EFFECTS OF TIME AND AMOUNT OF NUTRIENT ADDITIVES ON NUTRIENT STATUS AND DISTRIBUTION AND ON FRUIT QUALITY

Nutrient status and distribution in fruit trees and fruit quality are influenced by both the total amount of fertilizer added per year and the time of its application, i.e., the date and duration of nutrient availability.
A single large fertilizer application can have a different effect on nutrient uptake and fruit quality from repeated fertilizer applications throughout the year.
These differences are generally more obvious on light than on heavy soils because of the reduced sorptive capacity of the former; the type of soil management can also influence the fertilizer needs (Lüdders and Debor, 1979).

This paper surveys the effects of seasonally varied nitrogen and potassium nutrition on nutrient status and distribution in the tree and on the quality of the fruit.
The experiments were carried out on young apple trees in pot trials lasting three years (Figures 19.1 and 19.2). The eight-month growing period from 1 April to 30 November was divided into four two-month periods (April/May, June/July, August/September, October/November), ‘nutrient solution periods’. In each of these periods trees received either ‘L’ (= low

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Symposium on Mineral Nutrition and Fruit Quality of Temperate Zone Fruit Trees

P. LÜDDERS

https://doi.org/10.17660/ActaHortic.1980.92.19