Field evaluation of a botanical formulation from the milky mangrove Excoecaria agallocha L. against Helicoverpa armigera Huebner. in Abelmoschus esculentus (lady's finger) and Cajanus cajan (pigeon pea)

Objective: To evaluate a formulation from the milky mangrove tree Excoecaria agallocha L. (E. agallocha) against Helicoverpa armigera Hubner (H. armigera). Methods: About 3% aqueous ethanolic spray formulation derived from the lipophilic extract of E. agallocha (dry leaf) was evaluated against H. armigera in Abelmoschus esculentus (lady's finger) and Cajanus cajan (C. cajan) (pigeon pea), under field conditions. Results: On the 9th day of the 4th spray the larval count in the plot treated with 3% E. agallocha formulation drastically came down to 0.23 larva/plant, compared to 1.63 in the ethanol control plot and 1.60 in the unsprayed plot. Blocks sprayed with 3% E. agallocha formulation yielded 35.8 quintals/hectare (q/ha) of healthy pods compared to Ekalux registered (pod yield: 60.7 q/ha), 3% Vijay Neem registered (60.22 q/ha), yield plot (6 q/ha) and ethanol control (7 q/ha). In C. cajan, 1% E. agallocha, 3% Nimbecidine registered and 0.07% indoxacarb were equally potent in reducing the larval population of H. armigera and the non-target pest Spilosoma obliqua to 0%, from the 9th day (3rd spray). Indoxacarb plot recorded the maximum yield of 16.1 q/ha with 2.4% pod damage. Plots sprayed with 1% E. agallocha yielded 14.7 q/ha with 2.32% pod damage. The effect of 3% Nimbecidine registered spray (14.35 q/ha) was comparable to E. agallocha formulation. Unsprayed and ethanol control plots yielded 12.41 and 11.2 q/ha of pods with an average pod damage of 4.7%. Conclusions: E. agallocha formulation was found to be promising for the control of H. armigera, under field conditions.