Site and time-specific early weed control is able to reduce herbicide use in maize - a case study

Highlights- Efficacy of UAVs and emergence predictive models for weed control has been confirmed. - Combination of time-specific and site-specific weed control provides optimal results.- Use of timely prescription maps can substantially reduce herbicide use. Remote sensing using unmanned aerial vehicles (UAVs) for weed detection is a valuable asset in agriculture and is vastly used for site-specific weed control. Alongside site-specific methods, time-specific weed control is another critical aspect of precision weed control where, by using different models, it is possible to determine the time of weed species emergence. In this study, site-specific and time-specific weed control methods were combined to explore their collective benefits for precision weed control. Using the AlertInf model, which is a weed emergence prediction model, the cumulative emergence of Sorghum halepense was calculated, following the selection of the best date for UAV survey when the emergence was predicted to be at 96%. The survey was executed using a UAV with visible range sensors, resulting in an orthophoto with a resolution of 3 cm, allowing for good weed detection. The orthophoto was post-processed using two separate methods: an artificial neural network (ANN) and the visible atmospherically resistant index (VARI) to discriminate between the weeds, the crop and the soil. Finally, a model was applied for the creation of prescription maps with different cell sizes (0.25 m2, 2 m2, and 3 m2) and with three different decision-making thresholds based on pixels identified as weeds (>1%, >5%, and >10%). Additionally, the potential savings in herbicide use were assessed using two herbicides (Equip and Titus Mais Extra) as examples. The results show that both classification methods have a high overall accuracy of 98.6% for ANN and 98.1% for VARI, with the ANN having much better results concerning user/producer accuracy and Cohen's Kappa value (k=83.7 ANN and k=72 VARI). The reduction percentage of the area to be sprayed ranged from 65.29% to 93.35% using VARI and from 42.43% to 87.82% using ANN. The potential reduction in herbicide use was found to be dependent on the area. For the Equip herbicide, this reduction ranged from 1.32 L/ha to 0.28 L/ha for the ANN; with VARI the reduction in the amounts used ranged from 0.80 L/ha to 0.15 L/ha. Meanwhile, for Titus Mais Extra herbicide, the reduction ranged from 46.06 g/ha to 8.19 g/ha in amounts used with the ANN; with VARI the reduction in amounts used ranged from 27.77 g/ha to 5.32 g/ha. These preliminary results indicate that combining site-specific and time-specific weed control, has the potential to obtain a significant reduction in herbicide use with direct benefits for the environment and on-farm variable costs. Further field studies are needed for the validation of these results.

Download Full-text

Postemergence Control of Italian Ryegrass in Hazelnut Orchards

Weed Technology ◽

10.1017/wet.2021.41 ◽

2021 ◽

pp. 1-22

Author(s):

Marcelo L. Moretti

Keyword(s):

Weed Control ◽

Weed Management ◽

Field Studies ◽

Early Spring ◽

Italian Ryegrass ◽

Specific Response ◽

Record Keeping ◽

Effective Option ◽

Contrast Analysis ◽

Herbicide Use

Abstract Italian ryegrass has become a problematic weed in hazelnut orchards of Oregon because of the presence of herbicide-resistant populations. Resistant and multiple-resistant Italian ryegrass populations are now the predominant biotypes in Oregon; there is no information on which herbicides effectively control Italian ryegrass in hazelnut orchards. Six field studies were conducted in commercial orchards to evaluate Italian ryegrass control with POST herbicides. Treatments included flazasulfuron, glufosinate, glyphosate, paraquat, rimsulfuron, and sethoxydim applied alone or in selected mixtures during early spring when plants were in the vegetative stage. Treatment efficacy was dependent on the experimental site. The observed range of weed control 28 d after treatment was 13 to 76 % for glyphosate, 1 to 72% for paraquat, 58 to 88% for glufosinate, 16 to 97 % for flazasulfuron, 8 to 94% for rimsulfuron, and 25 to 91% for sethoxydim. Herbicides in mixtures improved control of Italian ryegrass compared to single active ingredients based on contrast analysis. Herbicides in mixture increased control by 27% compared to glyphosate, 18% to rimsulfuron, 15% to flazasulfuron, 19% to sethoxydim, and 12% compared to glufosinate when averaged across all sites, but mixture not always improved ground coverage of biomass reduction. This complex site-specific response highlights the importance of record-keeping for efficient herbicide use. Glufosinate is an effective option to manage Italian ryegrass. However, the glufosinate-resistant biotypes documented in Oregon may jeopardize this practice. Non-chemical weed control options are needed for sustainable weed management in hazelnuts.

