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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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Where there’s a weevil, there’s a way to end giant weed problem

Durie Rainer Fong -October 7, 2021 3:16 PM16Sharesfacebook sharing button 11

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Sabah’s Lake Tungog is covered with salvinia molesta. The giant weed can destroy freshwater fish species, submerged aquatic plants and deoxygenate the water. (Sabah Foresty Department pic)

KOTA KINABALU: Sabah is introducing a beetle species to its lakes and rivers in the hope of clearing them of the salvinia molesta, a type of an invasive aquatic plant.

Chief minister Hajiji Noor lauded the introduction of the Cyrtobagous salviniae weevils, by the state agriculture and fisheries ministry as an environmental-friendly effort to check the Salvinia molesta – or giant salvinia – infestations statewide.

Weevils are beetles that are often considered pests because of their ability to kill crops.

Speaking during the launching of a programme to introduce the bugs to all Sabah districts today, Hajiji said the giant salvinia weeds have infested at least 200 bodies of water such as rivers, waterways, fish ponds and padi fields throughout the state.

“This is a serious situation and has to be addressed immediately,” he said in a statement here.

He added that steps have to be taken to stop the spread of the weed in Kinabatangan, Sandakan, Lahad Datu, Tawau, Semporna, Beaufort, Kuala Penyu, Papar, Kota Kinabalu, Penampang, Kota Marudu, Kota Belud, Kudat, Tongod and Tuaran.

The Cyrtobagous salviniae weevils which feed on the giant weeds. (Wikipedia pic)

Native to Brazil, the Salvinia molesta grows on water surfaces and endangers biodiversity and freshwater species, including fish and submerged aquatic plants.

The weed was first sighted in Sabah in early 2000s.

While it has the potential to treat blackwater effluent for an environmentally friendly sewage system, its rapid growth clogs waterways and blocks sunlight needed by other aquatic plants, particularly algae, to perform photosynthesis.

On the other hand, the weevil is a biological pest control agent for the giant salvinia, or kariba weed, since both adults and larvae feed on the plant.

Hajiji said the state government fully supported the various steps taken by the Sabah agriculture department together with various agencies in monitoring the giant salvinia infestation.

“I call upon the people of Sabah to join in and help keep our bodies of water and environment pristine,” he said.

At the same time, Hajiji said the people must refrain from bringing in, selling or spreading any type of non-native plant, animal or microorganisms without going through the proper quarantine procedures as stipulated in the 1976 Plant Quarantine Act and 1981 Quarantine Regulations.

Chief minister Hajiji Noor (second right) receiving pamphlets on the cyrtobagous salviniae weevils from Sabah agriculture director Dzulkifli Ghulamdin in Kota Kinabalu today. (CM Dept pic)

Giant salvinia can be bought online as decoration for guppy fish aquariums.

Meanwhile, in a separate statement, deputy chief minister Jeffrey Kitingan said the giant salvinia is only one of more than 100 invasive alien species (IAS) in Sabah currently.

“The programme today is in accordance with the recommendations of the Convention on Biological Diversity (CBD) which is an international multilateral treaty under the United Nations (UN).

“This convention has been refined and translated into the Sabah Biodiversity Strategy 2012-2022 and the National Biodiversity Policy 2016-2025 policies,” he said.

Kitingan, who is also the state agriculture and fisheries minister, said one of the activities and targets outlined in the existing policies is the control of IAS.

He said Malaysia has also previously encountered invasive foreign species, such as the cocoa pod borer insect which was a pest of cocoa crops in the 1980s and also the golden apple snail which was a pest in rice fields in the 1990s.

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Plant hormones for weed control

Yeast and bacteria together biosynthesize plant hormones for weed control

Synthetic strigolactones could also improve nutrient uptake in crops

Date:September 18, 2021Source:University of California – RiversideSummary:Plants regulate their growth using hormones, including a group called strigolactones that prevent excessive budding and branching. Strigolactones also help plant roots form symbiotic relationships with microorganisms that allow the plant to absorb nutrients from the soil. These two factors have led to agricultural interest in using strigolactones to control the growth of weeds and root parasites, as well as improving nutrient uptake. These root-extruding compounds also stimulate germination of witchweeds and broomrapes, which can cause entire crops of grain to fail, making thorough research essential prior to commercial development. Now scientists have synthesized strigolactones from microbes.Share:FULL STORY


Plants regulate their growth and development using hormones, including a group called strigolactones that prevent excessive budding and branching. For the first time, scientists led by UC Riverside have synthesized strigolactones from microbes. The work is published in the open-access journal, Science Advances.

Strigolactones also help plant roots form symbiotic relationships with microorganisms that allow the plant to absorb nutrients from the soil. These two factors have led to agricultural interest in using strigolactones to control the growth of weeds and root parasites, as well as improving nutrient uptake.

These root-extruding compounds don’t come without risks. They also stimulate germination of witchweeds and broomrapes, which can cause entire crops of grain to fail, making thorough research essential prior to commercial development. Scientists are still learning about the physiological roles played by this diverse group of hormones in plants. Until recently, manufacturing pure strigolactones for scientific study has been difficult and too costly for agricultural use.

“Our work provides a unique platform to investigate strigolactone biosynthesis and evolution, and it lays the foundation for developing strigolactone microbial bioproduction processes as alternative sourcing,” said corresponding author Yanran Li, a UC Riverside assistant professor of chemical and environmental engineering.

Together with co-corresponding author Kang Zhou at National University Singapore, Li directed a group that inserted plant genes associated with strigolactone production into ordinary baker’s yeast and nonpathogenic Escherichia coli bacteria that together produced a range of strigolactones.

