DISTRIBUTION PATTERN ASSESSMENT OF A DUAL-PURPOSE DISC AGROCHEMICAL APPLICATOR FOR FIELD CROPS

A dual-purpose disc agrochemical applicator for field crops was developed to boost agricultural mechanization in crop production and also to overcome the safety concern of hazardous spray drift during agrochemical application by the field crop farmers. The dual purpose agrochemical applicator was mounted on a high clearance tractor and tested with respect to the granular fertilizer distribution patterns uniformity/liquid chemical uniformity of droplet sizes in spraying of the agrochemical. Results for NPK granular chemical indicated that, at low (50 kg/ha) and high (150 kg/ha) application rates with 550 rpm disc speed, distribution patterns skewed to the left whereas the distribution pattern at medium (100 kg/ha) application rates was good flattop. Also at high application rate with 1000 rpm disc speed, mean distribution pattern became poor (W-shape). For the liquid chemical herbicide HC 48 amine liquid, the mean values of volume median diameter (VMD) and number median diameter (NMD) were 108 ?m and 80 ?m at 90 lt/ha application rate at 5000 rpm rotary disc speed, and also 344 and 222 ?m at 30 lt/ha application rate with 2000 rpm rotary disc speed. The mean values of coefficient of uniformity for droplet sizes expressed as VMD/NMD found in this study were in the range of 1.35 to 1.55 for HC amine 48 liquid chemical.