Feeds:
Posts
Comments

Archive for the ‘Control tactics’ Category

Biological control training courses for advanced-level graduate students and junior faculty will concurrently be held in Beijing, China and Hanoi, Vietnam, September 02-09, 2017. If you are interested in further information or in applying to join these sessions please contact Dr. Kris Wyckhuys <k.wyckhuys@cgiar.org> or Mrs. My Hoang  <m.hoang@cgiar.org>.

E.A. Heinrichs

IAPPS Secretary General

iobc_1

iobc_2

Read Full Post »

Article taken from The Fruit Grower, written by Sue Jupe

Agrovista

30 January 2017

After three years of UK trials, BASF, working with Agrovista, has launched the first multi-pest pheromone disruption system, named RAK 3+4. Already commercially abailable in Europe, orchards are flooded with high rates of synthetic pheromones, and male moths become confused and give up trying to find a mate – mating is disrupted. With consumers being particularly wary of pesticide residues in fruit, this new approach to pest control in top-fruit offers real benefits for the control of challenging moth species.

Setting the scene, Simon Townsend of BASF said that, in line with other sectors of the industry, top fruit growers have lost valuable actives in the past 15 years following EC Regulation 1107/2009, changing the emphasis on plant protection products from a risk-based to a hazard-based system. Pest and disease challenges have been further compounded with growing biological resistance to some remaining actives.

Following approval through a mutual recognition label in Belgium, UK top fruit growers have a new IPM (integrated pest management) tool – RAK 3+4 – a mating disruption system for Codling Moth (Cydia pomonella) and Summer Fruit Tortrix (Adoxophyes orana). In addition, trials have produced observed efficacy against other Tortix species including Large Fruit Tree Tortix and Dark Fruit Tree Tortrix.

Adult Codling Moths emerge from cocoons in spring. Eggs laid on leaves and developing fruit hatch after a short time and the resulting larvae immediately bore into the fruit making control with insecticides difficult. As the moths directly damage the crop, the economic threshold is very low.

Importantly, in August or September there can be a partial second generation and, according to Agrovista’s Paul Bennett, this is particularly problematic as it necessitates insecticides being applied close to harvest. Whilst growers must adhere to strict harvest intervals, spraying at this stage has the potential for detectable residues to be found on the fruit, he warns.

Among the existing plant protection product options for Codling and Tortrix Moths are the ovicides Chlorantrantiliprole (Coragen) and Fenoxycarb (Insegar) and larvicides Spinosad (Tracer) and Methoxyfenozide (Runner).

How does it work?

As with all good IPM systems, the pest population should be monitored using an appropriate pest forecasting system or monitoring traps. “The new RAK 3+4 mating disruption system relies on the pheromones being in before the first target moths take flight in spring – around Arpil and before the end of the blossom,” explained Simon Townsend. “Designed to give season-long control, the pheromone cloud is released over nine months through to October.”

Simon went on to explain that in nature, female moths emit pheromones producing a concentration gradient which males travel down to locate a mate. “By releasing high rates of synthetic pheromones, male moths become confused and give up trying to locate a female. Mating is disrupted, no fertile eggs are laid and the population reduces,” he says.

With RAK 3+4, volatile female pheromone vapours are released from brown ampoules, each with two chambers – one containing Codling Moth pheromone the other Tortrix pheromone. By using multiple dispensers, a confusing cloud of pheromones is produced. BASF recommends that dispensers are used at a rate of 500 units/ha – at a uniform density of approximately one per 20 sq. metres. To prevent moths from adjacent areas encroaching into the treated orchard, and to maintain pheromone concentration at the edge of the treated area, additional product must be placed at the borders. BASF recommends doubling the dispenser rate at the edges of the treated area – such as orchard edges and along roads through orchards. “the dispensers should be hung in the top third of the tree, as the vapour is heavier than air, and at varying heights to achieve a ‘muddled’ vapour plune,” explained Simon Townsend. “The dispenser should be positioned so that it is clear of the body of the tree.”

