Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 3/3/2004
Publication Date: 6/20/2004
Citation: Harrison Jr, H.F., Jackson, D.M. 2004. Evaluation of plant breeding approaches to improve weed management in sweetpotato [abstract]. HortScience 39:668.
Technical Abstract: Weed management in sweetpotato is expensive, because most acreage is hand weeded. Thus, application of plant breeding approaches to reduce the expense of weed control may be feasible. Some sweetpotato varieties are allelopathic to certain weeds due to production of a group of phytotoxic compounds referred to as periderm resin glycosides (PRG). In a genetically diverse group of sweetpotato genotypes, PRG levels ranged from over 12% to less that 0.1% of the tissue dry weight. Several lines that produce high PRG levels have been identified, and preliminary studies indicate that PRG production is heritable. Development of advanced clones with high PRG content can be accomplished rapidly utilizing a relatively simple HPLC procedure. PRG also inhibits pathogen and insect growth, suggesting that they are part of the general defense chemistry of sweetpotato roots and may contribute to pest resistance. Sweetpotato genotypes also vary greatly in morphology which is another trait that may useful in weed management. A field evaluation of sweetpotato varieties with diverse growth habits indicated that yields of the variety, Carolina Bunch were reduced less by weed interference than any other. Yields of the predominant variety, Beauregard were greatly reduced by weed interference. A subsequent experiment comparing the effect of various weed free intervals on Beauregard and Carolina Bunch indicated that Carolina Bunch required a shorter weed free period for maximum yield. Varieties with compact vine and dense canopies like Carolina Bunch appear to require less weeding than varieties with trailing vines and more open canopies like Beauregard.