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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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Farming Online

Farming-online-main-menu-logo

 

New study looks at tilling for effective weed management

25 Jul 2017
Categories: Arable

With herbicide resistance on the rise, there is a renewed emphasis on soil tillage as a critical component of integrated weed management.

Although tillage is the subject of an ongoing debate – with studies released this month by NASA and the European Conservation Agriculture Federation emphasising the role minimising soil disturbance and building up soil carbon can play in reducing greenhouse gas emissions from farming – a newly published paper by researchers from the U.S. has backed tillage as a major means of suppressing weeds. The study stresses that, when it comes to weeds, timing matters and when tillage occurs can significantly impact both weed density and the composition of the weed community that emerges from seeds in the soil.

The paper, published in the journal Weed Science, looks at the impact of tillage on four sites in the northeastern U.S. that were tilled every two weeks during the growing season. Six weeks after each tillage cycle, researchers sampled random plots – 196 in total – to measure the density and species of weed seedlings.

They found that total weed density tended to be greatest when soil was tilled early in the growing season. In fact, more than 50 percent fewer weeds emerged after late-season tillage than after early-season tillage.

The composition of the weed communities in the test fields was also impacted by tillage timing. After early-season tillage there was greater unevenness among various weed species, with some species clearly dominating. After late-season tillage, the distribution among weed species tended to be much more even.

“Our results suggest that farmers may be able to better manage weed communities and to mitigate the impact of weeds on crop yields by adjusting the timing of their tillage, crop rotation and other cultural management practices,” says Matthew Ryan of Cornell University, a member of the research team.

Full text of the article can be read here.

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Iowa farmer

2017-05-06T20:00:00Z Non-herbicide tactics help manage weeds Iowa Farmer Today
May 06, 2017 8:00 pm

Editor’s note: The following was written by Lizabeth Stahl, Jared Goplen and Lisa Behnken, University of Minnesota Extension educators, for the university’s Minnesota Crop News website.


Weed management tools can be divided into three main categories: mechanical, cultural and chemical. Historically in conventional systems, chemical control options, or herbicides, have been relied on heavily.

Herbicide-resistant weed populations, however, are limiting herbicide options and effectiveness in many fields. Implementing non-chemical options, such as cultural and mechanical control tactics, can help make weed management systems more effective and durable.

To develop a more robust weed management program, consider the following three key strategies:

Account for weed emergence patterns

Weed emergence is driven by a number of factors, including temperature, light, nitrogen and/or chilling period, depending on the species.

University of Minnesota trials at Waseca in 2016 showed that delaying soybean planting until May 19 resulted in pre-plant tillage removing nearly 49 percent of the giant ragweed that emerged over the season. Soybean yield potential was still around 94 percent of optimal at the May 19 planting date, based on long-term research results, and the benefit was a much lower population of giant ragweed to control post emergence.

Soybean yield potential of the early planting date averaged 99 percent of optimal, however, pre-plant tillage removed less than 8 percent of the giant ragweed emerged over the season.

Pre-plant tillage can be an effective weed control tool, especially when planting is delayed. Flushes of early-emerging weeds, such as giant ragweed, common lambsquarters and winter annuals, can be taken out with pre-plant tillage, but be sure tillage is aggressive enough to destroy the weeds, and not just uproot and transplant them.

In contrast, waterhemp emerges later in the season, typically emerging over an eight to 10 week time period. This is why residual herbicides or the layering of residual herbicides (e.g. an application at planting and then 30 days later) is recommended for control of waterhemp.

Manage the weed seedbank

Seed production of weeds can vary significantly by species. Giant ragweed, for example, has been found to produce from 1,800 to 10,000 seeds per plant, while waterhemp can average over 350,000. Although competition with other plants can reduce seed production, dense weed populations have the potential to produce tremendous amounts of weed seed.

Common lambsquarter is a long-term survivor in the weed seedbank, and according to the University of Michigan, it takes an estimated 78 years to see a 99 percent depletion of the seedbank.

In contrast, University of Minnesota research demonstrated the giant ragweed seedbank could be depleted 97 percent in two years. University of Illinois research found the waterhemp seedbank could be depleted by more than 99 percent in 4 years.

