Performance of three spray applicators on weed control in hilly terrain.
In trials in rubber on hilly terrain in Malaysia, the efficiency of applying Garlon 250 [triclopyr] at 3 litres formulated product/ha to control of shrub-weeds such as wild rubber seedlings, Melastoma malabathricum, Ficus sp., Clidemia hirta and Breynia sp. was compared for 3 application methods. The herbicides required 67% less man-hours to apply with 11 litres of water/ha using a Micron Herbi controlled droplet applicator (CDA) and 10% less man hours with 460 litres of water/ha using a motorized power sprayer as compared to application with a conventional knapsack sprayer. For control of weeds such as Paspalum conjugatum, Ottochloa nodosa and leguminous covers which were treated with Roundup [glyphosate] at 1.5 litres/ha, CDA required 65% less labour (10 litres of water/ha) and the power spray required 15% less labour (540 litre of water/ha) compared to knapsack spraying. Thus CDA appears to be the best choice for weed control in rubber on hilly terrain, provided care is taken with protective clothing, weather conditions and choice of herbicides. Knapsack and power spraying were considered to be more suitable for areas of dense and/or tall weeds.