Producing strigolactones from yeast turned out to be very challenging. Although engineered yeast is known to modify the strigolactone precursor, called carlactone, it could not synthesize carlactone with any of the specific genes used by the researchers.

“This project started in early 2018, yet for over 20 months there was basically no progress. The gatekeeping enzyme DWRF27 is not functional no matter how we try in yeast,” Li said. “Kang developed a microbial consortium technique to produce a Taxol precursor in 2015 and that inspired this wonderful collaboration.”

The team turned toward E. coli, which had already been shown capable of producing carlactone. The carlactone it produced, however, was unstable and could not be further modified by engineered E. coli into any strigolactones. Li’s group managed to optimize and stabilize the carlactone precursor.

To their delight, when the yeast and bacteria were cultured together in the same medium, the E. coli and yeast worked as a team: E. coli made carlactone, and the yeast transformed it into various final strigolactone products. The method also produced enough strigolactones to extract and study. Using this platform, the group identified the function of multiple strigolactone biosynthetic enzymes, showing that sweet orange and grape have the potential to synthesize orobanchol-type strigolactones.

The team also engineered microbe metabolism to boost strigolactone production threefold to 47 micrograms per liter, enough for scientific study. Though commercial production of strigolactones is still a long way off, the new method for biosynthesizing them from a yeast-bacterium consortium will help scientists learn more about this important group of plant hormones, especially the enzymes involved.

Enzymes are protein catalysts and are responsible for modification of carlactone by yeast. Because carlactone is unstable, it cannot be purchased from commercial sources. As a result, many plant scientists have difficulty studying new enzymes that may work to transform carlactone into strigolactones.

“The new yeast-bacterium co-culture provides a convenient way for scientists to complete such works because the bacterium makes carlactone in situ,” Zhou said. “With discovery of more enzymes and optimization of the microbial consortium, we can manufacture strigolactones in quantity in the future.”

Li and Zhou were joined in the research by Sheng Wu, Anqi Zhou, and Alex Valenzuela of UC Riverside; and Xiaoqiang Ma at the Singapore-MIT Alliance for Research and Technology. The paper, “Establishment of strigolactone-producing bacterium-yeast consortium,” is available here.


Story Source:

Materials provided by University of California – RiversideNote: Content may be edited for style and length.


Journal Reference:

  1. Sheng Wu, Xiaoqiang Ma, Anqi Zhou, Alex Valenzuela, Kang Zhou, Yanran Li. Establishment of strigolactone-producing bacterium-yeast consortiumScience Advances, 2021; 7 (38) DOI: 10.1126/sciadv.abh4048

Cite This Page:

University of California – Riverside. “Yeast and bacteria together biosynthesize plant hormones for weed control: Synthetic strigolactones could also improve nutrient uptake in crops.” ScienceDaily. ScienceDaily, 18 September 2021. <www.sciencedaily.com/releases/2021/09/210918085833.htm>.

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Is THIS the key to wiping out ? Removal of moisture has a 100% success rate at killing the invasive plant – and is much more effective than herbicide, study finds

  • Scientists said removing moisture from Japanese knotweed kills invasive plant
  • They had a ‘100 per cent success rate’ after drying out plants in lab conditions
  • Their discovery shows that the plant it ‘not as indestructible’, researchers said
  • Japanese knotweed is a plant found in many areas of Europe and North America

By SAM TONKIN FOR MAILONLINE

PUBLISHED: 07:06 EDT, 19 August 2021 | UPDATED: 07:39 EDT, 19 August 2021

Japanese knotweed is a devastatingly invasive plant that can leave homeowners and gardeners in a bind. 

But scientists might just have a new solution on how to kill it that they say is much more effective than herbicide.

It involves removing moisture from the plants by drying them out in a lab, although researchers said more tests in the field are needed to see how this would work in the real world before any advice or commercial product is made available to the public.https://imasdk.googleapis.com/js/core/bridge3.476.0_en.html#goog_1797203280PauseNext video0:24Full-screenRead More

The study by the National University of Ireland Galway and University of Leeds found that removing moisture had a ‘100 per cent success rate’ in killing Japanese knotweed, which can break through bricks, concrete and mortar.

Their discovery shows that the plant is ‘not as indestructible’ as thought, according to the study’s co-author Dr Mark Fennell.Scientists might just have a new solution on how to kill Japanese knotweed that they say is much more effective than herbicide. Pictured are some of the samples they experimented with+6

Scientists might just have a new solution on how to kill Japanese knotweed that they say is much more effective than herbicide. Pictured are some of the samples they experimented withJapanese knotweed (pictured) is a problematic plant found in many areas of Europe and North America. Notably, in the UK, the species can cause issues with mortgage acquisition+6

Japanese knotweed (pictured) is a problematic plant found in many areas of Europe and North America. Notably, in the UK, the species can cause issues with mortgage acquisition

Japanese knotweed 

Japanese Knotweed is a species of plant that has bamboo-like stems and small white flowers.

Native to Japan, the plant is considered an invasive species. 

The plant, scientific name Fallopia japonica, was brought to Britain by the Victorians as an ornamental garden plant and to line railway tracks to stabilise the soil.

It has no natural enemies in the UK, whereas in Asia it is controlled by fungus and insects.

In the US it is scheduled as an invasive weed in 12 states, and can be found in a further 29.

It is incredibly durable and fast-growing, and can seriously damage buildings and construction sites if left unchecked.

The notorious plant strangles other plants and can kill entire gardens. 