Burial of seed by tillage can increase longevity in the seedbank, while seed left on the soil surface can be lost to predation and decay. For this reason, delaying tillage as long as possible in areas where weeds went to seed could help reduce long-term weed management challenges. Avoid deep tillage, which enhances seed longevity.

Not running the combine through a weed patch will help limit the spreading of weed seeds throughout the field. Also, manage weeds along field edges to help prevent buildup of the weed seedbank.

Incorporate sound agronomic tactics

Ensuring the crop is as competitive as possible (e.g. adequate fertility, planting population and disease and pest control) can help enhance weed control. Narrow rows, expanding crop rotations and cover crops have the potential to aid in weed control as well.

Cultivation is another effective tool, allowing you to remove weeds without setting back the canopy as some postemergence herbicides can, leading to faster canopy closure and a more competitive environment for weeds.

Cultivation was evaluated in Minnesota research trials in 2015 and 2016. A preemergence application of Boundary was followed by either Liberty or mechanical cultivation. In 2016, final waterhemp control was significantly better with the Boundary/Cultivation treatment (98 percent) compared to the Boundary/Liberty program at 89 percent.

Copyright 2017 Iowa Farmer Today. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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Southeast Farm Press

  • Soybeans were an effective trap crop, pheromone traps killed stink bugs in the trap crop, and buckwheat plants fed beneficial wasps that reduced stink bug numbers.
Agricultural Research Service

Cotton growers in the United States are concerned about native stink bugs that have attacked cotton and other crops for decades.

The green stink bug (Chinavia hilaris), southern green stink bug (Nezara viridula), and brown stink bug (Euschistus servus) continue to threaten cotton. But an Agricultural Research Service scientist in Georgia has found some environmentally friendly alternatives to insecticides.

“Cotton growers are increasingly interested in producing their crops in ways that have less impact on the environment,” says ARS entomologist Patricia Glynn Tillman, who is based in Tifton, Georgia.

The three native stink bugs are immune to the insect-killing toxins incorporated into most modern cotton varieties. Insecticides are effective, but they also kill the stink bug’s natural enemies, and they often require repeated use throughout the growing season. Organic growers can’t use conventional insecticides.

Stink bugs continue to pose a serious economic threat. Last year, they collectively infested roughly a million acres of cotton in Georgia alone, and growers there spent $12 million to control them. The bugs are a particular problem in the southeastern United States, where cotton is often grown alongside peanuts. Brown and southern green stink bugs develop in peanut fields and migrate into cotton. Green stink bugs move into cotton from nearby wooded areas.

Because of work by Tillman and others, some growers are planting “trap crops,” such as soybean and grain sorghum, to lure stink bugs away from cotton. Other options include pheromone-baited traps, which capture and kill stink bugs, and nectar-producing plants, such as milkweed and buckwheat, to feed native parasitoid wasps that attack stink bugs.

In previous work, Tillman showed the effectiveness of setting up plastic barriers between the cotton and peanut rows. Her recent study focused on whether combining a trap crop, a nectar-producing plant, and pheromone traps would control stink bugs where cotton and peanuts grow.

Tillman and her colleagues grew cotton and peanuts side by side for 2 years. In the first year, they planted soybeans as a trap crop (with and without pheromone traps), between the cotton and peanut plots. In other areas, they placed 6-foot-high plastic barriers between the plots.

In the second year of the study, they added nectar-producing buckwheat plants near the cotton. Each week of the May-to-October growing season, they counted stink bugs and stink bug eggs killed by wasps, and they documented damage to cotton bolls.

They found that the plastic barriers between peanut and cotton were the most effective tool, but the multipronged approach is an effective alternative if barriers are not feasible. Soybeans were an effective trap crop, pheromone traps killed stink bugs in the trap crop, and buckwheat plants fed beneficial wasps that reduced stink bug numbers.

“Protecting Cotton From Stink Bugs” was published in the July 2016 issue of AgResearch Magazine.

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ipm_in_8_principle_s_large

IPM in (8) principle(s)

August 05, 2015

An ENDURE team of 17 co-authors has just published a review paper on the European Union’s eight principles of Integrated Pest Management (IPM). The paper provides researchers, advisers and farmers with an approach for applying these legal requirements intelligently to promote local innovation while reducing reliance on pesticides and associated risks. The authors hope that interest in this approach may help garner support from European and national policy makers to set incentives promoting IPM extension work, demonstrations, research and implementation.

