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Archive for the ‘Herbicides’ Category

Stemming the tide of invasive weeds with world-first herbicide capsules

Amelia Limbongan using her equipment

2 December 2021

The University of Queensland

An innovative herbicide delivery system could revolutionise the way agricultural and environmental managers battle invasive weeds.

The ingenious method uses herbicide-filled capsules drilled into the stems of invasive woody weeds and is safer, cleaner and as effective as herbicide sprays, which can have negative health impacts on workers and surrounding areas.

PhD candidate Amelia Limbongan from The University of Queensland’s School of Agriculture and Food Sciences said the method was highly effective against a wide variety of weed species, which pose a major threat to farming and grazing systems.

“Woody weeds such as Mimosa bush stifle pasture growth, impede mustering and cause physical and financial damage to animals and property,” Ms Limbongan said.

“This method of weed control is practical, portable and far more convenient than other methods and we’ve already seen several professional operators and councils adopting the approach.”

The portability and convenience of the system, coupled with its proven efficacy and safety, meant the encapsulated herbicide could be used in a variety of settings and locations worldwide.

“This method uses 30 per cent less herbicide to kill weeds, and is just as effective as more labour-intensive approaches, which will save valuable time and money for farmers and foresters,” Ms Limbongan said.

“It could also lead to better management of weeds in agricultural and environmental systems across the globe, while also protecting workers by practically eliminating their exposure to harmful herbicides.

“There is a great market for this technology in countries where invasive weeds are a problem and where forestry is an industry, which would be almost every country.”

Professor Victor Galea said the process used a mechanical applicator called the InJecta, that quickly drilled a hole in the stem of the woody weed, implanting a dissolvable capsule containing the dry herbicide and sealing the capsule into the stem with a wooden plug, bypassing the need to spray over large areas of land.

“The herbicide is then dissolved by plant sap and kills the weed from the inside and, due to the small amount of herbicide used in each capsule, causes no leakage,” Professor Galea said.

“Another reason why this delivery system is so useful is that it protects non-target plants, which are often damaged through accidental contact when using traditional methods such as spraying.”

Researchers are continuing to trial the capsule method on several different weed species and have a number of similar products in line for distribution, which will help farmers, foresters and environmental managers eliminate invasive weeds.

“One of the products tested in this research paper, Di-Bak G (glyphosate), is already being sold in Australia along with the applicator equipment and can be purchased through agricultural supplies outlets across the country,” Professor Galea said.

“Three more products are being prepared for registration and we plan to expand this range over time.”

The research has been published in Plants (DOI: 10.3390/plants10112505).

Media: Amelia Limbongan, a.limbongan@uq.net.au, +61 (0)432 083 776, Professor Victor Galea, v.galea@uq.edu.au, +61 (0)7 5460 1282, Dominic Jarvis, dominic.jarvis@uq.edu.au, +61 (0)413 334 924.

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IAPPS Region X Northeast Asia Regional Center (NEARC)

Present committee members

Dr. Izuru Yamamoto, Senior Advisor

Dr. Noriharu Umetsu, Senior Advisor

Dr. Tsutomu Arie, a representative of the Phytopathological Society of Japan, the chair of Region X

Dr. Tarô Adati, a representative of Japanese Society of Applied Entomology and Zoology

Dr. Hiromitsu Moriyama, a representative of Pesticide Science Society of Japan, the secretary general of Region X

Dr. Rie Miyaura, a representative of The Weed Science Society of Japan

The Phytopathological Society of Japan and Pesticide Science Society of Japan became official partners of IYPH2020 by FAO of UN and Ministry of Agriculture, Forestry and Fisheries (MAFF) of Japan and endeavored to educate the society on plant protection. https://www.maff.go.jp/j/syouan/syokubo/keneki/iyph/iyph_os.html

Annual activities related to IAPPS especially to IPM of plant diseases, insects and weeds, and plant regulation (from April 2020 to March 2021)

The Phytopathological Society of Japan (PSJ)

2020 Kanto District Meeting, Online; Sep 21–22, 2020

2020 Kansai District Meeting, Online; Sep 21–22, 2020

2020 Tohoku District Meeting, Online; Oct 12–14, 2020

2020 Hokkaido District Meeting, Online; Oct 15, 2020

2020 Kyushu District Meeting, Online; Nov 24–26, 2020

2021 Annual Meeting, Online; Mar 17–19, 2021

Japanese Society of Applied Entomology and Zoology (JSAEZ)

65th Annual Meeting, online, March 23-26, 2021

28th Annual Research Meeting of the Japan-ICIPE Association, online, March 25, 2021

Pesticide Science Society of Japan

37rd Study Group Meeting of Special Committee on Bioactivity of Pesticides, online, Sep 18, 2020

40th Symposium of Special Committee on Agricultural Formulation and Application, Yokohama, Kanagawa; Oct 15–16, 2020 (Cancelled due to the spread of COVID-19)

43th Annual Meeting of Special Committee on Pesticide Residue Analysis, online, Nov. 5–6, 2020

46th Annual meeting, Fuchu, Tokyo and Online, March 8–10, 2021

The Weed Science Society of Japan (WSSJ)