Capable of growing eight inches in one day it deprives other plants of their key nutrients and water.https://5772890968515b3f00a684ae0e95aa20.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

The research found that incorrect herbicide treatment cannot control the growth and regeneration of Japanese knotweed, but that fully drying the plant material in a lab environment allowed it to be returned to the soil without risk of regrowth.

It also showed that if there are no nodes attached to the rhizomes (root-like underground shoots) there is no regeneration. Nodes are the points on a plant’s stem where buds and leaves originate.

Senior author of the study, Dr Karen Bacon, from NUI Galway, said: ‘Our finding that the removal of moisture has a 100 per cent success rate on killing Japanese knotweed plants and preventing regrowth after they were replanted also raises an important potential means of management for smaller infestations that are common in urban environments.’

She said it ‘requires additional field trials’ that her university hopes to carry out soon.

Japanese knotweed is a problematic plant found in many areas of Europe and North America. Notably, in the UK, the species can cause issues with mortgage acquisition. 

It can grow up to 10ft in height and can dominate an area to the exclusion of most other plants. 

Controlling Japanese knotweed is complicated by its ability to regenerate from small fragments of plant material; however, there remains uncertainty about how much rhizome is required and how likely successful regeneration is under different scenarios. 

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A race against time: The giant weeds taking over Lake Ossa in Cameroon

Lake Ossa, Cameroon

Lake Ossa, Cameroon   –   Copyright  AMMCOBy Nalova Akua  •  Updated: 12/05/2021

Cameroon’s coastal waters have been invaded by three of the world’s most dangerous water weeds, proving an existential threat to aquatic ecosystems and livelihoods of riparian communities.

The latest of these weeds, Salvinia molesta, is a free-floating, green-brown freshwater fern with branching horizontal stems. It has already invaded more than 40 per cent of Lake Ossa (4,000 hectares), the largest natural lake found on Cameroon’s coast, since 2016.

The weed doubles in size every 10 days.ADVERTISING

The other two, water lettuce and water hyacinth, appeared much earlier – in 1949 and 1970 respectively, according to the Cameroon National Herbarium, a collection centre for plant specimens.

As a flowering invasive aquatic plant, water hyacinth now covers 85 per cent of River Fiko and half of the Wouri River Basin – all water bodies found in Cameroon’s Littoral Region. Mats of this invasive weed double in size in five days.about:blank

The perennial evergreen floating plant known as water lettuce.htm) is found in patches on the surfaces of the Wouri River Basin and the lower reaches of the Sanaga River.

“Water lettuce doubles its biomass in just over five days; triples it in 10 days, quadruples in 20 days and has its original biomass multiplied by a factor of 9 in less than one month,” says Dr. Kenfack Voukeng Sonia Nadège, a Cameroonian weed scientist working with Green Connection, a local environmental conservation non-governmental organisation.

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“As floating weeds, they form dense mats on the surface of water bodies, disrupting aquatic flora and fauna underneath and thus adversely affecting the water ecosystem,” Dr. Kenfack adds.

“This hinders water flow, fishing, swimming, boating, water sports and navigation.”

All these invasive species are native to southeastern Brazil and northern Argentina but can be dispersed within an aquatic system by wind in the dissemination of spores; water currents, floods, and animals; as well as through human activities such as transportation by boat or canoe.

Uncontrolled industrial activities also favour the spread of invasive weeds in Cameroon’s coastal waters.

Pollution due to human activities favours the development of these plants.

Dr Kenfack 

“Being the economic capital, the Littoral Region and especially Douala is the most industrialised municipality in Cameroon with about 60 per cent of the country’s industries’ discharges often released in the open spaces,” says Kenfack.

“Besides, houses built without proper flushing systems contribute to the increase of the nutrients in the environment. Pollution due to human activities favours the development of these plants,” she says.

Canva
Salvinia molesta infests lakes and riversCanva

Dr. Kamla Takoukam Kamla, founder of the African Marine Mammal Conservation Organisation (AMMCO), agrees that poor land use triggers the proliferation of invasive aquatic weeds in Cameroon’s coastal regions given that the water columns are enriched with nutrients.

“Two main nutrients needed for invasive weeds to grow are nitrogen and phosphorous coming from upstream. Lake Ossa and the Sanaga River (the largest River in Cameroon) are connected by a 3km channel. Once this river gets polluted, the lake also gets polluted,” explains Kamla.

“It is possible that the nutrients are coming from the industries, plantations and hydroelectric dam reservoirs that are constructed upstream.”

A threat to the livelihood of humans and protected species

The Lake Ossa complex which contains three main lakes and over twenty islands is located in Dizangue, Littoral Region of Cameroon. In 1974, the complex was designated a faunal reserve and since 2018, has been serving as a National Park.

Before the Salvinia invasion, fishing was the major source of livelihood for over 80 per cent of the local population according to Global Water Partnership.

The lake was also an important habitat for many wildlife species including manatees, freshwater turtles, crocodiles, monitor lizards, snakes, aquatic birds and over 18 families of fish.

Before the Salvinia invasion, fishing was the major source of livelihood for over 80 per cent of the local population.

“The mats [of aquatic weeds] indirectly deplete dissolved oxygen, thereby asphyxiating and killing native fish and phytoplankton. With reduced fish supply, human nutrition in riverine communities where fish are the primary source of protein is jeopardized, leading to poor health,” explains Kenfack.

These invasive species “can rapidly out-compete native species and dominate the ecosystem, consequently reducing biodiversity by their exponential proliferation, depriving in return the native species of space, nutrients and moisture,” she adds.

AMMCO
Lake Ossa over the years, as the infestation has become worse.AMMCO

This results in a modification of the entire structure and functioning of the ecosystems.