Rather than searching for a universally applicable silver-bullet solution, the authors argue in favour of a broad approach that takes local specificities into account and allows all farmers to engage in IPM at any point within the continuum. Their vision stems from the realistic acceptance that pesticide-based crop protection is simple and efficient in generating spectacular short-term results. More sustainable alternative strategies will inevitably be more complex and knowledge-intensive in their initial development stage.

The process envisioned therefore requires learning, adaptation, and tweaking of a number of farm management practices. It requires extending the challenge of crop protection to larger spatial and temporal scales, and generating more complex cropping systems better adapted to the local context. It also requires attention to non-technical aspects such as the social environment in which farmers operate, collective learning and farmers’ inclination for step-wise rather than drastic changes.

But the approach is viable, and the authors offer real-life examples of successful experiences with the types of tactics and strategies suggested.

The authors note that 70 years of reliance on chemical protection has led to the development of cropping systems that have become inherently vulnerable to pests. By emphasising Principle 1 on prevention, the authors offer concrete illustrations on how to modify cropping systems to make them more robust in the absence of pesticides. The authors also identify the limits and opportunities associated with Principles 2 to 7 – a logical sequence starting with observation and ending with using chemicals as a last resort. Last but not least, a new slant is given on the question of evaluation (Principle 8) regarding the need for the development of new performance criteria and their routine use among the farming community.

For more information:

Barzman M, Bàrberi P, Birch ANE, Boonekamp P, Dachbrodt-Saaydeh S, Graf B, Hommel B, Jensen JE, Kiss J, Kudsk P, Lamichhane JR, Messéan A, Moonen AC, Ratnadass A, Ricci P, Sarah JL, Sattin M. 2015. Eight principles of integrated pest management. Agronomy for Sustainable Development , online first. doi 10.1007/s13593-015-0327-9. It is available here

ANNEX III of Framework Directive 2009/128/EC

General principles of Integrated Pest Management. For ease of reference, the authors have added shorthand titles to each principle

Principle 1 – Prevention and suppression The prevention and/or suppression of harmful organisms should be achieved or supported among other options especially by:

  • Crop rotation
  • Use of adequate cultivation techniques (e.g. stale seedbed technique, sowing dates and densities, under-sowing, conservation tillage, pruning and direct sowing)
  • Use, where appropriate, of resistant/tolerant cultivars and standard/certified seed and planting material
  • Use of balanced fertilisation, liming and irrigation/drainage practices
  • Preventing the spreading of harmful organisms by hygiene measures (e.g. by regular cleansing of machinery and equipment)
  • Protection and enhancement of important beneficial organisms, e.g. by adequate plant protection measures or the utilisation of ecological infrastructures inside and outside production sites
Principle 2 – Monitoring Harmful organisms must be monitored by adequate methods and tools, where available. Such adequate tools should include observations in the field as well as scientifically sound warning, forecasting and early diagnosis systems, where feasible, as well as the use of advice from professionally qualified advisers.
Principle 3 – Decision-making Based on the results of the monitoring the professional user has to decide whether and when to apply plant protection measures. Robust and scientifically sound threshold values are essential components for decision-making. For harmful organisms, threshold levels defined for the region, specific areas, crops and particular climatic conditions must be taken into account before treatments, where feasible.
Principle 4 – Non-chemical methods Sustainable biological, physical and other non-chemical methods must be preferred to chemical methods if they provide satisfactory pest control.
Principle 5 – Pesticide selection The pesticides applied shall be as specific as possible for the target and shall have the least side effects on human health, non-target organisms and the environment.
Principle 6 – Reduced pesticide use The professional user should keep the use of pesticides and other forms of intervention to levels that are necessary, e.g. by reduced doses, reduced application frequency or partial applications, considering that the level of risk in vegetation is acceptable and they do not increase the risk for development of resistance in populations of harmful organisms.
Principle 7 – Anti-resistance strategies Where the risk of resistance against a plant protection measure is known and where the level of harmful organisms requires repeated application of pesticides to the crops, available anti-resistance strategies should be applied to maintain the effectiveness of the products. This may include the use of multiple pesticides with different modes of action.
Principle 8 – Evaluation Based on the records on the use of pesticides and on the monitoring of harmful organisms the professional user should check the success of the applied plant protection measures.

