Effect of Alfalfa Cultivar on Pollinator Visitation, Seed Yield and Yield Components

Abstract

Seed production is a critically important trait in alfalfa breeding, and understanding the relationship between pollinator visitation and seed yield could help the development of high seed-yielding cultivars. The effect of three alfalfa cultivars on pollinator visit, seed yield and seed yield components was researched. To determine visitation rates, pollinators within a 1 m2 area were counted during a 30 min period in the morning, at noon and in the afternoon. Most pollinators were attracted to cv. K-28 (13.2). Cultivar NS Medijana was visited by 9.81 pollinators and cv. K-22 by 9.06. Cultivar K-28 attracted the highest number of honey bees (40.1 %), followed by cv. NS Medijana (31.3 %) and cv. K-22 (28.6 %). The ratio of honeybees to other observed pollinators was approximately 3:1. Cultivar K-28 achieved a seed yield of 553.3 kg ha−1, cv. Medijana 472.8 kg ha−1 and the seed yield of cv. K-22 was 469.4 kg ha−1. Cultivar K-22 had the most flowers and fertilized pods in the middle and highest inflorescences as well as seeds per pod in the highest inflorescences. Cultivar Medijana had the most flowers on the lowest inflorescences. Cultivar K-28 showed the highest values for other observed traits. Cultivar K-28 showed very significant differences from the other varieties in percentage of fertilized pods at the highest inflorescences. In relation to seed yield, numbers of flowers, pods and seeds per pod at the lowest inflorescences, cv. K-28 was significantly better than other cultivars, which positively correlated with the number of visiting pollinators. For other yield components, differences between cultivars were not statistically significant.