Peculiarities of pigment complex functioning of winter wheat plants depending on the fertilizer application method

Abstract

To obtain the maximum yield of winter wheat, it is necessary to further optimize the existing cultivation technologies in the direction of their adaptation to changing environmental conditions. One of the areas of adaptation of plants to adverse abiotic factors is the active functioning of the photosynthetic apparatus, which depends on the amount of nutrients introduced. The influence of fertilizer application on the condition of the pigment complex of winter wheat plants in the conditions of the Southern Steppe of Ukraine has been studied. Two varieties of winter wheat were selected for the study: Shestopalivka and Mason. The experiment scheme involved the application of fertilizers at sowing (K0; K12) and foliar treatment with various tank mixtures (urea; urea + magnesium sulfate; urea + magnesium sulfate + potassium monophosphate). The pigment content has been determined by grinding fresh leaves of winter wheat, followed by the addition of a solvent in the form of acetone. Measurements of pigments were performed using a spectrophotometer. According to the research results, it was established that before the foliar treatment the a-chlorophyll content and carotenoids was higher in the plant leaves of the Shestopalivka variety. At the same time, the b-chlorophyll content on the contrary was higher for plants of the Mason variety by 17%, which may be due to the adaptation of plants of this variety to lack of light. On the 3rd day after foliar treatment, a decrease in the pigment content in the plant leaves of all experimental variants has been observed, which was due to the active growth of the photosynthetic surface and a decrease in the total dry matter mass. There was no significant difference between the varieties of the content of photosynthetic pigments in this period. On the 10th day after foliar treatment, an increase in a- and b-chlorophyll content has been observed for both studied varieties, which may be the result of adaptation of the photosynthetic apparatus of winter wheat plants to lighting conditions. Foliar treatment of winter wheat plants with a tank mixture of urea with magnesium sulfate and potassium monophosphate contributed to a further increase in the content of a-chlorophyll by 12-23%, and b-chlorophyll by 5-37% depending on the variety compared to the control. The results of the research testify to the high efficiency of complex application of nitrogen-phosphorus-potassium fertilizers for foliar treatment of winter wheat plants in the BBCH 31 stage, both against the background of pre-sowing application of potassium fertilizers and without it.