Influence of Fertilizerforms and Rates on Tomato Fruit Quality Indices

Abstract

This paper discussesthe results findings on the effect of nitrogen fertilizers as urea-ammonia liquor (KAS-32) and ammonium nitrate of various application rates (40,80 and 120 kg of primary nutrient per ha) on the quality of tomato fruits grown on the field and under cover.Various research methods were tested. They made it possible to identify biologically active substances of tomato fruits which helped to examine fruit chemical composition of experimental vari-eties with the determination of dry solids, total sugar, vita-minC, total acidity, lycopene and nitrates. It was found that under cover, the application of nitrogen-containing fertiliz-ers increased dry solids by an average of 23-25%, total sugar -by 55-61%, vitamin C -by 33-41% as compared to the control. On the field, the dry solids content increased by 35-45%, total sugar -by 74-83% and vitamin C -by 37-42%. However, the application of the maximum rates of N120fertilizer decreased dry solids content by 5-6% as compared to N80. At the same time, there was an increase of fruit total acidity as compared to the control: up to 32% under cover, and up to 16% on the field. Although as sugar content increased, the acidity had almost no effect on the eating qualities. In all variants, the nitrate content did not exceed themaximum permissible concentration. The ob-tained data confirmed the positive effect of certain rates of nitrogen-containing fertilizers on the structure, quality and safety of the obtained tomatoes. This result will make it possible to recommend the testedmethods and rates of fertilization during the growing season.