Optimizing activity of herbicides at reduced rate on Emex spinosa campd. with adjuvants

In pot experiments, two adjuvants were evaluated for their efficacy in enhancing activity of five herbicides applied at reduced rates (75% of the recommended rates) on Emex spinosa at the cotyledon-leaf and at the two- to four- leaf stage. Herbicides (at recommended rates) including fluroxypyr+MCPA at 450 g a.i. ha-1, carfentrazone-ethyl at 20 g a.i. ha-1, bromoxynil+MCPA at 450 g a.i. ha-1, thifensulfuron-methyl at 75 g a.i. ha-1 and tribenuronmethyl at 75 g a.i. ha-1 alone and tank mixed at reduced rates with adjuvants, namely, alkyl ether sulphate sodium salt at 625 mL ha-1 or fatty alcohol ethoxylate at 375 mL ha-1. Addition of the adjuvants to reduced rates of fluroxypyr+MCPA and carfentrazone-ethyl, increased their efficacy with 100% mortality and biomass reduction of E. spinosa at the cotyledon- leaf stage and at the two- to four- leaf stage which was similar to their recommended rates without the adjuvants except for carfentrazone-ethyl at a reduced rate without adjuvants at the two- to four- leaf stage. Bromoxynil+MCPA at reduced rates with alkyl ether sulphate sodium salt also gave 100% control of E. spinosa over weedy check at the two- to four- leaf stage. Both the adjuvants generally increased the efficacy of tribenuron-methyl at reduced rates when sprayed at both leaf stages. These findings suggest that the use of adjuvants may increase the efficacy of the above mentioned herbicides against E. spinosa and it may be incorporated in an integrated weed management program.

Download Full-text

Optimization of Application Efficacy for POST Herbicides with Adjuvants on Three-Cornered Jack (Emex australis Steinheil) in Wheat

Weed Technology ◽

10.1614/wt-d-11-00130.1 ◽

2013 ◽

Vol 27 (3) ◽

pp. 437-444 ◽

Cited By ~ 6

Author(s):

Muhammad Mansoor Javaid ◽

Asif Tanveer

Keyword(s):

Sodium Salt ◽

Yield Components ◽

Wheat Yield ◽

Field Studies ◽

Alcohol Ethoxylate ◽

Alkyl Ether ◽

Maximum Increase ◽

Ether Sulfate ◽

Yield And Yield Components ◽

Tribenuron Methyl

Field studies were conducted to evaluate POST herbicides with adjuvants for the control of three-cornered jack in winter wheat. The herbicides evaluated were fluroxypyr 9.7% w/w + MCPA 38.8% w/w (formulated mixture [450 g ai ha−1]), carfentrazone-ethyl (20 g ai ha−1), bromoxynil 26.8% w/w + MCPA 40.0% w/w (formulated mixture [450 g ai ha−1]), thifensulfuron-methyl (75 g ai ha−1), and tribenuron-methyl (75 g ai ha−1), applied alone or tank mixed with the adjuvants alkyl ether sulfate sodium salt (625 mL ha−1) or fatty alcohol ethoxylate (375 mL ha−1). The addition of adjuvants to carfentrazone-ethyl resulted in > 94% control of three-cornered jack. Both adjuvants enhanced the efficacy of all herbicides for control of three-cornered jack, except thifensulfuron-methyl. However, a maximum increase in phytotoxicity on three-cornered jack was achieved with the addition of either adjuvant to tribenuron-methyl compared with herbicides used alone. Bromoxynil + MCPA and carfentrazone-ethyl gave maximum wheat yield and yield components.

Download Full-text

Effectiveness of Herbicides for Control of Hairy Vetch (Vicia villosa) in Winter Wheat

Weed Technology ◽

10.1614/wt-d-14-00139.1 ◽

2015 ◽

Vol 29 (3) ◽

pp. 509-518 ◽

Cited By ~ 11

Author(s):

William S. Curran ◽

John M. Wallace ◽

Steven Mirsky ◽

Benjamin Crockett

Keyword(s):

