Time of Day Impacts Postemergence Weed Control in Corn

2009 ◽  
Vol 23 (3) ◽  
pp. 346-355 ◽  
Author(s):  
Christie L. Stewart ◽  
Robert E. Nurse ◽  
Peter H. Sikkema
Keyword(s):  
Light Intensity ◽  
Weed Control ◽  
Air Temperature ◽  
Ambient Air ◽  
Field Trials ◽  
Time Of Day ◽  
Weed Species ◽  
Application Timing ◽  
Reducing Costs ◽  
Species Specific

Field trials were conducted from 2005 to 2007 at two locations in southwestern Ontario to investigate how weed control in corn was affected by the time of day that herbicides were applied. Weed control following the application of six POST herbicides (atrazine, bromoxynil, dicamba/diflufenzopyr, glyphosate, glufosinate, and nicosulfuron) at 06:00, 09:00, 12:00, 15:00, 18:00, 21:00, and 24:00 h was assessed. For many weed species herbicide efficacy was reduced when applications were made at 06:00, 21:00, and 24:00 h. Velvetleaf was the most sensitive to the time of day effect, followed by common ragweed, common lambsquarters, and redroot pigweed. Annual grasses were not as sensitive to application timing; however, control of barnyardgrass and green foxtail was reduced in some environments at 06:00 h and after 21:00 h. Only in the most severe cases was the grain yield of corn reduced due to decreased weed control. Daily changes in air temperature, relative humidity, and light intensity that cause species-specific physiological changes may account for the variation in weed control throughout the day. The results of this research suggest that there is a strong species-specific influence of ambient air temperature, light intensity, and leaf orientation on the efficacy of POST herbicides. These results should aid growers in applying herbicides when they are most efficacious, thus reducing costs associated with reduced efficacy.

Alternatives to Atrazine for Weed Management in Processing Sweet Corn

Weed Science ◽  
2016 ◽  
Vol 64 (3) ◽  
pp. 531-539 ◽  
Author(s):  
Zubeyde Filiz Arslan ◽  
Martin M. Williams ◽  
Roger Becker ◽  
Vincent A. Fritz ◽  
R. Ed Peachey ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Sweet Corn ◽  
Crop Yields ◽  
Production Systems ◽  
Field Trials ◽  
Management Systems ◽  
Weed Species ◽  
Application Timing ◽  
Production Areas

Atrazine has been the most widely used herbicide in North American processing sweet corn for decades; however, increased restrictions in recent years have reduced or eliminated atrazine use in certain production areas. The objective of this study was to identify the best stakeholder-derived weed management alternatives to atrazine in processing sweet corn. In field trials throughout the major production areas of processing sweet corn, including three states over 4 yr, 12 atrazine-free weed management treatments were compared to three standard atrazine-containing treatments and a weed-free check. Treatments varied with respect to herbicide mode of action, herbicide application timing, and interrow cultivation. All treatments included a PRE application of dimethenamid. No single weed species occurred across all sites; however, weeds observed in two or more sites included common lambsquarters, giant ragweed, morningglory species, velvetleaf, and wild-proso millet. Standard treatments containing both atrazine and mesotrione POST provided the most efficacious weed control among treatments and resulted in crop yields comparable to the weed-free check, thus demonstrating the value of atrazine in sweet corn production systems. Timely interrow cultivation in atrazine-free treatments did not consistently improve weed control. Only two atrazine-free treatments consistently resulted in weed control and crop yield comparable to standard treatments with atrazine POST: treatments with tembotrione POST either with or without interrow cultivation. Additional atrazine-free treatments with topramezone applied POST worked well in Oregon where small-seeded weed species were prevalent. This work demonstrates that certain atrazine-free weed management systems, based on input from the sweet corn growers and processors who would adopt this technology, are comparable in performance to standard atrazine-containing weed management systems.