The International Union for the Conservation of Nature (IUCN) has described the threat posed by Salvinia molesta to Lake Ossa and its ecosystem as “a conservation emergency.” At least 400 fishermen used to fish in Lake Ossa – fish being the main protein source for a couple of thousand people who live around the lake.

“In the past, I was able to make between 15 and 21 Euros daily as profit from selling fish. But today, I can barely make 6 Euros a day as profit,” says Dina Marie-Louise, a 51-year-old who has been selling fish caught in the lake for the past 22 years.

The lake was also an important habitat for wildlife species including manatees, freshwater turtles, crocodiles, monitor lizards, snakes, aquatic birds and over 18 families of fish.

The mother of 12 said the Salvinia attack on Lake Ossa – their main source of livelihood for generations – has shattered her plans of building a house for her family. Seven of her children have dropped out of school for want of means.

Kouoh Elinga Charles, 56, who has spent 30 years fishing in the lake, expressed the same concern adding that he has resorted to odd jobs to feed his polygamous home.

“The salvinia plant has disrupted fishing considerably,” he says.

Canva
Manatees used to live in Lake OssaCanva

“Initially I was able to save 15.32 euros from fishing daily. But today, it is difficult to fetch 1.53 euros from the activity which can hardly satisfy our household needs,” the father of eight said.

Water hyacinth and Salvinia invasions have also disrupted fishing and sand extraction in the Wouri River Basin and in the River Fiko – other main sources of income to the riparian communities.

Lake Ossa used to harbour a minimum of 50 individual African manatees, the least-studied of the three manatee species in genus Trichechidae. But their number is on the decline owing to the Salvinia attack on the lake. Manatees are large, slow-moving mammals that frequent coastal waters and rivers. They never leave the water but, like all marine mammals, manatees must surface about every five minutes to breathe.

When carpets of invasive weeds lock the surface of the lake, they prevent the African manatee from surfacing and breathing.

Dr Kamla 

“When carpets of invasive weeds lock the surface of the lake, they prevent the African manatee from surfacing and breathing. Consequently, they will likely leave Lake Ossa or move to another part of the lake not yet invaded by aquatic weeds,” Kamla said.

“If nothing is done, the lake will be completely invaded and there will be no fish, no manatees and no freshwater turtles which the lake is endowed with.”

Invasive species are considered the third most dangerous factor threatening world biodiversity, after habitat loss and over-exploitation, according to the International Union for the Conservation of Nature.

Can insects solve the problem?

To counter the spread of aquatic weeds in Cameroon’s coastal waters, the African Marine Mammal Conservation Organisation has partnered with similar international organisations and are considering the three existing approaches: manual removal, biological control and the integrated weed management control method.

The Integrated Weed Management (IWM) method entails combining multiple weed control systems into a single weed management programme, to contain the spread of a particular water weed according to Kenfack.

“Up to now, biological control offers a better opportunity to control the spread of these weeds, as compared to the other methods of control such as the chemical that could be dangerous to human and environment and the manual removal which is a very tedious process.

“Biological control uses host specific insects [Salvinia weevil in case of Salvinia molesta attack] which can only complete their life cycles on the target species to reduce the target plant populations. The insects are the plant’s natural enemies,” Kenfack said.

Salvinia weevils are small beetles which can eat the invasive weeds.

The first releases of the Salvinia weevil as a biological agent were at Lake Moondarra, Mount Isa, Australia in 1980.

AMMCO
The Salvinia weevil is a small beetle which can eat the invasive weeds.AMMCO

“Adults and larvae both feed on these floating ferns,” says Matthew Purcell, Director, USDA ARS Australian Biological Control Laboratory – a structure jointly operated by the Agriculture Research Service of the U.S. Department of Agriculture and the Commonwealth Scientific and Industrial Research Organisation (CSIRO).

“The effectiveness varies from site to site depending on environmental parameters, temperature, nutrient availability and water flow, shade, etc.

“The larvae initially feed on roots, then move to the buds, finally tunneling into the Rhizome which can kill the plant; adults feed on all plant parts externally,” adds Purcell.

Scientists say biological control is globally considered as one of the most cost-effective, environmentally friendly and sustainable ways of reducing the impacts of invasive species.

Nearly 6,000 individual Salvinia weevils are being mass-reared in a facility in Lake Ossa by AMMCO.

“They were brought in from the Louisiana State University in the United States with the authorization of the Cameroon government,” says Kamla.

Scientists say biological control is globally considered as one of the most cost-effective, environmentally friendly and sustainable ways of reducing the impacts of invasive species.

“We keep mass-rearing them until we receive authorisation from the government to release them into the areas affected by water weeds. We are now conducting an experiment to know how long it will take for the weevils to get rid of these aquatic weeds in lake Ossa.”

An effective biological control of Salvinia molesta by using the Salvinia weevil was also applied in the Senegal River in the early 2000s. Similarly, the release of the weevil into South Africa’s fresh water systems in 1985 successfully brought Salvinia molesta under control.

“For water hyacinth, biological control entails the deployment of the weevils Neochetina eichhorniae and N. bruchi which are among the first to be used worldwide in more than 32 countries to control the weed,’’ explains Kenfack.

“They were found in some sites in the Wouri Basin causing damage on the mats of water hyacinth. However, their population is still small and must be mass-reared to obtain effective control of this plant (no need of an import permit).” The biological control agent of water lettuce is different though, she stresses.

Nalova Akua
Locals want Lake Ossa to be clear once again, so that their livelihoods can resume and wildlife can be saved.Nalova Akua

Neohydronomus affinis was used successfully in countries such as Senegal, Benin, Congo, Cote d’Ivoire and South Africa.”

