Influence of Heat on Seed Germination of the Three Acacia Species in the Sudan

Abstract

The influence of temperature (dry heat) and electric burner on germination of Acaciasenegal, Acacia mellifera and Acacia laeta in Sudan was analyzed, in order to know the response of acacia seeds to dry heat treatments. Germination tests were carried out in plastic Petri dishes over 30 days. In general, the degree of seed germination promotion by dry heat treatments showed slight variation, the final germination level was not increased in all the studied species compared with the control with some exception. The thermal pretreatment with 45° C was not effective for the germination in Acacia senegal and Acacaia mellifera irrespective of heat exposure duration with the exception of Acacia laeta (North Kordofan, 20.25%). The germination rates after preheating were much lower than in mechanically scarified seeds by electric burner and closely resembled those of the untreated seeds, except for Acacia laeta (Gedarif), where it is t50 reached 11 days for temperature 45° C at two seconds. The response of these species to heat shock had no clear effects on germination.