The role of magnesium ions for the growth and development of tomatoes when growing in protected soil conditions

Abstract

Tomato is one of the main and popular vegetable crops not only in Ukraine, but throughout the world. According to the Food and Agricultural Organization (FAO), tomatoes occupy the first place in the world in terms of cultivated areas among all vegetables — more than 4 million hectares. In Ukraine, about 93,000 hectares — about 24% of the total area under vegetables — are devoted to this culture. With the advent of high-intensity technologies with the use of drip irrigation systems, tomato yields of 120–140 t/ha in open ground, and more than 50 kg/m2 in sheltered ground, became real. Nowadays, the method of small-volume hydroponics with the use of drip irrigation is becoming more and more widespread in greenhouse farms. As a substrate, special materials are used — mineral wool, coconut, peat, etc. The selected substrate functions as a medium for the roots, feeding is carried out by supplying a fertilizer solution. When growing on a substrate, it is necessary to dose fertilizers very accurately and provide plants with a sufficient amount of nutrients. The paper investigates the effect of the concentration of the macroelement magnesium in the mineral wool substrate on the growth and development of the Campari (cocktail) tomato culture in protected soil conditions. It was established that the photoelectrocolorimetric method for determining the magnesium content in mineral wool hoods is quite sensitive, simple, and recommended for use in serial analyses. The determined content of magnesium salts (72.0 mg/l) turned out to be insufficient for growing tomatoes in the period of mass fruiting. Controlling the magnesium content allows you to significantly prevent tomato chlorosis and obtain high-quality crops.