Thesis (M.Eng.) - Asian Institute of Technology, 1993

A thesis submitted in partial fulfilment of requirements for the Degree of Master of Engineering.

After making the necessary modifications into horizontal conveyor and overhead reel assemblies of JF Reaper Windrower, it was field tested to evaluate its performance for harvesting of rapeseed crop under agro-climatic conditions in Pakistan. The windrower was tested in the experimental area of National Agricultural Research Centre at three different speeds of tractor and two crop maturity levels of rapeseed (Canela type; Shiralee Variety). Average effective field capacity was found to vary from 0.33 to 0.67 ha/h at 30 and 15 percent seed moisture content when operating the machine at 2.28, 3.03 and 4.01 km/h in 2nd, 3rd and 4th low gears of tractor. Based on the combinations tested it can be concluded that performance of the windrower, the combination of 3.03 km/h of machine forward speed and 30 percent seed moisture content gave the better performance. Average total labour requirement of mechanical and manual reaping systems (including gathering and bundling operation) was found to be 57 and 146 man- h/ha, respectively. Average total machine losses after incorporating the modifications into horizontal conveyor and reel assemblies were reduced from 12.5 percent to 8.6 percent and the average field efficiency increased from 46.4 percent to 82.8 percent. Total cost for harvesting with mechanical reaper with tractor was found to be Rs 374 per hectare as compared to Rs 600 for manua 1 reaping. Tot a 1 cost for mechan i ca 1 harvesting inc 1 ud i ng gathering and bundling operation and value of total seed losses was estimated to be Rs 2233 per hectare as compared to Rs 2782 for manual reaping. The results showed that the performance of reaper was satisfactory, and economical for the farmers.