A simplified pruning method for profitable cotton production in the Yellow River valley of China

Intensive plant pruning involving removal of vegetative branches, topping, and continuously excising old leaves, growth tips of fruiting branches, excessive buds and empty fruit branches, has been widely adopted in the field management of cotton (Gossypium hirsutum L.) in China, but this practice is facing a serious of challenges because it is labor-intensive and time-consuming. In the present study, an extensive (simplified) pruning system was designed by concurrent removal of vegetative branches and the mainstem leaves below the first fruiting branch at squaring, topping by mid-July when there are 10-12 fruiting branches per plant, and omitting other pruning measures. The objective was to determine if the extensive pruning is better than intensive pruning and non-pruning (plant topping only) in yield and economic benefits. To achieve this goal, two field experiments were conducted at one site from 2011 to 2012 and at five sites in 2013 in the Yellow River delta of China. A split-plot design was used in both experiments with the main plots assigned to cotton cultivars and the subplots assigned to plant pruning (non-pruning, intensive pruning and extensive pruning). The effects of plant pruning, cultivar and their interactions on seed cotton yield were evaluated in both experiments, and on plant growth, harvest index, earliness, yield components and labor input in the first experiment. Both the intensive and extensive plant pruning were beneficial to plant height, harvest index, boll weight and seed cotton yield regardless of cotton cultivar. The extensive pruning was comparable to the intensive pruning system in cotton yield in the first experiment, but produced 43% and 4.8% more seed cotton than non-pruning in 2011 and 2012. Greater increases in cotton yield under extensive pruning were obtained in the multi-site experiment in 2013, with an average seed cotton yield increase of 7.7% compared with non-pruning. Both intensive and extensive pruning consumed more labor days than non-pruning, but the labor input under extensive pruning was 76-81% less than that under intensive pruning. Compared with non-pruning, extensive pruning increased the net revenue by 7.9% as a result of improved cotton yield, but intensive pruning decreased net revenue by 3.5% due to increased labor input. The overall results showed that extensive plant pruning is more simplified and beneficial than the traditional intensive pruning and should be a promising alternative in the Yellow River valley of China and other regions with similar ecological conditions. (C) 2014 Elsevier B.V. All rights reserved.