24.05.2010 um 04:30 Uhr

It's almost corn rootworm time, entomologist says

This year's corn rootworm hatch -- at least in central Illinois -- may be right around the corner, says University of Illinois Extension entomologist Mike Gray.

Degree-days is the best way to estimate when the rootworm hatch will happen; Gray says about half of the hatch happens when 684 to 767 degree-days have built up since the first of the year.

Gray says the state of Illinois shows between 400 and 600 degree-days since January 1, with the latter number more common in the central part of the state and lower numbers further north.


The timeframe for the rootworm hatch (which has not been reported in other Corn Belt states yet), if it comes a little later this summer, may prove the efficacy of Bt corn against the pest, Gray says in a university report.

"If the hatch occurs later than predicted over the next several years, we may begin to build a body of evidence that suggests we may be selecting for corn rootworm larvae that hatch later due to the extensive use of Bt corn hybrids," he says.


20.05.2010 um 03:26 Uhr

Use an integrated approach to fight leaf spot complex in potatoes

Late blight may have captured headlines last summer because of the devastation the fungal disease caused to tomatoes and potatoes on the East Coast.

But the leaf spot complex—a group of four early season fungal diseases—can be just as insidious and cause annual headaches for potato growers, say plant pathologists.

Compounding the problem is the difficulty in identifying the diseases within the complex and the limited number of products that control some of them.

The leaf spot complex comprises four fungal diseases—early blight, brown spot, black dot, and Botrytis cinerea or gray mold—in generally descending order of importance. The actual level of importance varies among regions.

“To the untrained eye, it can definitely be difficult,” says Neil Gudmestad, a plant pathology professor with North Dakota State University in Fargo. “I think they’re a real problem for potato growers—how much of what they have is early blight and how much of what they have is brown spot?”

To help growers and consultants, Gudmestad and his research assistant, Julie Pasche, have put together a two-page color guide that provides identification photos and tips for Midwestern potato diseases. It also includes an efficacy chart ranking all of the registered products available for potato disease control.

Companies can purchase the copyrighted publication, which includes free updates and customization with the company’s name.

Choosing a fungicide

Knowing the disease or diseases you have in your field is key to determining what crop protection materials to choose, Gudmestad says.

Early in the season when disease pressure is low, protectants such as mancozeb and chlorothalonil can be used.

As the season goes on and disease pressure increases, Gudmestad says growers will probably need one to four additional applications of other materials.

The strobilurins control early blight, but they’re ineffective against brown spot. In addition, early blight has become resistant to strobilurins in many areas, so growers should tankmix them with another mode of action.

The early blight organism— Alternaria solani —has mutated, and many populations carry the F129L resistance gene.

Those populations are 10 to 15 times more resistant to strobilurins than sensitive ones.

That doesn’t mean you can’t use a strobilurin against early blight, Gudmestad says. It just means the level of control if used without a tankmix partner is reduced to that of chlorothalonil.

In unpublished research, Gudmestad says he found the same F129L resistance gene in A. alternata, the brown spot organism. But that may be moot since strobilurins have never been particularly effective against that disease.

“In the Pacific Northwest, they’ve seen a shift from solani toalternata, and there’s a lot of interest in getting away from the strobis or having products that also contain other than a strobi with it,” says David Laird, fungicide brand manager for Syngenta Crop Protection in Greensboro, N.C.

Quadris Top, which will available in very limited quantities this year, is a combination of difenoconazole and azoxystrobin, a strobilurin, Laird says. In addition to early blight, Quadris Top controls brown spot and black dot.

“The only thing I would caution is these products do have some curative activity on alternata, but that doesn’t mean they have rescue activity,” Laird says. “If you have black dot in the mix that requires an early application probably prior to row closure, then I’d recommend Quadris Top very early because it will pick up black dot, early blight and brown spot.”

Revus Top, a premix of mandipropamid and difenoconazole from Syngenta, and Scala (pyrimethanil) from Bayer control both early blight and brown spot. Revus Top also is active against late blight.

In addition, Scala is effective against Botrytis but doesn’t control late blight, white mold or black dot, Gudmestad says.

He adds that Bayer hopes by the end of the year to have registration of Luna Tranquility, a premix of the active ingredients in Scala and fluopyram, which is in the same family as boscalid.

Field trials show Luna Tranquility is effective against early light, brown spot and Botrytis.

An integrated approach

Randy Cherney, an agronomist with Plover River Farms in Stevens Point, Wis., says he presumes most of the leaf spot diseases in the fields he oversees are early blight, although he hasn’t had them tested.

He says he takes an integrated approach to managing the disease, and “fungicide is just one part of the equation.”

Maintaining proper plant nutrition, keeping insect pressures low and properly irrigating to reduce plant stress are equally important.

“As long as your plant is healthy, it’s better at fighting off early blight,” Cherney says.

He typically applies his first fungicide—a protectant such as the chlorothalonil product Echo Zn—at about 300 P-days or just before row closure.

Then it’s on to a seven-day schedule, rotating an application of chlorothalonil with a tankmix of chlorothalonil and another fungicide, such as Scala, Quadris or Endura.

Chlorothalonil has a multi-site mode of action, so the chances of the early blight organism becoming resistant to it are much less than a single-site product, such as Scala or Endura, Cherney says.

“You have to use all of these different products that have different ai’s or [belong to] different classes. We wouldn’t use all Endura,” he says.