2020 Annual Meeting, The Weed Science Society of Kinki, Online; Dec 5, 2020

35th Symposium of Weed Science Society of Japan, Online; Dec 12, 2020

2020 Annual Meeting, Kanto Weed Science Society, Online; Dec 22, 2020

22th Annual Meeting, The Weed Science Society of Tohoku, Japan, Online; Feb 25, 2021

2020 Study Group Meeting of Weed Utilization and Management in Small Scale Farming, Online; Feb 26, 2021

Hono-Kai (means, Meeting who are appreciating agriculture)

35th Hono-Kai Symposium was cancelled due to the epidemic of COVID-19

Japan Biostimulants Association

rd Symposium, Online; Nov 2–30, 2020

Nodai Research Institute

2020-1 Biological Control Group Seminar, Setagaya; Tokyo; Jun 16, 2020 (Cancelled due to the epidemic of COVID-19)

2020-2 Biological Control Group Seminar, online, Nov 13, 2020

2021-1 Biological Control Group Seminar, online, Jun 15, 2021

2021-2 Biological Control Group Seminar, online, Nov 9, 2021

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Bayer develops herbicides for cassava to tackle weeds and raise yields

12 October 2021Bayer has developed and launched a new crop protection product known as Lagon to help farmers tackle the problem of cassava weeds in cassava and boost yield. Tested on more than 200 trials and demos across Nigeria and Tanzania, users rated Lagon among the best preemergence herbicides for controlling grasses and broadleaf weeds in cassava.

Bayer develops herbicides for cassava to tackle weeds and raise yields
Cassava Farmer, Marcos Antonio Dalevedove; Country Sales Manager, Bayer Nigeria Limited, Temitope Banjo; IITA Director for Development and Delivery, Dr Alfred Dixon; Nigeria Cassava Growers Association representative, Simeon Adetunji during the launch of Lagon for weed control in Cassava in Ibadan.

“The launch of Lagon today provides a big relief to farmers,” said Bayer Nigeria Country Sales Manager, Temitope Banjo. “These are exciting times for cassava farmers, and they need not worry about weeds anymore,” he added.

Weeds are a major challenge to increased cassava productivity in Nigeria and Africa in general, with women spending about 500 hours annually to keep a hectare of cassava weed-free using hoes. The manual method of weed control compromises the health of resource-constrained farmers, and in some cases, children are pulled out of school to support weeding.

When left uncontrolled, weeds compete with cassava for water, nutrients, and space, reducing yields by 40 to 90%. To tackle the menace of weeds, the IITA-managed Cassava Weed Management Project has screened more than 40 preemergence herbicides in the last eight years, both on-station and on-farm. The trials and subsequent demonstrations were conducted in Abia, Benue, Ogun, and Oyo states in Nigeria and in Tanzania.

Across the four states, which represent the key agroecological zones that predominantly grow cassava in Nigeria, cassava yields from Lagon-treated fields were more than double the national average and above 20 tons per hectare. Furthermore, cassava plants treated with Lagon were more robust than those on untreated fields or where the product was not used.

IITA Director for Development and Delivery Alfred Dixon said that the Cassava Weed Management Project team also conducted residue analysis on cassava leaves, stems, and roots. “The residue analysis provided negative results, meaning that Lagon is safe for application on field crops, particularly cassava,” Dixon added.

Farmers who use Lagon commended the Bayer preemergence herbicides for their efficacy.

According to Chichi Ngufan, using Lagon on farmers’ fields was doing “wonders” and helping farmers increase their yields and profits. Ngufan, a cassava commercial seed producer, said the use of Lagon has helped her group increase the size of their cassava farm in Benue.

“This is possible because we now manage weeds in cassava better,” she said, adding that with Lagon, farmers were saving more on weeding costs.

Ngufan called on the government to support the dissemination of Lagon so that more farmers could have access to the product and make more returns from growing cassava.FacebookTwitterEmailShare

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India gets first herbicide-tolerant & non-GM rice varieties; launch today

Indian Express, Oct. 19, 2021

The varieties — Pusa Basmati 1979 and Pusa Basmati 1985 — contain a mutated acetolactate synthase (ALS) gene making it possible for farmers to spray Imazethapyr, a broad-spectrum herbicide, to control weeds.

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Written by Harish Damodaran | New Delhi |
Updated: September 28, 2021 7:37:06 am

IARI director AK Singh at a trial field containing both herbicide-tolerant basmati and normal basmati (left plot), whose plants have been killed along with weeds after spraying Imazethapyr. (Photo by Harish Damodaran)

The Indian Agricultural Research Institute (IARI) has developed the country’s first-ever non-GM (genetically modified) herbicide-tolerant rice varieties that can be directly seeded and significantly save water and labour compared to conventional transplanting.

The varieties — Pusa Basmati 1979 and Pusa Basmati 1985 — contain a mutated acetolactate synthase (ALS) gene making it possible for farmers to spray Imazethapyr, a broad-spectrum herbicide, to control weeds. This dispenses with the need to prepare nurseries where paddy seeds are first raised into young plants, before being uprooted and replanted 25-35 days later in the main field.

