Fruit growing
and viticulture of South Russia

Annotation

The purpose of this work was to study the influence of separate and joint foliar fertilization with potassium and calcium on the accumulation of these elements in the apple fruit of the Sinap Orlovsky and Imrus varieties, as well as to study the influence of ratio of these elements on the fruits storage ability. The optimal ratio of these elements in the apple fruits is great important, since this indicator affects the yield quality, including the duration of fruits storage. The research were carried out in 2014-2015 in the field experiment on the study of the efficiency of foliar top dressings. It has been shown by the study that the effect of joint treatments of studied apple varieties by potassium and calcium-containing fertilizers differs from the effect of separate fertilization. The studied varieties manifest the different reactions, both to individual compounds and to their mixtures. There were significant differences for years, depending on the prevailing meteorological conditions, as well as difference of varieties. It was found that in the studied apple varieties the calcium content in the fruits is a more stable index, in comparison with the content of potassium, which significantly changed depending on meteorological conditions and the load of trees by harvest. Foliar top dressing with potassium sulfate and calcium chloride, having a significant effect on the level of potassium and calcium in the tissues of apple fruits, can increase in the risk of bitter pit developing. For the Sinap Orlovsky apple variety a significant increase in the K/Ca ratio was observed when 0.3% potassium sulfate solution treatment, for the Imrus apple variety � when the plants are sprayed with 1% solution of calcium chloride.