ANALYSIS OF BRANCHING IN SPRING-SOWN WHITE LUPINS (LUPINUS-ALBUS L) -THE SIGNIFICANCE OF THE NUMBER OF AXILLARY BUDS

Plant density and sowing date were shown to affect branching in spring -sown white lupin (Lupinus albus L.), but the response varied among en vironments. The patterns of primary and secondary branching in the cv. Lublanc were studied as a function of both the number of axillary bud s and the plant growth rate. Field experiments that used a wide range of sowing dates and plant densities to alter plant architecture were c onducted over 5 years, and these were supplemented with data from addi tional glasshouse and growth cabinet experiments. The number of axilla ry buds on the main stem or primary branches, which determined the pot ential number of branches, increased linearly with the number of nodes . In situations where all axillary buds did not produce branches, it w as found that the number of primary and secondary branches produced wa s related to the plant growth rate at the beginning of branch elongati on. Knowledge of the number of axillary buds improved the analysis of the interaction between cultural practices and environmental condition s on plant architecture. The variability of branching potential among genotypes was discussed. (C) 1996 Annals of Botany Company