EVALUATION OF SEED YIELD AND THOUSAND SEED WEIGHT OF CONFECTIONERY SUNFLOWER (Helianthus annuus L.) VARIETIES GROWN BY DIFFERENT FARMING TECHNIQUES IN THE NORTHERN STEPPE OF UKRAINE

The paper presents data on the seed yield and thousand seed weight of confectionery sunflower (Helianthus annuus L.) varieties cultivated in the Northern Steppe of Ukraine. The study was conducted on three varieties-populations and one F1 hybrid. The study design included two types of basic tillage, three doses of fertilizer, and three plant densities. The seed yield significantly (P = 0.05) depended on the year of testing (the contribution of the year factor to the total variability was 38.88%), plant density (29.30%) and fertilizer dose (14.43%). It also depended on the tillage type (3.01%) and varietal characteristics (0.87%). The highest yield of seeds (up to 4.24 t/ha) was obtained with moldboard plowing, NPK fertilizer doses of 40:60:60 and 60:80:80 and plant density of 40,800 plants/ha. The thousand seed weight significantly (P=0.05) changed under the influence of the year of testing (32.11%), plant density (26.75%) and variety (25.92%), as well as under the influence of fertilization (3.24%) and tillage (3.75%). The largest thousand seed weight (up to 122.3 g) was obtained with moldboard plowing, NPK fertilizer doses of 40:60:60 and 60:80:80 and plant density of 20,400 plants/ha. Recommendations on the farming technique for confectionery sunflower have been drawn up.