Comparison of Split or Single Application of Gypsum for Wild Lowbush Blueberry (Vaccinium angustifoliumAit.)

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.

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A Dieldrin Case Study: Another Evidence of an Obsolete Substance in the European Soil Environment

Agriculture ◽

10.3390/agriculture11040314 ◽

2021 ◽

Vol 11 (4) ◽

pp. 314

Author(s):

Petros Tsiantas ◽

Evangelia N. Tzanetou ◽

Helen Karasali ◽

Konstantinos M. Kasiotis

Keyword(s):

Active Substance ◽

Anthropogenic Activities ◽

Carcinogenic Risk ◽

The European Union ◽

Soil Environment ◽

Single Application ◽

Environmental Concentration ◽

Tandem Mass Spectrometric ◽

Potential Use

Soil constitutes a central environmental compartment that, due to natural and anthropogenic activities, is a recipient of several contaminants. Among them, organochlorine pesticides are of major concern, even though they have been banned decades ago in the European Union, due to their persistence and the health effects they can elicit. In the presented work, a gas chromatographic tandem mass spectrometric (GC-MS/MS) developed method was applied to soil samples after the suspected and potential use of formulations containing organochlorine active substance. One soil sample was positive to dieldrin at 0.018 mg kg−1. Predicted environmental concentration in soil (PECsoil) considering a single application of this active substance potentially attributed the finding in its past use. The subsequent health risk assessment showed negligible non-carcinogenic risk and tolerable carcinogenic risk. The latter signifies that repetitive and prolonged sampling can unveil the pragmatic projection of persistent chemicals’ residues in the soil.

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Response of seashore paspalum and bermudagrass to topramezone and triclopyr mixtures

Weed Technology ◽

10.1017/wet.2020.127 ◽

2020 ◽

pp. 1-8

Author(s):

Clebson G. Gonçalves ◽

Austin M. Brown ◽

Suma Basak ◽

J. Scott McElroy

Keyword(s):

Field Conditions ◽

Single Application ◽

Seashore Paspalum ◽

Application Timing ◽

Application Programs ◽

Over Time

Abstract Few options are available for controlling bermudagrass invasion of seashore paspalum. Bermudagrass and seashore paspalum tolerance to topramezone, triclopyr, or the combination of these two herbicides were evaluated in both greenhouse and field conditions. Field treatments included two sequential applications of topramezone (15.6 g ai ha−1) alone and five rates of topramezone + triclopyr (15.6 + 43.2, 15.6 + 86.3, 15.6 + 172.6, 15.6 + 345.2, or 15.6 g ai ha−1 + 690.4 g ae ha−1). Secondary greenhouse treatments included a single application of topramezone (20.8 g ha−1) or triclopyr (258.9 g ha−1) alone, or in combination at 20.8 + 258.9 or 20.8 + 517.8 g ha−1, respectively. Greenhouse and field results showed that topramezone applications in combination with triclopyr present opposite responses between bermudagrass and seashore paspalum. Topramezone increased bermudagrass injury and decreased seashore paspalum bleaching injury compared to topramezone alone. In field evaluations, topramezone + triclopyr at 15.6 + 690.4 g ha−1 used in sequential applications resulted in >90% injury to bermudagrass, however, injury decreased over time. Furthermore, sequential applications of topramezone + triclopyr at 15.6 + 690.4 g ha−1 resulted in >50% injury to seashore paspalum. Application programs including topramezone plus triclopyr should increase bermudagrass suppression and reduce seashore paspalum injury compared to topramezone alone. However, additional studies are needed because such practices will likely require manipulation of topramezone rate, application timing, application interval, and number of applications in order to maximize bermudagrass control and minimize seashore paspalum injury.

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Control of Helicoverpa zea in Tomatoes with Chlorantraniliprole Applied Through Drip Chemigation

Plant Health Progress ◽

10.1094/php-2009-0407-01-rs ◽

2010 ◽

Vol 11 (1) ◽

pp. 21 ◽

Cited By ~ 11

Author(s):

Thomas P. Kuhar ◽

James F. Walgenbach ◽

Hélène B. Doughty

Keyword(s):

North Carolina ◽

Helicoverpa Zea ◽

Field Trials ◽

Single Application ◽

Beneficial Arthropods ◽

Worker Exposure ◽

Anthranilic Diamide ◽

Mammalian Toxicity ◽

Tomato Fruitworm ◽

Reduced Risk

Chlorantraniliprole (=Rynaxypyr) is a novel anthranilic diamide insecticide that is of interest to vegetable growers because of its low mammalian toxicity and systemic properties. Field trials were conducted between 2006 and 2008 in North Carolina and Virginia to test the efficacy of chlorantraniliprole as a drip chemigation treatment on tomatoes. Drip chemigation of chlorantraniliprole at various rates and intervals significantly reduced the percentage of tomatoes damaged by tomato fruitworm (Helicoverpa zea) comparable to that typically achieved from multiple foliar applications of insecticides. The best control was achieved with two applications of chlorantraniliprole at 0.074 kg ai/ha, or a single application at 0.099 kg ai/ha. Residual ingestion bioassays showed that chlorantraniliprole was effectively taken up by the roots and was active in leaves up to 66 days after treatment (DAT), active in blossoms up to 22 DAT, but was not active in fruit. Drip chemigation of chlorantraniliprole may offer several advantages over foliar applications, including ease of application, reduced pesticide input into the environment, reduced worker exposure to pesticides, and reduced risk to beneficial arthropods. Accepted for publication 14 January 2010. Published 7 April 2010.

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