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Archive for the ‘Cultural control’ Category

Competitive sorghum crops will dent weed invasion

The Land

Bob Freebairn

14 Mar 2022, 5 a.m.

Cropping

Closer row spacing and heavier sowing rates play a vital part of reducing weeds in grain sorghum crops. Closer row spacing and heavier sowing rates generally have little to no detrimental adverse effect on crop yield.

 Closer row spacing and heavier sowing rates play a vital part of reducing weeds in grain sorghum crops. Closer row spacing and heavier sowing rates generally have little to no detrimental adverse effect on crop yield.

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Grain Sorghum Weed Control Guide, written for Pacific Seeds by nationally recognised weed authority Andrew Summervaille, is a comprehensive and outstanding publication dealing with all control aspects. These include herbicides, with lots of insightful comment, fair but often acknowledging limitation of specific products, as well as the important contribution of agronomic aspects to help combat weeds’ effect on yield.

Contributed by Qld Department of Agriculture and Fisheries research agronomist Michael Widderick, is an important section covering weed suppression by growing a competitive sorghum crop. Research over two years has shown that growing a competitive sorghum crop with increased density and reduced row spacing can significantly suppress growth and seed production of weeds like barnyard grass and Feathertop Rhodes grass.

While trial results were not always consistent, crops sown in 0.5 m rows generally suppressed weeds better than in the more traditional 0.75 and 1.0m row spacing. Increasing sorghum plant density from more traditional 5.0 plants sq/m to 10 plants sq/m also generally contributed to a more competitive crop against weeds.

Different varieties (of those tested) had no impact on suppressing weed growth, suggesting cultivar choice will have a lesser impact on sorghum competitiveness than agronomy. However, the researchers note that impact of cultivar may differ across seasons and locations. Also especially noteworthy, was that at least in favourably growing conditions sorghum at narrow row spacing and increased density, did not have any negative impact on sorghum yield.

Weed control in grain sorghum is important for crop yield, as well as for driving down the soil weed seed bank. A combination approach is important for weed control.

 Weed control in grain sorghum is important for crop yield, as well as for driving down the soil weed seed bank. A combination approach is important for weed control.

Therefore, gains in competitiveness and reduction in weed growth can be achieved without reducing yield. Again the researchers note that rarely will a sorghum crop be grown without herbicides, whether they be residual or knockdown, or a combination of both. Integrating a competitive sorghum crop with herbicides should provide an additive effect on reducing in-crop weed pressures, growth and seed production. Over time, this strategy should deplete the weed seed banks, and reduce their impact on sorghum production.

Also read: Perfect growing season sees great sorghum crops in north-west

A further valuable part of the publication is discussion of the role of Imidazolinone technology in sorghum, developed by Advanta Seeds. Sorghum has well and truly joined the list of crops with varieties that provide tolerance to Imidazolinone (IMI herbicides). Note this is not GMO technology. This technology allows the application of a new range of registered herbicides at recommended rates without causing crop damage.

Intervix (imazamox + imazapyr) is an example of an IMI herbicide. IMI products have broad spectrum activity with variation in the activity of individual herbicides for pre-emergence and post-emergence control. Control of broadleaf weeds post-emergence is normally limited to small weeds and relies to a measure on the effectiveness of crop competition occurring subsequent to application particularly for less susceptible species. While IMI herbicides like Intervix control a wide range of broadleaf and grass weeds it does, like most herbicides, have its limitations like not controlling fleabane or Feathertop Rhodes grass.

Grain Sorghum Weed Control Guide, written for Pacific Seeds by nationally recognised weed authority Andrew Summervaille, is a valuable reference.

 Grain Sorghum Weed Control Guide, written for Pacific Seeds by nationally recognised weed authority Andrew Summervaille, is a valuable reference.

Excellent tables are presented in the publication that covers aspects like effect of various herbicides on specific weeds. These are detailed in tables for pre-emergent and post emergent. Tables also detail aspects like plant back intervals, application timing, rates per ha, rainfall requirement and the like.

