Location: Sugarcane ResearchTitle: Bermudagrass: Spring weed control programs and biotype research) Author
Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 4/10/2013
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Research conducted from 2008 through 2012 evaluated bermudagrass control with Sencor (metribuzin) and Command (clomazone) plus Direx (diuron). Averaged across experiments, bermudagrass was controlled 54, 41, and 43% four weeks after Sencor application at 3 lb/A in mid-February, early-March, and mid-March, respectively; Command plus Direx at 3.3 pt + 2.5 qt/A controlled bermudagrass an average of 75, 58, and 55%, respectively. Six weeks after the mid-February application, control was 34% for Sencor and 61% for Command plus Direx. Sencor did not injure sugarcane, but whitening/bleaching and height reduction was observed when Command plus Direx was applied after sugarcane had emerged. Sugarcane yield when herbicides were applied in mid-February was greater for Command plus Direx compared with Sencor (41.5 vs. 40.5 ton/A). For application in early March, sugarcane and sugar yield were greater for Sencor compared with Command plus Direx (45.4 vs. 41.5 ton/A and 11,330 vs. 10,350 lb/A). Variability was observed for bermudagrass control among experiments and was expected due to the inherent ineffectiveness of the herbicides and differences in bermudagrass infestation at application. Observations from the weed control study in respect to variability in time of bermudagrass emergence following the winter dormant period and in growth characteristics prompted additional research. Bermudagrass was collected from 13 outfield locations used by the LSU AgCenter and the USDA-ARS for sugarcane variety field trials, from four additional farm sites, and from three LSU AgCenter research stations. Collected plants, designated as biotypes, were potted for use as planting material. In April of 2011, plants established in 2-in pots were transplanted into field plots 5 x 5 feet in size. Two plants spaced 2 feet from one another were planted in the center of each plot. At 84 days after planting, bermudagrass ground cover was less than 40% for biotypes J (Pointe Coupee Parish), N (Iberia Parish), and T (Tensas Parish), but greater than 80% for biotypes A (St. Martin Parish), C and D (St. Mary Parish), F (St. James Parish), Q (West Baton Rouge Parish), and R (Iberville Parish). Bermudagrass biotypes with the greatest plant height were A, B (Iberia Parish), E (St. John Parish), and Q, R, and S (Rapides Parish) (8.1 to 12.8 inches); plant height for biotype I (Terrebonne Parish) was 3.7 inches. Total dry weight over two years was greatest for biotype A (657 g/plot) and biotype Q (623 g/plot); lowest dry matter yield was observed for biotypes J and T. In April of 2012, seedhead emergence was greatest for biotypes G (Assumption Parish), H (Lafourche Parish), I, and P (St. Mary Parish). Differences observed among the bermudagrass biotypes in growth characteristics and ability to establish may help explain variability in control and competitiveness observed in sugarcane fields in Louisiana.