Scientists have expressed hope that Cameroon may just be the next country for the successful implementation of biological control to weed out invasive water weeds.

“Because Cameroon is tropical, the prospects for successful biological control are high. I would predict that there will be a significant reduction in cover within 18 months, if not less,” says Julie Coetzee, Deputy Director and Manager of the Aquatic Weed Biocontrol Programme at Rhodes University, South Africa.

“While the process is not perceived as quick, in comparison to herbicide, it is sustainable in the long term. Patience is key,” she adds.

But Dr. Kenfack is concerned Cameroon may be racing against time.

“Limited progress [to mass-rear and authorise release of weevils] means the watercourses (Lake Ossa, Wouri Basin and Fiko just to name those) and all their biodiversity will be negatively affected.

“This calls for an urgent action in order to reap the benefits from these watercourses not only for us, but for the future generation,” she concludes.

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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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The following link will take you to a recording of the parthenium webinar presented by the FTF Innovation Lab at VA Tech presented March 30, 2021.

https://drive.google.com/drive/folders/1BOSAFBic_HZo1k7qRa2MkqbDoXUQxDpm?usp=sharing

Housekeeping information/instructions                 Sara Hendery                     5 minutes           

Introduction to the webinar:                                   R. Muniappan                 10 minutes

Biological control of parthenium in Australia:       K. Dhileepan                      15 minutes

Biological control of parthenium in South Africa: Lorraine Strathie               10 minutes

Biological control of parthenium in East Africa:   Wondi Mersie                    10 minutes

Biological control of Parthenium in India:            N. Bakthavatsalam              5 minutes

Biological control of parthenium in Nepal:          P.K. Jha                               5 minutes

Biological control of parthenium in Pakistan       Kazam Ali                            5 minutes

Discussion/questions and answers                                                                  50 minutes

Closing remarks                                                  Van Crowder                   5 minutes

For further information contact:

Sara Hendery

Communications Coordinator

IPM Innovation Lab

saraeh91@vt.edu

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Damage from invasive species ‘trebling every decade’

Mosquitoes, rats and termites among species that have hitched ride on trade routes, causing at least $1.3tn of damage

Fall armyworm
The fall armyworm arrived in Africa in 2016 and has now invaded dozens of countries. Photograph: Grant Heilman Photography/Alamy

Damian Carrington Environment editor@dpcarringtonWed 31 Mar 2021 11.00 EDT

The costs of damage caused by invasions of alien species across the world is trebling every decade, research has found.

Mosquitoes, rats, ragweeds and termites are among the species that have hitched a ride on globalised trade routes, bringing disease, crop destruction and damage to buildings. The scientists calculated the costs at $1.3tn (£944bn) since 1970, and said even this “staggering sum” was likely to be a big underestimate as much damage is unreported.

The rapidly growing costs show no sign of slowing down, the researchers said, and are more than 10 times higher than the funding for preventing or dealing with these biological invasions. They said global action to combat invasive species remained limited, mostly because the “profound” impacts are poorly understood by the public and politicians.

Mosquitoes from the Aedes genus, such as the tiger mosquito, spread Zika, dengue, yellow fever and other viruses, and were responsible for the biggest recorded costs. Invasive rodents such as the black rat, grey squirrel, coypu and house mouse also cause severe damage to human health, crops and food stores and to native wildlife.

Formosan termites, voracious consumers of wood, are a particular problem in the US, while the red fire ant has spread from its South American home to Australia, New Zealand, several Asian and Caribbean countries and the US. The fall armyworm, which can destroy many crops, arrived in Africa in 2016 and has now invaded dozens of countries.

“The economic costs of invasive alien species since 1970 are tremendous, steadily increasing, but still massively underestimated,” said Christophe Diagne, at the Université Paris-Saclay, France, and who led the research. He said the rising damage mirrored the growth of international trade and the expanding area of farmland and settlements that the invaders can damage.Advertisement

Prof Corey Bradshaw, of Flinders University in Australia, who was part of the study team, said: “The quicker you detect invasive species and the quicker you act, the cheaper it is in the long run. So really good detection at ports and airports and then rapid responses are going to cost you orders of magnitude less money than the damage.”

He said consumers ended up paying for the damage via increased prices for food and other products, and higher healthcare costs.

The research, published in the journal Nature, analysed more than 1,300 estimates of damage by invasive animals and plants. Costs were highest in the US, India, China and Brazil, but this probably reflects where the problems have been most reported. There is little or no data in many other parts of the world.

Some earlier cost estimates indicated much higher damages – as much as $1.4tn a year – but Bradshaw said these were largely based on poor or speculative assessments. “Some were not even ‘back of the envelope’ – there was no envelope,” he said.

The new analysis was deliberately conservative, using only estimates based on observed data. “But there are so many unquantifiables from a monetary perspective, like ecosystem damage and lost productivity, so it’s still the tip of the iceberg,” said Bradshaw. The true costs could be 10 times higher, he said.

Biological invasions are known to be increasing and so the rising cost estimates are unlikely to be solely the result of increased reporting of damage. Either way, the scientists said, “they robustly show staggering amounts” and “a huge economic burden”.

Prof Helen Roy, of the UK Centre for Ecology & Hydrology, who was not part of the research team, said: “The most important aspect of this research is showing the rising costs, regardless of the exact figure. Overall it is a very useful paper and has some excellent recommendations. It also gives some cause for optimism – there are ways to prevent arrival or manage invasive alien species that become established.”