The two new varieties are scheduled to be officially released by Prime Minister Narendra Modi on Tuesday.https://56428c50993d1e8aab4b4fb64a9125c7.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.htmlRead |Need to think of ‘respectable jobs’ for landless and small farm households: NITI Aayog member

Paddy transplantation is both labour- and water-intensive. The field where the seedlings are transplanted has to be “puddled” or tilled in standing water. For the first three weeks or so after transplanting, the plants are irrigated almost daily to maintain a water depth of 4-5 cm. Farmers continue giving water every two-three days even for the next four-five weeks when the crop is in tillering (stem development) stage.

“Water is a natural herbicide that takes care of weeds in the paddy crop’s early-growth period. The new varieties simply replace water with Imazethapyr and there’s no need for nursery, puddling, transplanting and flooding of fields. You can sow paddy directly, just like wheat,” said A K Singh, director of IARI.Top News Right Now

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Imazethapyr, effective against a range of broadleaf, grassy and sedge weeds, can’t be used on normal paddy, as the chemical does not distinguish between the crop and the invasive plants. The ALS gene in rice codes for an enzyme (protein) that synthesises amino acids for crop growth and development. The herbicide sprayed on normal rice plants binds itself to the ALS enzymes, inhibiting their production of amino acids.

The new basmati varieties contain an ALS gene whose DNA sequence has been altered using ethyl methanesulfonate, a chemical mutant. As a result, the ALS enzymes no longer have binding sites for Imazethapyr and amino acid synthesis isn’t inhibited. The plants can also now “tolerate” application of the herbicide, and hence it kills only the weeds.Also Read |India must shed obsession with ‘marginal farmers’. Their future lies outside farms — in dairy, poultry, food retail

“This is herbicide-tolerance through mutation breeding, not GM. There isn’t any foreign gene here,” Singh pointed out.

Both Pusa Basmati 1979 and 1985 have been bred by crossing existing popular varieties — Pusa 1121 and Pusa 1509, respectively — with ‘Robin’. The latter is a mutant line derived from Nagina 22, an upland drought-tolerant rice variety. The mutant was identified for Imazethapyr-tolerance by S Robin, a rice breeder from Tamil Nadu Agricultural University in Coimbatore.Also Read |For easy access to schemes, Govt plans 12-digit unique ID for farmers, database

Farmers in Punjab and Haryana are already adopting direct seeding of rice (DSR) in response to labour shortages and depleting water tables. This year alone, roughly 6 lakh of the total 44.3 lakh hectares area under paddy in the two states has come under DSR.

DSR cultivation is currently based on two herbicides, Pendimethalin (applied within 72 hours of sowing) and Bispyribac-sodium (after 18-20 days). As Singh pointed out, “These are costlier than Imazethapyr (Rs 1,500 versus Rs 300/acre). Imazethapyr, moreover, has a wider weed-control range and is safer, as the ALS gene isn’t present in humans and mammals. Even in the herbicide-tolerant rice, the chemical will target only the weeds.”

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Transplantation in paddy typically requires about 30 irrigations, each consuming some 5 hectare-cm of water (one hectare-cm equals 100,000 litres). Puddling alone takes up about 15 hectare-cm. In all, DSR is estimated to need 30 per cent less water, save Rs 3,000 per acre in transplantation labour charges, and also 10-15 days’ time due to no nursery preparation.

But DSR’s success hinges on an effective herbicide solution — like breeding Imazethapyr-tolerant varieties.

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Pigweed shows resistance in spots to glyphosate, ALS, HPPD and PPOs

Eric Jones/NCSU_Eric Jones_NCSU-Waterhemp.jpgWes Everman urges farmers to be on the lookout for water hemp on their farms.Everman stresses the importance of pre-emergent herbicides, postemergent herbicides and residuals.

John Hart | Aug 24, 2021SUGGESTED EVENT

Events Page - Farm Progress Show 2021

Farm Progress ShowAug 31, 2021 to Sep 02, 2021

North Carolina State University Extension Weed Specialist Wes Everman continues to urge North Carolina farmers to be on the lookout for resistant waterhemp, redroot pigweed and Palmer amaranth across the state.

Speaking at the Blacklands Farm Managers Tour Aug. 4 at Turnpike Farms in Pantego, N.C., Everman said Palmer amaranth is now showing resistance in spots across North Carolina to glyphosate, ALS, HPPD and PPO technologies. He noted that testing is also underway to see if Palmer amarnath is resistant to atrazine. He also said resistant redroot pigweed is popping up in spots across the state. https://dc33b5251deac1ea475e6c827fe410e1.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

Once again, Everman urged farmers to use multiple modes of action as the key to resistance management. He stressed the importance of pre-emergent herbicides, postemergent herbicides and residuals.

“I see folks going out with jut 2,4-D, just dicamba, or just Liberty with no residual in the tank, no other  product in the tank. That’s a recipe for disaster,” Everman told the crowd at the Blacklands tour.