Download Full-text

Absorption, Translocation, and Phytotoxicity of Chlorimuron and 2,4-Db Mixtures in Peanut (Arachis Hypogaea) and Selected Weed Species

Weed Science ◽

10.1017/s0043174500052048 ◽

1993 ◽

Vol 41 (3) ◽

pp. 347-352 ◽

Cited By ~ 3

Author(s):

Glenn R. Wehtje ◽

John W. Wilcut ◽

John A. Mcguire

Keyword(s):

Weed Control ◽

Arachis Hypogaea ◽

Field Studies ◽

The Other ◽

Weed Species ◽

Greenhouse Experiments ◽

Crop Injury ◽

Treated Leaf ◽

Better Than

Mixtures of chlorimuron and 2,4-DB were additive with respect to crop injury and were either additive or slightly antagonistic with respect to weed control in greenhouse experiments. Absorption and translocation of14C following application of14C-chlorimuron and14C-2,4-DB were not affected by the presence of the other unlabeled herbicide, except in Florida beggarweed and peanut where 2,4-DB affected distribution of14C-chlorimuron in the treated leaf. In field studies, maximum efficacy was obtained with mixtures of chlorimuron plus 2,4-DB applied 7 or 9 wk after planting. Florida beggarweed control was greatest with chlorimuron or chlorimuron mixtures while the addition of 2,4-DB to chlorimuron improved morningglory and sicklepod control. At 9 and 11 wk after planting, addition of 2,4-DB to chlorimuron controlled Florida beggarweed better than chlorimuron alone. Peanut yields were increased by the addition of 2,4-DB at later applications.

Download Full-text

Evaluation of sequential applications of quizalofop-P-ethyl and florpyrauxifen-benzyl in acetyl CoA carboxylase-resistant rice

Weed Technology ◽

10.1017/wet.2020.114 ◽

2020 ◽

pp. 1-5

Author(s):

Tameka L. Sanders ◽

Jason A. Bond ◽

Benjamin H. Lawrence ◽

Bobby R. Golden ◽

Thomas W. Allen ◽

...

Keyword(s):

Weed Control ◽

Rice Yield ◽

Field Studies ◽

Growth Stages ◽

Acetyl Coa Carboxylase ◽

Weed Species ◽

Rough Rice ◽

Sequential Treatments ◽

Acetyl Coenzyme A Carboxylase ◽

Grass Weed

Abstract Information on performance of sequential treatments of quizalofop-P-ethyl with florpyrauxifen-benzyl on rice is lacking. Field studies were conducted in 2017 and 2018 in Stoneville, MS, to evaluate sequential timings of quizalofop-P-ethyl with florpyrauxifen-benzyl included in preflood treatments of rice. Quizalofop-P-ethyl treatments were no quizalofop-P-ethyl; sequential applications of quizalofop-P-ethyl at 120 g ha−1 followed by (fb) 120 g ai ha−1 applied to rice in the 2- to 3-leaf (EPOST) fb the 4-leaf to 1-tiller (LPOST) growth stages or LPOST fb 10 d after flooding (PTFLD); quizalofop-P-ethyl at 100 g ha−1 fb 139 g ha−1 EPOST fb LPOST or LPOST fb PTFLD; quizalofop-P-ethyl at 139 g ha−1 fb 100 g ha−1 EPOST fb LPOST and LPOST fb PTFLD; and quizalofop-P-ethyl at 85 g ha−1 fb 77 g ha−1 fb 77 g ha−1 EPOST fb LPOST fb PTFLD. Quizalofop-P-ethyl was applied alone and in mixture with florpyrauxifen-benzyl at 29 g ai ha−1 LPOST. Visible rice injury 14 d after PTFLD (DA-PTFLD) was no more than 3%. Visible control of volunteer rice (‘CL151’ and ‘Rex’) 7 DA-PTFLD was similar and at least 95% for each quizalofop-P-ethyl treatment. Barnyardgrass control with quizalofop-P-ethyl at 120 fb 120 g ha−1 LPOST fb PTFLD was greater (88%) in mixture with florpyrauxifen-benzyl. The addition of florpyrauxifen-benzyl to quizalofop-P-ethyl increased rough rice yield when quizalofop-P-ethyl was applied at 100 g ha−1 fb 139 g ha−1 EPOST fb LPOST. Sequential applications of quizalofop-P-ethyl at 120 g ha−1 fb 120 g ha−1 EPOST fb LPOST, 100 g ha−1 fb 139 g ha−1 EPOST fb LPOST, or 139 g ha−1 fb 100 g ha−1 EPOST fb LPOST controlled grass weed species. The addition of florpyrauxifen-benzyl was not beneficial for grass weed control. However, because quizalofop-P-ethyl does not control broadleaf weeds, florpyrauxifen-benzyl could provide broad-spectrum weed control in acetyl coenzyme A carboxylase–resistant rice.

