Duration of Broadleaf Weed Control with Isoxaben Using Soil Bioassays

1998 ◽  
Vol 12 (3) ◽  
pp. 542-547 ◽  
Author(s):  
Rakesh S. Chandran ◽  
Jeffrey F. Derr

A soil bioassay experiment was conducted in Blacksburg, VA, to determine the effect of isoxaben application timings and rates on duration of weed control. Flats containing soil were imbedded into the field. Isoxaben was applied in the spring, fall, and spring followed by fall (double application) at 0.56, 0.84, and 1.12 kg ai/ha. Flats were moved to a greenhouse at 0, 1, 3, 6, and 9 months after treatment (MAT) and seeded with yellow rocket, buckhorn plantain, and spotted spurge for the bioassays. Weed counts from treated flats were compared to those in untreated flats to determine percent control. Fall and spring followed by fall applications provided approximately 20% greater control of yellow rocket 3 MAT and 30% greater control 6 MAT, compared to a single spring application of isoxaben. Isoxaben at all rates controlled yellow rocket > 70% at 6 mo after fall application. At 3 MAT, fall and spring plus fall-applied isoxaben provided about 15 and 20% greater buckhorn plantain control, respectively, compared to spring application. The two highest rates of isoxaben controlled buckhorn plantain > 70% at 3 mo after fall application, but provided poor control at 6 MAT. Control of spotted spurge was similar among the three application timings for isoxaben and was unacceptable at most evaluation dates. Overall, isoxaben applied at 1.12 kg/ha provided better control of all three weed species for a longer time than the reference herbicide, oxadiazon, applied at 3.36 kg/ha.

HortScience ◽  
1998 ◽  
Vol 33 (2) ◽  
pp. 207f-208
Author(s):  
Annamarie Pennuci

Novel and standard herbicides were applied alone, sequentially, or tank-mixed to determine weed control efficacies and tolerances in 15 species of field-grown herbaceous perennials. Autumn applications provided excellent but short-term broadleaf (BL) and annual grass (AG) weed control. Early spring applications were equally effective and of longer duration. Mid- and late spring treatments provided moderate to poor control of AG and poor control of winter perennial BL. Single applications of prodiamine provided season-long control of AG and of spring germinating BL. Greatest number of weed species were controlled by DCPA. Increased duration occurred with tank-mixes of DCPA + pendlimethalin, DCPA + quinclorac. Quinclorac provided excellent pre/post control of AG and some BL. Crop injury was minimized with directed applications. Isoxaben provided excellent preemergent control of BL. Tank-mixes improved AG control. Treatments applied prior to, or at the same time as mulch applications increased weed control and lessened drought stress. Treatments applied over mulch were less effective, suppressed fewer weed species, were of shortened duration, and increased the likelihood of crop injury.


2020 ◽  
Vol 57 (3) ◽  
pp. 199-210
Author(s):  
Rajib Kundu ◽  
Mousumi Mondal ◽  
Sourav Garai ◽  
Ramyajit Mondal ◽  
Ratneswar Poddar

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.


