ANTAGONISM IS THE PREDOMINANT EFFECT OF HERBICIDE MIXTURES USED FOR IMIDAZOLINONE-RESISTANT BARNYARDGRASS (Echinochloa crus-galli) CONTROL

Abstract

-Herbicides mixtures are used in many situations without the adequate knowledge related with the effect on major target weeds. The objective of this study was to evaluate the effects of different herbicides mixtures used in irrigated rice in order to establish the adequate combinations for the prevention and management of herbicide resistance in barnyardgrass (Echinochloa crus-galli). Three experiments were performed at field conditions with all major post-emergent herbicides used in irrigated rice in Brazil. The first experiment was performed with barnyardgrass resistant to imidazolinone herbicides and herbicides applied at label rates. The second and third experiments were performed with barnyardgrass resistant and susceptible to imidazolinone herbicides applied at doses of 50 or 75% of the label rates. The occurrence of additive, synergistic and antagonistic effects was identified at 18, 18 and 64%, respectively, among the total of 50 different associations of herbicide and rates evaluated. In general, the mixture of ACCase inhibitors with ALS inhibitors, quinclorac, clomazone + propanil or thiobencarb resulted in antagonism. Sinergic mixtures were found in clomazone with propanil + thiobencarb, profoxydim with cyhalofop-butyl or clomazone, and quinclorac with imazapyr + imazapic, bispyribac-sodium or cyhalofop-butyl. The mixtures of quinclorac with profoxydim were antagonic. Rice grain yield varied according to the efficiency of weed control. Seveveral mixtures were effective for imidazolinone resistant barnyardgrass control.

2,4‐Dichlorophenoxyacetic‐N‐methylmethanamine and haloxyfop‐P‐methyl interaction: Sequential and interval applications to effectively control sourgrass and fleabane

“…To control Panicum dichotomiflorum , the interval between applications of imazethapyr and graminicides (in that order) was 5 d (Myers & Coble, 1992). The effects of antagonism that were observed can be minimized using application intervals (Matzenbacher et al., 2015), as noted in this study.…”

“…Tank‐mixing graminicides with broadleaf weed–controlling herbicides have been reported to cause antagonistic effects in grass weed control (Matzenbacher, Kalsing, Dalazen, Markus, & Merotto, 2015; Zhang, Hamill, & Weaver, 1995). An antagonistic effect was reported between clodinafop and 2,4‐D in italian ryegrass [ Lolium perenne ssp.…”

Optimising Clearfield and ExpressSun sunflower technologies for Central European conditions

“…e. crus-galli was not controlled by TBM. TM combinations of sulfonylureas with inhibitors of ACCase can cause a decrease of ACCase inhibitor efficacy and crop selectivity (Isaacs et al 2003;Kammler et al 2010;Matzenbacher et al 2015). Sunflower phytotoxicity of the TM combination of TBM + PQF was recorded in 2012, when a very cold period occurred after a very hot start to the growing season (minimum ground temperature ranged between 5°C and −5°C five days before and after application).…”

Interaction of spirodiclofen with insecticides for the control of Brevipalpus yothersi in citrus

“…Several studies have shown that the use of a combination of herbicides, insecticides, herbicides and insecticides, insecticides and fungicides, and acaricides and foliar fertilizers produces an antagonistic effect. However, studies investigating the effects of mixing acaricides with insecticides on the control of B. yothersi are lacking.…”

“…[11][12][13] Combining products may lead to degradation of these molecules, and even stimulate or inhibit a metabolic detoxification process in the target organism, which may potentiate the toxicity (synergism) or inhibit the action of one of the molecules (antagonism). 10,14 Several studies have shown that the use of a combination of herbicides, 15,16 insecticides, 17,18 herbicides and insecticides, 19,20 insecticides and fungicides, 21 and acaricides and foliar fertilizers 22 produces an antagonistic effect. However, studies investigating the effects of mixing acaricides with insecticides on the control of B. yothersi are lacking.…”