Yield and Composition of Sweet Pearl Millet as Affected by Row Spacing and Seeding Rate

Sweet pearl millet [Pennisetum glaucum (L.) R. BR.] seems promising for ethanol production, but optimal cropping practices are unknown for the cool and humid conditions of eastern Canada. We evaluated the effects of two row spacings (18 and 36 cm) and four seeding rates (5, 10, 15, and 20 kg ha(-1)) on biomass dry matter (DM) yield, water soluble carbohydrate (WSC) concentration and yield, and nutritive value of sweet pearl millet at two sites in Quebec, Canada. Increasing seeding rates decreased biomass DM and WSC yields at Sainte-Anne-de-Bellevue but had a limited effect at Saint-Augustin-de-Desmaures. Hence, a seeding rate of 5 kg ha(-1) resulted in maximum biomass DM (12.4-19.1 Mg ha(-1)) and WSC (1.56-2.64 Mg ha(-1)) yields. Row spacing did not affect biomass DM and WSC yields at Saint-Augustin-de-Desmaures but biomass DM yield was greater at a row spacing of 18 cm at Sainte-Anne-de-Bellevue. The WSC concentrations in leaves and stems were inconsistently affected by seeding rate but were not affected by row spacing. The WSC concentrations were greater in stems (140.7-162.4 g kg(-1) DM) than in leaves (35.7-48.1 g kg(-1) DM). Increasing the seeding rate generally decreased N concentrations of leaves and stems and digestibility of neutral detergent fiber (NDF) but increased concentrations of acid detergent fiber and NDF. Row spacing did not affect any nutritive value attributes. Seeding at 5 kg ha(-1) with a row spacing of 18 cm maximize biomass and WSC yield with minimal effect on forage nutritive value of sweet pearl millet.