To check efficacy during the season, pheromone monitoring traps (that attract male moths) should be installed in the treated orchards and checked weekly. If these traps no longer catch moths, this indicates that RAK 3+4 is working properly. However, it is always possible that mated females may enter the treated orchard from outside, and it is therefore important to check for fruit damage during the season. If the latest monitoring thresholds are exceeded, this is an indication that the moth population is too high, meaning that treatment with RAK pheromones alone may be insufficient. In this case, treatment with a conventional insecticide is necessary.

UK trials at Wisbech Contract Farming

Trials over several seasons at Wisbech Contract Farming in Norfolk have produced impressive results.

A modern progressive fruit farm, the highly uniform GPS-planted orchards employ modern post-and-wire hedgerow systems. Working closely with Paul Bennett of Agrovista, John Portass of Wisbech Contract Farming has trialled RAK 3+4 for the past three years on a total of 8ha.

The RAK 3+4 ampoules were distributed from a picking platform at the same time as workers carried out other operations, and took approximately 12 man-hours/ha. “In the first year of trials we selected an orchard with low moth pressure,” explained John. “The results gave us the confidence to extend the trial in the second year to a higher pest-pressure orchard. With no moths recovered in the traps we didn’t need to spray at all. We had extremely low level damage in fruit of just 1 or 2 per 1000 and as the season went on the moth population reduced.” In comparison, in untreated areas 60-70 codling-affected apples per 1000 fruit were recorded.

Summarising the results at the end of the third year of trials, Codling Moth numbers had been reduced by 95%, Summer Fruit Tortrix by over 89% and Fruit Tree Tortrix by over 99%. The economic thresholds were never exceeded and no caterpillar sprays were needed. Putting it in context, Paul Bennett said, “Using conventional pesticides the overwintering population tends to stay the same. Using 3+4 system the background population is reducing year-on-year.”

Impressed with the results, John Portass envisages rolling out the RAK 3+4 strategy to 60-70% of his 90ha in 2017. “We will be using it in high value varieties, such as the scab resistant Opal, but at this stage not the lower value Bramleys,” he says.

Commercial use in Europe

Mating disruption systems are already in commercial use in top fruit in Belgium, the Netherlands, Germany and France. It is estimated that 47% of top fruit in Belgium (7,000ha) currently uses mating disruption, with the RAK 3+4 system accounting for 20% and RAK 3 for a further 20%. While orchards receive a supplementary insecticide when required, or just around the outside rows, monitoring of 34 orchards in Wallonia showed 19 had used no additional insecticide.

According to Simon Townsend, pest pheromone disruption systems have been shown to work well in central Europe, withstanding extremes of temperature, and are already widespread in Germany in various crops, including vines. Trials in Belgium have shown that, compared to a reference orchard, RAK 3+4 delivers a major decrease in the number of males caught in traps and a significant decrease in infected fruit. The mating disruption system also showed a useful effect on many other species of Tortrix Moth including Fruit Tree Trotrix, Rose Trotrix an dMarbled Orchard Tortrix.

Simon Townsend is keen to point out that RAK 3+4 only controls specific moth species – Codling and Tortrix. It is therefore important that growers monitor for the occurence of these pests during the season, particularly at orchard borders. If thresholds are exceeded, BASF recommends that growers use a well-timed insecticide spray in addition to RAK 3+4. Under high pest pressure the level of control from RAK 3+4 can be reduced, making careful monitoring essential. “Growers should be mindful that using mating disruption does not rely on using any broad-spectrum insecticides, so new or past pest species may become a problem and will need to be controlled iwth appropriate IPM measures,” says Simon. “In some UK trials, there has been a resurgence of moth pests that have not previously been a problem (for example, Blastobasis sp). Other moth species not controlled that are potential pests in top-fruit include Spilonota sp and Epiphyas sp.

Read Full Post »

 

pigweed-butterfly-ga-field-2016 Brad Haire  Feb 06, 2017
Herbicide-resistant weeds didn’t fall from the sky or rise from fields in a mutant mutiny, but they are here nonetheless. With new herbicide technologies going mainstream this season, growers must continue dogged resistant-weed management programs to preserve viable chemistries for as long as possible.

Herbicide-resistant weeds didn’t fall from the sky or rise from fields in a mutant mutiny, but they are here nonetheless. With new herbicide technologies going mainstream this season, growers must continue dogged resistant-weed management programs to preserve viable chemistries for as long as possible.