2021 ◽  
pp. 1-28
Author(s):  
Nicholas T. Basinger ◽  
Nicholas S. Hill

Abstract With the increasing focus on herbicide-resistant weeds and the lack of introduction of new modes of action, many producers have turned to annual cover crops as a tool for reducing weed populations. Recent studies have suggested that perennial cover crops such as white clover could be used as living mulch. However, white clover is slow to establish and is susceptible to competition from winter weeds. Therefore, the objective of this study was to determine clover tolerance and weed control in established stands of white clover to several herbicides. Studies were conducted in the fall and winter of 2018 to 2019 and 2019 to 2020 at the J. Phil Campbell Research and Education Center in Watkinsville, GA, and the Southeast Georgia Research and Education Center in Midville, GA. POST applications of imazethapyr, bentazon, or flumetsulam at low and high rates, or in combination with 2,4-D and 2,4-DB, were applied when clover reached 2 to 3 trifoliate stage. Six weeks after the initial POST application, a sequential application of bentazon and flumetsulam individually, and combinations of 2,4-D, 2,4-DB, and flumetsulam were applied over designated plots. Clover biomass was similar across all treatments except where it was reduced by sequential applications of 2,4-D + 2,4-DB + flumetsulam in the 2019 to 2020 season indicating that most treatments were safe for use on establishing living mulch clover. A single application of flumetsulam at the low rate or a single application of 2,4-D + 2,4-DB provided the greatest control of all weed species while minimizing clover injury when compared to the non-treated check. These herbicide options allow for control of problematic winter weeds during clover establishment, maximizing clover biomass and limiting canopy gaps that would allow for summer weed emergence.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1326
Author(s):  
Calvin F. Glaspie ◽  
Eric A. L. Jones ◽  
Donald Penner ◽  
John A. Pawlak ◽  
Wesley J. Everman

Greenhouse studies were conducted to evaluate the effects of soil organic matter content and soil pH on initial and residual weed control with flumioxazin by planting selected weed species in various lab-made and field soils. Initial control was determined by planting weed seeds into various lab-made and field soils treated with flumioxazin (71 g ha−1). Seeds of Echinochloa crus-galli (barnyard grass), Setaria faberi (giant foxtail), Amaranthus retroflexus (redroot pigweed), and Abutilon theophrasti (velvetleaf) were incorporated into the top 1.3 cm of each soil at a density of 100 seeds per pot, respectively. Emerged plants were counted and removed in both treated and non-treated pots two weeks after planting and each following week for six weeks. Flumioxazin control was evaluated by calculating percent emergence of weeds in treated soils compared to the emergence of weeds in non-treated soils. Clay content was not found to affect initial flumioxazin control of any tested weed species. Control of A. theophrasti, E. crus-galli, and S. faberi was reduced as soil organic matter content increased. The control of A. retroflexus was not affected by organic matter. Soil pH below 6 reduced flumioxazin control of A. theophrasti, and S. faberi but did not affect the control of A. retroflexus and E. crus-galli. Flumioxazin residual control was determined by planting selected weed species in various lab-made and field soils 0, 2, 4, 6, and 8 weeks after treatment. Eight weeks after treatment, flumioxazin gave 0% control of A. theophrasti and S. faberi in all soils tested. Control of A. retroflexus and Chenopodium album (common lambsquarters) was 100% for the duration of the experiment, except when soil organic matter content was greater than 3% or the soil pH 7. Eight weeks after treatment, 0% control was only observed for common A. retroflexus and C. album in organic soil (soil organic matter > 80%) or when soil pH was above 7. Control of A. theophrasti and S. faberi decreased as soil organic matter content and soil pH increased. Similar results were observed when comparing lab-made soils to field soils; however, differences in control were observed between lab-made organic matter soils and field organic matter soils. Results indicate that flumioxazin can provide control ranging from 75–100% for two to six weeks on common weed species.


1996 ◽  
Vol 10 (2) ◽  
pp. 253-257 ◽  
Author(s):  
Joan A. Dusky ◽  
William M. Stall

Imazethapyr was evaluated PRE and POST in five lettuce types and chicory under Florida field conditions. The relative sensitivity of leafy crop vigor (most sensitive to most tolerant) to imazethapyr PRE, based on 20% inhibition determined using regression analysis, was as follows: Boston > bibb > crisphead > romaine > leaf > escarole > endive. Leafy crop injury increased as the rate of imazethapyr applied POST increased, with all leafy crops responding in a similar manner. Surfactant addition increased imazethapyr phytotoxicity. Imazethapyr PRE treatments at 0.067 kg ai/ha provided greater than 80% control of livid amaranth, common purslane, flatsedge, and common lambsquarters. Imazethapyr POST at 0.067 kg/ha, with surfactant provided control greater than 85% of all weed species. Greater than 85% spiny amaranth control was provided by imazethapyr POST at 0.017 kg/ha. Use of surfactant with imazethapyr did not improve spiny amaranth control over imazethapyr with no surfactant. POST treatments did not decrease leafy crop yield compared with the hand-weeded check. Imazethapyr applied PRE reduced crop yield compared to the POST treatments and the hand-weeded control.


