Determination of the Critical Period of Phytosanitary Treatment against Cowpea (Vigna unguiculata L. Walp) Pests in Southern Togo

Economically efficient and environmentally friendly technology is essential for sustainable agricultural production. To optimize cowpea production through an economically profitable and environmentally friendly phytosanitary treatment technology, trials were conducted in a station based on Acarius 18 EC at a rate of 1 liter/ha against the main cowpea insect pests. A complete randomized block device with three replications of four objects each with two sub-trials: an early competition (EC) sub-trial and a late competition (LC) sub-trial were adopted. Seed yield and the critical period for phytosanitary treatment have been determined. The best yields were obtained on objects that received the first treatment 28 days after sowing (DAS) (2.13 t/ha on average) for EC and on objects that received the last treatment 42 DAS (2.23 t/ha on average) for LC. Under the conditions of our study, the critical period of phytosanitary treatment against cowpea pests (VITOCO) for optimum yield is then between 28 and 42 DAS.