About 35 to 40 percent yield of mango has been wasted every year due to lack of awareness among growers by using traditional techniques in post-harvest process.According to agriculture department officials, mango growers had not proper skill in plucking the fruit from trees. Untrained labours usually did not follow recommended criteria which damaged 10 per cent mango on plucking stage, said officials. The labourers ignore grading stage and mix the damaged fruit with healthy ones which also spoil the whole lot, they added. The laboures pack mango in wooden boxes which also damage or leave bruises on the fruit, they said.