2006 ◽  
Vol 86 (3) ◽  
pp. 875-885 ◽  
Author(s):  
J. R. Moyer ◽  
S. N. Acharya

Weeds, especially dandelion (Taraxacum officinale Weber in F.H. Wigg.), tend to infest a forage alfalfa (Medicago sativa L.) stand 2 to 4 yr after establishment. To develop better weed management systems, experiments were conducted at Lethbridge, Alberta, from 1995 to 2002 and Creston, British Columbia, from 1998 to 2001, which included the alfalfa cultivars Beaver (standard type) and AC Blue J (Flemish type) and annual applications of metribuzin and hexazinone. These herbicides are registered for weed control in irrigated alfalfa in Alberta and alfalfa grown for seed. In addition, two sulfonylurea herbicides, metsulfuron and sulfosulfuron, and glyphosate were included. All of the herbicides except glyphosate controlled or suppressed dandelion and mustard family weeds. Metsulfuron at 5 g a.i. ha-1 almost completely controlled dandelion at both locations. However, after metsulfuron application at Lethbridge, dandelion was replaced with an infestation of downy brome, which is unpalatable for cattle. None of the herbicides increased total forage (alfalfa + weed) yield, and in some instances herbicides reduced forage quality by causing a shift from a palatable to an unpalatable weed species. However, it was observed that AC Blue J consistently yielded more than Beaver, and weed biomass was consistently less in the higher-yielding cultivar. AC Blue J was developed primarily for the irrigated area in southern Alberta and for southern British Columbia. Therefore, additional experiments should be conducted to determine which alfalfa cultivars have the greatest ability to compete with weeds in other regions of western Canada. Key words: Alfalfa yield, dandelion, forage quality, weed control


2005 ◽  
Vol 23 (4) ◽  
pp. 204-211
Author(s):  
Donna C. Fare ◽  
Patricia Knight ◽  
Charles H. Gilliam ◽  
James Altland

Abstract Four experiments were conducted to investigate herbicides currently labeled for field and/or container production for use in pot-in-pot production. Southern magnolia (Magnolia grandiflora L.), red maple (Acer rubrum Spach. ‘Autumn Flame’ and ‘Franksred’), ornamental pear (Pyrus calleryana Decne. ‘Bradford’ and ‘Cleveland Select’), river birch (Betula nigra L.), green ash (Fraxinus pennsylvanica Marsh. and F. pennsylvanica Marsh.‘Marshall's Seedless’), and zelkova (Zelkova serrata Spach ‘Village Green’) were evaluated for herbicide tolerance. Barricade 65WG, Surflan 4AS, and Pendulum 60WDG, used alone or in combination with Princep and Gallery 75 DF, had no adverse effect on tree shoot growth or trunk caliper growth when applied as a directed band application. Weed control varied depending upon local site conditions, herbicide rate and weed species.


2021 ◽  
Vol 1 (3) ◽  
pp. 1-9
Author(s):  
O. Ariunaa ◽  
T. Erdenenzorig ◽  
B. Dondov

