Differential effect of planting date on growth and yield of promising cotton varieties under arid sub-tropical climatic conditions

Cotton (Gossypium hirsutum) is considered to be a responsive crop to its surrounding environments and therefore, an appropriate planting date is very important for growers to ensure optimum yield. The present studies were conducted to determine optimum planting date for three cotton varieties in an arid sub-tropical climate in the areas of sub-recent flood plains on silt loam soils during the years 2007 and 2008 at Adaptive Research Farm, Vehari, Pakistan. Five planting dates commencing from May 01 to June 30 with 15 days interval were evaluated for three cotton varieties CIM-496, MNH-786 and CIM-534 during two consecutive seasons. The yield and yield contributing parameters such as number of bolls per plant, plant height, seed cotton yield and cotton leaf curl virus infestation were recorded. The two year results revealed that all the cotton varieties at early plantation performed better and produced higher seed cotton yield as compared to late plantation. It was found that cotton planted on May 01 gave highest seed cotton yield followed by May 15, May 30, June 15 and June 30 in descending order. Each delay in sowing cotton reduced seed cotton yield progressively. The cotton varieties were also differed significantly in their growth performance irrespective of planting date and MNH-786 showed superiority over others at all planting dates. Results concluded that early plantation of cotton, particularly MNH-786 was recommended for optimum harvesting of agro-environmental factors and higher economic benefits for the farming community in Vehari zone of Pakistan.