Analysis of sequential reproductive development in white lupin cv. Lublanc

Abstract

As for other legume crops with sequential flowering, the time-lags between the development of the different pods of white lupin affect the progress of intra-plant competition for assimilates, the pattern of seed yield distribution within the canopy, and the whole cycle duration. The objective of this study was to define a convenient indicator describing pod development, and to investigate the relationship between the plant vegetative architecture and the progression of the reproductive stages along the different inflorescence types. ‘Lublanc’ spring white lupin was grown in the glasshouse during 1 year and in the field during 4 years, with various sowing dates and plant densities. Current management techniques, including irrigation, were applied. The progress of seed water content allowed distinction of the period when seed abortion occurs from the seed filling phase. The progression rate of flowering up the racemes was related to the growth rate of the considered axes at the beginning of their flowering. The flowering delay between 2 successive orders of axes depended on both the leaf number on the branches and the individual branch growth rate during their elongation. The time of the reproductive stages at a pod position depended only on the time of flowering at that position. The duration of the seed filling phase did not vary among pod positions.