Especially valuable is Andrew Summervaille’s discussions about various herbicide products. He highlights advantages and disadvantages of the various herbicides. Planning for control of difficult weeds, like fleabane, Feathertop Rhodes grass, and even well known weeds like barnyard grass and liver-seed grass that have or are developing resistance to some herbicides, requires carful choice of herbicide and their application.

Further details obtain the booklet via http://www.pacificseeds.com.au/wp-content/uploads/2021/07/Pacific-Seeds-Grain-sorghum-weed-control-guide-_Low-Res.pdf

Next week: Ensuring legumes are a vital part of the pasture mix.

  • Bob Freebairn is an agricultural consultant based at Coonabarabran. Email robert.freebairn@bigpond.com or contact (0428) 752 149.

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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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Cover Crops Attract Pest Predators which Reduce Pesticide Use

(Beyond Pesticides, November 2, 2021) Cover crops create habitat that draw in pest predators and help mitigate crop injury, finds research published in the journals Agroecosystems and Biological Control from scientists at the University of Georgia. Expanded predator diversity can reduce pest pressure that drives conventional chemical farmers to apply toxic pesticides, and the authors of the study find the practice to be economically viable within these cropping systems. “There’s a motion of change going on where growers are thinking more about using natural systems instead of just using pesticides,” said co-author Jason Schmidt, PhD in a news release. “Producers must use all tools available to make a profit, so if they can promote beneficial insects in the system to aid in pest control,  fewer inputs are needed and that should lead to reduced costs of production. ”

To determine how beneficial cover crops were to cotton production, researchers began with experimental crops established over two years in 2016 and 2017 in Georgia. Twelve cover crops plots were established with crimson clover and rye, while a plot not planted with cover crops was used as a control. Researchers planted the cover crop in early November after the previous cotton crop was harvested, and terminated and rolled the cover crop 2 weeks prior to a May cotton planting. Cover crop residue was sucked up with a reverse leaf blower the scientists created and sampled six times at random locations. Analysis was then conducted on the gut content of the pest predators retrieved in order to determine what pests they were consuming.

Predator communities were found to be much more diverse (7 to 10x more) in cover cropped fields. While the cover cropped fields contained a range of spiders and other predaceous bugs, control fields mostly contained a specific type of beneficial beetle. Researchers found the benefits of cover cropping to be most pronounced in the early spring. But as the cover crop degrades, differences between cover cropped and control plot predator communities began to even out.

“There are early-season benefits of cover crops when cotton plants are small, said Dr. Schmidt. “The cover crop residue forms a complex habitat matrix with cotton seedlings popping out of it and there are insect predators in there that can defend those young plants from pests.” Dr. Schmidt indicates that the change occurs when there is more of the cotton crop above ground than the cover crop.  “Later in the season, you see similar communities. So, even though there’s a little bit of habitat on the ground from those cover crops, it doesn’t seem to matter in terms of the overall community in the system when cotton plants become the primary habitat available.”

A deeper review of the findings show that thrip populations, which can often hinder cotton crops in early growth stages, are mitigated by increased cover cropping. Cover crops also bring in predators that hamper stink bug damage to cotton bolls. An economic analysis found cover cropping to be a cost effective approach comparable in expense to a completely conventional chemically managed system. “These results suggest that conventional growers utilizing cover crops could reduce insecticide inputs through natural reductions in pest pressure, and overall do not incur additional production costs,” reads the study in Biological Control.

The scientists indicate that they will continue their work to better understand the complex interactions that occur between pest and predator in crop fields. “That’s our ultimate goal, understanding the functioning of diversity and the beneficial roles species play in production systems and best harvest these services for production systems, like cotton,” said Dr. Schmidt.

The study’s results are likely to be unsurprising for organic farmers and even many home gardeners that make certain they keep their soil covered with organic matter year-round. Key to soil conservation are practices that minimize soil disturbance, increase plant diversity, and continually keep soil covered with live plants or roots in the ground.

