Wide Screening of Germplasm for Herbicide Tolerance in Peanuts

During the summer and fall 2014, greenhouse studies were conducted to evaluate the tolerance of peanut breeding lines Pl-152146, Pl-356004, Pl-371521, and Pl-372271 and commercial cultivars Florida-07 and Georgia-OGG to several postemergence herbicides. The experiments were dose-response studies using 5 different rates of 2,4-D amine, dicamba, glufosinate, paraquat, and flumioxazin. Peanut injury and dry weight reductions were determined. 
The response of the peanut lines to increasing rates differed depending on the herbicide used. Therefore, results were analyzed using linear, exponential rise to a maximum (two parameters) and rectangular hyperbola (two parameters) models for injury (Table 1) and linear and exponential decay models (two and three parameters, respectively) for dry weight (DW) (Table 2). Pl-152146 exhibited one of the lowest rates of change (parameter m) in injury (Table 1) and DW (Table 2) in response to increasing rates of all herbicides. Conversely, Pl-371521 had the greatest response rate for injury and dry weight reduction (DWR) for all herbicides, except dicamba. Pl-356004 and Pl-372271 were the lines that suffered more injury and lost more DW when dicamba rate increased (Tables 1 and 2). Florida-07 and Georgia-OGG were consistently more tolerant than was Pl-371521 for all herbicides, but they were not as tolerant as Pl-152146 in all cases.