Investigation of the Efficiency of Two Kinds of Sprayers Based on Electrostatic Charge and Spinning Disc in Comparison with Hydraulic Motorized Sprayer Carried on Trolley in the Control of Rice Blast

Rice blast caused by Pyricularia grisea (Cooke) Sacc. is one of the most serious diseases of rice throughout the world، which is generally controlled by fungicides. Appropriate selection of sprayers with respect to the field conditions، increases the efficiency of pesticide application and reduces the environmental pollution. In this study the efficiency of five different types of sprayers namely: two types of knapsack micronair sprayers (Model: KP 4000-N10، and SKN-3000) as well as two types of electrostatic sprayers (Model: motorized knapsack mist blower sprayer equipped with electrostatic head and Model: GPS-5 TM) were compared with hydraulic motorized sprayer carried on trolley using two doses (1 and 0/75 kg/ha of tricyclazole (Beam® WP 75%) applied on rice blast disease. The factorial experiment was carried out based upon a Randomized Complete Block Design (RCBD) of 3 replications. The results demonstrated that motorized knapsack mist blower sprayer equipped with electrostatic head، hydraulic motorized sprayer on trolley (conventional sprayer) as well as knapsack micronair sprayer (Model: KP 4000-N10) were of the highest efficiencies. The mean severities were estimated 1. 67±0. 13، 2±0. 12 and 3. 5±0. 33 respectively. The pesticide solution taken up by the 3 sprayers were recorded as 48، 450 and 65 L/ha. respectively. This shows considerable reduction in the level of fungicide applied in the motorized knapsack mist blower sprayer equipped with electrostatic head and in knapsack micronair sprayer، leading to an increase in efficiency and decrease in operating costs. Evaluation through water-sensitive cards indicated that motorized knapsack mist blower sprayer (with electrostatic head) and knapsack micronair sprayer (Model: KP 4000-N10) led to a better distribution of droplets than hydraulic motorized sprayer carried on trolley did. It is recommended that the above mentioned technique be only applied to leaf rice blast، since it can not be beneficial to the crop when it is at its panicle stage and tall.