Tissue, please: Leaf analysis tells a vegetable’s tale


BLACKSBURG, Va. – Plasticulture strawberry and vegetable growers need to send their plant leaf tissue to a laboratory for analysis so they can use the information as part of the regular management of their crops.

The information from the plant leaf tissue analysis is critical for high cost enterprises such as plasticulture strawberries and vegetable crops, said Charlie O’Dell, horticulturist at Virginia Tech.

Private labs currently charge around $24.50 for a complete plant tissue analysis of leaves.

Researchers have established the amounts of each of the nutrients needed by small fruits and vegetable crops. Whenever a major or minor plant nutrient element falls below the range for that crop, both yields and fruit quality can suffer.

O’Dell said growers will not achieve the full potential for returns on investments of money, labor, management, equipment. and land resources if the plants are not getting the nutrients needed.

Each field, each crop.

Every small fruit and commercial vegetable grower should have at least one complete plant tissue nutrient analysis from each field for each crop before harvests begin. Once the growers have the information they can correct the crop nutritional status by a drip irrigation or foliar application of the particular plant nutrient.

“Growers have made big investments in horticultural crops,” O’Dell said. “It’s just common sense to let the crop tell you it’s doing great or that it needs help.”

O’Dell admitted that last year he had a block of strawberry plots that visually looked fine at spring bloom. Even though the plants appeared healthy, he decided to send a plant sample to a private tissue testing lab for a complete major and minor nutrients inventory. The report showed a zinc deficiency.

“We quickly applied a zinc nutrient product formulated specifically for rapid foliar intake and plant use, that was easily applied with a regularly scheduled Botryticide bloom spray.” The growth response was immediate and easily noted within about 48 hours, he said. Plants produced a bountiful crop of excellent quality fruit.

Some plant nutrients, such as calcium, for example, are more easily and rapidly corrected by foliar application than from a dripline application.

In another strawberry field O’Dell found from plant tissue analysis that calcium was below the sufficiency range. A quick soil pH test also confirmed a soil pH of only 5.0.

A quick foliar application of calcium formulated just for this purpose put those plants into overdrive, O’Dell said. The results again were gratifying in yield, fruit size, skin or fruit firmness and fruit shelf life quality.

Calcium-containing soluble fertilizers are often fertigated through the drip irrigation lines. But it is difficult for the calcium to quickly get to the plants when each of the double rows of berry plants is 8-9 inches or so away from the centered dripline in each raised, plastic mulched bed, compared to a foliar spray.

No visual problems.

In both of these real-life examples, O’Dell said that the experts thought the plantings were fine by looking at them. “We had gone by the book, applied recommended pre-plant major nutrients and were careful to not over-apply nitrogen pre-plant and to fertigate nitrogen during the spring.

Extension agents and growers can evaluate plant sample results from private labs such as A & L in Richmond, Va., and Spectrum Analytic in Ohio.


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