WINTER COVER CROPS AND NITROGEN FERTILIZER EFFECTS ON TOMATO AND BEAN PRODUCTION: A THREE YEAR SUMMARY

Abstract

Winter cover crops (wheat or rye and crimson clover) in combination with three levels of nitrogen fertilizer (0, 60, 120 kg/ha) were evaluated as to their influence on bean and tomato production (fruit yield, disease and insect injury on fruit) over a three year period (1991-1993). A split plot design was used with the cover crop as the main treatment and nitrogen rate as the split treatment. Results indicate that total marketable and cull yields for bean increased significantly in 1992 but decreased again in 1993. Tomato yields were significantly greater in 1991 than in 1992 and 1993 for both early and total marketable yields while early cull yield increased each year and total cull yield was highest in 1993. Cover crop had an effect on non-marketable tomato fruit. There was a higher incidence of cracked and insect damaged tomato fruit in association with clover or fallow treatment. Marketable yields responded in a quadratic manner while the number of cull fruit increased linearly for both bean and tomato as nitrogen rate increased. The incidence of diseased bean pods increased linearly as nitrogen rate increased. Catfaced tomato fruit responded in a quadratic manner and cracked tomato fruit increased linearly as nitrogen increased. Results from the three year evaluation do not indicate an influence of cover crop on marketable yields of bean and tomato.