Winter Wheat ◽

Weed Management ◽

Acetolactate Synthase ◽

Oxidase Inhibitor ◽

Management Program ◽

Integrated Weed Management ◽

Hairy Vetch ◽

Synthetic Auxins ◽

Als Inhibitors ◽

Tribenuron Methyl

A field experiment was conducted in 2009–2010 at Pennsylvania and Maryland locations, and repeated it in 2010–2011 to test the effectiveness of POST-applied herbicides at fall and spring timings on seeded hairy vetch in winter wheat. A total of 16 herbicide treatment combinations was tested that included synthetic auxins, acetolactate synthase (ALS) inhibitors, and a protoporphyrinogen oxidase inhibitor. Spring applications tended to be more effective than fall applications. Among synthetic auxins, clopyralid (105 g ae ha−1) and treatments containing dicamba (140 g ae ha−1) were effective at both timings, resulting in greater than 90% hairy vetch control at wheat harvest. Pyroxsulam and prosulfuron applied at 18 g ai ha−1 provided the most effective hairy vetch control (> 90%) at both application timings among ALS inhibitors. Spring applications of several herbicides provided moderate (> 80%) to high (> 90%) levels of hairy vetch control, including: 2,4-D amine (140 g ae ha−1), mesosulfuron-methyl (15 g ai ha−1), tribenuron-methyl (13 g ai ha−1), and thifensulfuron/tribenuron-methyl treatments (16 and 32 g ai ha−1). Winter wheat injury was evaluated, but symptoms were negligible for most treatments. Winter wheat yields declined with increasing hairy vetch biomass. Fall herbicides may be prioritized to reduce hairy vetch competition during the fall and early spring growing season. Our research has established that several synthetic auxin and ALS-inhibiting herbicides, applied POST in fall or spring, can be safely used in winter wheat to control hairy vetch in an integrated weed management program.

Download Full-text

Herbicide Timing and Rate Effects on Weed Management in Three Herbicide-Resistant Canola Systems

Weed Technology ◽

10.1614/wt-03-188r1 ◽

2004 ◽

Vol 18 (4) ◽

pp. 1006-1012 ◽

Cited By ~ 7

Author(s):

K. Neil Harker ◽

George W. Clayton ◽

John T. O'Donovan ◽

Robert E. Blackshaw ◽

F. Craig Stevenson

Keyword(s):

Weed Control ◽

Weed Management ◽

Management Practices ◽

Integrated Weed Management ◽

Weed Biomass ◽

Herbicide Resistant ◽

Leaf Stage ◽

Rate Effects ◽

Herbicide Timing ◽

Weed Removal

Herbicide-resistant canola dominates the canola market in Canada. A multiyear field experiment was conducted at three locations to investigate the effect of time of weed removal (two-, four-, or six-leaf canola) and herbicide rate (50 or 100% recommended) in three herbicide-resistant canola systems. Weeds were controlled in glufosinate-resistant canola (GLU) with glufosinate, in glyphosate-resistant canola (GLY) with glyphosate, and in imidazolinone-resistant canola (IMI) with a 50:50 mixture of imazamox and imazethapyr. Canola yields were similar among the three canola cultivar–herbicide systems. Yields were not influenced by 50 vs. 100% herbicide rates. Timing of weed removal had the greatest effect on canola yield, with weed removal at the four-leaf stage giving the highest yields in most cases. Percent dockage was often greater for GLU and IMI than for GLY. In comparison with the other treatments, dockage levels doubled for GLU after application at 50% herbicide rates. The consistency of monocot weed control was usually greater for GLY than for GLU or IMI systems. However, weed biomass data revealed no differences in dicot weed control consistency between IMI and GLY systems. Greater dockage and weed biomass variability after weed removal at the six-leaf stage or after low herbicide rates suggests higher weed seed production, which could constrain the adoption of integrated weed management practices in subsequent years.

Download Full-text

Effects of Repeat Annual Applications of Dichlobenil on Weed Populations and Yield Components of Cranberry

Weed Technology ◽

10.1614/wt-03-125r1 ◽

2004 ◽

Vol 18 (3) ◽

pp. 648-657 ◽

Cited By ~ 4

Author(s):

Hilary A. Sandler ◽

Joanne Mason ◽

Wesley R. Autio ◽

Thomas A. Bewick

Keyword(s):

