Tomatoes, okra, potatoes, and carrots are very susceptible to injury by the root knot nematode and favor buildup of this nematode in the soil. Sweet corn and other grasses suppress this nematode. Wireworms and white grubs thrive in grass turf, and a new garden plot will usually contain many active soil insects. Sweet corn, watermelons, and winter squash are better choices than the root or tuber crops for planting in newly tilled soil. It is wise to plant a crop which favors decomposition of organic matter after one which produces large amounts of coarse organic material.
Sweet corn produces a coarse crop refuse that resists decomposition.
Place crops in compatible sequence so that one which produces a toxic effect will not precede one that is susceptible to that toxin. Consider relationships between sweet corn and some other vegetables. Decomposition of sweet corn stubble liberates organic toxins which inhibit early season root growth of lettuce, beets, and onions. Grain corn and sweet corn are good alternate hosts for the fungus which causes pink root disease of onions. Onions following corn can have severe pink root disease even in soil where onions have never been planted.