 

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Entomology Today

http://entomologytoday.org/2015/06/15/ipm-strategies-to-fight-the-colorado-potato-beetle/

leptinotarsa-decemlineata

Colorado potato beetle (Leptinotarsa decemlineata). Photo by Scott Bauer, USDA Agricultural Research Service, Bugwood.org.

By Harvey Black

As the effectiveness of the primary chemical weapon against the Colorado potato beetle (Leptinotarsa decemlineata) starts to wane, new ways to manage this pest are needed where potatoes are intensively grown, according to an article in the the Journal of Integrated Pest Management.

Harvey Black

The beetle is a major problem in areas such as Wisconsin, Michigan, New York, and Maine. It attacks the foliage of the potato, thus interfering with photosynthesis and reducing energy that helps the potato grow. Both chemical and non-chemical methods can be used to deal with the pest, according to two of the authors — Anders Huseth, a postdoctoral associate at North Carolina State University and Russell Groves, a professor of entomology at the University of Wisconsin-Madison.

Neconicotinoid insecticides have been successfully used since 1995 to fight the beetle, but their effectiveness has been waning in some areas. While resistance is increasing, Huseth notes that it may not spread to all areas where potatoes are grown. Areas where potatoes are not grown year after year on the same soil are less likely to see insecticide-resistant potato beetles.

But to ward off resistance where it may become an issue, the researchers advocate moving away from broad-spectrum pesticides toward more highly targeted ones, as well as using non-chemical methods.

The beetle “has a long and decorated history of developing resistance to most of the chemical classes that have been used against it,” Groves said.

Hence, the researchers have devised a strategy of rotating various pesticides with different modes of action over the years in order to prevent, or at least significantly delay, the development of resistance.

For example, one strategy calls for using benzoylureas — an insect growth regulator that interferes with chitin synthesis — early in the season, followed by a late-season application of spinosyn, which interferes with the nervous system. The second year would begin with an early-season application of diamide, which affects muscle contraction.

The researchers also note that non-chemical, or cultural, means can be effective as well. For example, crop rotation can, in certain cases, be effective.

As Groves explained, the beetles are tired after emerging from under the ground after winter.

“It has used a lot of its energy to simply stay alive,” he said. “The vast majority have only enough energy reserves to walk about one quarter of a mile. If a grower can move the crop up to half a mile from last year’s [planting], it can have a significant effect.”

But that may be hard to do, given the location of farms and the nearby presence of housing, according to Amanda Gevens, assistant professor of plant pathology at the University of Wisconsin-Madison, who was not involved in the research.

One solution, said Groves, is what he calls area-wide pest management, in which various growers cooperate. But, he added, the “impetus to do that has never been great.”

Another non-chemical approach is called the spring trap crop, which is essentially a decoy for the beetle. According to Huseth, a small “trap” crop can be planted two weeks before the main commercial crop is planted.

“The idea is that the foliage is up and expanding before the primary crop emerges,” he said. “When the adults have colonized that trap crop, they are in a confined spot, so the crop can be destroyed with a mechanical method like a soil chopper (a device like a lawnmower) and you’re not using any insecticide, so there is no selection pressure, but you’re managing the adults before they get into the commercial crop, lay eggs, and attack the crop.”

However, Gevens cautions that this method may only be practical for small and moderate scale growers.

“When you move to larger fields that may be 80 acres or greater, fields are more highly concentrated and the trap crops won’t work as well, given the quantity of potato and attractive plant material for the insect pests,” she said.

While non-chemical means of controlling the beetle and other pests may be helpful, pesticides “used in a judicious way” will always be a factor in growing potatoes, according to Huseth.

“Pesticides in this system are important,” he said. “Pesticides are commonly used. That’s where growers are as far as their pest-management toolbox. A rapid transition away may not be in their best interests as far a profitable crop. To that end, we wanted to provide alternative recommendations that can help them manage resistance with cultural controls.”

Read more at:

Managing Colorado Potato Beetle Insecticide Resistance: New Tools and Strategies for the Next Decade of Pest Control in Potato


Harvey Black is a freelance science writer. A long-time resident of Madison, Wisconsin, he has written for numerous publications including Environmental Health Perspectives, Scientific American Mind, New Scientist, The Scientist, and the Milwaukee Journal Sentinel.

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