Efficacy of Aqueous Extract of the Seeds of Annona muricata L. in the Control of Late Blight (Phytophthora infestans) of Tomato (Lycopersicon esculentum Mill.) in the Field

Abstract

Objective: An experiment was conducted to propose an agroecological alternative to synthetic fungicides for the control of late blight of tomato in field. The aim of this study was to evaluate the effect of aqueous extract of Annona muricata seeds (AqEAM) against late blight and yield parameters of tomato. Methods: Two varieties (Rio Grande and Lindo F1) constituting the main plots and three treatments (aqueous extract of A. muricata, synthetic fungicide Mancozeb 800g/kg and control) represented sub-plots were used in a split-plot design with four replicates. The treatments were applied two weeks after transplanting and the dose of AqEAM used was 70g/L. Incidence, severity of late blight and agronomic parameters were evaluated. Results: The results show that the application of AqEAM significantly reduced the incidence of late blight in the field by 55.84% and the severity by 80.35% compared to the control at 76 days after transplanting (DAT). Furthermore, no significant differences were observed between AqEAM and the synthetic fungicide on the incidence and severity of late blight. In terms of yield (t ha-1), tomatoes treated with AqEAM showed a significant increase of 26.14% and 25.7% respectively compared to the control and the synthetic fungicide. The Lindo F1 variety yielded best (10.80t ha-1) than Rio Grande variety (6.60t ha-1). Conclusion: These results suggest that aqueous seeds extract of Annona muricata is effective as the synthetic fungicide and would therefore be recommended as an alternative in biological control of late blight of tomato.