Broadleaf Weed Management in Grain Sorghum with Reduced Rates of Postemergence Herbicides

2,4-D is the most widely used herbicide for weed control in grain sorghum in northern Tamaulipas, Mexico. Crop injury caused by 2,4-D drift to nontarget crops commonly occurs because of prevailing high winds. Field experiments were conducted from 2001 to 2003 to evaluate an integrated weed management program in grain sorghum with alternative postemergence herbicides to 2,4-D at registered and reduced rates. Bromoxynil applied at 480 (registered rate), 360, and 240 g/ha provided excellent broadleaf weed control when adequate rainfall occurred. Prosulfuron at 14.2 g/ha applied broadcast without cultivation provided excellent weed control and sorghum yield comparable with 28.5 g/ha (registered rate). This treatment represented a 32% cost reduction and 50% reduction in herbicide input compared with prosulfuron applied at registered rate without cultivation, and 31% cost reduction compared with 2,4-D at the registered rate (590 g ae/ha) plus cultivation, considered the commercial standard.

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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.

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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.

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Integrated Weed Management Using Planting Pattern, Cultivar, and Herbicide in Dry-Seeded Rice in Northwest India

Weed Science ◽

10.1614/ws-d-13-00115.1 ◽

2014 ◽

Vol 62 (2) ◽

pp. 350-359 ◽

Cited By ~ 11

Author(s):

Gulshan Mahajan ◽

Vikas Poonia ◽

Bhagirath S. Chauhan

Keyword(s):

Grain Yield ◽

Weed Control ◽

Weed Management ◽

Field Experiments ◽

Weed Suppression ◽

Integrated Weed Management ◽

Rice Grain ◽

Planting Pattern ◽

Weed Biomass ◽

Northwest India

Field experiments were conducted in Punjab, India, in 2011 and 2012 to study the integrated effect of planting pattern [uniform rows (20-cm spacing) and paired rows (15-, 25-, and 15-cm spacing)], cultivars (PR-115 and IET-21214), and weed control treatments (nontreated control, pendimethalin 750 g ai ha−1, bispyribac-sodium 25 g ai ha−1, and pendimethalin 750 g ha−1 followed by bispyribac-sodium 25 g ha−1) on weed suppression and rice grain yield in dry-seeded rice. In the nontreated control, IET-21214 had higher grain yield than PR-115 in both planting patterns. However, such differences were not observed within the herbicide treatment. IET-21214 in paired rows, even in nontreated control, provided grain yield (4.7 t ha−1) similar to that in uniform rows coupled with the sole application of pendimethalin (4.3 t ha−1) and bispyribac-sodium (5.0 t ha−1). In uniform rows, sequential application of pendimethalin (PRE) and bispyribac-sodium (POST) provided the highest grain yield among all the weed control treatments and this treatment produced grain yield of 5.9 and 6.1 t ha−1 for PR-115 and IET-21214, respectively. Similarly, in paired rows, PR-115 in paired rows treated with sequential application of pendimethalin and bispyribac-sodium had highest grain yield (6.1 t ha−1) among all the weed control treatments. However, IET-21214 with the sole application of bispyribac-sodium produced grain yield similar to the sequential application of pendimethalin and bispyribac-sodium. At 30 days after sowing, PR-115 in paired rows coupled with pendimethalin application accrued weed biomass (10.7 g m−2) similar to the sequential application of pendimethalin and bispyribac-sodium coupled with uniform rows (8.1 g m−2). Similarly, IET-21214 with bispyribac-sodium application provided weed control similar to the sequential application of pendimethalin and bispyribac-sodium. Our study implied that grain yield of some cultivars could be improved by exploring their competitiveness through paired-row planting patterns with less use of herbicides.

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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.

