If harvesting is delayed and the physiological maturity has been exceeded, the corn ear will tend to droop. This drooping helps prevent intrusion of water into the ear. Early maturing variety or hybrid can be harvested in 90-100 days from planting, while full season hybrid may be harvested in 105-120 days, depending on the hybrid, field condition and elevation, and climatic condition. In certain cases, early harvesting is recommended to
1. reduce risks of delay in harvesting due to rainy weather;
2. avoid excessive loss of grains in the field due to mechanical handling;
3. prevent kernel germination due to water-soaking caused by excessive rains;
4. prevent further development of ear rot fungi;
5. reduce pest damage such as insects and rodents;
6. prevent dropped ears and lodged plants.
A good practice we’ve noted in Central Luzon is the drying of ears prior to shelling. This is something that can maintain grain quality as well as minimize losses due to damaged or injured kernels caused by shellers. The following are some recommended preshelling operations for growers: