Efficiency of different methods and forms of microelements application in function of n fertilizer in apple trees

In order to achieve a high yield and quality of apple fruit, more effective ways of fertilization are required in the modern, high density apple orchards. The objective of this research was to determine the efficiency (partial nutrient balance, PNB) of different methods (foliar and fertrigation) and forms (chelates and salts) of microelements application in relation to the levels of N fertilization in apple orchard cultivar (‘Golden Delicious’). The combined effects of these fertilizers on the number of apple fruits per tree and on the yield per tree were also studied. Foliar application of Mn, Zn and Fe had significantly higher partial nutrient balance values compared to the soil application in both years of the experiment. However, most of the PNB values were below 10% indicating relatively low efficiency of the applied fertilizers with microelements

Controlling premature fruit drop of cultivar Idared by using α-naphthaleneacetic acid

Fruit drop before reaching technological maturity is one of the core problems in the apple industry. The aim of this paper is to examine the effect of the chemicals VBC 30033 based on aminoethoxyvinylglycine (AVG) and Dirager based on α-naphtalenacetic acid on the prevention of fruit drop of apple cultivar Idared, as affected by the time of application, the number of applications and the concentration. The research was conducted from 2009 to 2011 at the experimental field of the Faculty of Agriculture in Novi Sad. The special focus was placed on the double and triple applications of NAA which were considered the most effective in preventing fruit drop. The triple application of NAA 5 ppm and NAA 10 ppm showed equal effectiveness, therefore the treatment NAA 5 ppm is recommended due to the reduced use of the chemical