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Economics of integrated weed management in herbicide-resistant canola

Weed Science ◽

10.1614/ws-05-050r1.1 ◽

2006 ◽

Vol 54 (1) ◽

pp. 138-147 ◽

Cited By ~ 12

Author(s):

Bharat M. Upadhyay ◽

Elwin G. Smith ◽

G. W. Clayton ◽

K. N. Harker ◽

R. E. Blackshaw

Keyword(s):

Weed Control ◽

Weed Management ◽

Field Experiments ◽

Production Systems ◽

Statistical Significance ◽

Integrated Weed Management ◽

Seeding Rate ◽

Herbicide Resistant ◽

Leaf Stage ◽

Weed Removal

Integrated weed management (IWM) decision strategies in herbicide-resistant canola-production systems were assessed for net returns and relative risk. Data from two field experiments conducted during 1998 to 2000 at two locations in Alberta, Canada, were evaluated. A herbicide-based experiment included combinations of herbicide system (glufosinate-, glyphosate-, and imazethapyr-resistant canola varieties), herbicide rate (50 and 100% of recommended dose), and time of weed removal (two-, four-, and six-leaf stages of canola). A seed-based experiment included canola variety (hybrid and open-pollinated), seeding rate (100, 150, and 200 seeds m−2), and time of weed removal (two-, four-, and six-leaf stages of canola). For the herbicide-based experiment, strategies with glyphosate were profitable at Lacombe, but both imazethapyr and glyphosate strategies were profitable at Lethbridge. Weed control at the four-leaf stage was at least as profitable as the two-leaf stage at both sites. For the seed-based experiment, the hybrid was more profitable than the open-pollinated cultivar, seed rates of 100 and 150 seeds m−2were more profitable than 200 seeds m−2, and weed control at the two- and four-leaf stages was more profitable than at the six-leaf stage. When risk of returns and statistical significance was considered, several strategies were included in the risk-efficient set for risk-averse and risk-neutral attitudes at each location. However, the glyphosate-resistant cultivar, the 50% herbicide rate, and weed control at four-leaf stage were more frequent in the risk-efficient IWM strategy set. The open-pollinated cultivar, 200 seeds m−2rate, and weed control at the six-leaf stage were less frequent in the set. The risk-efficient sets of IWM strategies were consistent across a range of canola prices.

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Roller Applicator for Shattercane (Sorghum bicolor) Control in Row Crops

Weed Science ◽

10.1017/s0043174500040571 ◽

1982 ◽

Vol 30 (3) ◽

pp. 301-306 ◽

Cited By ~ 10

Author(s):

Gregory L. Schneider ◽

Curt B. Koehler ◽

James S. Schepers ◽

Orvin C. Burnside

Keyword(s):

Glycine Max ◽

Sorghum Bicolor ◽

Weed Control ◽

Field Experiments ◽

Grain Sorghum ◽

Row Crops ◽

Crop Injury

Greenhouse and field experiments were conducted with a roller applicator at Lincoln, Nebraska, during 1979 and 1980. Glyphosate [N-(phosphonomethyl)glycine] concentrations of 5, 10, and 20% and carpet saturations of 50 and 75% controlled shattercane [Sorghum bicolor(L.) Moench] when applied to the top 30 cm of the plant in greenhouse research. In the field, glyphosate concentrations of 5 to 20% with a carpet saturation of 50% controlled shattercane acceptably in soybeans [Glycine max(L.) Merr.], but a concentration of 2.5% with 25% carpet saturation did not. Weed control was comparable whether speed of application was 3.2, 6.4, or 9.6 km/h. Shattercane control in grain sorghum [Sorghum bicolor(L.) Moench.] was excellent at glyphosate concentrations of 5, 10, and 20% and at carpet saturations of 50 and 75%, and sorghum injury was minimal at 25 and 50% carpet saturations. The roller applicator was compared to a ropewick applicator for shattercane control in sorghum. Excellent weed control (90% or greater) with minimal crop injury was obtained with the roller applicator at glyphosate concentrations of 10 and 20% at application speeds of 3.2 and 6.4 km/h and with the ropewick applicator with glyphosate concentrations of 35 and 50% applied at 3.2, 6.4, and 9.6 km/h.

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Integrated Management of Weeds in Direct-Seeded Rice in Cambodia

Agronomy ◽

10.3390/agronomy10101557 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1557

Author(s):

Robert Martin ◽

Bunna Som ◽

Joel Janiya ◽

Ratha Rien ◽

Sophea Yous ◽

...

