Efficacy of triclopyr and synthetic auxin herbicide mixtures for common blue violet (Viola sororia) control

Abstract

Common blue violet is a widely distributed, perennial broadleaf that is difficult to control in lawns. Two experiments were conducted to evaluate the efficacy of synthetic auxin herbicides and their mixtures or rate for common blue violet control. A herbicide comparison experiment was conducted with treatments including a nontreated check; 2,4-D dimethylamine; 2,4-D isooctyl ester (2,4-D ester); dichlorprop (2,4-DP) ethylhexyl ester, MCPA dimethylamine; mecoprop dimethylamine; triclopyr butoxyethyl ester; quinclorac; and mixtures of triclopyr + quinclorac; 2,4-D ester + 2,4-DP; 2,4-D ester + triclopyr; 2,4-D ester + 2,4-DP + triclopyr. All herbicides were applied at 1.12 kg ae ha−1 except quinclorac (0.84 kg ha−1). Additionally, a triclopyr dose-response experiment was conducted using rates of 0, 0.14, 0.28, 0.56, 0.84, and 1.12 kg ha−1. Epinasty ranged from 80% to 99% at 21 d after application for triclopyr-containing treatments and no more than 28% for all other treatments. Plant mass from harvest and regrowth data from the comparison experiment indicated triclopyr-containing treatments provided the highest common blue violet control. Mixtures containing triclopyr did not differ from triclopyr alone, indicating there was no added effect between herbicide mixtures. The triclopyr dose-response experiment confirmed triclopyr efficacy across data collection types. As triclopyr dose increased, violet epinasty increased and chlorophyll content and dry weight decreased. Triclopyr applied at 0.81 kg ha−1 or greater concentration provided 75% or greater control, as indicated by regrowth data. Many herbicides containing triclopyr are registered for use in turf, but most apply a concentration not greater than 0.56 kg ha−1 triclopyr when applied at the high label rate. Thus, to achieve good (75%) common blue violet control, turf managers should select products that contain triclopyr and apply doses of at least 0.81 kg ha−1 when used according to the label.

Distribution, characterization and chemical management of noxious shrub weed (Dichapetalum stuhlmannii Engl) in cashew in southeastern Tanzania

“…The potential efficacy of triclopyr on D. Stuhlmannii was exhibited at a tender growth stage and at a double and triple spraying frequency. The efficacy was increasing with an increase of the application rate and frequency, complying with the results of other studies [ 33 , 62 , 63 ]. Efficacy of triclopyr on shrub weed was congruent with the efficacy on Cyperus sp.…”

“…Efficacy of triclopyr on shrub weed was congruent with the efficacy on Cyperus sp. In Rice [ 6 , 63 ], Viola sororia Wilding Lawns [ 33 ] and Cynodondactylon on Turf [ 64 ]. Triclopyr work through selectivity of woody and herbaceous broadleaf plants, systemic movement and Auxin mimicking [ 53 , 65 ].…”

“…The tank mixture surpassed the efficacy of single triclopyr herbicide, which indicate the possible synergistic effect of glyphosate plus triclopyr. The synergism of glyphosate and triclopyr have been observed on different weed species [ 20 , 33 , 70 ]. In addition, the synergism of glyphosate and other auxin mimic/synthetic auxin have been reported in various weeds management practices [ 55 , [71] , [72] , [73] ].…”

“…A split plot in a randomized complete block design with three replications was used per experiment field and repetition. Weed damage data were collected by scoring on six selected shrub stools (densely canopy) per plot at an interval of 7 days for five score rounds using a modified scale of Patton et al [ 33 ], as shown in Table 2 . Then, the weed damage scores were subjected to equation (1) below; …”

Sensibilidade de plantas de milho aos herbicidas dicamba e triclopyr

“…O triclopyr (ácido 3,5,6-tricloro-2-piridiloxiacético) é um herbicida auxínico, sistêmico, pertencente ao grupo químico dos ácidos carboxílicos. Este herbicida age da mesma forma que as auxinas naturais, porém, quando aplicados em doses maiores, causa ação herbicida nas plantas sensíveis (Patton et al, 2020). Nestas plantas, o herbicida causa intensa divisão celular, formando tumores, desenvolvimento de raízes aéreas, multiplicação e engrossamento de raízes e caules.…”