The Effects of Timing of an Interim Harvest on the Yield and Composition of Lablab purpureus

Lablab purpureus was grown in two field experiments in consecutive years to evaluate the effects of the timing of an interim harvest on the yield and nutritive value of the harvested material and the subsequent regrowth, which was determined from the second and final harvest. Delaying the first harvest to 50–70 days post-sowing increased the total (first plus second harvests) dry matter (DM) yield, with a greater first harvest and reduced second harvest DM yield. The delay also reduced the crude protein concentration of the first harvest and tended to increase its modified acid-detergent (MAD) fibre concentrations. The delay increased the crude protein concentration and decreased the MAD fibre concentration of the second harvest. The total crude protein yield of both harvests increased with late interim harvesting. The first harvest plant calcium concentration increased and phosphorus concentration decreased with a delay in the interim harvest. It is concluded that, in the difficult growing conditions of the Sahelian zone of sub-Saharan Africa, delaying the interim harvest of Lablab purpureus until 50–70 days post-sowing will have beneficial effects on total dry matter and crude protein yields.