Dry matter production and photosynthetic capacity in Gossypium hirsutum L. under conditions of slightly suboptimum leaf temperatures and high levels of irradiance

Oecologia. 1991 Jul;87(2):190-197. doi: 10.1007/BF00325256.

Abstract

Gossypium hirsutum L. var. Delta Pine 61 was cultivated in controlled-environment chambers at 1000-1100 μmol photosynthetically active photons m-2 s-1 (medium photon flux density) and at 1800-2000 μmol photons m-2 s-1 (high photon flux density), respectively. Air temperatures ranged from 20° to 34°C during 12-h light periods, whereas during dark periods temperature was 25° C in all experiments. As the leaf temperature decreased from about 33° to 27° C, marked reductions in dry matter production, leaf chlorophyll content and photosynthetic capacity occurred in plants growing under high light conditions, to values far below those in plants growing at 27° C and medium photon flux densities. The results show that slightly suboptimum temperatures, well above the so-called chilling range (0-12° C), greatly reduce dry matter production in cotton when combined with high photon flux densities equivalent to full sunlight.

Keywords: Cotton; Growth; High irradiance stress; Photosynthetic capacity; Temperature.