Impact of heat and drought stresses on size and quality of the potato yield

Potato (Solanum tuberosum L.) is a plant typical mainly for temperate climate and develops best at about 20 degrees C. Heat stress due to increased temperatures is an agricultural problem in many areas in the world. The aim of our work was to assess the response of selected new potato cultivars to heat and drought stress during the subsequent stages of plant growth starting from buds forming. The pot experiment was carried out over the course of two years with the following early cultivars: Lord, Milek, Gwiazda, Hubal, Oberon and Tetyda. The impact of heat ( 38 degrees C/25 degrees C) and drought stress on potato plants was tested in four periods of two weeks. In these periods half of the plants were watered to a level close to optimal while the other half remained without irrigation. Our studies demonstrated that tested potato cultivars' response to heat stress depends on the growth stage, in which the temperature acts on the plants and on the soil moisture. Besides the decrease in yield and tubers' diminution, the biggest problem was the presence of tubers with physiological defects, particularly of immature tubers. The response of cultivars was differentiated.