Bradshaw said cinnamon fungus, which rots the roots of plants including grape vines, was one of Australia’s most damaging invasive species. “I have a little farm and it’s killed all of my chestnuts. So we’re slowly replacing those with trees that are resistant”.

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The humble beetle that could rescue a town Share using EmailShare on TwitterShare on FacebookShare on Linkedin(Image credit: Alamy)

Salvinia has an enormously rapid growth rate and can engulf a lake, smothering the ecosystem and killing fish and mammals (Credit: Alamy)

By Nalova Akua29th March 2021An invasive water weed has decimated the wildlife and economy of one of Cameroon’s most significant lakes. But a tiny, ravenous weevil could reverse the region’s fortunes.A

A flock of water birds scavenges for insects on the dense, leafy weed that covers much of Lake Ossa, one of Cameroon’s largest lakes. The water weed is so closely packed that it looks like wide, flat green pasture, and the sure-footed birds pick their way freely across it as if they were walking on land.

Five years ago, Lake Ossa was teeming with freshwater turtles, crocodiles and more than 18 families of fish. It was also a bastion of the African manatee, a species listed as vulnerable on the International Union for Conservation of Nature’s Red List. But today, the lake is eerily quiet and almost empty.

The thick layer of vegetation is Salvinia molesta, a species known locally as kariba weed or simply Salvinia, and it is the cause of this dearth of life in the lake. The invasion has been declared a “conservation emergency” by the IUCN.

Salvinia, a free-floating, green-brown freshwater fern, has already invaded more than 40% of the lake’s 4,000-hectare (15.4-sq-mile) surface, according to the African Marine Mammal Conservation Organisation (AMMCO), a Cameroonian non-governmental environmental organisation.

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Not far from the lake’s shore, an army of weevils is now being mass-reared as a defence against Salvinia

Decimating the lake’s wildlife, and compromising the main source of income for the local population, the Salvinia takeover has been rapid and seemingly unstoppable. Lake Ossa is only one in a long line of freshwater bodies to be engulfed by Salvinia. As this invasive weed has spread around the world, from Brazil and Argentina to Australia, the efforts to control it have struggled to keep pace with the plant’s prolific growth.

But there is hope for Lake Ossa, and it comes in the shape of a small, innocuous-looking but remarkably powerful water-dwelling beetle. Not far from the lake’s shore, an army of weevils is now being mass-reared as a defence against Salvinia.Lake Ossa is one of the largest lakes in Cameroon, and was home to a wealth of biodiversity before Salvinia arrived (Credit: AMMCO)

Lake Ossa is one of the largest lakes in Cameroon, and was home to a wealth of biodiversity before Salvinia arrived (Credit: AMMCO)

Lake Ossa is today littered with weed-laden fishing nets – abandoned by the local fisherfolk out of frustration. Wooden fishing boats have been hauled onto the lake’s shorelines – some have been there so long they are starting to rot. Those local fishermen who are still actively fishing in the lake, and the women who sell the fish caught, say they have lost about 80% of their income.

Lake Ossa used to be home to scores of African manatees, one of the most sparsely studied manatee species. Their population in the lake now appears to be declining

In the sweltering late morning heat, I meet Dina Marie-Louise, a fish retailer and resident of the lakeside town of Dizangue, as she disembarks from a wooden fishing boat. In the local business for 22 years, Dina has been visiting fishermen in the lake to buy their catch. Today, she frowns at the few fish in her basket. “Salvinia is killing us,” she says. “Seven of my 12 children have dropped out of school because of financial difficulties caused by Salvinia.”

Roland Ngolle, who has been fishing in the lake for 12 years, paints a similar picture. “We are running out of space to fish in this lake. If nothing is done, Salvinia will engulf all of Lake Ossa,” Ngolle says. “More than 100 fishermen used to visit this lake in a single morning. Today less than five come to fish. Everybody is discouraged.”

As well as fish, Lake Ossa used to be home to scores of African manatees, one of the most sparsely studied manatee species. Their population in the lake now appears to be declining. Many of the manatees are thought to be leaving the lake for its surrounding rivers, where they have better access to food, says Aristide Takoukam Kamla, founder of AMMCO.The larvae of the Salvinia weevil are highly destructive and can bring a freshwater habtitat back into ecological balance (Credit: Alamy)

The larvae of the Salvinia weevil are highly destructive and can bring a freshwater habtitat back into ecological balance (Credit: Alamy)

Salvinia is native to southern Brazil and northern Argentina, but it can spread between water bodies by wind, water currents, floods, animals and people. “[The] human factor is partly to blame for the presence of the invasive plant in the Cameroon lake,” says Kamla.

As well as physically moving the plant from one place to another, for example when it hitches a ride on boats, human activity is also thought to be responsible for allowing Salvinia to thrive in the lake.

“We noticed a heavy concentration of nutrients such as nitrogen and phosphorous in Lake Ossa in 2016 – doubling from the historical value of 1985,” says Kamla. “This was a signal that something was happening in the lake called eutrophication, which is simply the enrichment of the lake in terms of nutrients.”

That made conditions perfect for Salvinia to proliferate. “The carpet formed by the plant at the surface prevents light from penetrating the water column and therefore reduces photosynthesis of phytoplankton on which most fish species feed,” says Kamla. “This results in a drastic depletion of fish production.”

