Carryover effect of nitrogen and potassium on subsequent growth stages of tomato grown in hydroponics

Abstract

Tomato (Solanum lycopersicum L.) is a highly economical and socially important vegetable in the world and a priority crop in greenhouse cultivation. Plant growth and yield increments through the over application of nitrogen and potassium fertilizers are commonplace in soilless culture in many regions of the world. It deteriorates the quality of produce, apart from the ill effects of this malpractice on the economic and environmental sustainability of the cropping system. The utilization of residual nutrients in the plants during subsequent growth stages; carryover effect has not much evidence for hydroponically grown plants. Therefore, this study was to find out the possible influence of the carryover effect of higher dosages of N and K fertilizer application at the vegetative stage on subsequent growth stages of tomato. This experiment was conducted as a replicated trial of different combinations of N and K rates for vegetative and other growth stages. The application of low rates of N and K during the vegetative stage did not affect the total marketable yield, nullifying the carryover effect of K and N plant nutrition of hydroponics tomato. Therefore, the optimum N application rates for vegetative, early reproductive, middle and late reproductive stages of hydroponics tomato were 10, 50, 90 and 140 mg/plant/day, respectively and optimum K rates 50, 200, 300 and 350 mg/plant/day respectively. Growth stage specific combinations of optimum N and K fertilizer application rates were effective in attaining the yield and quality targets of hydroponics tomato while their contribution to possible minimization of environmental pollution.