Efficiency of different plant foliar extracts on grain protection and seed germination in maize.

摘要

A study was undertaken to explore the pesticidal potential of certain Indian vegetable plant leaves for the post-harvest protection of maize seeds from stored pests and seed borne fungi. The crude extracts and purified fractions from leaves of papaya, Carica papaya L., ivy gourd, Coccinia indica Wight and Arn., bitter gourd, Momordica charantia L., curry leaf, Murraya koenigii L., chilli plant, Capsicum annuum L. and brinjal, Solanum melongena L. were evaluated for their capacity to control storage deterioration due to infestation by two major pests of maize, rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae) and red flour beetle, Tribolium castaneum H. (Coleoptera: Tenebrionidae). All crude extracts and the solvent eluted fractions were tested for their insecticidal activity in the vapor and contact form. The effects of treatment on maize viability and antifungal activity against the fungi associated with the germinating seedlings were also recorded. The crude extracts of C. annuum, M. charantia, S. melongena, C. papaya and M. koenigii caused significant mortality to both pests in fumigation method and the extracts of C. annuum and M. charantia exhibited a delayed toxicity (i.e., 72 h) in contact form. Ethyl acetate eluted fractions of C. annuum, S. melongena and M. charantia showed 100% mortality to T. castaneum and S. oryzae within 24 h of treatment in vapor form. The maize seeds treated with C. papaya, C. indica, M. charantia and S. melongena had germinated completely (100%). While the extracts M. koenigii, M. charantia and S. melongena were effective in reducing the incidence of seed born fungi, Aspergillus flavus during germination period.