Seed sorting of sesame (Sesamum indicum L.) by salt density and seed-borne fungi control with plant extracts

摘要

The effectiveness of sesame seed sorting by salt density and seed-borne fungi control by plant extracts was evaluated in Abeokuta, Nigeria. Seeds of two sesame cultivars (530-6-1 and NCRIBEN-03L) were soaked in 2%, 5%, 10% and 15% salt (NaCl) concentrations, separated as floated or sunken (immersed) seeds and assessed on blotter medium for fungal infection and viability. The effects of extracts of leaves of Azadirachta indica, Vernonia amygdalina, Musa paradisiaca and Anacardium occidentales as well as synthetic fungicides, Team (Carbendazin 12%+Mancozeb 63%) and Ridomil (Metalaxyl 60g+60 g CuO2) on seed infection by fungi, seed germination and seedling emergence was also evaluated. Unsorted (untreated) seeds served as control. Results showed that 10% and 15% salt concentrations did not separate healthy from unhealthy seeds, while 2% and 5% did. Seeds floated at 2% and 5% salt concentrations were characteristically discoloured, malformed, infected and lightweight. Fungal infection of such floated seeds was significantly (P0.05) higher than infection of sunken or unsorted seeds. Germination of seeds floated at 2% or 5% salt concentration was significantly (P0.05) lower than that of sunken or unsorted seeds. All plant extracts significantly (P0.05) reduced the fungal infection of seeds. A. indica leaf extract was comparable to the synthetic fungicides in reducing fungal infection of seeds. Leaf extracts of A. occidentales and M. paradisiaca enhanced significant (P0.05) seedling emergence. Alternaria sesamicola, Curvularia lunata and Fusarium spp. were most sensitive to A. indica and M. paradisiaca leaf extracts. Salt density and plant extracts have potential for sesame seed sorting and treatments respectively.