The study results are encouraging in the context of a system primarily reliant on chemical inputs. Termination of the cover crop utilized an unnamed chemical herbicide, for instance. Although herbicides are intended to target plant material, products like glyphosate threaten a broad range of species. A federal biological assessment published late last year found that glyphosate itself is likely to affect 93% of endangered species. Thus a range of predator insects that may have assisted in further, or more sustained pest management may have been killed off by the use of a chemical to terminate the cover crop. Non-toxic cover crop termination options include mowing, or the utilization a roller/crimper machine that bends plant residue uniformly over the surface of soil.

In study after study, results show that creating habitat that increases diversity enhances plant productivity and reduces toxic pesticide use.  Conventional cotton production can utilize these practices and see some ephemeral benefits, but when properly maintained, these practices decrease pest pressure and create more stable ecological systems that provide lasting ecological and economic benefits. To truly break out of a reliance on chemical inputs, conventional systems must move not only towards cover crop diversity, but crop diversity in general, as multi-crop farming practices produce higher yields than monoculture farmlands.

Most organic farmers, required to maintain or improve soil health under organic standards, are already conducting practices that work with natural systems. Help continue to grow organic, so that more farmers will adopt these safer practices, by purchasing organic products whenever possible. To help become part of the organic solution, join Beyond Pesticides today, and support our fight to maintain the integrity of organic standards from attacks by the conventional chemical industry.

All unattributed positions and opinions in this piece are those of Beyond Pesticides.

Source: AgroecosystemsBiological ControlUniversity of Georgia news release

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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. 

RELATED ARTICLES

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ALL LATEST NEWSNEWS AUGUST 2021NORTH AMERICASMART FARMINGSUSTAINABILITY

Benefit of cover crops: Covering up weed seeds

on August 12, 2021

More in All latest News:

Cover crops are not free, but they don’t have to be a cost. In fact, they can save farmers money. Researchers and farmers talked about the benefits during a recent session hosted by the Ontario Soil and Crop Improvement Association in Canada, as Matt McIntosh reports for Farmtario.

While there is always variability, weed suppression and population reduction are the chief – though not necessarily only – ways cover crops can better a farm’s bottom line. Cover cropping could be justified as another tool to help keep down weed populations as farmers struggle with more herbicide-resistant weeds.

More weeds equal more weed seeds if left uncontrolled. Over time, the weed seed bank within a given area can be substantial, requiring more time, resources and cash to address the problem. Herbicide-tolerant weeds can increase the price tag of effective control. 

Cover crops don’t have to be expensive or complex to have noticeable impacts. Cowbrough’s work shows oats, a comparatively cheap and available cover crop option, broadcast with potash at 50 pounds per acre, add an extra $16 per acre to production costs. Weed populations were much lower. 

Mike Cowbrough, weed management specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs, says cereal rye is another cheap “gateway” cover crop option that can drastically reduce weed populations, including those of common and problematic pigweed species, lamb’s quarters and others. 

“Smaller plants are much easier to kill with your herbicide program,” says Cowbrough. 

Source: Farmtario.com. Full story here
Cover photo: Start simple with cover crops and choose species based on goals. Courtesy Farmtario

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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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Cedar fight goes across fence and state lines

TAGS: CONSERVATIONLIVESTOCKCurt ArensA few members of the Bristow, Neb. area crew pose in front of the trucks they purchased to help on prescribed burnsCRUCIAL CREW: A few members of the Bristow, Neb., area crew pose in front of the trucks they bought to help on prescribed burns. Over the past eight years, this group has burned more than 30,000 acres in their fight to reclaim grasslands from invasive eastern red cedar.Working together has been a successful formula for Nebraska and South Dakota advocates of prescribed fire.

Curt Arens | Dec 23, 2020

Gathering landowners to work together on prescribed burn projects has been a winning model in the successful defeat of eastern red cedar encroachment on grazing lands. Normally, prescribed burn associations work across fence lines with neighboring landowners.

Over the past decade, eastern members of the Niobrara Valley Prescribed Fire Association, covering much of north-central Nebraska, have not only reached across fence lines, but also state lines into neighboring South Dakota, to beat the invasion of ERC.