Weed Management ◽

Fruit Set ◽

Negative Impact ◽

Field Studies ◽

Management Program ◽

Integrated Weed Management ◽

Leaf Biomass ◽

Herbicide Application ◽

Weed Density ◽

Marketable Fruit

To address grower concerns that repeated use of dichlobenil could negatively affect cranberry productivity, field studies were conducted at two commercial farms in either high weed density (HW) or low weed density (LW) areas. Data from 4 yr of repeat annual applications of 0, 1.8, and 4.5 kg ai/ha dichlobenil indicated minimal negative impact on cranberry vines. Herbicide application did not affect upright productivity, leaf biomass production, percent fruit set, or other yield parameters adversely; in addition, no improvement in these parameters was noted. Although the interaction of herbicide application with weed density on cranberry root length varied with sampling date, no consistent trend (adverse or positive) was seen. The presence of weeds, rather than herbicide application, was the important determinant of yield. Vines in LW areas produced more marketable fruit and had higher percentage of fruit set than vines growing in HW areas. Repeat annual applications of dichlobenil on commercial cranberry beds may be considered as part of a viable integrated weed management program with no adverse effect on crop growth or yield.

Download Full-text

Toleransi Galur Harapan Padi Sawah (Oryza sativa L.) pada Persaingan dengan Gulma Echinochloa crus-galli

Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy) ◽

10.24831/jai.v44i2.13476 ◽

2016 ◽

Vol 44 (2) ◽

pp. 111

Author(s):

Usman , ◽

Bambang Sapta Purwoko ◽

Muhamad Syukur ◽

Dan Dwi Guntoro

Keyword(s):

Weed Management ◽

Dry Matter ◽

Oryza Sativa L ◽

Management Program ◽

Integrated Weed Management ◽

Yield Reduction ◽

Barnyard Grass ◽

Main Plot ◽

Productive Tiller ◽

Dry Matter Weight

ABSTRACT Barnyard grass (Echinochloa crus-galli (L.) P. Beauv.) is a major weed competitor to rice production in Indonesia. In order to develop integrated weed management program, a research to select competitive rice lines to E. crus-galli was conducted in a green house of Indonesian Centre of Agricultural Biotechnology and Genetic Resource Research and Development Bogor. The research design was split plot with four replications, E. crus-galli was designed as the main plot (rice without E. crus-galli compared rice with four E. crus-galli per pot), and the sub-plots were 25 genotypes (23 lines, 1 tolerant variety and 1 sensitive variety). Level of tolerance was determined by the reduction percentage of grains weight, the number of productive tillers and dry matter weight. The results showed that rice competition with E. crus-galli reduced plant height, productive tiller numbers, filled spikelet numbers per panicle, dry matter weight and dry grain weight. Three lines, i.e., IR10L-155, IR10L-133 and BIO-R84-1 were classified as tolerant, 19 lines were moderate and 3 lines were sensitive to E. crus-galli competition. Keywords: Barnyard grass, competition, sensitive line, yield reduction

Download Full-text

Effective Preemergence Herbicides for Rigid Ryegrass (Lolium rigidum Gaud.) Control in Irrigated Bread Wheat (Triticum aestivum L.)

Journal of Agricultural Science ◽

10.5539/jas.v10n4p79 ◽

2018 ◽

Vol 10 (4) ◽

pp. 79 ◽

Cited By ~ 1

Author(s):

Abbes Tanji ◽

Mohamed Boutfirass

Keyword(s):

Bread Wheat ◽

Weed Management ◽

Heavy Rain ◽

Triticum Aestivum L ◽

Management Program ◽

Integrated Weed Management ◽

Shoot Biomass ◽

Herbicide Treatments ◽

Rigid Ryegrass ◽

Preemergence Herbicides

Three on-farm weed control experiments were conducted in irrigated bread wheat in the Doukkala perimeter, Morocco, in 2015-16 and 2016-17 in order to study the efficacy of 4 pre-emergence herbicide treatments for controlling rigid ryegrass that is resistant to 13 post-emergence herbicides. Results showed that 3 pre-emergence herbicides [i) chlorotoluron, 2000 g/ha + isoxaben, 74.8 g/ha; ii) prosulfocarb, 4000 g/ha; iii) prosulfocarb, 2000 g/ha + s-metolachlor, 300 g/ha] reduced rigid ryegrass shoot biomass by > 90% 1 to 3 months after treatments (MAT). Pendimethalin (1320 g ha-1) achieved 83-99% rigid ryegrass control 1 to 3 MAT. The four herbicide treatments were safe on wheat in one experiment, but reduced wheat density in 2 other experiments due to heavy rain (about 100 mm) after herbicide treatments and before crop emergence. Grain yields in sprayed plots ranged from 6.6 to 9.8 t ha-1, 4.4 to 7.4 t ha-1, 7.3 to 8.9 t ha-1 in experiments 1 to 3, respectively. Straw yields were 11.4 to 15.4, 9.6 to 15.8, and 10.1 to 14.5 t ha-1 in the 3 experiments, respectively. These preemergence herbicides need to be used by wheat growers as part of an integrated weed management program. Further research is needed to explore ways to avoid wheat injury, that could be occasionally caused by heavy rain or irrigation, after preemergence herbicide application and before crop emergence.

