A Comparison of Scenarios for the Effect of Global Climate Change on Cotton Growth and Yield

Abstract

If global surface temperatures change as projected because of radiative and physiological effects of a changing environment, we should expect important changes in crop production in the 21st Century. Experiments were conducted at ambient and twice ambient atmospheric CO 2 concentrations at five temperatures. The 1995 temperature in Mississippi was used as a reference with the other temperatures being 1995 minus 2¡C, and 1995 plus 2, 5 and 7¡C. Daily and seasonal variation and amplitudes were maintained. Seedlings had 4Ð6 times as much leaf area and dry weight at 20 d after emergence when grown at 28¡C as at 23¡C (1995 ambient) average temperature during that growth period. Number of days to first square, flower, and open boll decreased as temperature increased. Double atmospheric CO 2 did not affect these developmental rates. Temperatures above 28¡C, or 1995 average whole-season temperatures, were detrimental to mid-and late-season boll retention and growth. No fruits were retained to maturity at 1995 plus 5 or 7¡C. However, whole season vegetative growth was not significantly reduced by temperature 5Ð7¡C above the 1995 ambient conditions. Twice ambient CO 2 caused about 40% increase in vegetative dry matter accumulation across temperatures. In a separate experiment, similar results were obtained on fruiting cotton grown at a range of temperatures based on long-term average US Midsouth July temperatures. Therefore, if global warming occurs as predicted, food and fibre production in such high-temperature and humid environments may be more limited to vegetative structures and the animals that consume vegetative structures.

Growth and physiological responses of cotton (Gossypium hirsutum L.) to elevated carbon dioxide and ultraviolet‐B radiation under controlled environmental conditions

“…Cotton growth is often accelerated by CO 2 enrichment, as shown in Fig. 1 and in Reddy, Hodges & McKinion (1997). Thus, we observed more injurious effects from the UV‐B radiation in plants grown in elevated [CO 2 ], which was supported from measurements of P n and soluble sugars in the uppermost fully expanded leaves (Figs 2 and 4).…”

Temperature thresholds and crop production: a review

“…However, cotton reproductive progression has a lower Topt of 28 ∼ 30 • C (Reddy et al 1997 and. Reddy et al (2005) found that growth rate per boll has a Topt (1980), Baker et al (1989), Pan (1996), Thomas (2001), Boote et al (2005) 13.…”

“…Reddy et al (2005) found that growth rate per boll has a Topt (1980), Baker et al (1989), Pan (1996), Thomas (2001), Boote et al (2005) 13. Reddy et al (1999) and (2005) 28 ∼ 30 (RP) Reddy et al (1997) and (1999) 25 ∼ 26 (boll growth rate) Reddy et al (2005) 28 (boll harvest index)…”

Preliminary results of a UV-B effect incorporated GOSSYM model

“…Cotton (Gossypium hirsutum L.) is a major fiber-producing and economic crop grown on over 32 Mha worldwide in both tropical and temperate regions and on over 5 Mha in 2004 in the United States (NASS-USDA, 2005). The crop is sensitive to variations of weather factors, such as temperature, atmospheric CO 2 concentration, soil moisture, and UV-B radiation (Reddy et al, 1997a;Reddy et al, 2002;Zhao et al, 2005). Field and growth chamber experiments have revealed a variety of morphological, anatomical, growth, and physiological responses of cotton plant to enhanced UV-B radiation and its interactions with elevated CO 2 concentration and high air temperature Kakani et al, 2003a;Reddy et al, 2003;Zhao et al, 2003;Reddy et al, 2004;Zhao et al, 2004;Zhao et al, 2005).…”