Cover Cropping Systems for Brassicas in the Northeastern United States

Winter rye (Secale cereale L.) is the dominant cover crop used in the northeastern United States. At three different locations, rye was compared nwith systems using the winter-annual legume hairy vetch (Vicia villosa Roth) seeded alone and in combination with rye. These cover crops were seeded in the fall and managed the following spring. Management consisted of either incorporation or mow-killing the cover crops for enhanced weed suppression. Hairy vetch in combination with rye produced more biomass and gave as good or better weed suppression when left on the soil surface than either cover crop species alone. Leaving these cover crops on the soil surface as a dead mulch gave better weed suppression than incorporation of the cover crops. At one site, mowed "vetch + rye" suppressed weeds at least as effectively as plots that received conventional herbicides. The dead mulch led to decreased cabbage maggot egg (Delia radicum L.) and diamondback moth larvae (Plutella xylostella L.) infestation at one site and increased slug incidence at another site.