Quantitative and qualitative variation in floral nectar of soybean cultivars in southeastern Missouri

Nectar characteristics of 17 soybean (Glycine max ) cultivars grown in Hayti, Mo., were examined in order to assess the potential for preferential foraging by honey bees (Apis mellifera ). Nectar secretion occurred between ca. 0900 and 1500 h Central Daylight Time; individual flowers bloomed only one day. Mean nectar production per flower varied from 0.022 to 0.127 mu l among cultivars, while total nectar carbohydrate content varied from 301 to 1,354 mu g/ mu l. Fructose, glucose, and surcose content varied from 42 to 314 mu g/ mu l, 43 to 262 mu g/ mu l, and 97 to 986 mu g/ mu l, respectively. Total carbohydrate per flower varied from 16.0 to 134 mu g. The ratios of fructose:glucose:sucrose among cultivars were distributed along a broad continuum, from those with low sucrose (ca. 1.2:1.0:1.4) to those with high sucrose (ca. 1.2:1.0:6.7).