“In general, herbicide-resistant weeds become a problem over time when they are selected to survive by the overuse of a single herbicide or single mode of action. In all weed populations, there are very low levels or frequencies of herbicide-resistant plants in comparison to susceptible plants,” said Eric Prostko, University of Georgia Extension weed specialist during an American Society of Agronomy webinar “Growing for Tomorrow: How Weed Resistance Management Can Lead to Sustainability”Feb. 1 sponsored by BASF.

The U.S. leads the world with 156 unique cases of herbicide-resistant weeds. “If you grew up in the U.S. like me, you are likely always proud to see American athletes win Olympic gold medals. The more the better, right? Unfortunately, the U.S. is also the gold medal winner for herbicide resistant weeds,” Prostko said.

Australia currently comes in second place with 84 unique cases of herbicide-resistant weeds, and Canada takes third with 64 cases.

Worldwide there are 478 unique cases of herbicide-resistance weeds. The most frequent modes of action that weeds have developed resistance to are the ALS inhibitors (SUs and IMIs), PS II inhibitors (triazine and ureas)  and the ACCase inhibitors (dim and fop grass herbicides), he said.

The over-use of glyphosate on glyphosate-tolerant crops has led to the rapid development of glyphosate-resistant weeds over the last two decades, he said. Today, there are 36 weed species worldwide with resistance to glyphosate with 16 of those species in the U.S.

PPO-resistance is now a growing concern, too. “The evolution of PPO resistance is scary because many growers have been relying on herbicides with this mode of action to help manage herbicide-resistant pigweed. Currently, three weed species have evolved PPO-resistance in the U.S., including tall waterhemp, Palmer amaranth and giant ragweed. PPO-resistant Palmer amaranth is under investigation in Alabama, Mississippi, North Carolina and South Carolina,” he said.

But resistant weed problems do not necessarily result in yield loss. In Georgia where farmers have dealt with glyphosate-resistant pigweed for more than a decade, cotton and peanut yields have continued to increase. But it has come at great cost.

The cost to fight resistant weeds with herbicides in Georgia cotton, for example, has increased since 2004 from $28 per acre to $68 per acre plus a 10 percent to 20 percent increase in cost of mechanical cultivation and an increase in the need for hand weeding going from just under $3 per acre to almost $24 per acre today.

So what can growers do or do better, especially in handling herbicide-resistant Palmer amaranth?

1 – Start weed-free at planting using a combination of tillage, cover crops and herbicides. Although the benefits of reduced tillage systems are many, they have also helped contribute to some of our resistant weed problems. “The deeper and longer Palmer amaranth seeds are buried, the less seed germination will occur. Burying pigweed seed with a moldboard plow every three years or so can be beneficial, particularly in problematic fields. In some cases, deep tillage may not be a practical option,” he said.

2 – For growers who cannot or will not use deep tillage, well-managed cereal cover crops can be used to help reduced the emergence of some weeds. Since Palmer amaranth seed requires light for germination, a heavy rye biomass, for example, can prevent light from reaching the soil surface which ultimately influences germination and emergence. Getting an adequate crop stand in extreme cover crops can often be challenging and requires diligence and practice.

3 – Another tactic that exploit’s the influence of light on weed seed germination and emergence is narrow-row planting. Studies in many crops show narrower rows typically result in better overall weed control.

4 – Use herbicides with multiple effective modes of action. Most, if not all, herbicide labels today have their modes of action listed in plain view. “You no longer have to be a weed scientist to identify different modes of action,” he said.

5 – A strict crop rotation “can be extremely beneficial for the management of herbicide-resistant weeds because multiple herbicide modes of action can be used over time. In the case of a typical cotton-and-peanut rotation in the Southeast, eight different herbicide modes of action can be used over a two year period,” he said.

6 – Don’t cut rates to save money or for any other reason. “The use of reduced herbicide rates has been proven to be one of the factors that can increase the rate of herbicide resistance development. … The bottom line: only full-labeled rates should be used for weed control.”

7 – Reduce the seed bank in field. Many growers know it but it’s worth saying again: pigweed is a ‘seedy’ plant, producing 500,000 to 1 million seeds per plant.