The Effect of Time of Day on the Activity of Postemergence Soybean Herbicides

2013 ◽  
Vol 27 (4) ◽  
pp. 690-695 ◽  
Author(s):  
Gregory J. Stopps ◽  
Robert E. Nurse ◽  
Peter H. Sikkema
Keyword(s):  
Weed Control ◽  
Yield Loss ◽  
Early Morning ◽  
Field Trials ◽  
Time Of Day ◽  
Weed Species ◽  
Time Of Application ◽  
Late Evening ◽  
Chlorimuron Ethyl ◽  
Herbicide Activity

The effect of time of day (TOD) on the activity of six common POST herbicides was investigated in field trials from 2007 to 2009 at two locations in southwestern Ontario. Percentage weed control was assessed following application of bentazon, chlorimuron-ethyl, fomesafen, glyphosate, imazethapyr, or quizalofop-p-ethyl applied at 3-h intervals from 6:00 A.M. to midnight, when weeds averaged 15 cm tall. The effect of time of day varied with weed species, but weed control was generally reduced when herbicides were applied at 6:00 A.M., 9:00 P.M., and midnight. Herbicide activity on velvetleaf was most frequently reduced, especially for chlorimuron-ethyl, glyphosate, and imazethapyr. Control of common ragweed with glyphosate and imazethapyr was also affected by the timing of application, and pigweed species only showed an effect with glyphosate. Variation in temperature, relative humidity, and dew presence/absence at different times of the day, as well as morphological/physiological characteristics such as weed size at time of application and diurnal leaf movement in response to light intensity, may account for the variation in weed control at different times of the day. Significant soybean yield loss was not observed in this study, but may occur if herbicide efficacy is severely reduced by application at inappropriate times of day. These results provide valuable information for growers, and suggest that POST herbicides are most effective when applied midday, rather than in the early morning or late evening.

Influence of Herbicide Application Rate, Timing, and Interrow Cultivation on Weed Control and Corn (Zea mays) Yield in Glufosinate-Resistant and Glyphosate-Resistant Corn

1999 ◽  
Vol 13 (4) ◽  
pp. 807-813 ◽  
Author(s):  
Brent E. Tharp ◽  
James J. Kells
Keyword(s):  
Zea Mays ◽  
Weed Control ◽  
Field Trials ◽  
Application Rate ◽  
Corn Yield ◽  
Herbicide Application ◽  
Weed Species ◽  
Application Timing ◽  
Glufosinate Ammonium ◽  
Application Rates

Field trials were conducted in 1996 and 1997 to determine the influence of glufosinate and glyphosate application rates, application timings, and interrow cultivation on weed control and corn yield. Glufosinate-ammonium rates ranged from 0.18 to 0.41 kg ai/ha, while rates for the isopropylamine salt of glyphosate ranged from 0.21 to 0.84 kg ae/ha. Increasing rates of glufosinate and glyphosate often improved weed control. Control of many of the weed species was improved by delaying herbicide application timing. Weed control was most consistent from late postemergence (LPOST) applications of glufosinate at 0.41 kg ai/ha or glyphosate at 0.84 kg ae/ha. Corn yields were reduced due to incomplete weed control when the lowest rate of glufosinate was applied. Weed control from early postemergence (EPOST) glufosinate and glyphosate applications followed by cultivation was similar to weed control from LPOST glufosinate and glyphosate applications without cultivation. Interrow cultivation following glufosinate or glyphosate application did not affect corn yield.

Effect of Formulation and Application Time of Day on Detecting Dicamba in the Air under Field Conditions

Weed Science ◽  
2013 ◽  
Vol 61 (4) ◽  
pp. 586-593 ◽  
Author(s):  
Thomas C. Mueller ◽  
Daniel R. Wright ◽  
Kirk M. Remund
Keyword(s):  
Ambient Air ◽  
Field Studies ◽  
Field Trials ◽  
Time Of Day ◽  
Field Conditions ◽  
Sample Collection ◽  
Weather Variables ◽  
Application Timing ◽  
Time Period ◽  
Over The Top