Related: New strategy in battle against invasive cedars

It started in 2010 when Jerald Dennis, Bristow, Neb., sheared ERC trees in a large portion of family-owned grasslands on the south shore of Lake Francis Case in South Dakota, behind Fort Randall Dam. He piled the dead cedar trees for curing. In 2011, Dennis deferred grazing on the tract, to grow fuel for the prescribed burn he was planning the following spring.

“It took an entire year to plan the burn, coordinating between five landowners, four government agencies along with local law enforcement and fire departments,” Dennis explains. On that burn with Dennis, Dave Steffen from Gregory, S.D., and other interested landowners in the area watched as observers.

Dennis has worked at Nebraska State Bank in Bristow for nearly 40 years. Most of that time, he has also served on the Bristow Fire Department. His family owns about 2,000 acres of pasture in both states, so he’s been involved in prescribed burning for the past 13 years. The Prescribed Fire Association that Dennis works with has conducted burns on just over 30,000 acres since 2012.

They normally develop their burn schedule at a meeting each February, so 10 to 12 people can plan to be involved with each burn. The local members of the association bought two Army surplus pickup trucks to transport skid water pumping units with 250-gallon tanks, hoses and a reel they borrow from the Nebraska Game and Parks Commission.

The burn near Fort Randall encompassed 3,145 acres. “We had a well-seasoned crew of 12 from Nebraska working that burn,” Dennis says. “It also helped that we had Lake Francis Case to the north and a highway to the south.”

Steffen watched the Nebraska crew and became interested in conducting more prescribed burns locally. “The following year, Steffen and a few other interested parties came down from South Dakota and attended our local meeting, and a few controlled burns,” Dennis says. “We collaborated on burns in South Dakota by helping that group develop burn plans and assisting with the burns. Our motivation was to teach their group how to safely conduct controlled burns, so they could teach others in the state.”

In 2017, the South Dakota group formed its own Mid-Missouri River Prescribed Burn Association —the first in the state — with Steffen and several neighbors as driving forces in the effort.

“Cedar trees were just beginning to become a problem,” Steffen recalls. “I looked at maps that showed the encroachment problems, especially big bunches along the Missouri River.”  The aerial maps showed about one-third of Gregory County with cedar tree problems. “Thanks to funds from the South Dakota Grasslands Coalition, we sent out a questionnaire, asking landowners about cedars on their land, and if they would consider prescribed fire as a control.”

Jerald DennisA prescribed burnLIGHTING IT UP:  Two years before the actual burn near Fort Randall Dam in South Dakota, Jerald Dennis sheared several large cedar trees and pushed them up against mature live trees. In 2012, when they started their prescribed burn in that area, the sheared trees ignited easily and burned into the live trees.

Steffen says that working with the Nebraska group helped their association in South Dakota organize and conduct burns of its own.

“We’ve had burns in the hundreds of acres so far, mostly in Gregory County, but also in Charles Mix County. That included a couple of big ranches,” Steffen says. “In many cases, nonresident landowners contact us about conducting a burn on their property. In most cases, we like it when landowners participate in the burn themselves, but with some nonresidents, we accept a payment for doing the burns.”

The Mid-Missouri River group now covers four counties, including Gregory, Charles Mix, Brule and Lyman.

“From the prescribed burns, we have witnessed tremendous recovery of warm-season native grasses on those grasslands where there was grazing management to go along with it,” Steffen says. “There has been fantastic recovery to a typical native plant community in the rough hills and breaks of the Missouri River.”

Cedar treesDEAD TIMBER:  At specific heights, cedar trees do not stand a chance against a well-run prescribed burn. Most of the trees pictured here are completed destroyed. Grass recovery in an area like this is surprisingly rapid.

Steffen says that landowners are amazed with the amount of new grass growth there has been within a year’s time. “Keep in mind, we’ve had plenty of rain in recent years to grow grass, so we have been above normal in soil moisture,” he adds.

