Weed Interference and Control in Cowpea Production: A Review

In spite of the great economic potential of cowpea as both domestic and commercial crop, a number of constraints, which include insect pests, diseases and weeds, limits its production in West and many parts of Africa. Weeds reduced cowpea yield and value by competing for light, water and nutrients. Cowpea suffers from weeds particularly when the crop is in the early growth stages before ground cover. Yield losses cause by weeds alone in cowpea production can be as high as 76% depending on the cowpea cultivar, environment and weed management practices. A timely weed removal at the critical period, which falls within the first 40 days of cowpea growth, would help to prevent an unacceptable yield. Weed management in cowpea has been with low technology. Hand weeding is the most widely used weed control method in cowpea but they are usually expensive and labour intensive. Cultural practices such as narrow row spacing and planting of early maturing varieties are also used for weed control in cowpea. Herbicides, which are relatively easy to use and less expensive, have not been widely adopted for weed control in cowpea. There are limited number of selective herbicides with wide spectrum for weed control in cowpea. However, an integrated practices that involved pre-emergence weed control using herbicides or physical weeding, and a supplementary weed removal that would ensure weed control up to 40 days after cowpea emergence could substantially prevent yield losses associated with weed interference.

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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.

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Effect of Weed Management Practices on Weed Dynamics, Nutrient Depletion, Productivity and Profitability of Summer Mungbean (Vigna radiata) under Zero Tillage Condition

Legume Research - An International Journal ◽

10.18805/lr-4497 ◽

2021 ◽

Author(s):

Kuldeep Singh ◽

Hardev Ram ◽

Rakesh Kumar ◽

R.K. Meena ◽

Rakesh Kumar ◽

...

Keyword(s):

Weed Control ◽

Weed Management ◽

Management Practices ◽

Weed Competition ◽

Growth Stages ◽

Zero Tillage ◽

Yield Attributes ◽

Net Returns ◽

Free Treatment ◽

Crop Weed Competition

Background: Weeds are prime factor that adversely effects on growth, quality and yield of mungbean during summer and rainy season. Being a short duration crop, it faces heavy weed competition right from the early growth stages to harvesting. The critical period of crop weed competition in mungbean was initial 25-30 days, yield may be reduce up to 50-90% if weeds not manage at this stage. Hence, there is a need to find out the successful weed management strategies to realize higher growth and yield. The progressive transformation of agriculture concerning intensive use of herbicides is gaining status in recent years due to easy, lower cost, timeliness and successful controlling weeds. Therefore, keeping above information in view, the present study was undertaken to assess the effect of different weed management practices in summer mungbean under zero tillage condition to find out the better weed management, higher productivity and profitability.Methods: In this field-laboratory investigation during summer season, 2019, different herbicides were applied to manage weeds in mungbean. Eight treatments were applied based on various application windows. In the field and laboratory, the collected samples were determined for crop weed competition, yield attributes, yields and net returns. Result: The results revealed that weed free treatment was recorded lowest weed population at 30 DAS and harvest (1.8 and 2.9), weed dry weight (1.1 and 1.9g) and highest weed control efficiency (96.3 and 94.9%) followed by Pendimethalin (PE) fb one HW and Shaked (Propaquizafop + Imezathyper) application. The similar results also observed in nutrients removed by weeds. Among yield attributes, weed free treatment recorded the longest pod length, no. of pods/plant, no. of seeds/pod and test weight (7.9, 21.0, 9.7 and 43.0g, respectively) which was at par with Pendimethalin (PE) fb one HW and Shaked (Propaquizafop + Imezathyper) application. The magnitude of seed yield was increased under weed free (10.1 q/ha) and Shaked (Propaquizafop + Imezathyper) (9.5 q/ha) treatments by 127.9 and 113.8%, respectively over weedy check. Application of Shaked (Propaquizafop + Imezathyper) recorded highest net returns (Rs 55,079/ha) and B: C (2.8) over rest of the treatments. It can concluded that application of Shaked (Propaquizafop + Imezathyper) @ 2 L/ha at 20 DAS recommended for better weed control, higher yield and net returns of summer mungbean under zero tillage condition.

