VARIABILITY OF MORPHOMETRIC PARAMETERS AND PRODUCTIVITY INDICATORS OF SUNFLOWER
The research was carried out in 2015-2018 in JSC "Krasnoyaruzhskaya grain company" of the Belgorod region in which fully developed adaptive landscape farming system. Three-factor experience: factor A (relief conditions): 1. slope 0-3°, 2. slope 3-5° North exposure; factor B: 1. plowing (control), 2. subsurface tillage, 3. without processing (No-till); factor C: 1. without fertilizers; 2. straw-litter compost (20 t/ha); 3. green manure (white mustard). The aim is to assess the relationship between biometric and productivity parameters of the mid-season hybrid Neoma NC and their variability under the influence of agricultural practices. Biometric indicators, in addition to weather conditions, depended on the method of basic tillage: the absence of tillage led to their significant decrease. The influence of organic fertilizers as well as landscape conditions was not revealed. Only the assessment of the factors interaction showed that the compost utilization contributed to a significant increase in plant height by 7 cm on the slope spot, the basket diameter - by 2 cm - when it was applied under plowing, the leaves area - when No-till. Green manure in the most difficult conditions (No-till on a slope of 3-5°) contributed to a significant increase in plant height by 8 cm and the area of the assimilation surface of crops - by 1.4 thousand m<sup>2</sup> / ha. Biotic and abiotic factors that had a positive impact on the vegetative organs development, due to the conjugacy of the growth processes is indirectly through the productive properties of the generative organ (the number of seeds in the basket, the basket seeds weight and the weight of 1000 seeds) raised the yield and oil content of mid-season hybrid of sunflower.