Download Full-text

Season-long weed control with sequential herbicide programs in California tree nut crops

Weed Technology ◽

10.1017/wet.2020.70 ◽

2020 ◽

Vol 34 (6) ◽

pp. 834-842

Author(s):

Caio A. C. G. Brunharo ◽

Seth Watkins ◽

Bradley D. Hanson

Keyword(s):

Weed Control ◽

Field Experiments ◽

Control Program ◽

Early Spring ◽

High Rate ◽

Weed Species ◽

Tree Nut ◽

Herbicide Use ◽

Herbicide Programs ◽

Grass Weed

AbstractWeed control in tree nut orchards is a year-round challenge for growers that is particularly intense during winter through summer as a result of competition and interference with management and harvest operations. A common weed control program consists of an application of a winter PRE and POST herbicide mixture, followed by a desiccation treatment in early spring and before harvest. Because most spring and summer treatments depend on a limited number of foliar-applied herbicides, summer-germinating species and/or herbicide-resistant biotypes become troublesome. Previous research has established effective PRE herbicide programs targeting winter glyphosate-resistant weeds. However, more recently, growers have reported difficulties in controlling several summer-germinating grass weeds with documented or suspected resistance to the spring and summer POST herbicide programs. In this context, research was conducted to evaluate a sequential PRE approach to control winter- and summer-germinating orchard weeds. Eight field experiments were conducted in tree nut orchards to evaluate the efficacy of common winter herbicide programs and a sequential herbicide program for control of a key summer grass weed species. In the sequential-application strategy, three foundational herbicide programs applied in the winter were either mixed with pendimethalin, followed with pendimethalin in March, or applied as a split application of pendimethalin in both winter and spring. Results indicate that the addition of pendimethalin enhanced summer grass weed control throughout the crop growing season by up to 31%. Applying all or part of the pendimethalin in the spring improved control of the summer grass weed junglerice by up to 49%. The lower rate of pendimethalin applied in the spring performed as well as the high rate in the winter, suggesting opportunities for reducing herbicide inputs. Tailoring sequential herbicide programs to address specific weed challenges can be a viable strategy for improving orchard weed control without increasing herbicide use in some situations.

Download Full-text

Weed management with CGA-362622 in transgenic and nontransgenic cotton

Weed Science ◽

10.1614/p2002-014 ◽

2003 ◽

Vol 51 (6) ◽

pp. 1002-1009 ◽

Cited By ~ 19

Author(s):

Dunk Porterfield ◽

John W. Wilcut ◽

Jerry W. Wells ◽

Scott B. Clewis

Keyword(s):