For the group based in Bristow, fire has been a worthwhile tool in their war against ERC for more than a decade. “We add new, younger members to our group every year,” Dennis says. “Most of them are members of the fire department, so they are comfortable with conducting a burn. We all work together, and it is great knowing that the other guys have got your back.”

Learn more about Nebraska prescribed fire associations at the state’s Pheasants Forever and Quail Forever website, nebraskapf.com. Learn about the Mid-Missouri River Prescribed Burn Association of South Dakota online at midmissouririverpba.com.RELATEDYoung farmers get involved in ag groupsNovember 17, 2020Landowners band together to confront eastern red cedarJune 22, 2020

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Management of Fall Armyworm: The IPM Innovation Lab Approach

https://ipmil.cired.vt.edu/wp-content/uploads/2020/12/IPM-IL-FAW-Management.pdf.

By:

Sara Hendery

Communications Coordinator

Feed the Future Innovation Lab for Integrated Pest Management

Hendery, Sara saraeh91@vt.edu

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cover cropsJosh HiemstraPLANTING GREEN: Seventy-one percent of farmers responding to a national cover crop survey reported they had better weed control by planting green, and 68% reported better soil moisture management even during a wet spring.

National survey reveals farmers like cover crops

Survey documents a wide range of benefits as acreage expands.

Fran O’Leary | Aug 20, 2020

“Many U.S. farmers have turned to cover crops as part of their strategy to improve soil health while reducing input costs and maintaining yields,” reports Mike Smith, who managed the national survey for the nonprofit organization Conservation Technology Information Center.

Survey participants averaged 465 acres in cover crops in 2019, an increase of 38% in four years. The USDA Census of Agriculture found a 50% increase in cover crop acreage during the five-year period between 2012 and 2017.https://tpc.googlesyndication.com/safeframe/1-0-37/html/container.html

Multiple benefits

“Farmers are using cover crops for a variety of reasons, and many have tried new approaches to cover cropping,” Smith says. “This year’s survey also indicated that some of the concerns that many growers have had about the effects of cover crops on planting dates in a wet year turned out not to be true. In fact, in many cases, cover crops helped farmers plant earlier in the very wet spring of 2019.”

Despite the crippling rainfall that significantly delayed planting across much of the country in 2019, more than 90% of farmers participating in the survey reported that cover crops allowed them to plant earlier or at the same time as fields without cover crops. Among those who had “planted green,” seeding cash crops into growing cover crops, 54% said the practice helped them plant earlier than on other fields.

These findings are among several new insights from the 2019-20 National Cover Crop Survey, conducted by CTIC with financial support from the Sustainable Agriculture Research and Education program and the American Seed Trade Association. These organizations have worked together on several past national cover crop surveys, with the first survey dating back to 2012.

The 2019-20 survey, which includes perspectives from 1,172 farmers representing every state, is the first by SARE, CTIC and ASTA to include detailed exploration of planting green — a tactic employed by 52% of the respondents — as well as crop insurance use among cover croppers and the impact of cover crops on the profitability of horticultural operations.

According to Rob Myers, regional director of Extension programs for North Central SARE, “Many farmers are finding that cover crops improve the resiliency of their soil, and the longer they use cover crops, the greater the yield increases and cost savings that are reported by producers.”

The survey shows a majority of farmers are buying cover crop seed from cover crop seed companies and retailers.

“We are pleased to see farmers appreciate the expertise of cover crop seed companies, with 46% saying they buy from them and another 42% buying from retailers,” says Jane DeMarchi with ASTA. “Professionally produced cover crop seed is grown for seed from the start and has been selected, harvested, cleaned and tested for performance. The study shows farmers are using a range of cover crop seed and mixes to address their individual needs, with 46% paying $15 or under per acre.”

Of the 1,172 farmers who provided responses in the 2019-20 survey, 81% were commodity producers (corn, soybeans, wheat, cotton), and 19% categorized themselves as horticultural producers.

Following are some highlights from the survey.