Everman noted that when one product quits working, farmers shift to another and then switch again and switch again. “We don’t get away from resistance by doing that. We want to use these residuals, our Group 15s, Dual, Warrant, Zidua, and our Group 14s, Valor, Spartan and Reflex.”ADVERTISING

The use of both pre-emergence and postemergence herbicides is a must. He said such products as Flexstar, Cobra and Blazer can generally be used across the farm. He also said metribuzin is generally a safe option as well. He stressed the importance of rotating Liberty, Enlist and Xtend traits.

“If we can rotate them in a season, even better. We can’t just pick one technology and wear it out and then hope to go to the next. I don’t think that’s going to work, and we’re only talking about three products. How long do we have if we don’t start switching now?” Everman said.

Everman pointed out the new weeds are coming into the state primarily through equipment that is purchased from Midwestern states and then brought into North Carolina. He also said waterfowl can move weed seed from one part of the state to another. He said it has been confirmed that water hemp was introduced into North Carolina from a combine purchased in the Midwest and brought to North Carolina.

He urged farmers to be on the lookout for water hemp on their farms. It is different than Palmer and redroot pigweed in that it has thin leaves and shorter petioles. He said it is hairless, like Palmer.

“If you have a weed that looks like it might be Palmer, but looks a little funny, get in touch with your county agent or Charlie (Cahoon, also a North Carolina State Extension weed specialist) or me. We want to make sure. We don’t want to see water hemp pop up in too many places,” Everman said.

In addition to keeping an eye out for water hemp, redroot pigweed and Palmer amaranth, Everman urged Blackland farmers to be on the lookout for common ragweed. He said just north of the Blacklands, in northeastern North Carolina, common ragweed has shown three-way resistance to glyphosate, ALS and PPO inhibitors.

“It (common ragweed) could move on equipment down here. Water hemp came to North Carolina from the Midwest. Pretty much everything we have identified in North Carolina has moved on equipment. They brought it here and they brought along seed issues,” he said.

“The No. 1 piece you can move weed seeds with is a combine. If you have a weedy patch, if you’re bringing a combine from another farm, if you’re getting help from somebody, if you have time and you have the opportunity, clean that thing from front to back. Try  to get as much seed out of it as you can. This is an inherited problem, something that came along with the equipment,” Everman said.

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Preview(opens in a new tab)Add titleGene editing poised to spark innovation in herbicide- and disease-resistant sugar cane

Gene editing poised to spark innovation in herbicide- and disease-resistant sugar cane

Julie Wurth | CABBI | July 22, 2021

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Credit: Fawakih
Credit: Fawakih

This article or excerpt is included in the GLP’s daily curated selection of ideologically diverse news, opinion and analysis of biotechnology innovation.

Sugarcane is one of the most productive plants on Earth, providing 80 percent of the sugar and 30 percent of the bioethanol produced worldwide. Its size and efficient use of water and light give it tremendous potential for the production of renewable value-added bioproducts and biofuels.

But the highly complex sugarcane genome poses challenges for conventional breeding, requiring more than a decade of trials for the development of an improved cultivar.

Two recently published innovations by University of Florida researchers at the Department of Energy’s Center for Advanced Bioenergy and Bioproducts Innovation (CABBI) demonstrated the first successful precision breeding of sugarcane by using CRISPR/Cas9 genome editing — a far more targeted and efficient way to develop new varieties.

CRISPR/Cas9 allows scientists to introduce precision changes in almost any gene and, depending on the selected approach, to turn the gene off or replace it with a superior version. The latter is technically more challenging and has rarely been reported for crops so far.Follow the latest news and policy debates on agricultural biotech and biomedicine? Subscribe to our newsletter.SIGN UP

“Now we have very effective tools to modify sugarcane into a crop with higher productivity or improved sustainability,” [researcher Fredy] Altpeter said. “It’s important since sugarcane is the ideal crop to fuel the emerging bioeconomy.”

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Metabolic weed resistance theme of UT Weed Tour

Ginger RowseyLarrySteckelWeedTour.jpg

Larry Steckel, Extension weed scientist with the University of Tennessee shares information about his latest research during the 2021 Weed Tour.University research points to spreading metabolic weed resistance in Tennessee fields.

Ginger Rowsey | Jun 25, 2021SUGGESTED EVENT

Events Page - Farm Progress Show 2021

Farm Progress ShowAug 31, 2021 to Sep 02, 2021

The University of Tennessee held its annual Weed Tour on June 16 at the West Tennessee AgResearch and Education Center in Jackson. The overarching theme of the day — metabolic weed resistance is here and spreading.

“We’re clearly seeing metabolic resistance,” said Larry Steckel, UT Extension weed specialist. “It’s different than what we’ve always seen with target site resistance, which is what Roundup or PPO resistance was. With target site resistance, it seems like overnight, the herbicide, even applied at six to ten times the labeled rate quits working on a particular weed. While what we have seen with metabolic driven herbicide resistance typically involved more than one herbicide with the level of resistance two to four times.”https://a9ffbcfe2d577340816712d2d2a5ee6b.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

“We’re seeing it with dicamba and 2,4-D, but we’re also seeing more subtle declines in control with a number of different herbicides, including the Group 15 herbicides like Dual or Warrant,” he adds. “Not that they’re not working, but maybe they were working for 17 days and now they’re only holding 15-16 days.”

