Evaluation of Florpyrauxifen-Benzyl Herbicides for Control on Common Weeds in Transplanted Rice

The research to test the effectiveness of the herbicide Florpyrauxifen-Benzylin in controlling weeds in rice was carried out in Sragen, Central Java. March to August 2021. The herbicides tested are: T1) Florpyrauxifen-Benzyl 400 ml/ha, T2) Florpyrauxifen-Benzyl 600 ml/ha, T3) Florpyrauxifen-Benzyl 800 ml/ha, T4) Florpyrauxifen-Benzyl 1000ml/ha, T5) Aryloxyphenoxy propionate 800 ml/ha, T6) Penoxsulam 800 ml/ha, T7) Natrium Byspiribac 300 ml/ha T8) Metsulfuron Methyl, T9) Hand Weeding and T10) Untreated. The herbicides were applied with the help of a knapsack sprayer by using a T-jet nozzle. The calibration of the knapsack sprayer was done by spraying on a non-experimental area. The volume of water used for spray was 300 L per ha. The results showed that the application of florpyrauxifen-benzyl in various doses did not show toxicity to rice plants. application of florpyrauxifen-benzyl starting at a dose of 600 ml/ha had the same effectiveness in controlling weeds as companion herbicides. At the end of the study, E. crus-galli and L. chinensis still seemed to dominate all plots in all herbicide applications.

Seletividade e eficácia de herbicidas aplicados à cultura do trigo

As plantas daninhas ocasionam efeitos negativos na produtividade e na qualidade dos grãos da cultura do trigo quando não controladas de modo eficiente. Assim sendo, objetivou-se com os trabalhos avaliar a seletividade e a eficácia de herbicidas aplicados para o manejo de plantas daninhas infestante da cultivar de trigo TBIO Sinuelo. Foram instalados dois experimentos, um para avaliar a seletividade e outro a eficácia de herbicidas aplicados em trigo, em blocos casualizados, com quatro repetições. Os tratamentos testados foram: iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, clodinafope-propargil, [bentazon + imazamox], saflufenacil, bentazon, carfentrazone-ethyl, imazamox, pendimethalin, [sulfentrazone + diuron], mais duas testemunhas uma capinada e outra infestada. Os herbicidas que ocasionaram as maiores injúrias ao trigo foram o imazamox e a mistura comercial de [bentazon + imazamox] com fitotoxicidade próxima a 50%. A aplicação da mistura comercial de [sulfentrazone + diuron] demonstrou a maior produtividade de grãos do trigo. O uso de clodinafope-propargil e pyroxsulam apresentaram os melhores controles de Lolium multiflorum, com 100 e 98,25%, aos 21 dias após a aplicação dos tratamentos, respectivamente. Ocorreu controle acima de 90% de Raphanus raphanistrum com uso de iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, [bentazon + imazamox], saflufenacil, bentazon e carfentrazone. O clodinafope-propargil demonstra o maior controle para o azevém e o iodosulfuron-ethyl, pyroxsulam, metsulfurom-metílico, 2,4-D, saflufenacil e carfentrazone para o nabo. O pyroxsulam foi o tratamento que demonstrou, nos dois experimentos, os melhores resultados para os componentes da produção, especialmente para a produtividade da cultura.

Novel Encapsulated Herbicide Delivery Mechanism: Its Efficacy in Mimosa Bush (Vachellia farnesiana) Control

Mimosa bush (Vachellia farnesiana) is an invasive woody weed widely distributed in Australia. While it can be controlled using several mechanical and chemical techniques, this study evaluated a novel herbicide delivery mechanism that minimizes the risk of spray drift and potential non-target damage. This method, developed by Bioherbicides Australia, involves the implantation of encapsulated granular herbicides into the stem of intact plants or into the stump after cutting off plants close to ground level (cut stumps). Trials were implemented near Moree (New South Wales, Australia) on intact (two experimental runs) plants and cut stumped (two experimental runs) plants. For each trial, an untreated control plus the conventional basal bark application of a liquid formulation of triclopyr + picloram mixed with diesel was included for comparison. Encapsulated glyphosate, aminopyralid + metsulfuron-methyl, hexazinone and clopyralid were also tested in all trials. In addition, encapsulated triclopyr + picloram, and metsulfuron-methyl were included in one of the intact plant trials. Aminopyralid + metsulfuron-methyl was consistently most effective on cut stump and intact plants, whilst clopyralid provided highest mortality when applied to cut stumps and single-stemmed intact plants. Particularly for multi-stemmed intact plants, clopyralid should be applied to each stem. Overall, the highest efficacy was achieved on single stemmed plants, but with further refinement of the technique, it should be possible to achieve similar results for multi-stemmed individuals. This method resulted in a reduction in the use of herbicide and environmental contamination while significantly improving speed of treatment.

Experimental design optimization of RP-HPLC method for simultaneous estimation of metsulfuron-methyl, chlorantraniliprole and chlorimuron-ethyl residues in stems of Oryza sativa

Background The study aims to develop a chemometrics optimized D-optimal mixture design approach assisted RP- HPLC method for the determination of pesticide residues of metsulfuron-methyl, chlorantraniliprole, and chlorimuron-ethyl in the stems of Oryza sativa. Chromatographic separation was achieved on a C18 column using a mobile phase consisting of a pH 3.5 phosphate buffer and acetonitrile in the ratio 85:15. Results The optimized HPLC method gave a sharp resolution of metsulfuron-methyl, chlorantraniliprole and chlorimuron-ethyl at a retention time of 2.599 min, 3.805 min and 4.661 min receptively. Linearity was observed in the range 100‒500 µg/mL for metsulfuron-methyl (r2 = 0.999), 4‒20 µg/mL for chlorantraniliprole (r2 = 0.999) and 100‒500 µg/mL for chlorimuron-ethyl (r2 = 0.999). The developed method was validated as per ICH guidelines. Conclusion The proposed chemometrics optimized RP-HPLC method was found to be successful in the resolution of pesticide residues in the stems of O. sativa. The developed method can be applied to routine quantification of metsulfuron-methyl, chlorantraniliprole and chlorimuron-ethyl.

