Corn does not effectively compete with weeds when it is germinating. Hand pull weeds as they appear, or put down a weed barrier prior to planting, and cut slits for the corn to come up through. If using herbicides in the garden, make sure the spray does not contact the corn foliage.
Common insects that infest corn include earworm, corn borer, seed corn maggots, cutworms and corn rootworms. Planting as early as the soil reaches proper temperatures in your area helps prevent some insect damage. If insecticide use is required, apply once the corn has started to produce silk.
Many diseases of corn are exacerbated by weather. Poor kernel development can be attributed to dry weather. Proper irrigation can resolve this issue. Rotting of seeds can be reduced or eliminated by planting disease-resistant varieties when the soil temperatures have reached 55 degrees F.