Synthetic pyrethroids on cotton: a spray application strategy

The pyrethroids are a new class of insecticide in cotton pest control and it is essential that they should be used wisely and to maximum effect. A strategy is proposed which is based on the residual properties of the pyrethroids, and which takes into account variety and crop management, choice of equipment, spray timing and spray frequency. Penetration and under-leaf cover can be helped by using smaller droplets, spraying in turbulence and when the wind is towards the sun.