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Planting date influences critical period of weed control in sweet corn

Weed Science ◽

10.1614/ws-06-005r.1 ◽

2006 ◽

Vol 54 (5) ◽

pp. 928-933 ◽

Cited By ~ 45

Author(s):

Martin M. Williams

Keyword(s):

Weed Control ◽

Weed Management ◽

Critical Period ◽

Sweet Corn ◽

Relative Yield ◽

Planting Date ◽

Integrated Weed Management ◽

Yield Losses ◽

Yield Data ◽

Weed Interference

The critical period for weed control (CPWC) identifies the phase of the crop growth cycle when weed interference results in unacceptable yield losses; however, the effect of planting date on CPWC is not well understood. Field studies were conducted in 2004 and 2005 at Urbana, IL, to determine CPWC in sweet corn for early May (EARLY) and late-June (LATE) planting dates. A quantitative series of treatments of both increasing duration of interference and length of weed-free period were imposed within each planting-date main plot. The beginning and end of the CPWC, based on 5% loss of marketable ear mass, was determined by fitting logistic and Gompertz equations to the relative yield data representing increasing duration of weed interference and weed-free periods, respectively. Weed interference stressed the crop more quickly and to a greater extent in EARLY, relative to LATE. At a 5% yield-loss level, duration of weed interference for 160 and 662 growing-degree days (GDD) from crop emergence marked the beginning of the CPWC for EARLY and LATE, respectively. When maintained weed-free for 320 and 134 GDD, weeds emerging later caused yield losses of less than 5% for EARLY and LATE, respectively. Weed densities exceeded 85 plants m−2for the duration of the experiments and predominant species included barnyardgrass, common lambsquarters, common purslane, redroot pigweed, and velvetleaf. Weed canopy height and total aboveground weed biomass were 300% and 500% higher, respectively, for EARLY compared with LATE. Interactions between planting date and CPWC indicate the need to consider planting date in the optimization of integrated weed management systems for sweet corn. In this study, weed management in mid-June–planted sweet corn could have been less intensive than early May–planted corn, reducing herbicide use and risk of herbicide carryover to sensitive rotation crops.

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Weed Management Practices to Improve Establishment of Selected Lignocellulosic Crops

Energies ◽

10.3390/en14092478 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2478

Author(s):

Ioannis Gazoulis ◽

Panagiotis Kanatas ◽

Panayiota Papastylianou ◽

Alexandros Tataridas ◽

Efthymia Alexopoulou ◽

...

Keyword(s):

Weed Control ◽

Weed Management ◽

Sweet Sorghum ◽

Management Practices ◽

Cultural Practices ◽

Management Strategies ◽

Perennial Grasses ◽

Giant Reed ◽

Growth Stages ◽

Giant Miscanthus

Lignocellulosic biomass is one of the dominant renewable energy resources suited for the production of sustainable biofuels and other energy purposes. This study was focused on weed management strategies that can improve the establishment of six lignocellulosic crops. The studied crops included: giant miscanthus, switchgrass, giant reed, cardoon, sweet sorghum, and kenaf. Delayed planting, increased planting densities, and mulching techniques can suppress weeds in giant miscanthus. Weed competition is detrimental for switchgrass establishment. Seedbed preparation and cultivar selection can determine its ability to compete with weeds. Giant reed is unlikely to get outcompeted by weeds, and any weed control operation is required only for the first growing season. Competitive cultivars and increased seeding rates maximize the competitiveness of cardoon against weeds. Several cultural practices can be used for non-chemical weed management in sweet sorghum and kenaf. For all crops, pre-emergence herbicides can be applied. The available safe post-emergence herbicides are limited. Mechanical weed control during crucial growth stages can provide solutions for sweet sorghum, kenaf, and perennial grasses. Further research is required to develop effective weed management strategies, with emphasis on cultural practices, that can improve the establishment of these prominent lignocellulosic crops.