With a fast-growing plant that can double in size every 10 days, the plant’s growth is almost unstoppable. “The absence of [Salvinia’s] natural enemies in a foreign environment facilitates its fast growth rate,” says Lum Fontem, an independent plant scientist based in Cameroon.Numbers of the African manatee, pictured here in captivity, are in decline (Credit: Getty Images)

Numbers of the African manatee, pictured here in captivity, are in decline (Credit: Getty Images)

At every strategic corner of the bumpy earth roads around Dizangue, billboards carry messages alerting villagers and visitors to the Salvinia problem. Messages such as “Youths, Let’s Save Lake Ossa”; “Let’s Save Our Lake From Salvinia Invasion” appear on countless signs around the town. This may be Cameroon’s first experience of a Salvinia invasion, but there has already been an intensive response to it.

There are three main ways that the weed can be removed. The first, and most physically demanding, is removing it manually. “This includes hand-pulling, mostly for low infestation, and the use of specialised equipment, for high infestation,” says Fontem. “This method is labour-intensive, tedious and time-consuming.”

Since 2019, AMMCO has been mobilising locals to remove the plant manually to reduce the scope of spread. But it has not been without challenges. “This method is very demanding given that the invasive plant multiplies very quickly,” says Kamla. “We removed over 200 tonnes of Salvinia from the lake in 2019 and 2020. Yet, no impact was felt.”

This is because manual removal of Salvinia alone is not enough to control the weed, Lum says. Any plant left in the water will rapidly grow to replenish what has been stripped away.

The second option is chemical control, which involves the application of herbicides to kill the weed. But this comes with its own ecological drawbacks, as the herbicides pose a risk to other plants and could harm the lake’s other organisms. So far, the chemical approach has not been tried at Lake Ossa, and scientists including Fontem caution against trying it.

But there is one final option that could relieve Lake Ossa of Salvinia and restore its ecosystem: a small, brown-black water beetle native to Brazil known as the Salvinia weevil, which feeds almost exclusively on the weed. Measuring just 2-3.5mm long in its adult form, this tiny insect is equipped with a long, sturdy snout. But it is the weevil larvae that are devastating to the Salvinia by burrowing into the plant’s rootstalks and causing fatal damage.Removing Salivinia by hand is very labour intensive, but so far it is the only method that has been attempted at Lake Ossa (Credit: AMMCO)

Removing Salivinia by hand is very labour intensive, but so far it is the only method that has been attempted at Lake Ossa (Credit: AMMCO)

The Salvinia weevil was discovered by Wendy Forno, a scientist at Australia’s government research agency CSIRO, while carrying out surveys in South America between 1978 and 1982. The first releases of the weevil as a biological agent to destroy Salvinia were at Lake Moondarra, Mount Isa, Australia in 1980, with remarkable success.   

“Lake Moondarra is mostly clear of Salvinia today. Fifty thousand tonnes of Salvinia on the lake was killed by weevils over a 400-hectare (1.5-sq-mile) infestation,” says Matthew Purcell, director of the Australian Biological Control Laboratory, a facility run by the United States Department of Agriculture and CSIRO.

“The weevil – both adults and larvae – only feeds on this fern and not on other aquatic plants,” says Purcell. “As the plants increase seasonally, so do the weevils. The weevils [and] Salvinia constantly increase and decrease through the seasons in balance.” The weevils never fully eradicate the weed, but help to “return the system to a balance”, says Purcell.  

The weevil was also deployed in the Senegal River in the early 2000s, where it had similar success, says Arnold Pieterse, formerly a senior staff member of the Netherlands’ Royal Tropical Institute, now retired. He, too, underlines that the weevils’ strong preference for Salvinia as a food crop makes it an appealing choice for Salvinia control. “It has irrefutably been proven that the insects do not form any danger to the environment or crops,” says Pieterse.

South Africa, too, has successfully brought Salvinia molesta under control thanks to the release of the weevil into its fresh water systems since 1985. “South Africa had a number of systems infested with the weed throughout the country, mainly smaller impoundments and rivers,” says Julie Coetzee, deputy director and manager of the Aquatic Weed Biocontrol Programme at Rhodes University, South Africa. These waters took between one to three years to clear, depending on the nutrients in the water, and the climate. “We still do have some infestations appearing,” Coetzee says, but “once weevils have been released, we typically get clearing with a season”.The Salvinia weevil was first tried as a method to control the weed in Australia, where it has also invaded rivers and lakes (Credit: Getty Images)

The Salvinia weevil was first tried as a method to control the weed in Australia, where it has also invaded rivers and lakes (Credit: Getty Images)

Though the Salvinia has no defence against the weevil, the weevils themselves have weaknesses. “No drawbacks were experienced initially but nowadays, we have noticed that there are sites where infestations have persisted, particularly in shaded sites,” says Coetzee. “We have also discovered a parasitic alga infecting [the weevil] population.” This alga, called Helicosporidium, reduces the weevil’s ability to reproduce.

Nevertheless, Coetzee is optimistic that weevils could clear Cameroon’s Lake Ossa of Salvinia. “Implementing a biological control programme in Cameroon is the most ecologically friendly, economically sustainable option for control of Salvinia,” she says. “Given the size of the infestation on the lake, it is going to take a while for the control agent populations to build up to sizes that will damage the plants, and cause them to sink. This is not a fast process. Patience is key.”

Purcell, too, is hopeful that the weevils could rejuvenate Lake Ossa. “The weevils should work in Cameroon. Most control is achieved within three years,” he says. “The control lasts indefinitely, much better than spraying which must be reapplied every year and every season, with negative consequences to the aquatic environment.”

It may not be much longer before Lake Ossa becomes the next Salvinia-ridden water body to welcome weevils. A task force involving several of Cameroon’s government ministries has been set up to oversee the eradication of Salvinia in the lake through the release of the weevils.

