HERB and MSU-HERB Field Validation for Soybean (Glycine max) Weed Control in Mississippi

In 1994, herbicide efficacy and competitive index databases were adjusted in the soybean herbicide recommendation program HERB to best reflect data for Mississippi. Field experiments were conducted to compare efficacy and economics of postemergence herbicides recommended by HERB and MSU-HERB. The study was conducted utilizing four locations over 2 yr, which provided different soil types, weed spectra, and environmental conditions with which to evaluate weed control from herbicides recommended by these programs. HERB and MSU-HERB agreed on an herbicide recommendation in 62% of the modeling runs. Herbicides recommended by both software versions were generally effective for controlling the predominant weed species at each location. In instances where there was a significant difference in herbicide efficacy between herbicides recommended by HERB and MSU-HERB, improved weed control resulted from herbicides recommended by MSU-HERB. In 1994, excellent moisture conditions enabled soybean to gain a significant competitive advantage over weeds and, as a result, yield loss predictions after treatment were overestimated in most instances. Conversely, 1995 environmental conditions better represented average Mississippi growing conditions, and yield loss predictions after treatment were more accurate. Yield loss prediction accuracy of HERB versions was related to the length of interference between soybean and weeds. Thus, prediction accuracy of HERB and MSU-HERB was similar. Soybean yield increase and net economic gain following MSU-HERB recommendations was as high or higher than following HERB recommendations.

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Precision orientation herbicide spraying against weeds in plastic-mulched fields of spring hybrid millet

Emirates Journal of Food and Agriculture ◽

10.9755/ejfa.2019.v31.i11.2032 ◽

2019 ◽

pp. 837

Author(s):

Meijun Guo ◽

Xi-e Song ◽

Jie Shen ◽

Jianming Wang ◽

Xiatong Zhao ◽

...

Keyword(s):

Weed Control ◽

Field Experiments ◽

Comprehensive Evaluation ◽

Foxtail Millet ◽

Good Option ◽

Weed Species ◽

Efficacy Evaluation ◽

Application Range ◽

Significant Difference ◽

Herbicide Treatments

Foxtail millet (Setaria italic [L.] P. Beauv.) is an important food and fodder crop that is cultivated worldwide. However, weeds severely inhibit the growth of spring foxtail millet, and no suitable herbicide or method is available for weed control in foxtail millet fields. Field experiments were conducted to evaluate the efficacy of various herbicides and their safety toward hybrid foxtail millet, that is, ‘Zhangzagu 10’. The present study was conducted using seven herbicides applied by precision orientation spraying between plastic mulches in a foxtail millet field. All herbicide treatments exhibited no significant difference on foxtail millet shoot and root biomass. No difference in grain yield was observed among herbicide treatments, including MCPA (2-methyl-4-chlorophenoxyacetic acid), mesotrione, acetochlor, trifluralin, and pendimethalin, at the recommended dosage in field efficacy evaluation trial. For the same herbicide, the tendency of weed control increased with the increase in herbicide concentration. Following this finding, all herbicides applied at the highest dosage controlled weeds by 92.06% compared with the other treatments utilizing lower concentration. At the same concentration level, mesotrione controlled all weed populations was the highest observed among all herbicides, followed by prometryne and MCPA. Mesotrione controlled all weeds by at least 76.85%, exhibiting the highest weed injury among the herbicides and satisfying the requirement for weed species control. Finally, comprehensive analyses showed that mesotrione at 0.8 L ha-1, yielded the highest comprehensive evaluation value in foxtail millet field. Thus, this herbicide can be a good option in controlling weeds in foxtail millet field. This new model can aid in protecting hybrid ‘Zhangzagu 10’ foxtail millet seeds or seedlings against herbicide damage and is a good option in expanding the application range of herbicide in foxtail millet.

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Bio-efficacy of post emergence herbicides in boro rice nursery as well as main field and their residual effects on non-target microorganisms

ORYZA- An International Journal on Rice ◽

10.35709/ory.2020.57.3.4 ◽

2020 ◽

Vol 57 (3) ◽

pp. 199-210

Author(s):

Rajib Kundu ◽

Mousumi Mondal ◽

Sourav Garai ◽

Ramyajit Mondal ◽

Ratneswar Poddar

Keyword(s):

