High Temperature Stress on Floral Development and Yield of Cotton

Increased temperatures from global climate change are projected to cause substantial losses in crop productivity by the end of the twenty-first century. High temperature is predominant among the cardinal ecological factors that determine crop growth and productivity (Al-Khatib and Paulsen, 1999). In cotton, temperature is a primary controller of the rate of plant growth, developmental events, and fruit maturation (Baker, 1965). An optimum temperature range of 20 to 30oC has been reported for cotton (Reddy et al, 1991), but cotton is successfully grown at temperatures in excess of 40oC in India and Pakistan for example. There is no clear consensus about the optimum temperature for cotton as plant response varies with plant developmental stage and plant organ (Burke and Wanjura, 2009). The effects of high temperature on germination, seedling growth, vegetative growth and crop development have been well documented (e.g., Hodges et al., 1993; Reddy et al., 1996). Although adverse temperatures can affect all stages of development, the crop seems to be particularly sensitive to adverse temperatures during reproductive development (Oosterhuis, 2002). The objective of this review is to compile the literature of the effects of high temperature on reproductive development in cotton with emphasis on events occurring in the flower following pollination leading to fertilization and seed set.