Cotton and soybean seed traits tolerant to new formulations of dicamba and 2,4-D, which are on track to be widely available and legal to spray over the top of crops this season, are expected to be planted in some regions. Both herbicides are in the same auxin herbicide family. “First and foremost, these new auxin technologies are not a miracle cure for all your current weed problems. You will still need to start clean, use residuals and make timely postemergence applications,” he said.

“Although much is being said about the new auxin technologies these days, I am not hearing very much about the fact that auxin resistance in weeds has already occurred,” Prostko said. “These herbicides are not new. Currently, eight weed species in the U.S have already developed auxin-resistance. Auxin technology stewardship will be even more important as we head into the future.”

Chad Asmus, technical marketing manager for BASF, spoke during the webinar and echoed Prostko’s concerns and recommendations for growers to reduce the risk of herbicide resistance developing in their fields, highlighting the company’s newly formulated dicamba herbicide Engenia, which can be sprayed over the top of dicamba-tolerant cotton and soybean.

The new herbicide has a BASF patented molecule called BAPMA, which, Asmus said, is the lowest volatility salt of dicamba with the highest loading and lowest use rate at 12.8 fluid ounces per acre; and it’s rain fast in 4 hours.

The Engenia label comes with many requirements, including buffer areas. Asmus stressed that growers must follow the label requirements thoroughly. Here are a few of the general federal requirements for Engenia:

  • Use the TTI11004 spray nozzle.
  • Boom Height: ≤ 24” above the target.
  • Application Volume: ≥ 10 GPA.
  • Ground Speed: ≤ 15 MPH.
  • Wind Speed and Direction: 0 to 15 MPH
    • For wind speeds ≤ 3 MPH confirm there is no field level temperature inversion.
    • Do not spray with wind speeds >10 MPH blowing toward neighboring sensitive non-specialty crops.
    • Do not spray with any wind blowing towards neighboring specialty crops.

Asmus said growers need to also pay special heed to any state-specific label requirements that might apply to Engenia this year. An updated list of EPA-approved tank-mix products for Engenia can be found at http://www.EngeniaTankMix.com.

Read Full Post »

 

Pakistan’s papaya pest squashed through biocontrol

  • Pakistan’s papaya pest squashed through biocontrol

Copyright: G.M.B. Akash / Pano

Speed read

       >   With pesticides ineffective, mealybugs destroyed most of Pakistan’s papaya farms
  • An insect predator of the papaya mealybug now protects the crop in Pakistan
  • Success of the parasitoid deployment has encouraged replication in other countries
   

[ISLAMABAD] A severe infestation of the papaya mealybug (Paracoccus marginatus) nearly wiped out papaya orchards in Pakistan before the largely farmed country decided to replace conventional chemical pesticides that were ineffective with natural predators that proved to be successful.

The system was developed by agro-biotechnologists and entomologists at the Pakistani chapter of the UK-based Centre for Agriculture and Bioscience International (CABI) who introduced the use of Acerophagus papayae, a parasitoid (insects whose larvae parasite upon and eventually kill the host), to effectively control the mealybug infestation.

“Farmers are happy with this cost-effective, pesticide-free technique to deal with the mealybug and now see possibilities of recovering their papaya farms,” says CABI research coordinator Abdul Rehman.

He regrets though that by the time the biological method became available many farmers had already shifted to other crops.

Papaya once covered some 921 hectares in the two coastal provinces of Sindh and Balochistan, according to the National Agriculture Research Council (NARC). But, after the first mealybug attack on papaya was reported in 2008, the area under papaya had shrunk to 307 hectares by 2014.

“Demonstration of the bio-control technique and awareness building among farmers helped wide-scale adoption and resulted in over 80 per cent control of the papaya mealybug.”

Amjad Pervez, NARC

Rehman tells SciDev.Net that after the pest had gripped almost 80 per cent of the papaya orchards, CABI, US Development Agriculture and the US Agency for International Development initiated the biological control programme in close collaboration with NARC to stop the pest’s possible spread to other more important commercial crops.

In 2014, under CABI’s papaya pest management programme, A. papayae specimens were collected from the coastal areas near the port city of Karachi, reared in the laboratory and then released into papaya plantations after screening and environmental assessments.

CABI researchers also set up a Natural Enemies Field Reservoir on the farmers’ fields to breed the A. papayae parasitoid as well as eight other natural predators of the papaya mealybug.

