DATA FOR PHYSIOLOGICAL INTERPRETATION OF FRUIT LOAD ON STORAGE QUALITY OF ‘JONATHAN’ APPLES

Mineral analysis of leaves and fruits are widely used for prognosis of apple storability.
The relation of apple storability with nutritional status of trees can be characterised by multiple correlation:

• the potassium content in leaves is bilaterally influenced by the fruit load of the tree and the potassium availability in the soil.
  Consequently, the use of leaf K content is limited for given plantations, where changes from year to year may be interpreted;

• the fruit quality has positive correlation with the quantity of yield, therefore, mineral analysis results correlated to higher yields may be simultaneously correlated to better fruit quality, however, the relations of foliar elements to yield are variable in each cases;

• relation of foliar N and fruit load is polynomial, in the aspect of fruit load and fruit quality, an optimum level may be estimated at 2,4–2,6 p.c. of dry weight, respectively;

• the relation of leaf P-content and the fruit load is reciprocal, increasing yields are accompanied by decreasing P-concentrations in the leaves and lower storage losses;

• Ca and Mg-content of foliage gives increasing tendency with fruit load; increasing leaf Ca and Mg levels join with decreasing storage disorders;

• the relation of N, P, K and Mg-content in fruit and the concentration of the same nutrient element in leaves can be characterised with positive tendency, incorporation of Ca is uncertain;

• as a probable result of increasing sink power of fruits on under-loaded trees, decreasing fruit load may be accompanied by rising N, P, and Ca content in fruit, and such fruits are less suitable for storage;

• in general, fruit K and Mg contents of fruit have not been successfully related to fruit quality, however, in given years and, especially on given locations fruit K has been clearly- and negatively – related to fruit quality.

International Symposium Effect of Pre- & Postharvest factors in Fruit Storage

E. Szücs, T. Kállay

nutrient, sink effect, multiple regression, determination

https://doi.org/10.17660/ActaHortic.1999.485.50