Higher yields, lower costs

The previous five national cover crop surveys sponsored by SARE, CTIC and ASTA all reported yield boosts from cover crops, most notably in the drought year of 2012 — soybean yields were 11.6% improved following cover crops, and corn yields were 9.6% better.

In 2019, when wet early conditions prevailed across much of the corn and soybean regions, yield gains were more modest but still statistically significant. Following the use of cover crops, soybean yields improved 5% and corn yields increased 2% on average, while spring wheat yields improved 2.6%.

Many farmers reported economic benefits from cover crops beyond yield improvements. Of farmers growing corn, soybeans, spring wheat or cotton, the following percent had savings on production costs with fertilizers and/or herbicides:

  • Soybeans: 41% saved on herbicide costs and 41% on fertilizer costs
  • Corn: 39% saved on herbicide costs and 49% on fertilizer costs
  • Spring wheat: 32% saved on herbicide costs and 43% on fertilizer costs
  • Cotton: 71% saved on herbicide costs and 53% on fertilizer costs

While cover crop seed purchase and planting do represent an extra cost for farmers, most are finding ways to economize on cover crop seed costs. Whereas earlier surveys from 2012 and 2013 reported on a median cover crop seed cost of $25 per acre, most farmers reported paying less in 2019.

Of the responding farmers, 16% paid only $6 $10 per acre for cover crop seed, 27% paid $11 to $15 per acre, 20% paid $16 to $20 per acre, and 14% paid $21 to $25 per acre. Only about one-fourth paid $26 or more per acre, according to the report.

Planting green

Planting green refers to planting a cash crop such as corn, soybeans or cotton into a still-living cover crop, and then terminating it soon after with herbicides, a roller-crimper or other methods. In this year’s survey, 52% of farmers planted green into cover crops on at least some of their fields. In the 2016-17 report, 39% of respondents had planted green.

Of the farmers planting green:

  • 71% reported better weed control
  • 68% reported better soil moisture management, which is particularly valuable during a wet spring

The majority of farmers said levels of early-season diseases, slugs and voles — often feared as the potential downsides of planting green into cover crops — were about the same or better after planting green into cover crops. Though many farmers noted they did not have problems with voles, several pointed out challenges with cutworms when planting green.

The top two reasons farmers plant cover crops:

  1. Most use cover crops to improve soil structure or soil health.
  2. Many plant cover crops to improve weed management.

The majority of farmers responding to the survey said they plant cereal rye as a cover crop. Radishes are the second most popular cover crop. But when they are using a mix, radishes are the No. 1 most planted cover crop, followed closely by a rye mix. Half of respondents say they are increasing the number of crops in their cover crop mix.

For the full survey report, including past years’ survey reports, visit sare.org/covercropsurvey.

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JULY 20, 2020

Returning to farming’s roots in the battle against the ‘billion-dollar beetle’

by University of Arizona

Returning to farming's roots in the battle against the 'billion-dollar beetle'
Western corn rootworm larvae can devour the tips of corn roots, robbing the plants of nutrients and making them susceptible to falling over. Credit: Cyril Hertz, Lingfei Hu and Matthias Erb, University of Bern, Switzerland

Nicknamed the “billion-dollar beetle” for its enormous economic costs to growers in the United States each year, the western corn rootworm is one of the most devastating pests farmers face.https://3777ec3032f89ac36b1a5fe5c7568749.safeframe.googlesyndication.com/safeframe/1-0-37/html/container.html

“They are quite insidious. They’re in the soil gnawing away at the roots and cutting off the terminal ends of the roots—the lifeblood of corn,” said Bruce Tabashnik, Regents Professor and head of the University of Arizona Department of Entomology. “And if they’re damaging enough, the corn plants actually fall over.”

Genetically modified crops have been an important tool in the battle against pests such as these, increasing yields while reducing farmers’ reliance on broad-spectrum insecticides that can be harmful to people and the environment.

Corn was genetically engineered to produce proteins from the bacterium Bacillus thuringiensis, or Bt, that kill rootworm larvae but are not toxic to humans or wildlife. The technology was introduced in 2003 and has helped keep the corn rootworm at bay, but the pest has begun to evolve resistance.

