The effect of genotype and agronomic factors on crop growth and yield in field peas (Pisum sativum L.) as influenced by radiation interception and utilisation

Three trials were conducted in 2006/07 and 2007/08 growing seasons aiming to find the effect of genotype, crop and weed population densities, herbicide, and sowing date on crop growth and yield in Pisum sativum as influenced by radiation interception and utilisation. The first experiment was a split plot with two cyanazine treatments as main plots. Subplots were a factorial combination of three pea genotypes and three plant population densities. Experiment 2 was also a split plot with three sowing dates as main plots. Sub-plots were a factorial combination of two pea genotypes, and two herbicide treatments. Experiment 3 treatments were a factorial combination of four pea populations and three sown artificial weed population densities arranged in a randomised complete block. Each of the three experiments had three replicates. Dry matter and radiation were measured throughout the growing season and seed yield was measured at harvest. There were significant (p ≤ 0.05) herbicide by population interactions on total dry matter (TDM) and seed yield. Early pea sowing was associated with greater total radiation accumulation. The August sowing gave the highest seed yield 547 g m⁻² , which was 45% more than the lowest yield in October. The higher yield was a result of increased accumulative radiation interception. Increased pea population density increased yield. However, very high density (400 plants m⁻² ) resulted in reduced seed yield