SWEET CORN YIELD AND INSECT DAMAGE AS AFFECTED BY COVER CROPS AND NITROGEN
The effects of cover crops and nitrogen on yield and insect damage of sweet corn were examined. In 1989, sweet corn was grown in bare soil plots, plots covered with rye (Secale cereale), and plots covered with hairy vetch (Vicia villosa). In 1990 a black plastic mulch treatment was substituted for the hairy vetch treatment. Each soil cover was fertilized with 45, 90, 134, or 179 kg/ha nitrogen (N) in 1989, and 34, 101, 168, 235, or 302 kg/ha N in 1990. Covers were planted in the fall, followed by sweet corn the following spring. There was no mowing or tilling of the cover crops. Corn yields were lower each year in the rye covered plots. There were more corn earworms on the rye covered plots. Corn pollination was poorer on the rye covered plots, but responded positively to increasing rates of N.