Landscape palms were surveyed for cold damage 8 to 10 months after the coldest weather episode recorded this century in the New Orleans, La., area. Fourteen genera and 21 species of palms totaling 9039 individuals were surveyed and assigned to one of three condition categories within six geographic areas. Area 1, north of Lake Pontchartrain, was not a reliable area for the majority of the 21 species found. South of Lake Pontchartrain, areas 2-6 were considered statistically better for overall palm survival, with area 3 best followed by areas 4, 2, 5, and 6. Although species survival depended somewhat on area, 10 species were found to be statistically reliable south of Lake Pontchartrain: Brahea armata, Chamaedorea microspadix, Phoenix canariensis, Rhapidophyllum hystrix, Sabal mexicana, S. minor, S. palmetto, Sabal spp., Sabal spp. seedlings, and Trachycarpus fortune;. Two species, Phoenix reclinata and Phoenix spp., were found to be marginal and seven species were found to be unreliable: Butia capitata, Chamaerops humilis, Livistona chinensis, Rhapis excelsa, Syagrus romanzoffiana, Washingtonia filifera, and W. robusta. Due to low individual numbers, survival for three species could not be reliably estimated: Arenga engleri, Phoenix dactyfifera, and Serenoa repens.
Severn C. Doughty, Daniel J. Gill, and David C. Blouin
Donnie K. Miller, Thomas M. Batts, Josh T. Copes, and David C. Blouin
Commercialization of crops tolerant to application of 2, 4-dichlorophenoxyacetic acid (2,4-D) and dicamba is a cause of major concern for sweetpotato (Ipomoea batatas) producers regarding potential negative impacts due to herbicide drift or sprayer contamination events. A field study was initiated in 2016 and repeated in 2017 to assess impacts of reduced rates of combinations of glyphosate with 2,4-D or dicamba on sweetpotato growth and production. Reduced rates of 1/10x, 1/33x, 1/66x, and 1/100x of a 1x rate of glyphosate at 1 lb/acre plus 2,4-D choline at 0.94 lb/acre and glyphosate at 1 lb/acre plus diglycolamine salt of dicamba at 0.5 lb/acre were applied to ‘Beauregard’ sweetpotato at 10 or 30 days after transplanting. With respect to visual injury, in general glyphosate plus dicamba proved to be more injurious than glyphosate plus 2,4-D, especially within the lower rate range. In most cases injury was greater at the later application timing. In either case, typical hormonal herbicide symptomology was quite evident 35 days after application. With respect to U.S. No. 1 and total (U.S. No. 1, canner, and jumbo grade) sweetpotato yield, greatest negative impact was observed with herbicide application at the upper rate range, particularly the 1/10 and 1/33x rates, and at the later application timing regardless of herbicide applied.