North Carolina ◽

Weed Control ◽

Weed Management ◽

Field Studies ◽

Palmer Amaranth ◽

Management Systems ◽

Weed Species ◽

Crop Tolerance ◽

Prickly Sida ◽

Smooth Pigweed

Field studies conducted at three locations in North Carolina in 1998 and 1999 evaluated crop tolerance, weed control, and yield with CGA-362622 alone and in combination with various weed management systems in transgenic and nontransgenic cotton systems. The herbicide systems used bromoxynil, CGA-362622, glyphosate, and pyrithiobac applied alone early postemergence (EPOST) or mixtures of CGA-362622 plus bromoxynil, glyphosate, or pyrithiobac applied EPOST. Trifluralin preplant incorporated followed by (fb) fluometuron preemergence (PRE) alone or fb a late POST–directed (LAYBY) treatment of prometryn plus MSMA controlled all the weed species present less than 90%. Herbicide systems that included soil-applied and LAYBY herbicides plus glyphosate EPOST or mixtures of CGA-362622 EPOST plus bromoxynil, glyphosate, or pyrithiobac controlled broadleaf signalgrass, entireleaf morningglory, large crabgrass, Palmer amaranth, prickly sida, sicklepod, and smooth pigweed at least 90%. Only cotton treated with these herbicide systems yielded equivalent to the weed-free check for each cultivar. Bromoxynil systems did not control Palmer amaranth and sicklepod, pyrithiobac systems did not control sicklepod, and CGA-362622 systems did not control prickly sida.

Download Full-text

OpenWeedLocator (OWL): an open-source, low-cost device for fallow weed detection

Scientific Reports ◽

10.1038/s41598-021-03858-9 ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Guy Coleman ◽

William Salter ◽

Michael Walsh

Keyword(s):

Open Source ◽

Weed Control ◽

Technology Development ◽

Low Cost ◽

Yield Potential ◽

Low Density ◽

Weed Detection ◽

Site Specific ◽

South Wales ◽

Control Community

AbstractThe use of a fallow phase is an important tool for maximizing crop yield potential in moisture limited agricultural environments, with a focus on removing weeds to optimize fallow efficiency. Repeated whole field herbicide treatments to control low-density weed populations is expensive and wasteful. Site-specific herbicide applications to low-density fallow weed populations is currently facilitated by proprietary, sensor-based spray booms. The use of image analysis for fallow weed detection is an opportunity to develop a system with potential for in-crop weed recognition. Here we present OpenWeedLocator (OWL), an open-source, low-cost and image-based device for fallow weed detection that improves accessibility to this technology for the weed control community. A comprehensive GitHub repository was developed, promoting community engagement with site-specific weed control methods. Validation of OWL as a low-cost tool was achieved using four, existing colour-based algorithms over seven fallow fields in New South Wales, Australia. The four algorithms were similarly effective in detecting weeds with average precision of 79% and recall of 52%. In individual transects up to 92% precision and 74% recall indicate the performance potential of OWL in fallow fields. OWL represents an opportunity to redefine the approach to weed detection by enabling community-driven technology development in agriculture.

Download Full-text

Mefluidide as an Enhancing Agent for Postemergence Broadleaf Herbicides in Soybeans (Glycine max)

Weed Technology ◽

10.1017/s0890037x00029353 ◽

1987 ◽

Vol 1 (2) ◽

pp. 149-153 ◽

Cited By ~ 1

Author(s):

Michael R. Blumhorst ◽

George Kapusta

Keyword(s):

Glycine Max ◽

Weed Control ◽

Field Studies ◽

Weed Species ◽

Nitrobenzoic Acid ◽

Petroleum Oil

In field studies, mefluidide {N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl] amino] phenyl] acetamide} was most effective as an enhancing agent for bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] and/or acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid} when applied as a tank mixture compared to sequential applications. The influence of mefluidide rate on weed control was not consistent. Additives improved the control of several weed species evaluated, but mefluidide generally was only equal to petroleum oil concentrate (phytobland petroleum oil plus emulsifiers in an 83:17 ratio) as an enhancing agent for bentazon and/or acifluorfen.

