TITLE:
Interaction of Seedling Germination, Planting Date, and Flumioxazin on Peanut Physiology under Irrigated Conditions
AUTHORS:
Nicholas L. Hurdle, Timothy L. Grey, Cristiane Pilon, W. Scott Monfort, Donn G. Shilling
KEYWORDS:
Diclosulam, Flumioxazin, Peanut, Arachis hypogaea L., Photosynthesis, Electron Transport
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.11 No.12,
December
14,
2020
ABSTRACT: Diclosulam and flumioxazin applied preemergent (PRE)
results in direct peanut exposure to these herbicides prior to seedling
emergence. Flumioxazin has been reported to induce injury in adverse weather (i.e. cool-wet soil conditions) at crop
emergence. Research at Ty Ty and Plains, Georgia evaluated the physiological
effects of PRE herbicides to emerging peanut in 2018 and 2019. Peanut seed with
variable germination and different planting dates were evaluated as additional
factors. Peanut plant physiological measurements included electron transport
(ETR), net assimilation rate (Anet),
quantum yield of PSII (ΦPSII), and stomatal conductance to water
vapor (GSW). Data were obtained from V3 to R1 peanut growth stages using a
LiCOR 6800, along with stand counts and plant width measures. In 2018,
diclosulam reduced peanut ETR when measured across multiple growing degree days
(GDD) after planting, compared to the nontreated control (NTC). Flumioxazin
reduced peanut ETR compared to the NTC, at several sample timings for each
planting date. In 2018 and 2019 at both locations, flumioxazin impacted Anet less than ETR, but was
consistently similar to/or greater than the NTC. Peanut ΦPSII responded similarly as Anet at each location and yr. GSW was variable in both years; however flumioxazin treated plants had higher GSW
rates than other treated plants. Peanut stand counts, plant widths, and pod
yields noted few differences compared to the physiological measures. Though
some peanut plant physiological differences were noted when measured at varying
GDD’s after planting with the different PRE treatments, planting date, and seed
vigor, no specific trends were observed. Growers will often observe peanut
injury from flumioxazin early in the season. However, it is transient and does
not affect yield.