The local people of Lake Ossa, though, are frustrated at the pace of action. “Fishing is our only source of income. We are running out of patience,” says Jean Pierre Nga, a fisherman. Dora Sih, a fish seller in the business for 25 years, agrees: “Things are not moving.”

But in AMMCO and their partners’ facilities in Dizangue, the stock of weevils is steadily growing. “They will be released into the lake as soon as we receive the authorisation permit from the government,” Kamla says. “And we hope that after two or three years, we will overcome this invasive plant.”

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John Deere using machine learning to reduce herbicide use

Melody Labinsky

Melody Labinsky@MelodyLabinsky4 Mar 2021, 4:30 p.m.On Farm

John Deere Australia and New Zealand managing director Luke Chandler spoke at the Rural Press Club of Queensland last week.

 John Deere Australia and New Zealand managing director Luke Chandler spoke at the Rural Press Club of Queensland last week.Aa

Machine learning technology is set to reduce herbicide use by up to 80 per cent, according to John Deere’s Australia and New Zealand managing director Luke Chandler.

Mr Chandler said this would be achieved by moving from a whole-of-field approach to a plant-by-plant management strategy.

He said global agriculture was at an inflection point and technological developments would help drive productivity.

Farmers across the world have been chasing economies of scale and the company’s focus had been on building bigger, faster and stronger machinery to meet that growth, he said.

“That’s still important but as we shift towards this next frontier of agriculture, we really see machinery being driven by automation, easier to use, more precise types of technologies.”

In 2017, John Deere acquired Silicon Valley company Blue River Technology for US$305 million.

By using Blue River’s deep learning algorithms and artificial intelligence programming and embedding it on the “hard iron of John Deere machines”, the company hopes to take agriculture’s productivity to the next level.

Mr Chandler spoke about the company’s focus on innovation and how it can help farmers grow the food and fibre sector at the Rural Press Club of Queensland last week.

“While you might hear a lot about ag tech being a new industry, it’s not new for us and it’s not new for us in Australia,” he said.

Mr Chandler pointed to the role of cotton and grains farmers in northern NSW in helping to develop GPS and yield mapping technology, which has become a major part of precision agriculture, and is used around the world.

John Deere has grown from its humble beginnings in Illinois 184 years ago, into one of the world’s largest agricultural machinery manufacturers.

Together with dealerships, the company employs 4500 people across Australia and New Zealand.

John Deere is also looking to bring its total number of tech apprentices to 1200, predominately in rural and regional communities.
SHARETWEETAa

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Controlling herbicide resistance takes persuading

TAGS: WEEDSRESISTANCE MANAGEMENTBrad Hairebrad-haire-farm-press-pigweed-smallish-cotton-GA.jpgCharlie Cahoon urges farmers to be on the lookout for Palmer amaranth surviving 2,4-D or dicamba. Integrated pest management is key for tackling herbicide resistance.

John Hart | Jan 04, 2021

The answers to managing herbicide resistance are fairly simple, the hard part comes in persuading farmers to implement the practices that do the most good.

Charlie Cahoon, North Carolina State University Extension weed specialist, says integrated pest management is key. Farmers need to rotate herbicide chemistries and turn to cultural and mechanical methods to alleviate some of the pressure on over-used herbicides.

“As Extension specialists, we’ve been using fire and brimstone. We think one of the tactics that drives folks to change practices on their farm is to scare them to death,” Cahoon said in a presentation at the virtual North Carolina Crop Protection School Dec. 2.

“My daddy has trained bird dogs his whole life. He used to think the way to train a dog was to use discipline. My three-year old daughter just taught him it is quite easy to train a dog with a handful of treats. There are studies to back this up, rewarding good behavior. I think that’s what we are having to learn right now with pesticide resistance: How do we get our growers to put into practice the tactics we’ve been preaching for years,” Cahoon said.

One option, Cahoon says, is providing farmers an economic incentive to implement integrated pest management practices. But where will the incentive come from?

Companies do have inventive programs, but Cahoon believes the incentive programs must cross company lines to encourage farmers to rotate modes of action and implement cultural practices to better control weeds.

Moreover, incentives must be in place for farmers to use cover crops, better crop rotation and other tools such as harvest weed seed control. “It really needs to be a whole industry initiative where we all get on the same page and say, ‘hey let’s reward some of these good behaviors and try to get ahead of this pesticide resistance issue,” Cahoon said.

Herbicide resistance is a problem that’s not going away.

In North Carolina, Cahoon says there is widespread Palmer amaranth resistance to glyphosate and ALS inhibitors, plus expected resistance to PPO inhibitors. There is common ragweed resistance to glyphosate and ALS inhibitors, primarily in the eastern part of the state. And there is widespread Italian ryegrass resistance to ALS inhibitors, mostly in the southern Piedmont.

Looking to the future, Cahoon said he won’t be surprised if North Carolina farmers begin to see resistance to group 15 herbicides, such a Dual, Warrant, Harness and Zidua.

“We use them repeatedly in most of our crops —  corn, soybeans, cotton, peanuts, and sweet potatoes. We are putting quite a bit of pressure on the group 15s, and there is already group 15 Palmer amaranth resistance in Arkansas and also a cousin to Palmer amaranth, waterhemp, is resistant to the group 15s in Illinois,” Cahoon said.

And as the use of dicamba and 2,4-D continues to grow, resistance to these chemistries can be expected as well. “There is evidence we are abusing dicamba and 2,4-D like we did glyphosate. That is unacceptable,” Cahoon said.RELATED Pigweed continues to outflank herbicidesNovember 11, 2020More resistant weeds popping up in North CarolinaMarch 5, 2020Building respect and value for soybeansNovember 24, 2020

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