Optimum volume of spray application for the control of coffee leaf rust :

Employing the degree of physical performance (correct droplet size, good penetration, distribution and coverage of the sprayed material) and the reduced rate (3.85 and 4.64 kg/ha) of Copper Nordox, optimum volume for the coffee Leaf rust (Hemileia vastatrix) control was in the range of 400 l/ha and 600 l/ha respectively. Even though, copper at the rate of 7.7 kg/ha and applied suspended in each of the volumes used in this study, was as effective as the reduced rates of copper in the control of this disease at these rates, Leaf rust infection peak was reduced significantly (P = 0.05) and coffee yields were increased. Chemical concentrations appeared to play a major role compared to spray volume in the overall Leaf rust control. The practical implications of these results are discussed in this paper