Determination of standard values of elements in the leaves of fruit species and their relation to the productivity of trees and soil management
1990
Hudska, G.
Twenty years ago we investigated the nutrition status and determined standard and critical values of nutrient elements in the leaves of apple and some stone fruit trees. For this purpose leaf samples were collected from high productive orchards situated in different soil and climatic zones of Czechoslovakia, from trees without symptoms of nutrient deficiency. These studies demonstrate that the nutrient element distribution can be related to the nutrient status. The results obtained are utilized by Agricultural Test Laboratories and by fruit growers. Simultaneously we have evaluated the relation between fruit production and changes of leaf nutrient contents. The relation between soil management, migration of N, P, K, Ca and Mg into lower layers and their content in the leaves of five apple varieties was followed under two various climatic and soil conditions. A close correlation was found between the content of NO3 in the soil and the yield. The level of nitrogen in leaves was highest in the herbicide treated plots and the lowest in plots with grass and cultivation. Phosphorus content was highest in the herbicide and grass plots. Potassium and Mg contents were highest in the plots with mulch followed by grass and herbicide treated plots. A method for calculation of nutrient doses was developed on the base of the mineral content in leaves and the expected yield.
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