Keyword(s):

Weed Control ◽

Weed Management ◽

Rice Field ◽

Field Experiments ◽

Integrated Management ◽

Weed Suppression ◽

Crop Damage ◽

Integrated Weed Management ◽

Crop Tolerance ◽

Direct Seeded

The objective of this work was to determine the value of improved establishment methods and herbicide applications as alternatives to high seeding rates to improve weed suppression in rice. Field experiments were carried out in 2010 and 2011 to determine optimal seeding rates and seeding methods with and without weed competition in wet-seeded rice. Under wet seeding conditions, drum seeding at 80 kg ha−1 was the most profitable treatment for both weed-free and unweeded rice. Although pre-emergence herbicides are beginning to be adopted in wet-seeded rice, they are seldom used in dry direct-seeded rice in Cambodia. Experiments were carried out in 2018 and 2019 to test crop tolerance and the efficacy of butachlor, oxadiazon, pendimethalin and pretilachlor applied post-sowing and pre-emergence to dry direct-seeded rice. Oxadiazon and butachlor, with the option for a post-emergence herbicide, provided effective weed control and a high grain yield in dry direct-seeded rice. Pretilachlor did not effectively control weeds under dry seeding conditions. Although pendimethalin exhibited good weed control, crop damage was a risk in poorly prepared seedbeds which typify Cambodian rice systems. With an effective integrated weed management strategy, it might be possible to safely reduce seeding rates below 80 kg ha−1 using drum or drill seeding machines.

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Weed Management Programs with Pyroxasulfone in Field Corn (Zea mays)

Weed Technology ◽

10.1017/wet.2017.39 ◽

2017 ◽

Vol 31 (4) ◽

pp. 496-502 ◽

Cited By ~ 1

Author(s):

Daniel O. Stephenson ◽

Jason A. Bond ◽

James L. Griffin ◽

Randall L. Landry ◽

Brandi C. Woolam ◽

...

Keyword(s):

Zea Mays ◽

Weed Control ◽

Weed Management ◽

Field Experiments ◽

Management Program ◽

Post Treatment ◽

Palmer Amaranth ◽

Corn Yield ◽

Field Corn ◽

Herbicide Treatment

Field experiments were conducted in Louisiana and Mississippi from 2011 through 2013 to evaluate crop injury, weed control, and yield in field corn following pyroxasulfone applied PRE and POST. Pyroxasulfone PRE or POST did not injure corn at any evaluation. Barnyardgrass control was not improved with the addition of any POST treatment to pyroxasulfone alone or atrazine plus pyroxasulfone PRE; however, all POST treatments increased barnyardgrass control to at least 95% at all evaluations following atrazine PRE. All treatments that contained a PRE followed by POST application controlled browntop millet ≥90% at all evaluations. All POST treatments increased ivyleaf morningglory control to ≥92% following atrazine or pyroxasulfone alone PRE. However, control with atrazine plus pyroxasulfone PRE was similar or greater 28 d after POST than all treatments that received a POST application. In the absence of a POST treatment, pyroxasulfone or atrazine plus pyroxasulfone PRE controlled Palmer amaranth 93 to 96% at all evaluations, but atrazine alone PRE provided 84, 82, and 66% control 7, 14, and 28 d after POST, respectively. All programs that contained a PRE followed by POST herbicide treatment controlled Palmer amaranth >90% at all evaluations. Corn yield following all treatments except atrazine alone PRE and the nontreated were similar and ranged from 10990 to 12330 kg ha−1. This research demonstrated that pyroxasulfone can be a valuable tool for weed management in a corn weed management program.