Download Full-text

Response of Selected Weed Species to Postemergence Imazethapyr and Bentazon

Weed Technology ◽

10.1017/s0890037x00023277 ◽

1995 ◽

Vol 9 (2) ◽

pp. 236-242 ◽

Cited By ~ 17

Author(s):

Troy A. Bauer ◽

Karen A. Renner ◽

Donald Penner

Keyword(s):

Weed Control ◽

Field Research ◽

Dry Weight ◽

Field Studies ◽

Weed Species ◽

Eastern Black Nightshade ◽

Black Nightshade ◽

Redroot Pigweed ◽

Treated Leaf ◽

Petroleum Oil

Imazethapyr and bentazon were applied with petroleum oil adjuvant in a factorial arrangement to weed species in greenhouse and field research to determine if postemergence weed control by imazethapyr was antagonized when bentazon was tank-mixed. Tank-mixing 840 g/ha of bentazon with 13 or 27 g/ha of imazethapyr increased redroot pigweed and eastern black nightshade dry weight as compared to Colby's expected values in the greenhouse. However, weed control was not reduced in field studies. Subsequent greenhouse studies indicated that soil interception and resulting root uptake of imazethapyr increased redroot pigweed control. Bentazon decreased foliar absorption of14C-imazethapyr by 15% and translocation of14C from the treated leaf by more than 50% compared tol4C-imazethapyr applied alone.

Download Full-text

Influence of Crop Canopy, Weed Maturity, and Rainfall on Acifluorfen Activity

Weed Science ◽

10.1017/s004317450005877x ◽

1984 ◽

Vol 32 (2) ◽

pp. 185-190 ◽

Cited By ~ 10

Author(s):

Ronald L. Ritter ◽

Harold D. Coble

Keyword(s):

Weed Control ◽

Field Studies ◽

Ambrosia Artemisiifolia ◽

Simulated Rainfall ◽

Weed Species ◽

Common Ragweed ◽

Control Efficiency ◽

Weed Control Efficiency ◽

Excellent Control ◽

Plant Emergence

In greenhouse studies, control of common ragweed (Ambrosia artemisiifoliaL. ♯ AMBEL) and common cocklebur (Xanthium pensylvanicumWallr. ♯ XANPE) was achieved whether or not soybeans [Glycine maxL. (Merr.) ‘Ransom’] partially shielded the weeds from foliar applications of acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid}. Excellent control (> 90%) of common ragweed was obtained in the greenhouse 2 and 4 weeks after plant emergence. Best control (> 90%) of common cocklebur was obtained 2 weeks after plant emergence. A simulated rainfall of 0.6 cm occurring 1 min after acifluorfen application did not decrease control or fresh weight of common ragweed in greenhouse studies. The weed control efficiency of acifluorfen on common cocklebur was reduced when the herbicide was applied intermittently within 6 h of the 0.6-cm simulated rainfall. The weed control efficiency of acifluorfen on both weed species was also reduced when the herbicide was applied intermittently within 6 to 12 h of a 1.3-cm simulated rainfall in greenhouse studies. In field studies, 2.5 cm of simulated rainfall within 12 to 24 h after acifluorfen application reduced control of common ragweed.

Download Full-text

Rice (Oryza sativa) Weed Control with Soil Applications of Quinclorac

Weed Technology ◽

10.1017/s0890037x00037404 ◽

1993 ◽

Vol 7 (3) ◽

pp. 600-604 ◽

Cited By ~ 25

Author(s):

Joe E. Street ◽

Thomas C. Mueller

Keyword(s):

Oryza Sativa ◽

Weed Control ◽

Rice Yield ◽

Field Studies ◽

Moist Soil ◽

Weed Species ◽

Application Timing ◽

Soil Application ◽

Pitted Morningglory ◽

Dry Soil

Field studies were conducted from 1988 to 1990 on a Sharkey clay to evaluate residual weed control in rice with quinclorac applied PPI, PRE to dry soil, and PRE to moist soil. Quinclorac applied at 0.4 or 0.6 kg ai ha−1PPI or PRE to dry or moist soil controlled more than 80% of barnyardgrass, pitted morningglory, and hemp sesbania without rice injury. Quinclorac applied at 0.3 kg ha−1controlled these three weed species substantially but inconsistently. No rice injury was observed from any quinclorac treatment. Except for one of three years when irrigation was delayed for 7 d after PRE application to dry soil, application timing did not consistently affect weed control or rice yield.

Download Full-text