Effect of vermicompost tea on yield and nitrate reductase enzyme activity in saladette tomato

Abstract

In conventional agriculture, heavy doses of chemical fertilizers and pesticides are often used to improve the yield of various horticultural crops. These chemical fertilizers and pesticides cause health problems among consumers. Due to the adverse effects of chemical fertilizers, there is interest in the use of organic fertilizers. It has long been recognized that the rate-limiting step for nitrogen assimilation, the reduction of NO 3 to NO 2 catalyzed by nitrate reductase (NR), is highly regulated. An increase in the amount and activity of NR leads to a corresponding increase in the potential for nitrate reduction and confers a greater capacity for general amino-acid synthesis, protein synthesis or total nitrogen assimilation. The aim of the current experiment was to determine the effect of organic and conventional fertilizers on yield and nitrate reductase activity in saladette tomato.Tomato plants were grown under controlled greenhouse conditions and treated with either organic or conventional fertilizer. We evaluated five treatments: F1, sand + inorganic fertilizer; F2, sand + vermicompost tea; F3, a 1:1 mixture of sand: compost + vermicompost tea; F4, a 1:1 mixture of sand: vermicompost + vermicompost tea; and F5, a 2:1:1 mixture of sand: compost: vermicompost + vermicompost tea. The evaluated variables were yield, fruit size, number of fruits, fruit quality, chlorophyll content, and in vivo nitrate reductase enzyme activity. Fertilizer type strongly influenced the yield, fruit size, and fruit quality. The best organic fertilizer for tomatoes was sand + vermicompost tea. Tomatoes in this treatment group produced the second highest yield, the best NO 3 assimilation, the greatest nitrate reductase