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Use of the Recirculating Sprayer to Control Tall Weed Escapes in Crops

Weed Science ◽

10.1017/s0043174500061750 ◽

1981 ◽

Vol 29 (2) ◽

pp. 174-179 ◽

Cited By ~ 5

Author(s):

D. R. Carlson ◽

O. C. Burnside

Keyword(s):

Sorghum Bicolor ◽

Weed Control ◽

Field Experiments ◽

Grain Sorghum ◽

Asclepias Syriaca ◽

Selective Method ◽

Weed Growth ◽

Crop Injury ◽

Final Treatment ◽

Three Stages

Field experiments were conducted with the recirculating sprayer (RCS) at Lincoln, Nebraska from 1974 through 1978. Different spray pressures, spray nozzles, and spray volumes with the RCS showed no significant differences in shattercane [Sorghum bicolor(L.) Moench] control or soybean [Glycine max(L.) Merr.] injury when herbicides were applied at three stages of weed growth. When shattercane was treated in a grain sorghum [Sorghum bicolor(L.) Moench] field, poor weed control and excessive crop injury occurred during treatment at the early growth stage as compared with treatments applied 2 weeks later. The final treatment date gave selective weed control in grain sorghum, but many of the shattercane heads had already developed viable seed. A weed-to-crop height differential of at least 45 cm resulted in maximum weed control with minimum crop injury. Common milkweed (Asclepias syriacaL.) control in soybeans varied considerably, but treatments giving over 80% control were glyphosate [N-(phosphonomethyl)glycine] at 1.1 to 4.5 kg/ha applied through the RCS. Other herbicides were less effective. Volunteer corn (Zea maysL.) was controlled selectively at 75 to 100% in soybeans with glyphosate or paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) when applied through the RCS. Shattercane was controlled 95 to 100% in soybeans with glyphosate at 3.4 kg/ha. Unless spray drift and splash can be prevented when using the RCS, glyphosate and paraquat will not give selective control when applied to weeds growing in grain sorghum. Glyphosate applied through the RCS, however, can be a selective method of controlling weed escapes in soybeans because soybeans are not as sensitive to glyphosate as is sorghum.

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Effect of integrated weed management and nitrogen fertilization on the performance of rice under flood-prone lowland conditions

The Journal of Agricultural Science ◽

10.1017/s0021859697004887 ◽

1997 ◽

Vol 129 (4) ◽

pp. 409-418 ◽

Cited By ~ 9

Author(s):

A. R. SHARMA

Keyword(s):

Grain Yield ◽

Weed Control ◽

Water Depth ◽

Weed Management ◽

Field Experiments ◽

Conventional Tillage ◽

N Fertilizer ◽

Integrated Weed Management ◽

Growth Stages ◽

Crop Cultivation

Field experiments were conducted at Cuttack, India during 1991–94 to study the effect of tillage, methods of crop establishment and weed control at varying levels of N fertilizer on the performance of rice under flood-prone lowland conditions (0·60 cm water depth). The loss in grain yield of direct-sown rice caused by unchecked weed growth ranged from 18·2 to 59·2% in the different years, and was greater when N fertilizer was applied and when the conventional practice of ploughing the fields just before sowing was followed. Increasing the number of tillage operations before sowing improved the crop stand, reduced weed infestation and, thereby, increased the yield significantly compared with that achieved by conventional tillage. Summer ploughing rather than conventional tillage decreased weed dry weight at harvest by 15·8–53·2% and increased grain yield by 47·4–56·3%. A pre-emergence application of thiobencarb at 2·0 kg/ha, hand weeding once at 20 days of growth and post-establishment inter-crop cultivation at 37–42 days provided effective weed control and increased yield by 32·7–34·7, 36·7 and 28·7–83·9%, respectively. The efficiency of weed control and the resulting increase in rice yield were comparatively greater under puddling than with inter-crop cultivation and herbicide application. The loss in yield due to weeds was negligible when the crop was transplanted due to the incorporation of weeds during puddling and a greater water depth in the later growth stages. Therefore, the grain yield of rice was highest with transplanting followed closely by the direct-sown crop with post-establishment inter-crop cultivation. The response of direct-sown rice to N fertilization up to 60 kg N/ha decreased with fewer ploughings when no weed control measures were adopted. However, the grain yield increased significantly with N application up to 40 kg N/ha when weeds were controlled by cultural or chemical methods. The results suggested that an integrated weed management strategy involving summer ploughing, thiobencarb application and inter-crop cultivation is essential for effective weed control in direct-sown, flood-prone, lowland rice, in order to ensure higher N-use efficiency and crop productivity.

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