Amjad Pervez, director-general at the NARC’s Karachi-based regional office, says that the advantage of the bio-control approach lies in its simplicity and in the fact that it is self-sustaining.

“Demonstration of the bio-control technique and awareness building among farmers helped wide-scale adoption and resulted in over 80 per cent control of the papaya mealybug,” Pervez says. “Besides, the process was non-laborious, highly affordable and simple enough for farmers not to need support from government agencies.”

Rehman’s team has hammered out a three-pronged plan to promote the field reservoirs through public-private partnerships.

“The bio-control approach has saved the papaya (farming) and also increased profits by reducing expenses on the pesticide sprays once used to fight the pest.”

Abdul Majeed Nizamani, Sindh Abadgar Board

“The plan shall be implemented to boost research and development to strengthen the bio-control process to completely contain papaya mealybug. Sindh and Balochistan provinces’ farmers’ organisations and vegetable and fruit traders’ associations will also be engaged in this regard as key stakeholders,” Pervez explains.

“Controlling the papaya mealybug has helped contain its potential spread to commercial crops like citrus, tomato, aubergine, peppers, mulberry, beans and peas, sweet potato, mango, cherry, and pomegranate. Annual losses, had these crops been affected, would have run into millions of dollars,” says Pervez.

Rehman says Pakistan’s experience in safely controlling the mealybug has been shared with CABI chapters in the Asia-Pacific, European, and African countries.

“Entomologists and fruit pest experts have already communicated possibilities for replication of the bio-control approach, with some necessary modifications in countries like Congo, Indonesia, Malaysia, Nigeria, Sri Lanka, Taiwan and Thailand” he says.

Pesticide resistance

Mealybugs have great resistance to most pesticides. For one thing they exude waxy secretions that can insulate them against chemicals and for another they have developed resistance to most commonly used chemical insecticides, according to a comprehensive Indian study published by Springer earlier this year.

First detected in Mexico in 1955, the papaya mealybug had spread to the Caribbean and Latin America by the 1990s and to the Pacific and South Asian countries through the first decade of this century.

Abdul Majeed Nizamani, president of the Sindh Abadgar Board, a farmers’ organisation, believes that papaya farming would have been completely wiped out in Pakistan if not for the bio-control measures.

“The bio-control approach has saved the papaya (farming) and also increased profits by reducing expenses on the pesticide sprays once used to fight the pest,” Nizamani says.

This piece was produced by SciDev.Net’s Asia & Pacific desk

This article is part of a series on invasive species supported by CABI

Read Full Post »

veg-ipm-book-img_2871

The majority of the information in this book is drawn from technologies developed, tested, validated, and implemented by the Integrated Pest Management Innovation Lab (previously known as the  Integrated Pest Management Collaborative Research Support Program-IPM CRSP), supported by  USAID  Cooperative Agreements awarded to Virginia Tech.

Contents

Chap.1 – IPM for Food and Environmental Security in the Tropics

Chap. 2 – IPM Packages for Tropical Vegetable Crops

Chap. 3 – Virus Diseases of Tropical Vegetable Crops and Their Management

Chap. 4 – Exploring the Potential of Trichoderma for the Management of Seed and Soil-Borne Diseases of Crops

Chap. 5 – Physical, Mechanical and Cultural Control of Vegetable Insects

Chap. 6 – Integrated Pest Management of Cruciferous Vegetables

Chap. 7 – Integrated Pest Management of Okra in India

Chap. 8 – Integrated Pest Management of Onion in India

Chap. 9 – IPM Packages for Naranjilla: Sustainable Production in an Environmentally Fragile Region

Chap. 10 – IPM Technologies for Potato Producers in Highland Ecuador

Chap. 11 – Integrated Pest Management for Vegetable Crops in Bangladesh

Chap. 12 – Development and Dissemination of Vegetable IPM Practices in Nepal

Chap. 13 – IPM Vegetable Systems in Uganda

Chap. 14 – Impacts of IPM on Vegetable Production in the Tropics

 

ISBN 978-94-024-0922-2  ISBN 978-94-024-0924-6 (eBook)

Library of Congress Control Number: 2016957790

 

E.A. Heinrichs

IAPPS Secretary General

Asia Program Manager, IPM Innovation Lab

Read Full Post »

Spray That Stays

spray that stays.png

When farmers spray their fields with pesticides or orange growers spray water on their crops to prevent frost damage, only about 2 percent of the spray sticks to the plants. The rest of the droplets either bounce right back off the leaves or get blown away by the wind. All that waste costs money and, in the case of pesticide application, contributes to pollution of waterways and exposes farmers unnecessarily to hazardous chemicals. But a team of MIT researchers has found a way to fix that.

