DEVELOPMENT AND PERFORMANCE EVALUATION OF A WINDROWER UNIT FOR KAU ROOT CROP HARVESTER

Abstract

A tractor-operated root crop harvester was developed by KAU especially for harvesting coleus, turmeric and ginger. The developed machine increased the yield and reduced the losses and damages caused to the tuber/ rhizome when compared to the conventional method of harvesting. However, there was a need for separating the soil adhered to the tuber/ rhizome and windrow the tuber/ rhizome at the rear end of the machine for easy collection. Therefore, in the present study, a windrower unit attachment to the KAU root crop harvester was developed and evaluated the performance of the developed machine for optimizing the operational parameters. The soil and crop properties relevant to the design of the windrower unit were determined. The major components of the developed windrower unit are the mainframe, power transmission system which includes the chain sprocket system and the crank rocker mechanism and the windrower unit with a soil separator. The developed prototype was provided with to and fro as well as vertical oscillatory motion. The overall dimension of the developed unit was 1000 × 900 mm, with a windrowing width of 180 mm. The operational parameters for optimizing the machine were at three levels of amplitude of oscillation (60, 100 and 140 mm), inclination of windrower unit (5, 10 and 15 deg.) and crank rotational speed (220, 270 and 300 rpm). The performance of the machine was determined by considering the parameters including soil separation index, conveying efficiency, damage percentage, power requirement, fuel consumption, field capacity and field efficiency. The soil separation index for coleus was maximum with 83.27 per cent, followed by turmeric and ginger with 78.29 and 77.96 per cent respectively at 100 mm amplitude, 10 deg. inclination and 270 rpm rotational speed. The maximum conveying efficiency for coleus, turmeric and ginger were 92.06, 93.16 and 92.92 per cent respectively obtained at 140 mm amplitude, 10 deg. inclination and 270 rpm rotational speed. The minimum damage percentage of 1.99, 1.51 and 1.30 was obtained at 100 mm amplitude, 10 deg. inclination and 270 rpm rotational speed for 137coleus, turmeric and ginger respectively. The minimum power requirement for coleus, turmeric and ginger was 2.58, 3.38 and 3.67 kW respectively at 100 mm amplitude of oscillation, 5 deg. inclination and 220 rpm rotational speed. The fuel consumption of 5.34, 5.56 and 5.13 L h -1 was observed for harvesting coleus, turmeric and ginger respectively. The effective field capacity for coleus and ginger was 0.15 ha h -1 with a field efficiency of 0.16 per cent. For turmeric, the field capacity and field efficiency determined were 0.16 ha h -1 and 94.12 per cent respectively. The standardized machine parameters are 100 mm of amplitude of oscillation, 10 deg. of inclination of windrower unit and 270 rpm of crank rotational speed. The fabrication cost of the developed prototype was computed as Rs 20000. The cost of operation per hour and hectare is Rs 996 and Rs 6640 respectively. The total cost of harvesting using harvester including collection and bagging was observed as Rs 28390 per ha. The cost savings for harvesting including collection was 67.37 per cent for coleus and 60.84 per cent for turmeric and ginger. The savings in labour for coleus harvesting was 75 per cent whereas for turmeric and ginger, it was about 70 per cent when compared to the conventional method. About 34 per cent of cost reduction and 30 per cent of labour reduction was observed when the KAU root crop harvester was operated with the developed windrower attachment. The break-even point and payback period of the machine were 67.78 hours per annum and 1.46 years respectively.