Weed Control ◽

Weed Management ◽

Field Experiments ◽

Block Design ◽

Resistance Index ◽

Residual Effects ◽

Cost Ratio ◽

Main Field ◽

Weed Species ◽

Similar Treatment

Field experiments were conducted at research farm of Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India (22°97' N latitude and 88°44' E longitude, 9.75 m above mean sea level) under natural weed infestations in boro season rice (nursery bed as well as main field) during 2017-18 and 2018-19 to evaluate the herbicidal effects on weed floras, yield, non-target soil organisms to optimize the herbicide use for sustainable rice-production. Seven weed control treatments including three doses of bispyribac-sodium 10% SC (150,200, and 250 ml ha-1), two doses of fenoxaprop-p-ethyl 9.3% EC (500 and 625 ml ha-1), one weed free and weedy check were laid out in a randomized complete block design, replicated thrice. Among the tested herbicides, bispyribac-sodium with its highest dose (250 ml ha-1) resulted in maximum weed control efficiency, treatment efficiency index and crop resistance index irrespective of weed species and dates of observation in both nursery as well as main field. Similar treatment also revealed maximum grain yield (5.20 t ha-1), which was 38.38% higher than control, closely followed by Fenoxaprop-p-ethyl (625 ml ha-1) had high efficacy against grasses, sedge and broadleaf weed flora. Maximum net return (Rs. 48765 ha-1) and benefit cost ratio (1.72) were obtained from the treatment which received bispyribac-sodium @ 250 ml ha-1. Based on overall performance, the bispyribac-sodium (250 ml ha-1) may be considered as the best herbicide treatment for weed management in transplanted rice as well as nursery bed.

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The critical weed-free period in glyphosate-resistant soybean in Ontario is similar to previous estimates using glyphosate-susceptible soybean

Canadian Journal of Plant Science ◽

10.1139/cjps-2018-0049 ◽

2019 ◽

Vol 99 (4) ◽

pp. 437-443

Author(s):

Nader Soltani ◽

Robert E. Nurse ◽

Amit J. Jhala ◽

Peter H. Sikkema

Keyword(s):

Growth Stage ◽

Field Experiments ◽

Yield Loss ◽

Growth Stages ◽

Weed Species ◽

Weed Biomass ◽

Weed Density ◽

Weed Interference ◽

Beginning Of Flowering ◽

Minimal Reduction

A study consisting of 13 field experiments was conducted during 2014–2016 in southwestern Ontario and southcentral Nebraska (Clay Center) to determine the effect of late-emerging weeds on the yield of glyphosate-resistant soybean. Soybean was maintained weed-free with glyphosate (900 g ae ha−1) up to the VC (cotyledon), V1 (first trifoliate), V2 (second trifoliate), V3 (third trifoliate), V4 (fourth trifoliate), and R1 (beginning of flowering) growth stages, after which weeds were allowed to naturally infest the soybean plots. The total weed density was reduced to 24%, 63%, 67%, 72%, 76%, and 92% in Environment 1 (Exeter, Harrow, and Ridgetown) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 soybean growth stages, respectively. The total weed biomass was reduced by 33%, 82%, 95%, 97%, 97%, and 100% in Environment 1 (Exeter, Harrow, and Ridgetown) and 28%, 100%, 100%, 100%, 100%, and 100% in Environment 2 (Clay Center) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 stages, respectively. The critical weed-free periods for a 2.5%, 5%, and 10% yield loss in soybean were the V1–V2, VC–V1, and VC–V1 soybean stages in Environment 1 (Exeter, Harrow, and Ridgetown) and V2–V3, V2–V3, and V1–V2 soybean stages in Environment 2 (Clay Center), respectively. For the weed species evaluated, there was a minimal reduction in weed biomass (5% or less) when soybean was maintained weed-free beyond the V3 soybean growth stage. These results shows that soybean must be maintained weed-free up to the V3 growth stage to minimize yield loss due to weed interference.

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Interference between hemp sesbania (Sesbania exaltata) and soybean (Glycine max) in response to irrigation and nitrogen

Weed Science ◽

10.1017/s0043174500092523 ◽

1997 ◽

Vol 45 (1) ◽

pp. 91-97 ◽

Cited By ~ 18

Author(s):

C. Andy King ◽

Larry C. Purcell

Keyword(s):

