| dc.description.abstract | Smutgrass (Sporobolus indicus) is a non-native perennial weed that is problematic due to its poor palatability to cattle and its difficulty to control once established. Currently there is limited literature on the effectiveness of labeled herbicide options, other than hexazinone, on smutgrass and injury to forages. The first objective of this research was to evaluate labeled options for controlling smutgrass, and to observe the most effective options over seasonal applications. The second object was to evaluate pre-emergent herbicides and hexazinone for the control of smutgrass germinating from seed. Lastly, the third objective was to evaluate the use of UAV mounted RGB and NIR spectroscopy for the identification and biomass estimation of smutgrass. Applications of hexazinone, nicosulfuron + metsulfuron-methyl, and glyphosate + imazapic were the most effective treatments, while quinclorac had very little activity on smutgrass. Common bermudagrass (Cynodon dactylon) forage in all treatments recovered fully by 3 months after application. Hexazinone, nicosulfuron + metsulfuron methyl, glyphosate and imazapic were observed over spring, summer, and fall applications. Summer applications of hexazinone resulted in the highest level of control, while spring treatments provided the least control. Treatments of hexazinone and glyphosate applied in the summer incurred the greatest amount of smutgrass control, while fall applications sustained the least forage injury. Results from the pre-emergent study indicate that treatments of indaziflam and hexazinone provide adequate control of germinating smutgrass seedlings in the greenhouse at 0.25, 0.5, and 0.75X rates of the lowest recommended labeled rate for grass seedling control. Indaziflam treatments did not allow for any visible tissue to germinate, hexazinone fully controlled the germinating seedlings by 21 DAT, while pendimethalin significantly reduced seedling numbers at the 0.50 and 0.75X rates.
Smutgrass was successfully identified in a bermudagrass pasture in imagery captured by a UAV equipped with consumer grade cameras. OBIA and SfM technique image analysis using a RGB and NIR imagery couple with CHM were used to delineate areas containing smutgrass. Furthermore, regression analysis indicated a relatively poor relationship (R2 =0 .38) of pixel coverage to smutgrass biomass. | en |
