Efficacy of neem extracts in the control of tomato insect pest Helicoverpa armigera in Southern Benin

Abstract

Helicoverpa armigera, Hübner, 1808 (Lepidoptera: Noctuidae) is a major carpophagous insect pest of tomato in Benin. The damages by this insect pest and its resistance to most synthetic insecticides have necessitated the need for alternative methods to limit its damages on tomato. This study carried out in Toffo District in Southern Benin, aims to evaluate the effectiveness of neem extract (Azadirachta indica Juss.) on tomato (Lycopersicon esculentum Mill.) insect pest Helicoverpa armigera. Thus, two neem extract doses (1.5 l/ha and 2 l/ha) were compared to a chemical pesticide K-OPTIMAL (Lambdacyhalothrin + Acetamiprid at a rate of 1 l/ha) in a randomized complete block design with four replications. The results indicated that neem extract has reduced tomato fruits infestation by H. armigera from 76.72 to 77.22%. The highest infestation reduction of this pest (81.26%) and the highest fruit yield (29.13 tons/ha) were observed in the plots treated with K-OPTIMAL. The yields obtained with neem extract (26.68 and 28.38 tons/ha respectively with 1.5 l/ha and 2 l/ha) were statistically lesser than tomato treated with KOPTIMAL. However, neem extract allowed obtaining 33.86 to 42.39% yield profit compared to control plot. Neem extract showed its effectiveness to H. armigera control by reducing infestation rates and giving high tomato yield. The neem extract economic profit is lesser than chemical control. While the use of neem extract in agriculture protects environment, human and animal health.