Alternative Strategies for Broadleaf Weed Management in Residential Lawns
Weed management treatments were examined as alternatives to conventional chemical herbicides. Site preparation and post-establishment treatments were tested in a randomized complete block factorial design, over two years. There were no site preparation treatment effects of untreated control, glyphosate, acetic acid, and flame weeding. Of the post-establishment treatments, lactic/citric acid and corn gluten meal were ineffective. Sclerotinia minor provided minimal results. Chelated iron, mecoprop/2,4-D/dicamba, and sod reduced the weed cover to < 5%. The efficacy of S. minor on Taraxacum officinale was evaluated three controlled environment studies. Treatments included five temperatures: 12, 16, 20, 24, and 28C and thirteen leaf wetness durations (LWD): 0 to 96 hrs, in 8-hr increments. The main effects (temperature and LWD) and interaction were significant with respect to disease severity over time. A LWD of 48 hrs at 20C and 72 to 96 hrs at 12 and 16oC was required for high disease severity.