Steckel’s take home message for managing metabolic weed resistance: Use the max rate of pre-emergence herbicide for any given soil type. Then, overlay another pre-emergence herbicide. You’ll need two passes of post-emergence herbicides. Be as timely as you can with those post applications.

Visitors to the Weed Tour were able to see dozens of herbicide treatments in the university’s research plots. The tour was led by Steckel, along with Clay Perkins and graduate student Delaney Foster. In addition to plots at the AgResearch Center, Steckel and his crew conduct on-farm research where they are seeing more evidence of metabolic resistance. Even documenting Palmer amaranth escapes from applications of auxin herbicides made at the 4X rate.ADVERTISING

“We’ve got to start thinking about some different ways to manage for it,” he added. “One is to be as timely as possible, which is easier said than done. The other is relying more on pres. Based on my conversations with farmers and retailers, I think we’re using more pre’s this year, and I think that’s helped. They’ve worked for the most part pretty well. But now we’re in the crunch time when all the posts are going out, and I’m expecting some calls from folks who are disappointed in their herbicide performance.”

Combating metabolic weed resistance

Cytochrome P450 is a naturally occurring enzyme that detoxifies foreign chemicals. It’s found in plants and animals, but plants have more genes for the P450 enzyme. Over time growers inadvertently select for weeds with higher numbers of these enzymes in their genetic makeup. These enzymes can then detoxify herbicides applied to the weed.

Researchers often test for metabolic resistance by mixing the herbicide in question with malathion. Malathion, along with all the organophosphate insecticides, are known cytochrome P450 inhibitors. That means they’ll bind up the enzyme that is detoxifying the herbicide.

“When you inhibit those P450’s, the thought is the herbicide will now kill the weed,” Foster said.

Steckel and Foster were hopeful malathion could be a solution. In greenhouse research this past winter, they saw promising results, with malathion improving auxin herbicide control as much as 32% in some treatments. But results in field trials were not as good.

“It worked a little better with 2,4-D than dicamba,” Foster said, “but here we didn’t see a big malathion difference. That doesn’t mean this herbicide resistance isn’t metabolism based. There are hundreds of P450 enzymes and lots of P450 inhibitors. Malathion targets one. We’ll continue evaluating other P450 inhibitors and hopefully figure out what the mechanism of resistance is here.”TAGS: CROPS

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Ceylon Daily News

Plans to produce powerful natural herbicide using invasive species

Saturday, June 19, 2021 – 01:16Print EditionLocal

The Environment Ministry plans to produce a powerful natural herbicide using several invasive species that are to be removed from the environment immediately in support of the President’s organic farming programme.

The purpose of this is to prevent the use of chemical pesticides and herbicides along with the ban on the use of chemical fertilizers and to prevent farmers from getting into trouble due to the lack of a suitable herbicide for weed control.

Environment Minister Mahinda Amaraweera instructed Ministry officials on Thursday to be prepared to make a special contribution to the promotion of organic farming under the Ministry.

The discussion was attended by Ministry Secretary Dr. Anil Jasinghe and heads of the Central Environmental Authority, Geological Survey and Mines Bureau, Technical Services Company and many other external institutions.ht

“The decision taken by the President to stop the use of chemical fertilizers for cultivation and to introduce organic farming instead is a historic decision. Other Ministries cannot remain silent, leaving these matters to the Ministry of Agriculture alone. Therefore, as the Ministry of Environment, we have a great responsibility to intervene in this matter,” said Minister Amaraweera.

“Farmers are currently demanding chemical fertilizers. The decision taken by the President for organic farming will be implemented from this Maha season. Therefore, there is a need to provide chemical fertilizers during the Yala season this year. It was also proposed to set up a medium scale factory for this purpose in the Hambantota District where these invasive plants are in abundance,” the Minister said.

“Pesticides and herbicides along with chemical fertilizers have also been banned, making it difficult for farmers as well as cultivators to get sufficient manpower in the tea and rubber industry as well as in paddy cultivation. There is a possibility of producing a successful herbicide using these invasive plants as a solution. It is also 100% chemical free and eco-friendly. Arrangements have been made to hold further discussions in this regard at the Divisional Secretariat in Hambantota today (19). These invasive plants are species recommended by the Ministry of Environment for immediate destruction,” Minister Amaraweera said.

The Minister also said that steps will be taken to launch a number of small and medium scale projects for the

production of organic fertilizer required for agriculture in the Hambantota District during the Maha season this year.

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Soil Biodiversity Under Grave Threat from Pesticides – Most Comprehensive Review Ever

Posted on May 7 2021 – 3:00pm by Sustainable Pulse« PREVIOUSNEXT »Categorized as

new study published Tuesday by the academic journal Frontiers in Environmental Science finds that pesticides widely used in American agriculture pose a grave threat to organisms that are critical to healthy soil, biodiversity and soil carbon sequestration to fight climate change. Yet those harms are not considered by U.S. regulators.

