Different sowing dates affected cotton yield and yield components

This study was conducted to determine whether selecting an optimum sowing date couldimprove yield. The experiment consisted of sowing a film-covered, drip-irrigated cotton field onfour sowing dates from April to May in 2011-2012 at the Agrometeorological ExperimentalStation of Wulanwusu, which was in an arid region of north-western China. Late sowing datesproduced less yield and water-use efficiency than did the normal sowing dates. The yieldincreased with the increases of mean diurnal temperature range (DTR) from full bloom tomaturity, mean temperature and sunshine hours (SH) during the whole growing season (WGS),accumulated temperature (AT) and days from squaring to anthesis and mean temperature duringthe reproductive growth stage. However, the main effect factors of meteorological parameterswere AT from squaring to anthesis, mean temperature during the WGS and AT from sowing toemergence. The main effect factors of yield component were boll number per plant, gin turnoutand boll weight. Boll number per plant suffered from mean DTR from boll setting to maturityand SH during the WGS. Gin turnout was affected by mean temperature during the WGS andmean DTR from boll setting to maturity. Sowing date, year and their interactions allsignificantly affected the yield. Sowing date was an important factor affecting the yield andreproductive duration. With climate change, an earlier planting date might be an efficientmethod of increasing yield.