Comparing peanut seed vigor and planting date for physiological plant response for flumioxazin herbicide when subjected to differing environmental conditons

Data was analyzed separately by location in SAS 9.4. Both locations noted minial differences with respect to electron transport in each year. Peanuts at Ty Ty also noted no differences in PSII, yet tlumioxazin was noted to be lower than the NTC at the 284 growing degree day mark of plant date 3. The tlumioxazin treated peanuts were also noted to have lower photosynthetic rate when compared to the NTC at the 271 and 485 growing degree day mark of plant date 2. Finally, numerous differences were noted in Plains with respect to the peanut photosynthetic rate. During plant date 1, differences were recorded at 252 and 556 growing degree days in which tlumioxazin treated plants noted a lower photosynthetic rate than the NTC. Plant date 2 plants noted differences at all 4 measurements. These differences can be explained as Plains had a significant rainfall event in which soil surface tlumioxazin was splashed onto growing plant matter injuring the plant, therefore reducing the photosynthetic rate. Stand counts were not affected, while plant diameter did have treatment differences in Ty Ty at plant date 2 and 3, and Plains at plant date 3. 
Though differences were noted for PSII quantum yield and photosynthesis, a trend was not noted, indicating that tlumioxazin is safe to apply as a PRE herbicide in peanut production. Though injury may be noted at specific times and after rainfall events with exposed green plant matter, this injury is transient and will not affect crop yield. 
Further research is currently being conducted investigating the effects of tlumioxazin on peanut development. Flumioxazin at multiple rates and at different application timings studies are being conducted at numerous locations. Stand counts, plant diameter, and percent visual injury are being recorded.