The development of dicamba-tolerant and other auxin-tolerant crops will enable the use of these effective herbicides in soybean and cotton at application timings such as at planting or over-the-top that are not currently possible. This research examined the effect of various factors on detection of postapplication amounts of dicamba in the air under field conditions by coupling a sample collection system with advanced chemical analysis of those samples. The quantity of dimethylamine salt of dicamba that was detected within 48 hr after application was two times greater (P < 0.05) than the quantity of diglycoamine salt formulation based on field studies in 2009. Regardless of application timing, the amount of detected dicamba was greatest during the 0 to 12 hr time period after application. However, the total detected after 48 hr was less for evening applications (5 micrograms [µg]) compared with midday (17 µg) or morning (14 µg) applications based on 2010 field trials. Average ambient air temperature (and other weather variables) correlated with higher detection levels of dicamba in the air in the field.

Influence of Time of Day on Dicamba and Glyphosate Efficacy

2021 ◽  
pp. 1-20
Author(s):  
Jacob R. Kalina ◽  
Chris B. Corkern ◽  
Donn G. Shilling ◽  
Nicholas T. Basinger ◽  
Timothy L. Grey
Keyword(s):  
Weed Control ◽  
Time Of Day ◽  
Genetically Engineered ◽  
Herbicide Application ◽  
Weed Species ◽  
Application Timing ◽  
Group 4 ◽  
Crop Varieties ◽  
Prickly Sida ◽  
Multiple Field

Abstract Renewed interest in studying auxin herbicides (WSSA group 4) is increasing due to the release of genetically engineered crop varieties that are tolerant to PRE and POST applications of specific formulations of dicamba. The development of auxin-resistant crops was in response to the development of herbicide-resistant weed species to glyphosate and other herbicides. Research was conducted at multiple field locations in Georgia in 2018 and 2019 to examine weed control when POST herbicides were applied to dicamba and glyphosate-resistant cotton at eight different points in time over a 24-hr period. Applications occurred at 1-hr prior to sunrise all the way up to midnight in one day to examine the effect of herbicide application timing on broadleaf weed control. Glyphosate, dicamba, and glyphosate plus dicamba were applied at each timing. Visual ratings of weed control were evaluated at 7, 14, 21, and 28 days after treatment (DAT). Weed control was affected by herbicide application timing. Midnight applications resulted in the lowest levels of control. Sicklepod, pitted morningglory, and prickly sida control was 49, 38, and 41% respectively. Greatest control of all three species (up to 99%) occurred from the noon to 1-hr prior to sunset application timings. Orthogonal contrasts of timing of application indicated that weed control was improved with day > night and pre-dawn > midnight.

The Potential Use of Vinegar and a Clove Oil Herbicide for Weed Control in Sweet Corn, Potato, and Onion

2009 ◽  
Vol 23 (1) ◽  
pp. 120-128 ◽  
Author(s):  
G. J. Evans ◽  
R. R. Bellinder
Keyword(s):  
Weed Control ◽  
Sweet Corn ◽  
Field Trials ◽  
Clove Oil ◽  
Weed Species ◽  
Marketable Yield ◽  
Yield Data ◽  
Application Timing ◽  
Time Of Application ◽  
Potential Use

Natural products might provide an organic means of weed control. Our objective was to evaluate the potential use of vinegar and a clove-oil product with regard to how volume, concentration, and application timing affect weed control and crop response. Treatments included broadcast applications of 200- and 300-grain vinegar at 318 liters per hectare (L/ha), 150- and 200-grain vinegar at 636 L/ha, a 3.4% v/v clove oil mixture in water (318 L/ha), and a 1.7% clove oil mixture in 200-grain vinegar (318 L/ha). Field trials were conducted in sweet corn, onion, and potato. Weed control, weed biomass, crop injury, and yield data were collected. Corn treated at 15 and at 30 to 45 cm was initially burned and stunted by these products. By 4 wk after application much of the initial injury was outgrown. Late applications significantly reduced yields of early-maturing sweet corn ‘Trinity’. With the exception of the 200-grain vinegar (318 L/ha) treatment, early applications to sweet corn ‘Avalon’ did not reduce marketable yield. Two hundred-grain vinegar (636 L/ha) applied to pre-emergence–flag stage onion reduced the duration of the first handweeding by 59 to 67%. All treatments reduced onion yields when treated at the 2-leaf stage. Potato treated early (2 to 10 cm) and late (30 cm) were injured by all vinegar treatments 59 to 83%, 1 d after treatment (DAT). Potato yield losses were insignificant with applications of 3.4% clove oil and with some low-volume (318 L/ha) vinegar treatments. Product efficacy was dependent on the weed species and their size at the time of application. Weed control was greatest (83%, 1 DAT) with 200-grain vinegar (636 L/ha). Broadcast applications of vinegar and clove oil have potential for use on young, actively growing sweet corn, onion, and potato.

