Effects of Precision Seeding without Thinning Process on Yield and Yield Components of Cotton

Abstract

Thinning is a considerably popular practice in cotton field management in the Yellow River Valley of China, but such a traditional practice is currently facing a big challenge because of labor costs and time consuming. The objective of the present study was to determine the effects of precision seeding on seed cotton yield and yield components so as to provide a new alternative technique to simplify cotton cultivation in the region. A three-year field experiment was conducted at four experimental sites(Linqing, Xiajin, Huimin, and Dongying) to comparatively investigate the effects of precision seeding without thinning on plant population density, seed cotton yield and yield components, with conventional seeding with thinning(seeding rate of 22.5 kg ha–1 and thinning seedlings two times after emergence) as the control. There existed significant interaction effects among planting years, experimental sites and planting patterns on plant density, seed cotton yield and number of bolls per unit area. In 2011–2013, the plant population reached 4.5–8.5 plants m–2 in precision seeding treatment at ten out of twelve sites, and number of bolls per unit area and seed cotton yield were equivalent to those of conventional seeding at these ten sites. However, the seed cotton yield of precision seeding treatment at Dongying in 2011 and at Huimin in 2012 was significantly reduced by 14.2% and 5.5% owing to the low density(3.53 and 3.63 plants m–2) and their boll number was reduced by 13.8% and 9.7% relative to that of conventional seeding treatment. There was no significant difference in single boll weight between the two seeding patterns. The yield reduction of precision seeding treatment at two experimental sites was mainly attributed to the decrease in number of bolls per unit area as a result of reduced plant density. Therefore, costs saving without yield reduction can be realized through precision seeding under the support of improved seeding quality and a relatively high plant density. Precision seeding without seedling thinning can be one ofthe simplified cultivation measures of cotton production in the Yellow River valley of China.