Effect of boron application on seed production of New Zealand herbage legumes

Abstract

Six rates of boron (B) were applied to 2 white clovers (Trifolium repens L.), alsike clover (Trifolium hybridum L.), 3 red clovers (Trifolium pratense L.), and lucerne (Medicago sativa L.) in the glasshouse on a soil which was known to be low in available B. None of the 7 cultivars produced seed without added B, and red clovers also did not produce seed at low B rates. Maximum seed yields and the amount of B required to produce them were higher for red clovers and lucerne than for white and alsike clovers. The increase in seed yield of lucerne from B application was due entirely to an increase in the number of flowers formed and setting seed. In contrast, increases in white clover seed yields were due entirely to increases in the number of seeds per flower. For red clovers, increases in both the number of flowers and seeds per flower contributed to increased seed yields. It is concluded that B application may be beneficial in areas such as Marlborough and Canterbury for commercial herbage legume seed crops.

Keywords:

• boron
• seed yields
• herbage legumes
• white clovers
• red clovers
• lucerne