Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Proceedings
Publication Acceptance Date: 10/28/2002
Publication Date: 2/10/2003
Citation: Harrison Jr, H.F., Labonte, D.R. Response of Sweetpotato (Ipomoea Batatas) Cultivars to Weed Interference. 2003. Proceedings Weed Science Society of America Abstracts. 43:104.
Technical Abstract: Two field experiments were conducted to assess how sweetpotato cultivars respond to weed interference. The first experiment included 11 sweetpotato cultivars and breeding clones with markedly different growth habits and canopy architecture. Over five repetitions of the experiment at two locations, average yields of weedy subplots in comparison to weed-free subplots were reduced from 14% for `Carolina Bunch' to 68% for `Beauregard'. Under weed-free conditions, sweetpotato canopies were 2 fold different in percentage of soil surface covered at 42 days after transplanting, and canopy biomass at harvest ranged from 132 to 423 g dry weight/m2. Neither of these canopy characteristics were correlated with yield or response to weed interference. Average weed biomass taken from weedy subplots at harvest ranged from 194 g dry weight/m2 for Carolina Bunch to 544 g/m2 for Carolina Nugget, and this parameter was correlated with percent yield reduction by weeds. A second experiment was conducted to compare the response to weed interference of the cultivar most sensitive to weed interference in the first experiment, Beauregard, with the least sensitive cultivar, Carolina Bunch. The experiment was arranged in a split plot design where subplot treatments were cultivars and main plot treatments were weed free periods of 0, 10, 20 and 30 days and the full growing season. Although there were differences between years, a longer weed free period was required to prevent yield reduction for Beauregard than for Carolina Bunch. These findings indicate that it is feasible to develop or select highly competitive sweetpotato cultivars that require less weed control than less competitive cultivars.