EFFECT OF HIGH TEMPERATURES ON THE GROWTH, DEVELOPMENT AND REPRODUCTION OF CRAMBI (Crambe abyssinica, Hochst)

Abstract

In studying the adaptation of crambe (Crambe spp.) to the arid Southwest, U.S.A., a low seed production and quality was observed. This behavior was supposed to be associated with the high temperatures occurring during the late Spring and the early Summer, when plants were at the flowering and seed filling stages of development. In order to study such effet, the cultivars 'Meyer' and 'Prophet' were evaluated under low temperature (25/18 C, day/night) and under high temperature (35/25 C, day/night). The treatments used were: (1) Low temperature during the whole plant cycle; (2) Low temperature in the vegetative stage and high temperature from flowering to maturity; (3) High temperature in the vegetative stage and low temperature from flowering to maturity; and (4) High temperature during the whole plant cycle. High temperature during the vegetative development estimulated
leaf expansion, biomass accumulation in stems and roots, and an early flowering; however, during the seed fill ing stage, high temperature increased seed abortion and decreased seed set.