Groundnut is the major Kharief crop of Barani areas in Pakistan. Groundnut yield is the major source of income for these farmers. Groundnut is grown over 0.106 million hectares and resulting the annual yield of 77.6 thousand tons. The average yield of groundnut in Pakistan is nearly 0.88 tons/ha. Conventional diggers/pullers are used to harvest groundnut/peanuts from the soil. These diggers do not shake or invert the crop which is necessary for good threshing after sun drying. The existing digger/shaker was tested at Agricultural Mechanization Research Institute (AMRI) Wing, Jhang Road, Faisalabad. During field testing, the machine performance was found unsatisfactory. The bridging/blocking of heavy crop due to low clearance between upper supporting bars, conveyor and slippage of the peanut plants on the conveyor was also noticed. The slicing action of the blade was poor. The blade was performing shear action instead of slicing. The machine had 0.27 ha/h effective field capacity, 85.60% field efficiency, 85.40% digging efficiency, 6.50% recoverable loss and 9.50% irrecoverable loss. Keeping in view, the above problems, the necessary modifications were incorporated to improve the field efficiency of the digger. During modification, the space between the supporting bars and conveyors was optimized. The blade was divided into three continuous welded pieces, front roller was removed and small pegs were welded on the front conveyor to overcome these problems. Finally, the field test was conducted at the farms of Barani Agricultural Research Institute, Chakwal for machine evaluation. Field performance of the digger was evaluated at three maturity levels of the crop (65%, 75% and 85% matured pods), three plot sizes at three different speeds of machine. Data regarding productive, seenable and unseenable weights were collected and statistically analyzed. The best digging efficiency was 89.31% at 75% maturity level, the field efficiency was 89.31% at 1.85km/h, recoverable loss was 5.14 % at 1.85km/h and irrecoverable loss was 5.55% at 1.85km/h. The field test expressed that the AMRI groundnut digger/shaker was improved reasonably after modification. It became more fuel efficient resulting in energy saving.
