Evaluation of different sprayers used for the protection of cocoa farms in Nigeria

Abstract

A comprehensive laboratory and field evaluation of 12 hydraulic knapsack sprayers, 1 motorized knapsack sprayer and 4 trombone sprayers were carried out to determine their effectiveness as pesticide application equipment for the control of cocoa pests. The evaluations were carried out at the Cocoa Research Institute of Nigeria, Headquarters, Ibadan between 2003 and 2008. The inbuilt tank capacities for the Hydraulic and Motorised Knapsack (H & M K) sprayers are of various sizes ranging from 10L, 15L, and 16L to 20Litres, respectively. The trombone sprayers do not have a tank and its hose is usually fitted into an improvised 5L or 10L plastic keg/bucket. The total number of cocoa trees covered by the H & M K, and trombones sprayers ranged from 35 to 42 trees per 9 litres of the spray mixture. The Pulmic, Rosy and Osatu gave the highest horizontal thrust of 11.5m, 10.9m and 9.8m, respectively, while a vertical thrust of 7.5m, 7m, 6m and 5.9m, respectively were recorded for Matabi, Pulmic, Rosy and Osatu. The motorized knapsack sprayer gave a lower horizontal thrust of 3m and a vertical thrust of 7m. Osatu, Neptune, Kizan, Pulmic and Jacto each gave a discharge rate of 680mls, 650mls, 650mls, 610mls and 600mls per minute, respectively. However, considering the number of strokes required to build up pressure, Pulmic, Kizan, Titan, Jacto and Neptune gave a discharge rate per stroke of 101.67mls, 92.86mls, 80.83mls, 77mls and 72.22mls respectively. The motorised knapsack sprayer, which is machine powered gave the highest discharge of 1,140mls spray mixture per minute. New spraying equipment were screened regularly at CRIN and those found suitable were recommended for use by cocoa farmers.