Field Experiments ◽

Yield Loss ◽

Individual Species ◽

Weed Species ◽

Soybean Yield ◽

Sesbania Exaltata ◽

Competition For Light ◽

Hemp Sesbania ◽

Chamber Studies ◽

Growth Chamber Studies

Soybean yield loss from weed interference depends upon weed density and competitiveness of crop and weed species in response to environment. Soil water availability and nitrogen fertility were evaluated for their effect on competitiveness of individual species in field experiments. Early-season temperatures in 1995, which were cool compared to 1994, slowed hemp sesbania growth without affecting soybean growth. This resulted in negligible competition with soybean by hemp sesbania at densities of 3 or 6 plants m−2. In 1994, hemp sesbania grew above the soybean canopy, decreasing soybean light interception 29 to 68%, and reducing soybean yield 30 to 48%. Fertilizer nitrogen increased soybean competitiveness, as indicated by biomass production, only in irrigated plots with hemp sesbania at 3 m−2, but did not affect soybean yield. Apparently, competition for light is a primary cause of soybean yield loss from hemp sesbania infestations. In growth chamber studies, simulating temperatures from the field, hemp sesbania growth was stimulated more by warm temperatures than was soybean. Hemp sesbania and soybean dry weights increased 4.4- and 2.7-fold, respectively, at 30/20 C day/night temperatures compared to 25/15 C.

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The Critical Period for Weed Control (CPWC) in Potato (Solanum tuberosum L.)

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha43210031 ◽

2015 ◽

Vol 43 (2) ◽

pp. 355-360 ◽

Cited By ~ 1

Author(s):

Dogan ISIK ◽

Adem AKCA ◽

Emine KAYA ALTOP ◽

Nihat TURSUN ◽

Husrev MENNAN

Keyword(s):

Weed Control ◽

Weed Management ◽

Critical Period ◽

Field Experiments ◽

Yield Loss ◽

Cropping Systems ◽

Control Period ◽

Relative Yield ◽

Yield Data ◽

Weed Interference

Accurate assessment of crop-weed control period is an essential part for planning an effective weed management for cropping systems. Field experiments were conducted during the seasonal growing periods of potato in 2012 and 2013 in Kayseri, Turkey to assess critical period for weed control (CPWC) in potato. A four parameter log-logistic model was used to assist in monitoring and analysing two sets of related, relative crop yield. Data was obtained during the periods of increased weed interference and as a comparison, during weed-free periods. In both years, the relative yield of potato decreased with a longer period of weed-interference whereas increased with increasing length of weed free period. In 2012, the CPWC ranged from 112 to 1014 GDD (Growing Degree Days) which corresponded to 8 to 66 days after crop emergence (DAE) and between 135-958 GDD (10 to 63 DAE) in the following year based on a 5% acceptable yield loss. Weed-free conditions needed to be established as early as the first week after crop emergence and maintained as late as ten weeks after crop emergence to avoid more than 5% yield loss in the potato. The results suggest that CPWC could well assist potato producers to significantly reduce the expense of their weed management programs as well as improving its efficacy.

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Interference between pigweed (Amaranthusspp.), barnyardgrass(Echinochloa crus-galli), and soybean (Glycine max)

Weed Science ◽

10.1017/s0043174500091050 ◽

1998 ◽

Vol 46 (5) ◽

pp. 533-539 ◽

Cited By ~ 53

Author(s):

Paul Cowan ◽

Susan E. Weaver ◽

Clarence J. Swanton

Keyword(s):

Competitive Ability ◽

Field Experiments ◽

Yield Loss ◽

Seedling Emergence ◽

Growth Time ◽

Weed Species ◽

Soybean Yield ◽

Competitive Index ◽

Loss Maximum ◽

Weed Emergence

Field experiments were conducted to determine the influence of time of emergence and density of single and multispecies populations of pigweed and barnyardgrass on soybean yield and competitive abilities of pigweed and barnyardgrass. Pigweed and barnyardgrass were established at selected densities within 12.5 cm on either side of the soybean row. Pigweed and barnyardgrass seeds were sown concurrently with soybean and at the cotyledon stage of soybean growth. Time and density of pigweed and barnyardgrass seedling emergence relative to soybean influenced the magnitude of soybean yield loss. Maximum soybean yield loss ranged from 32 to 99%, depending upon time of emergence relative to soybean. Pigweed was more competitive than barnyardgrass across all locations, years, and time of weed emergence. When pigweed was assigned a competitive index of 1 on a scale from 0 to 1, the competitive ability of barnyardgrass ranged from 0.075 to 0.40 of pigweed, depending upon location and time of emergence. This is the first multiple weed species study to include time of weed emergence relative to the crop. Competitive index values for multiple weed species must be calculated from field experiments in which weeds are grown with the crop under differing environmental conditions.

