Effect of plant extracts on seed germination and fungal infections of sesame varieties cultivated in Chad

Abstract

Sesame (Sesamum indicum L.) production has become an important cash crop enterprise in Chad due to its high demand both locally and internationally. However, the scale of production of the crop remains low and does not meet consumer demand, partly due to fungal diseases that hinder its cultivation. The objective of this study was to investigate the efficacy of selected plant extracts against some major fungal diseases in seeds of sesame in Chad. Mature seeds from nine sesame varieties that were collected in Chad, were treated separately in extracts of Cassia sieberiana, Vachellia nilotica, Ricinus communis and Calotropis procera, for six hours, at concentrations of 25, 50 and 75 mg ml-1. This was done before being sown in Petri dishes containing blotting paper. Data were collected on seed germination, seedling vigour index and the extent of disease infection. The results showed that aqueous extracts of V. nilotica and C. procera at 75 mg ml-1 showed 100% of germination and 0% of infection in the S42-ITRAD, Makaye, Ker Ndaa and Locale Guéra varieties. All seeds treated with different plant extracts at 75 mg ml-1, presented significantly higher seedling vigour than seedlings from the negative control. These findings suggest that using these plant extracts could reduce fungal infections in sesame seedlings; and enhance seed germination and seedling vigour.