Orchard crops and Olives – leaf analysis
24/10/2011 12:37:23 PM
Bryan McLeod
Are unidentified nutrient deficiencies eating away at your profits?
If you can see symptoms you may have already lost 30% of your potential production.
Testing for nutrient deficiencies
Leaf testing is an invaluable and cost effective way of identifying “hidden” deficiencies before they become obvious and potential losses occur. In fact once you see the deficiency symptoms, you may already have lost 20-30% of potential production. Treating identified limiting nutrients is as simple as using a good foliar (leaf nutrient spray) program formulated from the analysis.
Ensure optimum returns and profitability with an APAL total nutrient leaf analysis.
Knowing the nutrient levels in your trees is invaluable in helping you to achieve your goals by:
- identifying limiting nutritional factors – these can be different from those in your soil
- achieving optimum tree health – poor tree health is reflected in fruit quality and poor storage life
- achieving optimum yields
- achieving optimum fruit quality – identifying nutrient deficiencies will help to guarantee fruit quality and minimise losses through rejection.
- achieving maximum financial return – unidentified nutrient deficiencies will eat away your profits
- achieving optimum bud initiation for the next crop
Factors that can affect the visual identification of mineral deficiencies include:
- intensity/severity of deficiency
- rate of plant growth at the time of sampling
- occurrence of multiple deficiencies
- confusion with insect and/or root disease effects on crops
- chemical damage
Growers need to use leaf tissue analysis as the most reliable tool for the immediate identification of mineral deficiencies in their orchard
A total APAL nutrient analysis enables you or your agronomist to formulate a foliar program that matches your trees’ needs exactly.
Bryan McLeod has been working with many orchardists in the Adelaide Hills area over the past 25 years. Their programs consist of annual soil and leaf tests. Soils are taken in March to April to enable soil deficiencies to be addressed prior to the winter liming/gypsum applications and the spring fertiliser amendments. Leaf samples are taken in December to early January.
The results of the leaf analysis are used to identify mineral deficiencies or excesses and to then formulate special foliar applications to ensure good quality fruit is harvested.
Growers using this extensive program comment on improved and continued soil and plant health plus enhanced fruit flavour and extended shelf life.
Being able to identify limiting factors takes the guess work out of a good nutritional program.
Bryan McLeod and Phil Flavell in his orchard
Understand the difference between leaf and soil analysis and the importance of both
There are significant differences between a soil and plant leaf analysis
- Leaf Tissue Analysis - Measures tree nutrient levels as a result of nutrient uptake. Uptake of elements from the soil is determined by their soil concentration but also by any nutrient imbalances in the soil. Therefore leaf analysis does not always reflect soil levels of any nutrient.
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Soil Analysis - Measures available soil elements and identifies mineral imbalances. Tree uptake can be influenced by soil imbalances.
The effect of soil imbalances
A leaf analysis can often be seen as a reflection of the soil in that it shows what nutrients the soil’s mineral balance is allowing the tree to extract.
Examples:
High soil potassium inhibits plant uptake of magnesium.
High magnesium soils inhibit plant potassium
High sodium inhibits plant potassium and calcium
High soil calcium inhibits plant uptake of most trace elements
Therefore we often see a mineral deficiency in trees even when there are ample levels in the soil. As long as there is antagonism between minerals in the soil we will always see deficiencies in the leaf.
Growth patterns.
Another factor to consider when interpreting leaf analysis is that during periods of high growth, elements are more diluted in the plant tissue and may appear as deficiencies in an analysis.
Foliar fertilisers are essential for balancing plant nutrition. Mineral fertilisers consisting of both major and trace elements are readily absorbed through the leaf surface and can provide essential nutrients to correct identified deficiencies and excesses.
Foliar fertilisation should be based on a leaf analysis combined with the results of a soil analysis if available.
Advantages of foliar fertilisers:
- Precise application rate according to crop requirements
- Precise application timing according to crop requirements
- Effects of interactions with other nutrients avoided
- They can correct deficiencies quickly
- Used correctly they can increase efficiency of soil applied nutrients
At least two applications are required for optimum results
Foliar spray rates need to be in proportion with the crop demand and recommended application rates should never be multiplied with the hope of a better response.