The study, by researchers at the Center for Biological Diversity, Friends of the Earth U.S. and the University of Maryland, is the largest, most comprehensive review of the impacts of agricultural pesticides on soil organisms ever conducted.

The researchers compiled data from nearly 400 studies, finding that pesticides harmed beneficial, soil-dwelling invertebrates including earthworms, ants, beetles and ground nesting bees in 71% of cases reviewed.

“It’s extremely concerning that 71% of cases show pesticides significantly harm soil invertebrates,” said Dr. Tara Cornelisse, an entomologist at the Center and co-author of the study. “Our results add to the evidence that pesticides are contributing to widespread declines of insects, like beneficial predaceous beetles and pollinating solitary bees. These troubling findings add to the urgency of reining in pesticide use.”

The findings come on the heels of a recent study published in the journal Science showing pesticide toxicity has more than doubled for many invertebrates since 2005. Despite reduced overall use of insecticides, the chemicals most commonly used today, including neonicotinoids, are increasingly toxic to beneficial insects and other invertebrates. Pesticides can linger in the soil for years or decades after they are applied, continuing to harm soil health.

The reviewed studies showed impacts on soil organisms that ranged from increased mortality to reduced reproduction, growth, cellular functions and even reduced overall species diversity. Despite these known harms, the Environmental Protection Agency does not require soil organisms to be considered in any risk analysis of pesticides. What’s more, the EPA gravely underestimates the risk of pesticides to soil health by using a species that spends its entire life aboveground — the European honeybee — to estimate harm to all soil invertebrates.

“Below the surface of fields covered with monoculture crops of corn and soybeans, pesticides are destroying the very foundations of the web of life,” said Dr. Nathan Donley, another co-author and scientist at the Center. “Study after study indicates the unchecked use of pesticides across hundreds of millions of acres each year is poisoning the organisms critical to maintaining healthy soils. But our regulators have been ignoring the harm to these important ecosystems for decades.”

Soil invertebrates provide a variety of essential ecosystem benefits such as cycling nutrients that plants need to grow, decomposing dead plants and animals so that they can nourish new life, and regulating pests and diseases. They’re also critical for the process of carbon conversion. As the idea of “regenerative agriculture” and using soil as a carbon sponge to help fight climate change gains momentum around the world, the findings of this study confirm that reducing pesticide use is a key factor in protecting the invertebrate ecosystem engineers that play a critical role in carbon sequestration in the soil.

“Pesticide companies are continually trying to greenwash their products, arguing for the use of pesticides in ‘regenerative’ or ‘climate-smart’ agriculture,” said Dr. Kendra Klein, a co-author who’s also a senior scientist at Friends of the Earth. “This research shatters that notion and demonstrates that pesticide reduction must be a key part of combatting climate change in agriculture.”

“We know that farming practices such as cover cropping and composting build healthy soil ecosystems and reduce the need for pesticides in the first place,” said co-author Dr. Aditi Dubey of the University of Maryland. “However, our farm policies continue to prop up a pesticide-intensive food system. Our results highlight the need for policies that support farmers to adopt ecological farming methods that help biodiversity flourish both in the soil and above ground.”

Background

The review paper looked at 394 published papers on the effects of pesticides on non-target invertebrates that have egg, larval or immature development in the soil. That review encompassed 275 unique species or groups of soil organisms and 284 different pesticide active ingredients or unique mixtures of pesticides.

The assessment analyzed how pesticides affected the following endpoints: mortality, abundance, richness and diversity, behavior, biochemical markers, impairment of reproduction and growth, and structural changes to the organism. This resulted in an analysis of more than 2,800 separate “cases” for analysis, measured as a change in a specific endpoint following exposure of a specific organism to a specific pesticide. It found that 71% of cases showed negative effects.

Negative effects were evident in both lab and field studies, across all studied pesticide classes, and in a wide variety of soil organisms and endpoints. Organophosphate, neonicotinoid, pyrethroid and carbamate insecticides, amide/anilide herbicides and benzimidazole and inorganic fungicides harmed soil organisms in more than 70% of cases reviewed.

Insecticides caused the most harm to nontarget invertebrates, with studies showing around 80% of tested endpoints negatively affected in ground beetles, ground nesting solitary bees, parasitic wasps, millipedes, centipedes, earthworms and springtails.

Herbicides and fungicides were especially detrimental to earthworms, nematodes and springtails.

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Combine old with new for resistant weed management

TAGS: HERBICIDEHERBICIDE RESISTANT WEEDSAdam Hixon, BASFadam-hixson-pigweed-glyphosate.jpgSignificant pigweed infestation remains in this field after two applications of glyphosate.Getting back to the basics is critical to managing herbicide resistant weeds.

Ron Smith | Apr 19, 2021

Weeds resistant to herbicides are a way of life for farmers, one more concern to complicate an already complex production system.