“So, now the efficacy of this technology is threatened and if farmers were to lose Bt corn, the western corn rootworm would become a billion-dollar pest again,” said Yves Carrière, a professor of entomology in the College of Agriculture and Life Sciences.

Crop Rotation in Mitigating Pest Resistance

Carrière is lead author of a study to be published in PNAS that evaluated the effectiveness of crop rotation in mitigating the damage caused by resistant corn rootworms. Tabashnik and colleagues from North Carolina State University, the University of California-Davis, McGill University and Stockholm University coauthored the study.

Crop rotation, the practice of growing different crops in the same field across seasons, has long been used for pest control. In 2016, the U.S. Environmental Protection Agency mandated crop rotation as a primary means of reducing the damage to Bt corn fields caused by resistant corn rootworms, but there have been limited scientific studies to support the efficacy of this tactic.https://googleads.g.doubleclick.net/pagead/ads?client=ca-pub-0536483524803400&output=html&h=280&slotname=5350699939&adk=2265749427&adf=625945176&w=750&fwrn=4&fwrnh=100&lmt=1595996918&rafmt=1&psa=1&guci=2.2.0.0.2.2.0.0&format=750×280&url=https%3A%2F%2Fphys.org%2Fnews%2F2020-07-farming-roots-billion-dollar-beetle.html&flash=0&fwr=0&rpe=1&resp_fmts=3&wgl=1&dt=1595996918602&bpp=11&bdt=88&idt=147&shv=r20200727&cbv=r20190131&ptt=9&saldr=aa&abxe=1&cookie=ID%3Dfd49ee1f356c7aad-2230268791c20026%3AT%3D1595996908%3AS%3DALNI_MZ__AIkhsEMsw1AjrlZUCXlh_wvFw&correlator=2622896222429&frm=20&pv=2&ga_vid=683244895.1595996911&ga_sid=1595996919&ga_hid=1573871060&ga_fc=0&iag=0&icsg=2271232&dssz=26&mdo=0&mso=0&u_tz=-300&u_his=2&u_java=0&u_h=1080&u_w=1920&u_ah=1040&u_aw=1920&u_cd=24&u_nplug=3&u_nmime=4&adx=447&ady=2184&biw=1903&bih=969&scr_x=0&scr_y=0&oid=3&pvsid=1003068873479674&pem=0&rx=0&eae=0&fc=896&brdim=0%2C0%2C0%2C0%2C1920%2C0%2C1920%2C1040%2C1920%2C969&vis=1&rsz=%7C%7CpeEbr%7C&abl=CS&pfx=0&fu=8320&bc=31&ifi=1&uci=a!1&btvi=1&fsb=1&xpc=7ptrOeJu1R&p=https%3A//phys.org&dtd=154

Carrière and his team rigorously tested this approach by analyzing six years of field data from 25 crop reporting districts in Illinois, Iowa and Minnesota—three states facing some of the most severe rootworm damage to Bt cornfields.

The results show that rotation works. By cycling different types of Bt corn and rotating corn with other crops, farmers greatly reduced rootworm damage.

Most notably, crop rotation was effective even in areas of Illinois and Iowa where rootworm resistance to corn and soybean rotation had been previously reported.

According to the study, crop rotation provides several other benefits as well, including increased yield, reductions in fertilizer use and better pest control across the board.

“Farmers have to diversify their Bt crops and rotate,” Carrière said. “Diversify the landscape and the use of pest control methods. No one technology is the silver bullet.”

Returning to farming's roots in the battle against the 'billion-dollar beetle'
Western corn rootworm beetle on corn tassels. Credit: Joseph L. Spencer, Illinois Natural History Survey, University of Illinois at Urbana-Champaign

A Multipronged Approach

Tabashnik relates the research back to UArizona’s work with the pink bollworm, in which researchers spearheaded a management program to suppress the pink bollworm’s resistance to Bt cotton.

