Compared efficacy of two aqueous essences from leaves of Calotropis procera and Crataeva religiosa in the fight against tomato destroyers

Abstract

Tomato has become one of the most consumed vegetables across the world. However, insect attacks check its growth. Chemical  treatments recommended by experts appear to be ineffective, in that insects develop capacities of resistance, needless to evoke the  harmful effect of pesticides on the environment. To limit damage caused by insects, organic fight has been used as an alternative  solution. This work aims to contribute to the understanding of the tomato entomofauna, and the fight against this speculation devastator  insects in Dakar suburban zone. The study was carried out according to a randomised Fisher block mechanism in three  repetitions, with four formulas: T1 (400g/l of essences from fresh leaves of Calotropis procera), T2 (200g/l of essences from fresh leaves of   Crataeva religiosa), T3 (mixed solution), and T0. Results showed that treatment with the mixed solution (T3) appeared to be effective  on winged greenflies and on Chrysodeixis chalcites larvae, but had no impact on Bemisia tabaci, Spodoptera littoralis, and Liriomiza sp. T2  seemed to be more effective against C. chalcites larvae and winged greenflies. The different formulas have no significant effect on  Helicoverpa armigera larvae. T1 was without effect on destroyer insects, but enhances yield.