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.

Comparison of materials of different solubility as sources of boron for plants

“…Red clover plants were also severely stunted and some had died. The greater sensitivity of 'Grasslands Turoa' red clover than lucerne to a high rate of B in the seed bed is consistent with a report by Sherrell (1983b). Sunflower sensitivity appears to be intermediate between the other 'species.…”

“…This response pattern is similar to that obtained in previous work with this soil in which there was no response to B in DM yield by clovers and lucerne in the first cut but there was in subsequent cuts (Sherrell 1983a). The response to B in total yield in lucerne and red clover, 79 and 84% respectively, is also similar to that reported by Sherrell (1983a).…”

“…This is well within the deficiency range (Cox & Kamprath 1972) and good responses to B in lucerne and clovers have been obtained with this soil in field and pot trials (Sherrell & Toxopeus 1978;Sherrell 1983a). …”

“…Additional support for this suggestion is obtained from B absorption by lucerne. There were deficiency symptoms at the final cut on lucerne treated with borax, fertiliser borate, and the normal rate of colemanite and B concentrations on these treatments were equally low and in the deficiency range (Sherrell 1983a) suggesting that the B added in all 3 materials had been almost used up. Total B absorbed (treatment-control) was 1.70 mg B/pot from borax and colemanite and 1.87 mg B/pot from fertiliser borate ( Table 4).…”

Response of Pulse and Oilseed Crops to Boron Application: A Review

“…In addition, the boron application also increased pod set and seed yield. Boron application increased dry matter yield and concentration of B in white clover and lucerne grown on silty loam soils of New Zealand with pH 5.9 and available boron content 0.28 ppm (Sherrell, 1983a;Sherrell, 1983b). Dear and Lipsett (1987) reported in cerealclover rotation, herbage yields of subterranean clover increased by 25 per cent with application B but seed yield increased 21-fold with B application.…”