Harvesting is the operation of gathering the useful part or parts of the plant and is carried out at the time when all the nutrients have developed and the edible parts have reached the appropriate degree of maturity.
In general, the harvest takes place 10 or 15 days after the grain has reached physiological maturity. At the time of maturity, the grain has specific moisture content and special physical characteristics. The most appropriate time of harvest is determined based upon the length of the growing cycles (which differ according to the crop and varieties) and also the degree of maturity of the grain.
The following Table shows the degrees of moisture content considered appropriate for good harvest conditions and the characteristics permitting assurance of physiological maturity:
The harvest should take place at a time when the grain has moisture content in the range 15-20%. Clearly, the higher the moisture of the grain at harvest time, greater the risks of losses from moulds, insects and germination. On the other hand, the longer the grain remains in the field (for further drying of the product), the greater are the risks of losses due to shattering of grains, or from attacks by birds, rodents and other pests.
Harvesting of pulse crops is generally done by hand with simple farming implements like sickle or by machines when the pods are ripe but not yet open. To harvest the pulse crops by hand, the plants are pulled up and allowed to pre-dry in the sun. This operation should be done early in the morning, while the dampness of the night minimizes the risk of shattering losses. In some places, before the harvest, the plants are treated with chemical defoliants. This treatment is intended to hasten drying of the plants and reduce the quantity of plant matter to prevent its slowing up threshing operations. On an average, it takes about 80-100 man-hours per hectare to cut the plants by sickle.
Mechanized harvesting of legumes is usually done with combine-harvesters designed for wheat but adapted for pulses crops. However, it be used only in large fields and that too which has been levelled before sowing and then planted with varieties which are erect in nature and reach maturity simultaneously. The capacity of these machines generally varies from 0.9– 1.1 h/ha. Mechanized harvesting in case of pulse crops is minimal due to unavailability of mechanical harvesters at affordable price. However, some designs of reapers are available which can be used for harvesting of chickpea. The use of such machines should be encouraged to cut down the cost of harvesting and thereby reducing the cost of production.