Microtubules assembly inhibitors in combination with PPO, ACCase and ALS inhibitors herbicides for the management of multiple herbicide-resistant Phalaris minor in wheat under Indo-Gangetic Plains: a threat to sustainable wheat production

Abstract

Field experiments were carried out during Rabi season 2020–21 and 2021–22 at Agronomy Research Farm, CCS HAU, Hisar, for the management of multiple herbicide-resistant Phalaris minor in wheat. Experiment was performed using randomized block design and replicated thrice with a total number of 15 treatment consisting of different combination of pre (PRE) and post-emergence (POST) herbicides. Herbicides selected in this study have different modes of action, i.e. clodinafop and pinoxaden are acetyl-CoA carboxylase (ACCase) inhibitors, sulfosulfuron, mesosulfuron, iodosulfuron and metsulfuron belongs to acetolactate synthase (ALS)/Acetohydroxy acid synthase (AHS) inhibitor group, pendimethalin and pyraxosulfone inhibits the microtubule assembly and long chain fatty acids synthesis, respectively, while metribuzin is Photosystem-II (PS-II) inhibitor and flumioxazin is from protoporphyrinogen oxidase (PPO) inhibitor group. Among different treatments, application of flumioxazin + pendimethalin fb clodinafop propargyl + metribuzin (RM) resulted in significantly lower density and dry weight of P. minor and broadleaved weeds and maximum weed control efficiency at 60 DAS. It was statistically comparable to application of flumioxazin, flumioxazin + pendimethalin, pyroxasulfone + pendimethalin fb mesosulfuron + iodosulfuron (RM), or pinoxaden + metsulfuron (TM) or clodinafop propargyl + metribuzin. Sequential application of pyroxasulfone + pendimethalin (TM) fb mesosulfuron + iodosulfuron (RM) resulted in significantly higher grain yield (5847 and 5369 kg/ha) when compared to rest of the treatments. It was statistically comparable to PRE pyroxasulfone + pendimethalin (TM) fb POST pinoxaden + metsulfuron (TM) or clodinafop propargyl + metribuzin (RM). In conclusion, pre-emergence application of pyroxasulfone + pendimethalin (TM) followed by post-emergence application of either mesosulfuron + iodosulfuron (RM), pinoxaden + metsulfuron (TM) or clodinafop propargyl + metribuzin resulted in better control of resistant P. minor and broadleaved weeds along with higher grain yield.