The Growth of Banana Plants in Relation to Temperature

Abstract

Bananas (cv. Williams) were grown for 12 weeks in sunlit growth chambers at day/night temperatures of 17/10, 21/14, 25/18, 29/22, 33/26 or 37/30°C. Humidity was not controlled. At 17/10°C, the plants showed chilling injury and heat injury occurred at 37/30°C. Total plant dry weight was greatest at 25/18°C while leaf area was greatest at 33/26°C. At high temperatures proportionately less dry matter was present in the roots and corm compared with plants at 25/18°C. High temperatures produced more horizontal leaves but, to compensate for this, the laminae folded more readily. Lamina folding was closely associated with relative water content of the laminae, except under cool conditions where laminae folded despite high (97-99%) leaf relative water contents. Unit leaf rate (increase in whole plant dry weight per unit leaf area per unit time) was greatest at 21/14°C (5.8 g m^-2 day^-1) and least at 37/30°C (1.7 g m^-2 day^-1.) and had a strong negative association with whole-plant leaf resistance. Leaf relative water content was more closely associated with vapour pressure deficit than temperature and even at 37/30°C was high at 94%.