scholarly journals FLUAZIFOP-P-BUTYL EFFICACY AS A FUNCTION OF APPLICATION TIME AND HERBICIDE DOSE

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
L.F. CIESLIK ◽  
R.A. VIDAL ◽  
A.B. MACHADO ◽  
M.M. TREZZI
Keyword(s):  
Relative Humidity ◽  
Common Bean ◽  
Weed Control ◽  
Air Temperature ◽  
Field Experiments ◽  
Time Of Day ◽  
Leaf Angle ◽  
Herbicide Application ◽  
The Common ◽  
Bean Crop

ABSTRACT Grass weeds are common in summer crops and strongly decreases the grain yield of the common bean crop. The time of herbicide application influences the variability of environmental conditions and affects the product performance. The objectives of this work were to identify the time of fluazifop-p-butyl (fluazifop) application which gives best grass weed control in the common bean crop and to elucidate the environmental variables most important for the efficacy of this herbicide. Field experiments were conducted involving five application times (2 a.m., 6 a.m., 11 a.m., 4 p.m. and 9 p.m.) and five doses of fluazifop (80, 110, 140, 170 and 200 g ha-1), with additional no-herbicide control. At the time of the herbicide application it was determined the air temperature, relative humidity, the photosynthetically active radiation (PAR) and the leaf angle, whereas the weed control and the dry mass of the weed Urochloa plantaginea was assessed at 20 days after treatment (DAT). Efficacy on grass control with fluazifop was dependent on the herbicide dose and on the time of day that the product was applied. Spray at early morning hours (6 a.m.) showed better efficacy on weed control in relation to periods during warmer conditions of the day (11 a.m. and 4 p.m.). Nocturnal fluazifop application had better weed control when compared to herbicide sprayed in the afternoon. The air temperature, relative humidity and PAR were correlated to weed leaf angle, which correlated the most with fluazifop performance.

Evaluating the EPA's Comparative Product Performance Testing Guidelines for Herbicides in Snap Bean (Phaseolus vulgaris)

1998 ◽  
Vol 12 (2) ◽  
pp. 215-222
Author(s):  
Robin R. Bellinder ◽  
Marija Arsenovic ◽  
Jonathan J. Kirkwyland ◽  
Russell W. Wallace
Keyword(s):  
Weed Control ◽  
Environmental Protection Agency ◽  
Performance Testing ◽  
Good Control ◽  
Field Trials ◽  
Weed Species ◽  
Snap Bean ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Product Comparison

Following suggested guidelines developed by the Environmental Protection Agency (EPA), comparative snap bean herbicide performance field trials were conducted from 1993 to 1995 in New York. Data were obtained on crop injury, weed control, and weed biomass, and crop yield, quality, and losses during harvest. Trifluralin, EPTC, and pendimethalin applied preplant incorporated (PPI) and applications of metolachlor applied preemergence (PRE) provided less than adequate control of redroot pigweed, common lambsquarters, and hairy galinsoga. Cultivation improved weed control with PPI and PRE applications. Metolachlor + fomesafen PRE provided good control of hairy galinsoga, adequate redroot pigweed control, and marginal control of common lambsquarters. Fomesafen applied postemergence (POST), combinations of metolachlor applied PRE with fomesafen or bentazon applied POST, and fomesafen + bentazon applied POST adequately controlled the three weed species without cultivation. Herbicide treatments had little measurable impact on snap bean quality or losses during harvest. Information from product comparison trials may be useful in developing recommendations for growers but may prove less than adequate in providing data necessary for a thorough evaluation of the relative benefits of individual herbicides as intended by EPA guidelines. Difficulties were encountered in following the guidelines, and costs of conducting the product comparison trials for a single crop in one growing region exceeded $90,000 over 3 yr.