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Competition and control of weeds in soybean

Weed Science ◽

10.1017/s004317450009072x ◽

1999 ◽

Vol 47 (1) ◽

pp. 107-111 ◽

Cited By ~ 10

Author(s):

Rajender Singh Chhokar ◽

Rajender Singh Balyan

Keyword(s):

Weed Control ◽

Broad Spectrum ◽

Weed Management ◽

Critical Period ◽

Management Practices ◽

Field Experiments ◽

Growth Stages ◽

Single Application ◽

Reduced Rate ◽

And Control

Two field experiments were carried out from 1993 to 1995 to evaluate the critical period of weed control and to develop suitable weed management practices for jungle rice, horse purslane, and cockscomb in soybean. Horse purslane was more competitive during early growth stages (up to 45 days after sowing [DAS]) and cockscomb was more competitive during later growth stages, whereas jungle rice was competitive throughout the growing season. The critical period of weed control was found to be 30 to 45 DAS. Weed-free maintenance up to 45 DAS resulted in a 74% increase in grain yield of soybean over the unweeded control. Keeping soybean weed free for 45 d or allowing weeds to remain in the crop for less than 30 d resulted in no significant yield loss. Sequential application of a reduced rate of soil-applied trifluralin 1.0 kg ha–1(0.67 ×) with postemergence fluazifop 0.75 kg ha–1(0.75 ×) or a reduced rate of soil-applied trifluralin or pendimethalin at 1.0 kg ha–1(0.67 ×) followed by hand hoeing 35 DAS provided better control of a broad spectrum of weeds than a single application of a postemergence herbicide applied at reduced or recommended rates. Integration of reduced rates of soil-applied herbicides with post-emergence herbicides or hand hoeing 35 DAS produced soybean yields similar to the hand-weeded treatment. Compared to the weed-free or integrated weed control, a single application of soil-applied or postemergence herbicide did not control a broad spectrum of weeds and reduced soybean yield.

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Phosphorus Application Influences the Critical Period of Weed Control in Lettuce

Weed Science ◽

10.1614/ws-d-12-00107.1 ◽

2013 ◽

Vol 61 (3) ◽

pp. 410-414 ◽

Cited By ~ 6

Author(s):

Dennis C. Odero ◽

Alan L. Wright

Keyword(s):

Weed Control ◽

Weed Management ◽

Critical Period ◽

Management Practices ◽

Natural Populations ◽

P Fertilization ◽

Weed Species ◽

Weed Interference ◽

Fertilization Level ◽

Phosphorus Application

Field studies were conducted in 2010 and 2011 at Belle Glade, FL, to evaluate the influence of phosphorus (P) applications (98, 196, and 293 kg P ha−1) on the critical period of weed control (CPWC) in lettuce. Natural populations of mixed weed species were allowed to interfere with lettuce in a series of treatments of both increasing duration of weed interference and the duration of weed-free period imposed within 98, 196, and 293 kg P ha−1levels added to the soil. The beginning and end of the CPWC for each P fertilization level based on a 5% acceptable marketable fresh lettuce yield loss level was determined by fitting log-logistic and Gompertz models to represent the increasing duration of weed interference and the duration of weed-free period, respectively. The CPWC in lettuce was estimated to be 4.6, 3.4, and 2.3 wk at 98, 196, and 293 kg P ha−1, respectively. The beginning of the CPWC was delayed at the highest P fertilization level (293 kg P ha−1), whereas the end of the CPWC was hastened at the same P fertilization level. Our study shows that inadequate levels of P fertilization in lettuce result in the need for more-intensive weed management practices to attain acceptable yields.

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Weed Management in Small Grains Harvested for Grain

EDIS ◽

10.32473/edis-wg009-2020 ◽

2020 ◽

Vol 2020 (3) ◽

Author(s):

Jason Ferrell ◽

Gregory MacDonald ◽

Pratap Devkota

Keyword(s):

Weed Control ◽

Weed Management ◽

Chemical Control ◽

Management Practices ◽

Good Management ◽

Small Grains ◽

Crop Competition

Successful weed control in small grains involves using good management practices in all phases of production. In Florida, winter weeds compete with small grains for moisture, nutrients, and light, with the greatest amount of competition occurring during the first six to eight weeks after planting. Weeds also cause harvest problems the following spring when the small grain is mature. This 4-page publication discusses crop competition, knowing your weeds, and chemical control. Written by J. A. Ferrell, G. E. MacDonald, and P. Devkota, and published by the UF/IFAS Agronomy Department, revised May 2020.

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Weed Management in Peanuts

EDIS ◽

10.32473/edis-wg008-2020 ◽

2020 ◽

Vol 2020 (3) ◽

Author(s):

Pratap Devkota

Keyword(s):

Weed Control ◽

Weed Management ◽

Management Practices ◽

Application Rate ◽

Good Management ◽

Peanut Production

Successful weed control in peanuts involves use of good management practices in all phases of peanut production. This 11-page document lists herbicide products registered for use in Florida peanut production, their mode of actions group, application rate per acre and per season, and reentry interval. It also discusses the performance of these herbicides on several weeds under Florida conditions. Written by J. A. Ferrell, G. E. MacDonald, and P. Devkota, and published by the UF/IFAS Agronomy Department, revised May 2020.