Download Full-text

Allelopathic Effects of Aqueous Extracts of Sorghum (Sorghum bicolor L. Moench) on the Early Seedling Growth of Sesame (Sesamum indicum L.) Varieties and Selected Weeds

International Journal of Agronomy ◽

10.1155/2019/5494756 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

J. C. Murimwa ◽

J. T. Rugare ◽

S. Mabasa ◽

R. Mandumbu

Keyword(s):

Weed Control ◽

Seedling Growth ◽

Weed Management ◽

Economic Benefits ◽

Sesamum Indicum ◽

Management Program ◽

Integrated Weed Management ◽

Aqueous Extracts ◽

Chlorophyll Content And Fluorescence ◽

Resource Poor

Sesame (Sesamum indicum L.) production is lucrative to resource poor farmers in marginalised areas of Zimbabwe, although most farmers have reportedly been failing to derive maximum economic benefits from sesame production due to poor productivity. Low productivity has been attributed to several factors including challenges of weed control due to absence of registered herbicides for use in sesame in Zimbabwe. Laboratory enzyme assays were conducted using different sorghum aqueous leaf and stem extract concentrations at 0, 2.5, 5.0, 7.5, and 10.0% wv−1 to determine the effect of sorghum aqueous extracts on plant defense enzymes polyphenol oxidase (PPO), peroxidase (POD), and phenylalanine ammonia lyase (PAL) in sesame and selected weeds. Greenhouse experiments were conducted to assess the effect of sorgaab or sorgaab-Agil postemergence sprays on the seedling growth and physiology of sesame and weeds. The exposure of sesame, black jack, and goose grass to sorghum aqueous extracts caused a significant (p<0.05) concentration-dependent increase on the activity of antioxidant enzymes PAL, POD, and POD. Similarly, postemergence sprays of sole sorgaab, herbicide, and sorgaab-herbicide combination significantly (p<0.05) increased sesame and black jack seedling growth, chlorophyll content, and fluorescence but not of goose grass. From this study, it could be concluded that the allelochemicals in sorghum aqueous extracts were not effective at inhibiting the growth and physiological processes of sesame and the weeds. Therefore, resource-poor farmers cannot rely on sorgaab to control weeds in sesame but there is a need to integrate weed control options to form an effective integrated weed management program.

Download Full-text

Chaff collection reduces seed dispersal of wild oat (Avena fatua) by a combine harvester

Weed Science ◽

10.1614/ws-03-109r2 ◽

2005 ◽

Vol 53 (4) ◽

pp. 465-470 ◽

Cited By ~ 49

Author(s):

Steven J. Shirtliffe ◽

Martin H. Entz

Keyword(s):

Seed Dispersal ◽

Weed Management ◽

Management Program ◽

Avena Fatua ◽

Integrated Weed Management ◽

Wild Oat ◽

Collection System ◽

Oat Seeds ◽

Combine Harvester ◽

Combine Harvesters

Combine harvesters have the potential to disperse weed seeds great distances. Reducing this dispersal may be important in an integrated weed management system. The objectives of this study were to determine the distance that wild oat seeds are dispersed by a combine harvester and the effect of chaff collection on combine harvester seed dispersal. This was measured by sampling wild oat seeds at varying distances behind a combine equipped with a removable chaff collection system after it passed through a wild oat patch. Chaff collection consistently reduced the amount and distance that wild oat seeds were dispersed. This occurred because more than 74% of the total wild oat seed that were ejected from the combine were in the chaff. Because most of the chaff falls in a row directly behind the combine, chaff collection only affected dispersal in this area. In 1996, chaff collection reduced wild oat seed dispersal past the wild oat patch to less than 10 seeds m−2at 45 m, whereas without chaff collection, there was greater than 10 seeds m−2up to 145 m. At distances beyond 145 m, chaff collection had no significant effect on seed dispersal. Chaff collection may be an important tool in an integrated weed management program because it may slow weed invasions and reduce the expansion of weed patches.

