Use of Plant Biocidal Substances Based on Crataeva Religiosa Against Tuta Absoluta (Lepidoptera: Gelichiidae) Devastator of Tomato Crops

Abstract

The tomato leaf miner, Tutaabsoluta causes serious losses in production. It can feed on all the green parts of the tomato and can cause up to 100% damage if not controlled. Presently, the most effective method of pest control is the use of chemicals. The purpose of this study is to give alternative solutions based on natural products. The objective was to know the biocidal power of the aqueous extracts of Crataevareligiosa leaves on T. absoluta. The work was conducted on a field at the Niayes area. Three formulations were used: formulation with dry leaves (200g/l, 150g/l and 100g/l), formulation with fresh leaves (200g/l) and soapy formulation (100g Crataeva + 25g soapy) and two controls (C0, S). Each treatment was repeated twice as well as the controls. The results showed a significant decrease (P <0.0001) of the larvae compared to the blank control. However, the fresh formulation (200g/l) had double effect by reducing the number of pest larvae and a positive effect on number of the predator N. tenuis in addition to a positive impact on the agronomic traits. The dry formulation, which certainly reduced the T. absoluta larvae, had no impact on N. tenuis and H. armigera.

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

“…On the other hand, parcels treated with C. religisa had a weaker attack rate (23.4%) compared with the other parcels. Similarly, the mixed solution minimizes damage but is less effective than T2 (24.44%) which corroborate studies by Ba et al (2019) who saw that aqueous essences from C. religiosa drastically reduces attacks from caterpillars of H. armigera. According to Gahn (2018), C. religiosa reached its biggest effectiveness against P. xylostella larvae.…”

“…In terms of vegetable expenses, fresh tomato comes in fourth position behind onion, potato, and cabbage; that is to say 7% of households' vegetable consumption (Huat and David-Benz, 2000). However, it is prone to numerous depredations, notably ravaging insects (Shankara et al, 2005) of which, the most important are lepidopteron, in particular the "Noctua of tomato", Helicoverpa armigera (Hübner), and the "South-American under minor", Tuta absoluta (Meyrick) which can lead to losses up to 100% of harvest (Ba et al, 2019). Chemical fight is the major strategy for market gardeners to protect their crops, but these practices are really harmful both for human beings and the environment.…”

“…The current tendency consists to fight against insects in using natural products, in order to preserve the environment and human health (Naïka et al, 2005). These last years, plant natural substances have been used as insecticides to reduce damage caused by these destroyers, and results are encouraging (Ba et al, 2019;Diome et al, 2019;Ngom, 2019). These substances have the advantage of being biodegradable, non-remanent in the environment, and are within the reach of minor producers (Traoré et al, 2015).…”