Models predict a continued increase in global atmospheric temperature of about 1.5°C by the end of the 21st Century. This global warming is predicted to negatively affect plant growth and agricultural production, especially in tropical and subtropical areas where temperatures are already high, due to the damaging effect of heat stress on plant development and seed yield.
One of the obvious solutions to heat stress is to select and develop crop species with improved tolerance to heat stress and desirable agronomic traits to maintain economic yield under high temperatures. This project aimed to identify thermotolerant genotypes in three legume species differing in growth habit, usage and production areas and seasons in South Africa. The species included Aspalathuslinearis, Vigna unguiculata (cowpea) and Cicer arietium (chickpea).
Aspalathus linearis is an important commercial crop in the Western Cape produced by over 450 farmers, and is used to make a mild-tasting tea associated with important health benefits and medicinal value. Cowpea and chickpea are important food security crops for smallholder low-resource farmers in the tropics and semiarid tropics. Grain legumes are second to cereals in providing food for humans and are a rich source of proteins throughout the world. The effect of high temperature on these species was determined in the field along a gradient of temperatures and in the glasshouse under high temperature conditions. Data on morphological, physiological, reproductive development and seed yield were collected.
We worked to unravel the effect of temperature changes on these species at different times of the year, and the response of the different legumes to the temperature changes. We hypothesized that growth and seed yield of the three legume species would be adversely affected when maximum average temperatures exceed 35°C.