The purpose of the research is to evaluate samples of biennial sweet clover in a competitive variety trial and submit to the State Commission for Variety Testing of Agricultural Crops a new variety suitable for cultivation in the forest-steppe zone of the Middle Volga region, adapted to local agroclimatic conditions, high productivity of dry matter and seeds, with a reduced content of coumarin, resistant to major diseases. Experimental work was carried out in 2021-2023 on the experimental field of the Federal Research Center for Bast Fiber Crops – Separate division "Penza Research Institute of Agriculture". During the years of research, agroclimatic conditions were different, both during the growing season as a whole (HTC 0.8-1.0 – dry weather conditions), and by development phases. On average, over two plantings in the competitive variety testing of biennial sweet clover, the yield of green mass (32.1-34.8 t/ha) of 5 samples significantly exceeded the standard (28.4 t/ha) by 13.0-22.5%. In terms of dry matter collection (8.89-9.46 t/ha) 3 samples significantly exceeded the standard (8.24 t/ha) by 7.9-14.8%. In terms of the collection of digestible protein (0.66-0.87 t/ha) 8 samples significantly exceeded the standard indicators (0.60 t/ha) by 10.0-45.0%. In terms of seed yield (748-883 kg/ha) 7 samples significantly exceeded the standard (644 kg/ha) by 16.1-37.1%. Based on the test results, the most promising sample B-707 (hairy clover – Melilotus hirsutus Lipsky.) was transferred to the State Commission (application No. 89858/7653469 dated October 18, 2023) as a new variety – Yantar. The variety is winter-hardy, drought-resistant, resistant to downy mildew and powdery mildew, with a low coumarin content (0.35%). The Yantar variety exceeded the standard for green mass yield (34.8 t/ha) by 22.5%, dry matter collection (9.3 t/ha) – by 12.8%, seeds (876 kg/ha) – by 36.0%.
Timoshkin et al. (Sat,) studied this question.