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Decision Rules for Postemergence Control of Pigweed (Amaranthusspp.) in Soybean (Glycine max)

Weed Science ◽

10.1017/s0043174500093656 ◽

1996 ◽

Vol 44 (1) ◽

pp. 126-132 ◽

Cited By ~ 47

Author(s):

Anita Dieleman ◽

Allan S. Hamill ◽

Glenn C. Fox ◽

Clarence J. Swanton

Keyword(s):

Weed Control ◽

Weed Management ◽

Economic Model ◽

Yield Loss ◽

Control Function ◽

Decision Rules ◽

Optimal Dose ◽

Weed Species ◽

Weed Density ◽

Control Decision

Weed control decision rules were derived for the application of postemergence herbicides to control pigweed species in soybean. Field experiments were conducted at two locations in 1992 and 1993 to evaluate soybean-pigweed interference. A damage function was determined that related yield loss to time of pigweed emergence, density, and soybean weed-free yield. A control function described pigweed species response to variable doses of imazethapyr and thifensulfuron. The integration of these two functions formed the basis of an economic model used to derive two weed control decision rules, the biologist's “threshold weed density” and the economist's “optimal dose.” Time of weed emergence had a more significant role than weed density in the economic model. Later-emerging pigweed caused less yield loss and therefore, decision rules lead to overuse of herbicides if emergence time is not considered. The selected herbicide dose influenced the outcome of the control function. Depending on the desired level of weed control, a herbicide could be chosen to either eradicate the escaped weed species (label or biologically-effective doses) or reduce the growth of the weed species and thereby offset interference (optimal dose). The development of a biologically-effective dose by weed species matrix was recommended. Decision rules should not be utilized as an exclusive weed management strategy but rather as a component of an integrated weed management program.

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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.

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Utility of Clomazone for Annual Grass and Broadleaf Weed Control in Peanut (Arachis hypogaea)

Weed Technology ◽

10.1017/s0890037x00039142 ◽

1994 ◽

Vol 8 (1) ◽

pp. 23-27 ◽

Cited By ~ 3

Author(s):

David L. Jordan ◽

John W. Wilcut ◽

Leslie D. Fortner

Keyword(s):

Weed Control ◽

Arachis Hypogaea ◽

Field Experiments ◽

Systems Approach ◽

Annual Grass ◽

Weed Species ◽

Common Ragweed ◽

Prickly Sida ◽

Better Than ◽

Large Crabgrass

Field experiments conducted in 1988 and 1989 evaluated clomazone alone and in a systems approach for weed control in peanut. Clomazone PPI at 0.8 kg ai/ha controlled common ragweed, prickly sida, spurred anoda, and tropic croton better than ethalfluralin and/or metolachlor applied PPI. POST application of acifluorfen plus bentazon was not needed to control these weeds when clomazone was used. Acifluorfen plus bentazon improved control of these weeds when clomazone was not used and generally were necessary to obtain peanut yields regardless of the soil-applied herbicides. Alachlor PRE did not improve clomazone control of any weed species evaluated. Fall panicum and large crabgrass control was similar with clomazone or clomazone plus ethalfluralin.

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Field Pea and Lentil Tolerance to Interrow Cultivation

Weed Technology ◽

10.1017/wet.2017.90 ◽

2017 ◽

Vol 32 (2) ◽

pp. 205-210 ◽

Cited By ~ 1

Author(s):

Katherine A. Stanley ◽

Steven J. Shirtliffe ◽

Dilshan Benaragama ◽

Lena D. Syrovy ◽

Hema S. N. Duddu

Keyword(s):

Weed Control ◽

Field Experiments ◽

Yield Loss ◽

Growing Season ◽

Field Pea ◽

Crop Damage ◽

Growth Stages ◽

Row Crops ◽

Narrow Row ◽

Mechanical Weed Control

AbstractInterrow cultivation is a selective, in-crop mechanical weed control tool that has the potential to control weeds later in the growing season with less crop damage compared with other in-crop mechanical weed control tools. To our knowledge, no previous research has been conducted on the tolerance of narrow-row crops to interrow cultivation. The objective of this experiment was to determine the tolerance of field pea and lentil to interrow cultivation. Replicated field experiments were conducted in Saskatchewan, Canada, in 2014 and 2015. Weekly cultivation treatments began at the 4-node stage of each crop, continuing for 6 wk. Field pea and lentil yield linearly declined with later crop stages of cultivation. Cultivating multiple times throughout the growing season reduced yield by 15% to 30% in both crops. Minimal yield loss occurred when interrow cultivation was conducted once at early growth stages of field pea and lentil; however, yield loss increased with delayed and more frequent cultivation events.

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