Planting date and row spacing affects grain yield and height of pearl millet Tifgrain 102 in the Southeastern coastal plain of the United States

Pearl millet (Pennisetum glaucum) is a drought tolerant cereal grain typically grown as a forage crop in the United States. New high-yielding dwarf grain pearl millet hybrids have generated interest in millet as a substitute for maize and sorghum because of its ability to reliably produce grain on sandy, acidic, low fertility soils of the southeastern United States. The objectives of this study were to determine optimum planting date, row spacing, and nitrogen rate for grain production. Rust resistant hybrid Tifgrain 102 was drilled in a split-split plot, randomized complete block design with four replications nested in date. Planting date was the main effect, and there were 7, 8 and 9 planting dates in 2001, 2002 and 2006, respectively. Planting date was split into four row spacings (0.2 m, 0.4 m, 0.5 m and 0.9 m), and further split for two nitrogen levels (90 kg ha -1 and 140 kg ha -1 ). There was a significant (P ≤0.001) interaction of year by planting date for both yield and height. Planting date within years was significant (P ≤0.001) for yield and height. Yield at 0.4 m row spacing was greater than at 0.9 m spacing and nearly significant for yield at 0.5 m spacing and 0.2 m. Height significantly (P ≤0.005) increased with wider row spacing. Yield and height were not affected by nitrogen rate.