Іnfluence of mineral fertilizers on photosynthetic productivity of grain sorghum

Abstract

Grain sorghum is a crop that has significant advantages over other crops due to its economically valuable biological features. Due to the xenomorphic structure of plants, drought and heat resistance, salt tolerance, unpretentiousness to growing conditions, the culture forms a high grain productivity and is widely known in agriculture world. Grain sorghum is used for food, feed and technical purposes. Therefore, the study of elements of cultivation technology, namely the application of mineral fertilizers, is one of the urgent tasks that will contribute to the formation of high photosynthetic productivity of the culture.

The article presents the results of research on the effect of different doses of mineral fertilisers on leaf surface area, photosynthetic activity and net productivity of photosynthesis of sorghum plants in the Right-Bank Forest-Steppe of Ukraine.

The purpose of the research is to investigate the influence of mineral nutrition of plants on the photosynthetic productivity of grain sorghum in the Right-Bank Forest-Steppe of Ukraine.

The research was conducted in 2016–2020 in the conditions of the Bila Tserkva research and selection station of the Institute of Bioenergy Crops and Sugar Beets NAAS on the Right-Bank Forest-Steppe of Ukraine.

It was investigated that the increase in the leaf surface area of sorghum plants was due to the increase in doses of mineral fertilisers. It was highest with the estimated application (N₅₀P₄₀K₇₀) and high doses of fertilisers (N₉₀P₉₀K₉₀ and N₁₂₀P₁₂₀K₁₂₀) during the period of panicles' ejection – flowering. The net productivity of photosynthesis and grain yield of both varieties in these variants of the experiment were also the highest.

A linear correlation was found between leaf surface area and net photosynthesis productivity, which is described by the regression equation
y = 2.0818x + 26.668 (R² = 0.9596) and y = 2.8377x + 21.114 (R² = 0.975), as well as between net productivity photosynthesis and grain yield of sorghum:
y = 1.0421x + 0.8623 (R² = 0.9441) and y = 1.3854x − 1.0694 (R² = 0.938).