Effectiveness of potassium nitrate foliar fertilization on development and productivity of tomato (Solánum lycopérsicum L.)

Abstract

In world production, the share of tomatoes (Solánum lycopérsicum L.) is almost 20 % of all produced vegetables. Tomatoes are the most popular vegetable crop in the world, which is why increasing the yield of tomatoes is an essential requirement of modern production. One of the most important and promising ways to increase tomato productivity in greenhouses is the use of modern drugs and resource-saving technologies. In connection with this, the importance of agrotechnical measures for ecologically safe improvement of the efficiency of agricultural production is increasing. The article presents the results of the study of the effect of foliar fertilizing with potassium nitrate on the processes of growth, plant development, and yield of tomatoes throughout the vegetative period. The field experiment was conducted during 2018–2021 for the cultivation of the indeterminate Panekra F1 tomato hybrid in unheated spring film greenhouses. According to the research results, a significant effect on the biometric indicators of plants of foliar fertilizing with potassium nitrate was established, both in the phase of mass flowering (increase by 6–21 % from the control) and in the phase of mass fruiting (increase by 9–28 % from the control). The results of studies on the formation of tomato yield by months of the fruiting period indicate that an increase in the concentration of potassium nitrate increases the monthly yield of fruits, during July and September, by 13–19 % relative to the average level of yield per month. The yield level varied depending on the climatic conditions of the growing year, from the maximum in 2019 – 16.7–18.7 kg/m2 to the minimum in 2021 – 7.6-9.0 kg/m2. The research results show that the highest yield rate (15.8 kg/m2, 13.4 % more than the control) was recorded for the option of treating tomato plants with a potassium nitrate solution with a concentration of 20 g/l. The use of higher concentrations of the drug (up to 30 g/l) did not lead to a significant increase in this indicator (yield at the level of 15.2 kg/m2). The prospect of further research is to establish the relationship between the composition of microfertilizers and their influence on the processes of yield formation when applied by foliar fertilizing methods.