But options exist not only to manage resistance but also to reduce the size of the weed seed bank.https://82ae8ac4f4c5904dfe4704d0077ebf4f.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

“Resistance is here to stay,” said Adam Hixson, BASF technical service representative for Texas, Oklahoma, and New Mexico, during a recent media update on managing herbicide resistant weeds in the Southwest.

swfp-shelley-huguley-adam-hixon-profile.jpgAdam Hixson, BASF technical service representative for Texas, Oklahoma, and New Mexico. (Photo by Shelley E. Huguley)

“We’ve heard the expression, ‘out with the old and in with the new,’” Hixson said. “I want to change that to ‘in with the old and in with the new.’”

Back to basics

Getting back to basics, he said, is crucial to managing herbicide resistant weeds. He called on Texas A&M AgriLife Professor and Extension Weed Specialist Pete Dotray to put the problem in perspective.

“According to the International Survey of Herbicide Resistant Weeds, we have eight resistant weed species in Texas,” Dotray said. “The first case of resistance in the state was noted 30 years ago, but in the last 10 years, glyphosate resistance has created a lot of concern.”

Dotray said Roundup resistant Palmer amaranth, also known as pigweed and carelessweed, was first identified on the Texas High Plains about 10 years ago, later than in some Mid-South and Southeastern states. He believes a key to that late arrival was that High Plains farmers never abandoned residual herbicides, especially the yellow herbicides like Treflan and Prowl.

shelley-huguley-dotray-profile.jpgTexas A&M AgriLife Professor and Extension Weed Specialist Pete Dotray (Photo by Shelley E.Huguley)

Overuse of Roundup, using the same chemistry over and over, and use of fewer herbicide and tillage inputs provided an open door for the increase in resistant weed populations, Dotray said. “Resistant weeds were likely already out there in extremely low numbers.”

Palmer amaranth resistance has complicated weed management, Hixson added. “We’ve seen multiple applications of glyphosate at labeled rates fail to control Palmer amaranth.”

He said remedies include manual control, such as hoeing, which is expensive and time-consuming. “Also, we’re always looking for that next ‘shiny object’ that will solve the problem.”

Shiny things have been scarce in recent years, however, so Hixson offers a different option. “We need to use what we have today, but use it in a more calculated, knowledge-based approach. We have to get back to the fundamentals of weed control.”

Year-round effort

He and Dotray agree that successful weed control strategies do not focus solely on in-season herbicide applications. “Good weed management has to be a well-planned, year-round venture,” Hixson said.

Weed identification is a priority. “It’s important to identify the weeds and to understand fully the biology. Know when specific weed species are most vulnerable.”

He explained that Kochia, sometimes “a huge problem and resistant to several herbicides,” emerges early in the spring and typically has only one flush. An effective residual herbicide, applied at the right time, will take care of most Kochia issues.

Palmer amaranth, however, emerges from early in the season well into fall and requires a season-long management program.

Dotray said Palmer seed that emerge late in the season remain a threat to replenish the seed bank and create problems for the next crop year.

“We’ve looked at the abundance of seed one plant can produce,” he said. “Palmer that emerges early produces as many as 500,000 to 600,000 seed, maybe more, per plant. That’s a lot of seed. But a Palmer plant that emerges in August will still produce as many as 20,000 seed, also a lot. As late as September, emerging plants will produce 2,000 seed, and still hundreds by October. Even plants that emerge as late as November can produce some viable seeds.”

“Leaving just one plant,” Hixson said, “may add to the weed seed bank, a key factor for the next season. One seed per square inch represents more than 6 million seeds per acre.” So, next season’s weed control should start before this season ends.

Good news

Dotray said recent research shows a bit of good news about the longevity of Palmer seed. Studies have shown that some weed seed will retain viability for as long as 120 years.

“We had no good answer for how long Palmer seed remain viable, so five years ago we set up a test to see. We buried Palmer seed at various depths across the state.”

They uncover them at intervals, beginning at six months, again at 12 months, and yearly after that. Based on data from the first 48 months of the research, “Palmer seed viability begins to decline significantly after 12 months. Those findings were the same across all locations and at all depths. A second study initiated in 2018 has shown the same results so far,” Dotray said.

“The good news is that a farmer who does a good job of managing Palmer amaranth effectively with a systematic program can get them down to a manageable level in a short time.”

That system should include late applications to prevent escapes, he said.

Knowledge is key

Hixson said an effective weed management program also depends on knowing not only the weed species vulnerabilities but also the interactions of soils and chemistry.

He said using herbicides with multiple, effective modes of action should be a critical part of weed management

“But also understand the properties of the herbicides and how they respond to different conditions, including soil types and moisture. Soil leaching properties will affect herbicide efficacy,” he said. “Also, the more water soluble a product is, the deeper it will move into the soil profile. Less soluble usually means more soil binding.”

He said different soil types — changes in clay content, sand, organic matter level — all may affect herbicide activity.

He said in situations with good moisture, a product like Zidua could be the best option. “In dryland or subsurface drip irrigation conditions, Outlook would be ideal.”Adam Hixon, BASFadam-hixson-timely-applications.jpg

Timely applications, with overlapping residuals (Prowl H2O herbicide followed by Outlook herbicide), along with an effective postemergence herbicide (Engenia herbicide), provide exceptional control of Palmer amaranth.

