Yield of spring vetch (Vicia sativa L.) cultivars in mixed crops with white mustard

Purpose. To identify the cultivars of spring vetch adapted for mixed cropping with white mustard. Methods. The research was conducted at the Bila Tserkva Experimental and Breeding Station. The preceding crop was grain corn. Soil tillage − disk harrowing of the field was carried out in summer and in November, the field was ploughed. A seed mixture of spring vetch and white mustard was sown at the seeding rates of 1.5 million/ha and 0.2 million/ha, respectively. Breeding cultivars of spring vetch were compared with two standard vetch cultivars in four replications. Harvesting of the mixed crops was performed at the full maturity stage by direct combine harvesting. Weather conditions in the years of the study were characterised by insufficient precipitation and higher air temperatures compared to the long-term averages, which negatively affected vetch growth at all stages of development. As the result, the productivity was reduced. At the same time, there were favourable conditions for evaluating and selecting breeding cultivars. Results. The research revealed that breeding cultivars of spring vetch with high yields as monocrop often had lower yields in mixed cropping with mustard, especially under unfavourable weather conditions. Breeding cultivars 728-19, 793-19, and 797-19 showed high yields in the mixed cropping with white mustard, showing results comparable to the average standard and yields of 1.64, 1.52, and 1.18 t/ha, respectively, which is comparable with standard varieties. Indices based on three-year data were used to characterise spring vetch in mixed crops with white mustard. Higher indices indicated a greater influence of conditions on productivity, while lower indices indicated better stability. It was found that weather conditions had a greater impact on seed yield than the mixed cropping, especially in varieties ‘BTs 96’, ‘Yaroslava’, and breeding cultivars 913-16, 747-17, in which phenotypic variability was caused by reactions to weather conditions. In some cases, adverse annual conditions diminished the effect of the mixed crops, but certain vetch cultivars (829-17, 715-18, 897-17) showed greater stability. These cultivars demonstrated higher and more stable productivity in mixed crops with mustard compared to others. Conclusions. Cultivars of spring vetch adapted for mixed cropping with white mustard have been identified. In general, variety testing and application of the proposed method allowed to select breeding genotypes with high and stable parameters of competitive stability in mixed sowings with mustard. These breeding genotypes will be further used to develop new varieties of spring vetch.