A clever combination of inexpensive additives allowed the researchers, led by associate professor of mechanical engineering Kripa Varanasi and grad student Maher Damak, to drastically cut down on the amount of liquid that bounces off, potentially making it possible to use just one-tenth as much pesticide or other spray as would otherwise be needed.

Previous attempts to reduce this droplet bounce rate have relied on additives such as surfactants, soaplike chemicals that reduce the surface tension of the droplets and cause them to spread more. But tests have shown that this yields only a small improvement; the speedy droplets bounce off while the surface tension is still changing, and the surfactants cause the spray to form smaller droplets that are more easily blown away.

The new approach uses two different kinds of polymer additives, each added to a separate portion of the spray.  One gives its part  of the solution a negative electric charge; the other causes a positive charge. When two of the oppositely charged droplets meet on a leaf, they form a hydrophilic (water-attracting) “defect” that sticks to the surface and makes other droplets more likely to adhere.

The project was developed in collaboration with the MIT Tata Center for Technology and Design, which aims to develop technologies that can benefit communities in India and throughout the developing world. Spraying of pesticides there is typically done manually with tanks carried on farmers’ backs, and since the cost of pesticides can be a significant par of a farmer’s budget, reducing the amount that’s wasted could improve the overall economics of small-scale farming. It could also reduce soil and water pollution and spare farmers excessive exposure to the spray chemicals. And for those spraying water, limiting the waste of often-limited freshwater resources can be significant.

“We can use normal sprayers, with two tanks at a time, and add one material to one tank and the oppositely charged material to the other,” Damak says. The farmer “would do everything as usual, just adding our solutions.”

David L. Chandler

www.technologyreview.com                                                                                                                                                                           November/December 2016  MIT News                                                                                                                              9

Read Full Post »

Scientists Use Insects to Control an Invasive Weed

An arundo gall wasp depositing eggs into the main stem of a giant reed. Photo by John Goolsby.

The release of tiny insects to combat an invasive weed is paying off, according to a recent study by the U.S. Department of Agriculture.Scientists from the USDA’s Agricultural Research Service released arundo gall wasps (Tetramesa romana) and arundo scale insects (Rhizaspidiotus donacis) several years ago as part of a biocontrol program to kill a weed called “giant reed” (Arundo donax) along the Rio Grande in Texas. The weed, also known as “carrizo cane” and “Spanish reed,” clogs streams and irrigation channels, weakens river banks, stifles native vegetation, affects flood control, reduces wildlife habitat, and impedes law enforcement activities along the international border.

Recent research conducted by entomologist John Goolsby demonstrates that these insects have helped control giant reed over more than 550 river miles. Measurements taken in 2014 documented a 22-percent decrease in plant biomass along the Rio Grande since the insects’ release in 2009. Measurements in 2016 show a further decrease of 28 percent and significant recovery of native riparian vegetation.

Giant reed grows between three and seven inches a day and reaches heights of 30 feet along the Rio Grande. The weed increases the population of cattle fever ticks by creating an ideal habitat for them, which makes it difficult for USDA inspectors to detect tick-infested cattle and deer. As the riverbank transitions back to native vegetation, the plant community supports greater abundance and diversity of tick-feeding ants and beetles that act as biological control agents.

To accelerate weed removal, scientists have combined “topping” — mechanically cutting cane — with insect releases. Topping suppresses growth for more than a year and makes plants more susceptible to insect attacks. Combining topping and insect releases gives a high, long-term suppression of cane and allows native trees to grow and start shading giant reed.

“We’ve thinned the cane out significantly,” Goolsby said. “The biggest decline in plants correlates with the greatest number of our biocontrol agents—the wasp and scale.”

Read Full Post »

Older Posts »