They key is understanding the weed, the environment, and the herbicide properties, then using the proper material for the target weed under those specific conditions.

Timing and coverage

He added that application timing and coverage also matter.

“Also remember, the cottonseed trait package you plant determines the herbicides you can use.”

“Using residual herbicides, identifying weeds and understanding the difference in solubility and where a product fits best based on soil and moisture are critical to a systems approach to weed management,” Dotray added.

In response to a question about new dicamba labels, Hixson said BASF would not veer from the requirements established by the federal label in Texas, Oklahoma, and New Mexico

Dotray noted that the new registrations come with some significant changes, including bigger buffers, volatility reduction adjuvant requirements and application timing.

“Also, last year some states used 24-C exemptions to alter some regulations. So far this year, states that have applied for a 24-C have been denied.”

Hixson announced that BASF does have one “shiny object” in the pipeline, a new seed trait with tolerance to four herbicides –GLIXTP, pending regulatory approval. He anticipates introduction in 2023, with potentially more availability in 2024.

In the meantime, he said, “Old chemistry still has value.”

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What have we learned about kochia management?

TAGS: MANAGEMENTPhoto courtesy of Nevin LawrenceKochia in a continuous corn field after four years of ALS-inhibiting herbicideKOCHIA CONTROL: Kochia is a tough weed to beat, and it can cause real trouble in crops if it is not controlled. In this photo, you can see the kochia pressure in a continuous corn field after four years of using an ALS-inhibiting herbicide.Extension Crop Connection: Kochia remains a tough weed, but integrated weed management can help win the battle.

Nevin Lawrence | Apr 12, 2021

Kochia remains one of the most challenging weeds to control in western Nebraska. Kochia can be resistant to Group 5 (atrazine), Group 2 (imazamox), Group 9 (glyphosate) and Group 4 (dicamba) herbicides in western Nebraska.

While there are still many herbicides available to irrigated corn growers, those who grow dry beans and sugarbeets have few options because of crop rotation restrictions. When a grower runs out of herbicide options, what can they do?

IWM to the rescue

Integrated weed management is often discussed as the solution. A simple definition of IWM is the strategic use of all the tools a farmer has available, including herbicides, tillage, crop selection, crop rotation, cover crops and other cultural practices.

Does IWM actually work? In 2014, a study was established in Scottsbluff, Neb., to find out. The study ran for four years, concluding in 2017. The goal of this study was to use IWM to target kochia in an irrigated crop rotation.

Each site was established by seeding a mix of kochia biotypes of which 95% were susceptible to Group 2 (ALS-inhibiting herbicides) and 5% were resistant to Group 2 herbicides. The seed mixture used created a “low level” of resistance in the seed bank, which simulates the early stages of herbicide-resistance development.

3 strategies

There were three IWM strategies, including the use of tillage, crop rotation and herbicide strategy. The tillage strategy used two different treatments — minimal tillage or intensive tillage.

Four crop rotations were established — four years of continuous corn; a corn-sugarbeet-corn-sugarbeet rotation; a corn-sugarbeet-corn-dry bean rotation; and finally, a small grain-sugarbeet-corn-dry bean rotation.

The final strategy was herbicide use, with three different treatments. This included a Group 2 herbicide-only treatment, where only herbicides that wouldn’t control the resistant kochia were applied every single year.

Table shows Kochia density per square yard on various crops after 4 yearsAnother was a herbicide mode-of-action rotation, where a Group 2-alternative herbicide rotation and herbicide effective for Group 2-resistant kochia were used every other year. In corn for example, the effective herbicide was a tank mixture of glyphosate and dicamba.

The last treatment was mixing MOAs, where an effective herbicide treatment was mixed with a Group 2 herbicide each year. For the rotation herbicide treatment, in 2014 and 2016, the alternative herbicide was used, and in 2015 and 2017, the Group 2 herbicide was used.

Results are in

After four years, kochia density ranged from as low as 0 to 40 kochia plants per square yard, with seed production as high as 8,000 seeds per square yard. Yield reduction was significant — sugarbeet and dry bean plots experienced total yield loss, and corn yield was reduced from 200 to 60 bushels per acre from the highest kochia densities. Wheat, however, was not greatly affected by kochia competition, always yielding between 55 to 60 bushels.

So, what worked in reducing kochia numbers over four years? The obvious winner was using herbicide mixtures, with low kochia density observed regardless of tillage system or crop rotation.

But what if good herbicides are not available? Including wheat in the rotation helped tremendously, even when an ALS herbicide was used every year. In the sugarbeet-corn and sugarbeet-corn-dry bean rotation, kochia density was reduced from near 40 plants every square yard down to only seven, even when using an herbicide that didn’t work.

Wheat, in irrigated systems, is great at reducing kochia emergence early in the season. Although this study didn’t consider wheat as a cover crop, a similar benefit may be observed by using any small grain — wheat, barley, oats, rye or triticale — as a cover crop preceding other crops. Small grains close rows quickly and smother early plants before they have a chance to emerge in the spring.

Lawrence is a Nebraska Extension weed management specialist.

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