Plant and Soil Science

To maximise the yield of winter wheat, it is necessary to further optimise modern cultivation technologies to adapt them to changing environmental conditions. One of the aspects of plant adaptation to unfavourable abiotic factors is the active functioning of the photosynthetic apparatus, which depends on the number of nutrients applied. This paper investigates the effect of fertilisation on the state of the pigment complex of winter wheat plants in the Southern Steppe of Ukraine. Two varieties of winter wheat were selected for the study: Shestopalivka and Mason. The scheme of the experiment included the application of fertilisers during sowing (К₀; К₁₂) and foliar processing with various tank mixtures (urea; urea + magnesium sulphate; urea + magnesium sulphate + potassium monophosphate). The pigment content was determined by grinding fresh leaves of winter wheat with further addition of a solvent in the form of acetone. The pigments were measured using a spectrophotometer. The results of the studies showed that before foliar fertilisation, the content of chlorophyll a and carotenoids was higher in the leaves of plants of the Shestopalivka variety. At the same time, the content of chlorophyll b was higher for Mason plants by 17%, which may be a consequence of the adaptation of plants of this variety to a lack of light. A decrease in the pigment content in the leaves of plants of all experimental variants caused by the active growth of the photosynthesising surface and a decrease in the total dry matter mass was observed on day 3 after the foliar fertilisation. There was no significant difference between varieties in the content of photosynthetic pigments during this period. On the 10th day after foliar spraying, an increase in the content of chlorophyll a and b was observed for both studied varieties, which may be the result of the adaptation of the photosynthetic apparatus of winter wheat plants to lighting conditions. Foliar fertilisation of winter wheat plants with a tank mixture of urea with magnesium sulphate and potassium monophosphate contributed to a further increase in the content of chlorophyll a by 12-23% and chlorophyll b by 5-37%, depending on the variety compared to the control. The results of the conducted research indicate the high efficiency of the complex application of nitrogen-phosphorus-potassium fertilisers for foliar spraying of winter wheat plants at the stage of BBCH 31 both on the background of pre-sowing potassium fertilizers and without it

Triticum aestivum, foliar fertilisation, chlorophylls a and b, carotenoids, LHC