

Physical State of the Tree

During stress condition, such as drought, disease/insect attack, nutrient levels are likely to be low.

When the tree is pushing out a new flush of growth nutrients are moving into the new shoots and often out of the old leaves.

The best time to take samples is when the flush has hardened off and matured.

Waterlogging

Waterlogging also reduces the uptake of most nutrients, so even though soil nutrient levels are adequate, they may not be taken up by the plant and leaf levels will indicate deficiencies.



Nutrient ImbalancesMaintaining a correct balance between elements is important, as high levels of one element can affect the uptake and levels of another, e.g. high N levels can cause low Ca levels.

Variety/Rootstock

Most fruit trees show different standard levels between varieties. Rootstocks can also have an effect.


Weed infestation


WeedsWeeds compete for nutrients, especially N. Often the effective use of herbicides, where weeds have built up, increases N levels in the plant without fertilizer being applied.

Recent foliar applications of trace elements, fertilizers or fungicides will raise the levels of these elements in leaves even after they have been washed.

Fungicides/Foliar Fertilizers


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Plant tissue analysis for testing nutrients deficiency in grape