Herbicide Options to Control Naturalised Infestations of Cereus uruguayanus in Rangeland Environments of Australia

While there are many high profile Opuntioid cactus species invading rangeland environments in Australia, Cereus uruguayanus Ritt. ex Kiesl. has also naturalised and formed large and dense infestations at several locations. With no herbicides registered for control of C. uruguayanus in Australia, the primary aim of this study was to identify effective herbicides to control it using a range of techniques. This involved a large screening trial of twelve herbicides and four techniques, followed by a rate refinement trial for cut stump applications and another to test residual herbicides. Despite most treatments (except monosodium methylarsonate (MSMA)) taking a long time to kill plants, at least one effective herbicide was identified for basal bark (triclopyr/picloram), cut stump (aminopyralid/metsulfuron-methyl, glyphosate, metsulfuron-methyl, triclopyr/picloram, triclopyr/picloram/aminopyralid), stem injection (glyphosate, MSMA, triclopyr/picloram/aminopyralid) and foliar applications (aminopyralid/metsulfuron-methyl, MSMA, triclopyr, triclopyr/picloram/aminopyralid) due to their ability to kill both small and large plants. Ground application of residual herbicides was less conclusive with neither hexazinone nor tebuthiuron causing adequate mortality at the rates applied. This study has identified effective herbicides for the control of C. uruguayanus using several techniques, but further research is needed to refine herbicide rates and develop integrated management strategies for a range of situations and infestation sizes and densities.

Effect of Pre and Post-Emergence Herbicides on Yield, Economics and Weed Control in Linseed (Linum usitatissimum L.) Under Irrigated Medium Land Condition of Jharkhand

Linseed (Linum usitatissimum L.) production is affected by several factors, out of which weed is one of the most important factors responsible for causing tremendous loss in yield. An experiment was conducted during rabi season of 2018-2019 and 2019-2020 at Research Farm of Birsa Agricultural University, Kanke, Ranchi, Jharkhand to study the effect of pre and post-emergence herbicide on yield, economics, weed count, weed dry matter and weed control efficiency in linseed. The treatments comprised of weed management practices viz., T1-Weedy Check, T2-Hand weeding twice at 30 and 60 DAS, T3-Metribuzin 250 g/ha + Oxyflourfen 125g/ha (Pre.), T4-Pendimethalin 1 kg/ha (Pre.) fb. metsulfuron methyl 4 g/ha (Post.), T5-Imazethapyr 75 g/ha (Post.), T6-Oxyflourfen125 g/ha (Pre.), T7-Metsulfuron methyl 4 g/ha (Post.), T8-Clodinafop 60 g/ha (Post.), T9-Clodinafop 60 g/ha + metsulfuron methyl 4 g/ha (Post.) and T10-Oxadiargyl 80 g/ha (Pre.), and were replicated thrice. The research outcomes revealed that Hand Weeding twice at 30 and 60 DAS resulted in maximum seed yield (14.26, 15.66 and 14.96 q/ha), net return (Rs. 41635, 45907 and 43771/ha), in 2018-19, 2019-20 and pooled data respectively while among weed parameters hand weeding recorded minimum total weed count at 30 DAS (1.19 and 1.22 /m2) and 60 DAS (3.04 and 3.19 /m2), minimum total weed dry matter at 30 DAS (1.17 and 1.18 g/m2) and at 60 DAS (3.43 and 3.57 g/m2) and maximum weed control efficiency at 30 DAS (97.08 and 96.97%) and at 60 DAS (80.66 and 79.24%) in 2018-19 and 2019-20 respectively.

The Basis of Tolerance Mechanism to Metsulfuron-Methyl in Roegneria kamoji (Triticeae: Poaceae)

Roegneria kamoji, a perennial monocot weed that belongs to the tribe Triticeae (family: Poaceae), is an emerging problematic weed in winter wheat (Triticum aestivum) fields in China. We have previously confirmed four R. kamoji populations tolerant to acetyl-CoA carboxylase (ACCase) inhibitors, and failed control of these populations by metsulfuron-methyl was observed. The objective of this study was to characterize the level of tolerance to metsulfuron-methyl, the basis of tolerance mechanism, and cross-tolerance to acetolactate synthase (ALS) inhibitors in R. kamoji. A whole-plant dose–response assay showed that plants of all R. kamoji populations (both from wheat fields and uncultivated areas) exhibited high tolerance to metsulfuron-methyl, based on their 100% survival at 6-fold recommended field dose (RFD) and ED50 values >6.84-fold RFD, no susceptible population was found. Gene sequencing indicated that no reported amino acid substitutions associated with resistance to ALS inhibitor were found in the ALS gene among the R. kamoji populations. Pretreatment with the known cytochrome P450 monooxygenases (CytP450) inhibitor malathion reduced the ED50 values of metsulfuron-methyl in two R. kamoji populations. These populations also exhibited cross-tolerance to RFD of mesosulfuron-methyl and bispyribac-sodium. The activities of glutathione-S-transferase (GST) and CytP450 could be induced by metsulfuron-methyl in R. kamoji, which is similar to the known tolerant crop wheat. This is the first report elucidating metsulfuron-methyl tolerance in R. kamoji. The reversal of tolerance by malathion and the GST and/or CytP450 enhanced herbicide metabolism suggests that non-target-site mechanisms confer tolerance to metsulfuron-methyl in R. kamoji.