|ISAKEIT, THOMAS - Texas A&M University|
|COLLINS, DELROY - Texas A&M University|
|ROONEY, WILLIAM - Texas A&M University|
Submitted to: Plant Disease Management Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2013
Publication Date: 3/11/2013
Citation: Isakeit, T., Collins, D.D., Rooney, W.L., Prom, L.K. 2013. Effect of fungicides on the reaction of sorghum hybrids to anthracnose in Burleson County, Texas, 2012. Plant Disease Management Reports. 7:FC044.
Interpretive Summary: Grain mold and anthracnose are two important diseases of sorghum. In this study, three fungicides Headline, Quilt Xcel, and Topguard were sprayed on two sorghum hybrids NC+7R34 and Warner W851-DR to determine their effects in controlling these two diseases. Frequent rains during flowering to grain maturity significantly increased the levels of disease in the field. Averaged across the hybrid NC+7R34, plots treated with the fungicide Headline had less anthracnose than control plots. Fungicide treatments did not reduce grain mold infection on both hybrids. Warner W851-DR had less anthracnose but more grain mold than NC+7R34. Additional studies with these and other fungicides will be conducted to determine whether fungicides can be used to control grain mold/weathering and anthracnose.
Technical Abstract: The use of three fungicides to control grain mold/weathering and anthracnose on two sorghum hybrids NC+7R34 and Warner W851-DR was conducted during the 2012 growing season. Three fungicides Headline, Quilt Xcel, and Topguard were used. On May 26, plots were inoculated by putting 10 Colletotrichum sublineolum colonized seeds into the whorls of plants. Fungicides were applied on June 1 to the middle two rows with a CO2 backpack sprayer, at 30 psi in a spray volume of 15 gal/A, using Teejet DG 80015VS flat fan tips. Four nozzles, spaced 19 in. apart, treated the two rows. The spray solution included 0.125% Induce, a nonionic wetter and spreader adjuvant. The field was furrow irrigated as needed. Disease pressure was high because of frequent rainfall (4.38 in. over 15 days from 8 Jun, to 19 Jul ranging from 0.02 in. to 0.80 in. per day). Averaged over the hybrids, Headline treatment had less (P=0.001) anthracnose than the control or other fungicide treatments. Headline treatment reduced the anthracnose in the susceptible hybrid NC+7R34, but not the resistant Warner W851-DR, in comparison with the control (P=0.01). The fungicide treatments did not reduce the grain mold infection in both hybrids. Warner W851-DR had less anthracnose, but more grain mold, than NC+7R34 (P=0.001). There were no significant effects of fungicide or hybrid on grain yield. The grain mold severity of Warner W851-DR was greater (P=0.001) than that of NC+7R34, which was the opposite observation of experiments from previous years.