“The key to eradicating pink bollworm in the U.S. was integrating Bt cotton with other control tactics,” Tabashnik said. “We succeeded, whereas this voracious invasive pest rapidly evolved resistance to Bt cotton in India, where the genetically engineered crop was used alone.”

In collaboration with cotton growers, UArizona scientists sustained the efficacy of Bt cotton against pink bollworm by establishing the “refuge strategy,” in which non-Bt crops are planted near Bt crops to allow survival of susceptible insects. The strategy has become the primary approach used worldwide to delay the adaptation of insect pests to genetically engineered crops.

Although farmers have used refuges to thwart the rootworm’s resistance to Bt corn, this strategy alone has proven insufficient against the pest.

“During the last decade, we have learned that refuges are often not sufficient to delay resistance in pests like the corn rootworm,” Carrière said. “It would be wise to diversify management tactics before such pests evolve resistance. This approach, called integrated pest management, is vital for preserving the benefits of biotechnology.”

Returning to Agricultural Roots

In many ways, the study reaffirms traditional agricultural knowledge.

“People have been rotating crops since the dawn of farming. The new agricultural technology we develop can only be sustained if we put it in the context of things we’ve known for thousands of years,” Tabashnik said. “If we just put it out there and forget what we’ve learned in terms of rotating crops, it won’t last.”

The authors emphasize that increasing crop rotation is essential for sustaining the economic and environmental benefits provided by rootworm-active Bt corn. During the six years of the study, the average percentage of corn rotated to other crops per state ranged from about 55-75%.

“This is one of the most important applications of Bt crops in the United States,” Carrière said. “If we lose this technology and we start using soil insecticides again, it’s going to have a big negative environmental impact.”


Explore furtherScientists offer recommendations for delaying resistance to Bt corn in western corn rootworm


More information: Crop rotation mitigates impacts of corn rootworm resistance to transgenic Bt corn, PNAS (2020). DOI: 10.1073/pnas.2003604117Journal information:Proceedings of the National Academy of SciencesProvided by University of Arizona

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fall-armyworm-frontal-MER-563x744

‘Push-pull’ crop system to curb fall armyworms

Report

from EastAfrican

Published on 13 Feb 2018 View Original

In Summary
– Intercropping maize with drought-resistant greenleaf desmodium and planting Brachiaria grass on the farm’s edge helps curb fall armyworms.

Researchers have found intercropping maize with drought-resistant greenleaf desmodium and planting Brachiaria grass on the farm’s edge helps curb fall armyworms.

Desmodium and Brachiaria grass are high quality animal fodder plants.

The leguminous greenleaf desmodium becomes repellent, emitting a blend of compounds that help push armyworms away from maize while Brachiaria Mulato II grass around field edge produces chemicals attractive to the pests.

The International Centre of Insect Physiology and Ecology (Icipe) said that the “push-pull” crop system also promotes soil fertility and hinders the striga weed from attaching roots of cereal crops.

Icipe together with Rothamsted Research of Britain studied 250 maize farms that have adopted the push-pull method in western Kenya, eastern Uganda and northern Tanzania and found that the climate-adapted push-pull technology controls fall armyworm in smallholder farming systems in East Africa.

The method was initially developed for control of cereal stem borers and striga weed.

The scientists studied Kenya’s Bungoma, Busia, Siaya, Vihiga, Migori and Homa Bay sub Counties, Tarime district in Tanzania, Uganda’s Iganga, Bugiri ,Tororo and Bukedea districts.

Data on number of fall armyworm larvae on maize, percentage of maize plants damaged by larvae and grain yields was collected. Each farmer had a set of two plots, a climate-adapted push–pull and a maize monocrop.

There was 82.7 per cent reduction in number of fall armyworm larvae per plant and 86.7 per cent drop in plant damage per plot with push-pull systems. Grain yields were significantly higher, 2.7 times in systems plots.

“The farmers in the push-pull project reported that their fields were free of fall armyworm infestation while neighbouring monocrop plots were being ravaged by the pest,” said ICIPE’s Pull-Push Leader Prof Zeyaur Khan.

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