Our country has provided about 52% of vegetables from domestic production, the rest part imported others from outside. Thus, imports of potatoes and vegetables have been reduced last year, for this reason, main vegetable seeds, were produced domestically and provided over 80 percent of the country’s demand. In the future domestic production demand of vegetable goal set working to provide by 100 percent from government our country in this connection issues urgent need to solve sowing seeds, variety supply, seed production, and plant protection. According to our research, during the growing season, 150-350 weeds growing per 1m2 of rounded onions shows that the amount of crop damage is relatively high. For the purpose of control against weeds in the onion field with 3 repetitions of 7 variants of 2 types of herbicides are conducted experimental research. These include; pre-emergent Estamp (Stomp) herbicide applied in doses 2.5; 3.5 l/ha that controls all types of weeds, but showed results of 65.2-72.4%. The growing season during a selective post-emergent of Gaur herbicide in doses 0.7; 0.9l/ ha used against broadleaf and grassy weeds that became clear of weed species density reduced by 92.7-93.4%. It was tested in this study Pendimethalin, 33% + Oxyfluorfen 24 % mixture herbicides have reduced the number of weeds by 92.4-94.1%.


1992 ◽  
Vol 10 (1) ◽  
pp. 43-45 ◽  
Author(s):  
W.A. Skroch ◽  
M.A. Powell ◽  
T.E. Bilderback ◽  
P.H. Henry

Abstract Five organic mulches (pine bark, hardwood bark, cedar chips, longleaf pine needles, shortleaf pine needles), used alone or in combination with two inorganic mulches (black polyethylene, woven polypropylene), were evaluated over two years for weed control, durability, aesthetic value, and influence upon soil temperature. Organic mulches reduced total weed counts by 50% compared to control plots. and underlaying organic mulches with polyethylene resulted in complete control. Polypropylene, used in combination with organic mulch, was ineffective in controlling perennial weed species. Pine bark was the most durable organic mulch, requiring the least replenishment (70% initial volume) after 630 days. Durability of organic mulches increased when underlaid with polyethylene. Longleaf pine needles were rated most attractive, and underlying organic materials with either polyethylene or polypropylene enhanced appearance. Organic mulches reduced maximum daily temperatures at the soil surface by 2.2–3.3°C (4–6°F) and increased minimum daily temperatures by 1.1–2.2°C (2–4°F). However, the type of organic mulch did not affect temperatures at the soil surface.


2011 ◽  
Vol 25 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Jared R. Whitaker ◽  
Alan C. York ◽  
David L. Jordan ◽  
A. Stanley Culpepper

Glyphosate-resistant (GR) Palmer amaranth has become a serious pest in parts of the Cotton Belt. Some GR cotton cultivars also contain the WideStrike™ insect resistance trait, which confers tolerance to glufosinate. Use of glufosinate-based management systems in such cultivars could be an option for managing GR Palmer amaranth. The objective of this study was to evaluate crop tolerance and weed control with glyphosate-based and glufosinate-based systems in PHY 485 WRF cotton. The North Carolina field experiment compared glyphosate and glufosinate alone and in mixtures applied twice before four- to six-leaf cotton. Additional treatments included glyphosate and glufosinate mixed withS-metolachlor or pyrithiobac applied to one- to two-leaf cotton followed by glyphosate or glufosinate alone on four- to six-leaf cotton. All treatments received a residual lay-by application. Excellent weed control was observed from all treatments on most weed species. Glyphosate was more effective than glufosinate on glyphosate-susceptible (GS) Palmer amaranth and annual grasses, while glufosinate was more effective on GR Palmer amaranth. Annual grass and GS Palmer amaranth control by glyphosate plus glufosinate was often less than control by glyphosate alone but similar to or greater than control by glufosinate alone, while mixtures were more effective than either herbicide alone on GR Palmer amaranth. Glufosinate caused minor and transient injury to the crop, but no differences in cotton yield or fiber quality were noted. This research demonstrates glufosinate can be applied early in the season to PHY 485 WRF cotton without concern for significant adverse effects on the crop. Although glufosinate is often less effective than glyphosate on GS Palmer amaranth, GR Palmer amaranth can be controlled with well-timed applications of glufosinate. Use of glufosinate in cultivars with the WideStrike trait could fill a significant void in current weed management programs for GR Palmer amaranth in cotton.


Sign in / Sign up

Export Citation Format

Share Document