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Seasonal Nonstructural Carbohydrate Patterns in Dewberry (Rubus spp.) Roots

Weed Science ◽

10.1017/wsc.2020.96 ◽

2021 ◽

pp. 1-23

Author(s):

Katherine M. Ghantous ◽

Hilary A. Sandler

Keyword(s):

Weed Management ◽

Management Practices ◽

Soluble Sugars ◽

Leaf Expansion ◽

Control Measures ◽

Growth Stages ◽

Phenological Stages ◽

Long Term Storage ◽

Nonstructural Carbohydrate ◽

Fruit Maturity

Abstract Applying control measures when carbohydrate levels are low can decrease the likelihood of plant survival, but little is known about the carbohydrate cycles of dewberry (Rubus spp.), a problematic weed group on cranberry farms. Weedy Rubus plants were collected from areas adjacent to production beds on commercial cranberry farms in Massachusetts, two locations per year for two years. For each site and year, four entire plants were collected at five phenological stages: budbreak, full leaf expansion, flowering, fruit maturity, and after onset of dormancy. Root sections were analyzed for total nonstructural carbohydrate (TNC; starch, sucrose, fructose, and glucose). Overall trends for all sites and years showed TNC were lowest at full leaf expansion or flowering; when sampled at dormancy, TNC concentrations were greater than or equal to those measured at budbreak. Starch, a carbohydrate form associated with long-term storage, had low levels at budbreak, leaf expansion and/or flowering with a significant increase at fruit maturity and the onset of dormancy, ending at levels higher than those found at budbreak. The concentration of soluble sugars, carbohydrate forms readily usable by plants, was highest at budbreak compared to the other four phenological samplings. Overall, our findings supported the hypothesis that TNC levels within the roots of weedy Rubus plants can be predicted based on different phenological growth stages in Massachusetts. However, recommendations for timing management practices cannot be based on TNC cycles alone; other factors such as temporal proximity to dormancy may also impact Rubus plants recovery and further research is warranted. Late-season damage should allow less time for plants to replenish carbohydrate reserves (prior to the onset of dormancy), thereby likely enhancing weed management tactics effectiveness over time. Future studies should consider tracking the relationship between environmental conditions, phenological stages, and carbohydrate trends.

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Integrating Economics in the Critical Period for Weed Control Concept in Corn

Weed Science ◽

10.1614/ws-d-13-00184.1 ◽

2014 ◽

Vol 62 (4) ◽

pp. 608-618 ◽

Cited By ~ 3

Author(s):

Martina Keller ◽

Geoffroy Gantoli ◽

Jens Möhring ◽

Christoph Gutjahr ◽

Roland Gerhards ◽

...

Keyword(s):

Weed Control ◽

Critical Period ◽

Logistic Models ◽

Crop Growth ◽

Growth Stages ◽

Corn Yield ◽

Leaf Stage ◽

Weed Interference ◽

Free Interval ◽

Crop Growth Stages

The effect of weed interference on corn yield and the critical period for weed control (CPWC) were determined in Germany and Benin. Treatments with weed control starting at different crop growth stages and continuously kept weed-free until harvest represented the “weed-infested interval.” Treatments that were kept weed-free from sowing until different crop growth stages represented the “weed-free interval.” Michaelis–Menten, Gompertz, logistic and log–logistic models were employed to model the weed interference on yield. Cross-validation revealed that the log–logistic model fitted the weed-infested interval data equally well as the logistic and slightly better than the Gompertz model fitted the weed-free interval. For Benin, economic calculations considered yield revenue and cost increase due to mechanical weeding operations. Weeding once at the ten-leaf stage of corn resulted already profitable in three out of four cases. One additional weeding operation may optimize and assure profit. Economic calculations for Germany determined a CPWC starting earlier than the four-leaf stage, challenging the decade-long propagated CPWC for corn. Differences between Germany and Benin are probably due to the higher yields and high costs in Germany. This study provides a straightforward method to implement economic data in the determination of the CPWC for chemical and nonchemical weed control strategies.

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