Response of Cotton to Early-Season Square Abscission under Elevated CO2
Wu, G. | Chen, F.J. | Sun, Y.C. | Ge, F.
Received for publication May 3, 2006. A field study was performed to quantify the compensation capacity of cotton (Gossypium hirsutum L.) for simulated damage of square buds loss by manual removal method during early growing season in 2004 and 2005 in combination with elevated CO2 relative to ambient CO2. Square buds of cotton plants were wholly removed manually for 1 wk (SR1 treatment) and two consecutive weeks (SR2 treatment) in contrast to no square bud removal (SR0 treatment) after squaring stage, and their compensation ability is quantified by measuring plant growth and production. Two levels of CO2 (ambient and double-ambient) and three types of manual removal of square buds (SR1 and SR2 vs. SR0) were deployed in a completely randomized design with six treatment combinations. Cotton plants grown in elevated CO2 had significantly higher leaf area per plant on each sampling date for SR1 treatment compared with SR0 treatment in 2004 and 2005. Significantly higher seedcotton yield, maturity, and harvested biomass were also observed for SR0, SR1, and SR2 treatments under elevated CO2 relative to ambient CO2 in 2004 and 2005. Moreover, there were significant interactions between CO2 level x square removal treatment on seedcotton yield and boll maturity, and significance between square removal treatment x investigation year on plant harvested biomass. Results from these studies provide a profile for developing strategies for future management of cotton ecosystems in Northern China.Show more [+] Less [-]