Influence of Simulated Rainfall and Soil Moisture on Herbicidal Activity of Cinmethylin

Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 267-272 ◽  
Author(s):  
Steven G. Russell ◽  
Thomas J. Monaco ◽  
Jerome B. Weber
Keyword(s):  
Weed Control ◽  
Sandy Loam ◽  
Field Trials ◽  
Herbicidal Activity ◽  
Herbicide Application ◽  
Weed Species ◽  
Green Foxtail ◽  
Loam Soil ◽  
Dry Soil ◽  
Prickly Sida

Field trials were conducted in 1986 and 1987 to determine the effects of moisture on herbicidal activity of cinmethylin applied preemergence at 0.0, 0.3, 0.6, and 0.9 kg ai ha to both dry and moist sandy loam soil. Herbicide application was followed by varying amounts of irrigation. Weed species included velvetleaf, prickly sida, green foxtail, and barnyardgrass. When cinmethylin was applied to a moist soil or when 2.5 cm of irrigation was applied 5 days after cinmethylin application to a dry soil, overall weed control was reduced. Optimum weed control resulted from cinmethylin application to dry soil followed either by a 2.5-cm irrigation within 8 h or a 7.6-cm irrigation within 36 h.

Weed Control and Selectivity of Pethoxamid Alone and in Mixture as a Delayed Preemergence Application to Rice

2018 ◽  
Vol 32 (5) ◽  
pp. 537-543
Author(s):  
John Godwin ◽  
Jason K. Norsworthy ◽  
Robert C. Scott
Keyword(s):  
Weed Control ◽  
Herbicide Resistance ◽  
Field Trials ◽  
Shoot Density ◽  
Red Rice ◽  
Weed Species ◽  
Viable Option ◽  
Long Chain Fatty Acid ◽  
Herbicide Resistant ◽  
Sites Of Action

AbstractThe evolution of herbicide resistance is making it extremely difficult for US rice producers to use chemical control on weed species such as barnyardgrass and red rice. To combat herbicide resistance, it is imperative that alternative herbicide sites of action (SOAs) be incorporated into rice whenever possible. There are currently no very-long-chain fatty acid–inhibiting herbicides (WSSA Group 15) labeled for use in US rice; however, pethoxamid is one such herbicide currently under development. If appropriate rice tolerance and weed control can be established, pethoxamid would represent a unique herbicide SOA for use in US rice. We conducted field trials near Stuttgart, AR, in 2015 and near Colt and Lonoke, AR, in 2016 to assess selectivity of pethoxamid and weed control alone and in combination with other herbicides as a delayed preemergence (DPRE) application in drill-seeded rice. Pethoxamid was applied at 0, 420, or 560 g ai ha–1 alone and in combination with clomazone, imazethapyr, pendimethalin, and quinclorac. Minimal rice injury occurred with any treatment assessed. A reduction in rice shoot density and plant height compared to the nontreated control followed the use of pethoxamid; however, no decrease in yield resulted. The highest levels of barnyardgrass control followed the use of imazethapyr at 91% and quinclorac at 89% regardless of the presence of pethoxamid near Lonoke; however, pethoxamid applied at both rates in combination with clomazone and quinclorac increased barnyardgrass control compared to clomazone and quinclorac applied alone. Near Colt, barnyardgrass control of 92% and 96% resulted from pethoxamid alone, averaged over the high and low rates. Based on these data, rice can tolerate pethoxamid when applied DPRE, and adequate levels of barnyardgrass control can be achieved at the rates evaluated within a program; hence, pethoxamid appears to be a viable option for use in rice to allow for increased rotation of herbicide SOAs to combat herbicide-resistant and difficult-to-control weeds.

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