Submitted to: Proceedings of Southern Weed Science Society
Publication Type: Abstract only
Publication Acceptance Date: 3/8/2005
Publication Date: 7/20/2005
Citation: Harrison Jr, H.F., Jackson, D.M. 2005. Killed cover crop mulches for sweetpotato production. Proceedings of Southern Weed Science Society [Abstract]. 95:S115. Interpretive Summary: None.
Technical Abstract: A no-till cultural practice where an oat and crimson clover cover crop mixture was left on the soil surface to serve as mulch for the following sweetpotato crop was evaluated in 2002. The experiment was arranged in a split plot design where the four main plot treatments were (1) cover crop mulch that was hand-weeded, (2) cover crop mulch with no weed control, (3) conventional tillage, hand-weeded, and (4) conventional tillage, weedy. Subplots were three sweetpotato varieties, Ruddy, SC 1149-19 and Beauregard. Ruddy is a recently released insect resistant variety; SC 1149-19 and Beauregard are insect susceptible. The objectives were to (1) assess weed suppression by the mulch, (2) determine the effectiveness of insect resistant sweetpotato varieties in no-till, (3) determine the effect of cover crop mulch on sweetpotato yield and quality. Annual grass seedling counts were 10 times higher in conventional tillage plots and broadleaf weed seedling counts were three times higher in the conventional tillage plots at 3 weeks after planting. Weed suppression by the cover crop mulch was also reflected in the yields. Yields averaged over varieties of the weedy, mulched cover crop treatment were higher than those of the weedy, conventional tillage plots. SC1149-19 produced more storage roots and total yield than the other two varieties. The insect resistance of Ruddy held up well under the killed-cover crop conditions, and it had higher percent clean roots and lower infestations by WDS (Wireworm-Diabrotica-Systena complex), sweetpotato flea beetles, grubs, and sweetpotato weevils than the two susceptible genotypes. In general, injury to sweetpotato roots by soil insect pests was lower in the cover crop mulch plots than in the conventional tillage plots. This was somewhat surprising because most studies suggests that insect populations should be higher in the cover crop mulch plots due to the presence of crop litter. The results of this experiment indicate that the cover crop mulch production system may be useful in sweetpotato production.