Temperature Effects on Cotton Fruit Retention

Abstract

Temperature is a major environmental factor that affects cotton (Gossypium hirsutum L.) production. Temperatures of 35 to 40°C are frequently observed in cotton‐producing areas. High‐temperature environments are sometimes associated with cotton sterility and boll retention problems; however, there is little specific information available on cotton sensitivity to temperature. We conducted a series of experiments in naturally lit growth chambers where the temperature was accurately controlled so we could measure its effects on cotton fruiting site production, abscission of flower buds (squares), flowers, and bolls. Cotton plants grown from seedlings at 40°C for 12 h d−1 shed all their squares. Plants grown from seedlings in the natural environment, then exposed to daytime temperatures of 30, 35, or 40°C during the fruiting period accumulated 47, 5.7, and <1%, respectively, of their mass as bolls. The time of day when plants were exposed to high temperature did not influence percent boll retention. Number of bolls produced, bolls retained, and percent retention were progressively reduced as time per day at 40°C was increased. Three week exposure to 40°C for 2 or 12 h d−1 resulted in 64 or 0% bolls, respectively, retained on the plants. Cultivars appeared to be similar in sensitivity to high temperature. Cultivars tolerant to short periods of high temperature would probably be more productive in today's environment and increased tolerance to high temperature will be even more essential in a warmer environment.

Screening for High‐Temperature Tolerant Cotton Cultivars by Testing In Vitro Pollen Germination, Pollen Tube Growth and Boll Retention

“…The number of bolls retained on the cotton plant was very strongly controlled by temperature regimens (Reddy et al 1999). The optimum temperature for boll retention is 28 °C and the young bolls are shed when the average daily temperature exceeds the optimum, with a longer the exposure to above-optimum temperatures resulting in a higher frequency of boll abscission (Reddy et al 1992(Reddy et al , 1999. In the cottongrowing areas of China, especially the Yangtze River valley, several episodes of high temperatures greater than 35 °C usually occur in July and August, a period when cotton flowering and boll loading are in their developmental phases, resulting in the abscission of bolls and a reduction of lint yield (Zhou et al 1996;Miao et al 1998).…”

“…It has been demonstrated that young bolls abscise when exposed to average daily temperatures above 28°C and the longer the exposure to the above-optimum temperature, the higher the abscission frequency (Reddy et al 1992). At present, climatic changes are a major concern to agriculturalists throughout the world.…”

Effects of Plant Density on Boll Retention and Yield of Cotton in the Mid-South

“…Boll retention is complex and can be affected by many interacting factors such as genetics, physiology, nutrition, water stress, temperature, competition for photosynthates, insects or a combination of any of these [3] [13] [14] [15] [16]. These same factors can also affect boll weight.…”

Vulnerability of field crops to midcentury temperature changes and yield effects in the Southwestern USA

“…The sensitivity of FC to changing temperatures was estimated using a literature-derived SF on a scale of 1 to 3 to represent general thermal sensitivities where crops classified as 1 are the (Reddy et al 2005;Oosterhuis 1999); 20-32°C (Burke et al 1988;Reddy et al 1991); 28-32°C (pollination; (Brown 2008;Snider et al 2011)); T failure = 35°C (Reddy et al 1992(Reddy et al , 1997 Rice Oryza sativa T opt = 23-26°C (Baker et al 1995;Horie et al 2000); T failure = 35°C (Baker et al 1995) Wheat Triticum T opt = 20-30°C (Fageria 1992); T max = 35°C (Torabi et al 2015) Thermal range (TR) is the summer maximum temperature where 95% of the crop was cultivated in 2012 with analyses reflecting changes in 2012 area and potential cultivation area.…”