PECULIARITIES OF WATER REGIME AND EVALUATION OF HEAT RESISTANCE OF USSURI PEAR UNDER BIOFERTILIZER USE

The aim of the study is to determine the indicators of drought resistance and heat resistance of Ussuri pear growing in a semiarid climate using biofertilizers (using the city of Orenburg as an example). Drought resistance of plants is one of the important factors for the successful cultivation of new taxa in climatic conditions in the presence of limiting factors. Excessive high temperature causes rapid cell damage or death, which leads to catastrophic changes in the entire plant organism. The use of certain types of fertilizers can increase the resistance of cultivated plants to various types of stress, including exposure to high temperatures. Heat resistance, total water content, water deficit, water-holding capacity and the level of mobile moisture in leaf blades were determined using generally accepted methods in laboratory conditions. For this purpose, the leaves were weighed: freshly picked, after 24 hours, after complete saturation, absolutely dry. The resistance of the samples to high temperatures was assessed using a water bath. It was established that the experimental plants, with the introduction of the studied fertilizer, significantly increase their heat resistance and they belong to the group of highly heat-resistant plants. The degree of drought resistance is also higher in experimental samples, compared to the control. Having assessed the degree of water regime using a modified technique for the climate of the Orenburg Region, the authors conclude that the experimental samples belong to the group of plants with high drought resistance, the control ones - to the group of moderately drought-resistant plants.