Download Full-text

Influence of Cereal Rye Management on Weed Control in Soybean

Frontiers in Agronomy ◽

10.3389/fagro.2020.600568 ◽

2020 ◽

Vol 2 ◽

Author(s):

Kurt M. Vollmer ◽

Mark J. VanGessel ◽

Quintin R. Johnson ◽

Barbara A. Scott

Keyword(s):

Weed Control ◽

Weed Management ◽

Cover Crop ◽

Management Program ◽

Weed Suppression ◽

Integrated Weed Management ◽

Weed Species ◽

Delayed Effect ◽

Cereal Rye ◽

Winter Annual

Cereal rye as a cover crop is often used to improve soil health and as part of integrated weed management programs. Despite this, cereal rye biomass is often not managed for optimal weed suppression. This study evaluated the effects of managing cereal rye as part of an integrated weed management strategy in soybean. Factors consisted of levels of cereal rye management (no cereal rye, no nitrogen, or 20 kg/ha of nitrogen); cereal rye termination timing (20 or 10 d before soybean planting); and residual herbicide treatment applied at cereal rye termination (with or without). Winter annual weed control with cereal rye was generally greater compared to no cereal rye. Winter annual weed control was consistently better when cereal rye was terminated at 20 d before soybean planting compared to 10 d; while summer annual weed control was improved if termination was delayed. Effect of cereal rye management on summer annual weed control varied by weed species. In the absence of residual herbicides, Palmer amaranth control responded to the different levels of cereal rye management. However, morningglory spp. only responded to rye with supplemental N applications. Large crabgrass control was similar for treatments containing cereal rye, regardless of nitrogen input. Our results demonstrate the importance of cover crop management when incorporating cereal rye into an integrated weed management program for soybean.

Download Full-text

Tank Mix of Saflufenacil with Glyphosate and Pendimethalin for Broad-spectrum Weed Control in Florida Citrus

HortTechnology ◽

10.21273/horttech.21.5.606 ◽

2011 ◽

Vol 21 (5) ◽

pp. 606-615 ◽

Cited By ~ 6

Author(s):

Megh Singh ◽

Mayank Malik ◽

Analiza H.M. Ramirez ◽

Amit J. Jhala

Keyword(s):

Weed Control ◽

Weed Management ◽

Field Experiments ◽

Management Program ◽

Integrated Weed Management ◽

Control Efficacy ◽

Citrus Production ◽

Herbicide Mixture ◽

Florida Citrus ◽

Citrus Trees

Citrus (Citrus spp.) is one of the most important crops in Florida agriculture. Weed control is a major component in citrus production practices. If not controlled, weeds may compete with citrus trees for nutrients, water, and light and may also increase pest problems. Herbicides are an important component of integrated weed management program in citrus. Saflufenacil, a new herbicide registered for broadleaf weed control in citrus, can be applied alone or in a tank mix with other herbicides to improve weed control efficacy. A total of six field experiments were conducted in 2008 and 2009 to evaluate the efficacy of saflufenacil applied alone or in a tank mix with glyphosate and pendimethalin for weed control. In addition, experiments were also conducted to evaluate phytotoxicity of saflufenacil applied at different rates and time intervals in citrus. The results suggested that saflufenacil applied alone was usually effective for early season broadleaf weed control; however, weed control efficacy reduced beyond 30 days after treatment (DAT) compared with a tank mix of saflufenacil, glyphosate, and pendimethalin. For example, control of weeds was ≤70% when saflufenacil or glyphosate applied alone compared with tank mix treatments at 60 and 90 DAT. Addition of pendimethalin as a tank mix partner usually resulted in better residual weed control compared with a tank mix of saflufenacil and glyphosate, and this herbicide mixture was comparable with grower's adopted standard treatment of a tank mix of glyphosate, norflurazon, and diuron and several other tank mix treatments. Saflufenacil applied once in a season at different rates or even in sequential applications did not injure citrus trees when applied according to label directions. It is concluded that with its novel mode of action, saflufenacil tank mixed with glyphosate and pendimethalin would provide citrus growers with another chemical tool to control broadleaf and grass weeds.

Download Full-text