Depending on the variety and the length of growing season, Cherney says he may make eight, nine or possibly 10 fungicide applications for early blight. He continues spraying until vine kill.

“If you can keep the early blight low in your fields in August, your plants will stay green and you’ll get really good bulking, especially in the late-season varieties,” Cherney says.

Contact Vicky Boyd at or (209) 571-0414.

Consider several factors for identification

Identifying whether you have early blight or brown spot or both can be a challenge. Neil Gudmestad, a plant pathology professor with North Dakota State University in Fargo, recommends examining several factors, including visual symptoms, disease behavior on the plant and in the field, climatic conditions and variety.

Early blight, caused by Alternaria solani, produces larger lesions with concentric circles. Brown spot, caused by A. alternata, involves more, but smaller, lesions that are scattered all over the leaf in a shotgun pattern. The lesions may eventually coalesce or merge together.

But looks can be deceiving, says Koen van den Eynde, Raleigh, N.C.-based North American vegetables and sugar crop manager for Bayer CropScience. Bayer and several researchers conducted identification tests using PCR, which is similar to the DNA genetic fingerprinting used in crime labs.

Plant pathologists were asked to send in samples of what they thought was early blight and brown spot.

“There was no correlation whatsoever with what they saw on the leaves with the PCR results,” van den Eynde says. “For example, they thought a leaf with many little spots was brown spot, but this wasn’t necessarily the case. The bottom line—even the experts had a hard time distinguishing between one and the other.”

That is one reason why Gudmestad says growers and consultants should use several factors when making an identification.

Early blight tends to develop from the bottom of the plant up, he says. A. solani is aggressive on senescing tissue, starting on the yellowing leaves and working its way up.

Brown spot, on the other hand, tends to start on the top of the plant and works down. It will be more prominent on the top of the canopy and on new foliage.

Brown spot also tends to develop in pockets in a field whereas early blight will be more evenly distributed throughout a field.

Varietal susceptibility also should be factored in, Gudmestad says. Atlantic, Pike, Ranger Russet and Yukon Gold tend to be very susceptible to brown spot. Russet Norkotah, on the other hand, is susceptible to early blight but not so much to brown spot.

Climate also plays a roll in what disease or diseases typically are found in a field. The chronic morning dews of the Midwest are conducive to early blight epidemics and also contribute to brown spot development.

“With Midwestern conditions, we can’t get season-long disease control of this complex with mancozeb and chlorothalonil,” Gudmestad says of the protectant products. “We need one to four [applications] of specialty products to control those diseases.”

The specialty products he was referring to include Scala, Luna Tranquility, Revus Top, Quadris Top and Endura.

19.05.2010 um 09:25 Uhr

USDA opens a CRP land rush




“获得土地是农民面临的一个新的挑战最大,”梅里根说。 “过渡奖励计划是一个多工具包工具在保护和支持家庭农场,美国农业部开始农民和弱势社群。”

对于退休农民,要求包括出售或有农民合同出售给一家或少数农民开始。土地所有者或者必须有至少5年启动了农民长期租赁。 CRP的土地拥有者可以申请该计划CRP的土地时,他们的合同是在其去年。







不像美国农业部开始农民贷款方案,这需要青年农民有一些经验,为提示的规则说没有什么稀奇的。 “我想这几乎是自我实施的。土地所有者不会租用没有经验的人,”他说。






19.05.2010 um 09:24 Uhr

USDA opens a CRP land rush

Young farmers typically spend a lot of time trying to find land to rent or buy. Thursday the USDA rolled out a new program authorized by the 2008 Farm Bill that may open a few fields of opportunity.

Starting Monday, farmers who have land coming out of CRP and plan to retire in five years can apply to get two extra years of their CRP payments if they sell or lease their land to a startup producer.

Agriculture Deputy Secretary Kathleen Merrigan announced the new CRP Transition Incentives Program, or TIP, Thursday.

"Access to land is one of the greatest challenges faced by new farmers," Merrigan said. "The Transition Incentives Program is one more tool in the USDA toolkit to protect family farms and support beginning and socially disadvantaged farmers."

For the retiring farmer, requirements include selling or having a contract for sale to a beginning farmer or minority farmer. Or the landowner must have a long-term lease with the startup farmer for at least five years. CRP landowners can apply for the program when their CRP land is in its last year of the contract.

For a beginning farmer to qualify, he or she must have been farming for no more than 10 years and be substantially involved in the operation. And the young farmer must have a conservation plan approved by the Natural Resources Conservation Service.

With more than 4 million acres of CRP land potentially coming out of the program this year, and 15 million acres expiring over the next three years, the potential help for beginners seems big. But USDA has set aside only about $25 million over 10 years for the TIP payments.

"I think that will be adequate for the kind of traffic we'll have," Ferd Hoefner of the National Sustainable Agriculture Coalition told

Hoefner's coalition fought to get TIP into the 2008 farm bill. Because TIP started with the 2008 farm bill, the signup for this new program is retroactive for land that came out of the CRP in 2008 and 2009, he said.

The deadline for any retroactive applications is September 30, so landowners with land that came out of the CRP in those years will have to hurry to meet it, Hoefner said.

"Making a match between the landowner and new farmer and working out a deal is all going to take time," he said.

Unlike USDA's beginning farmer loan program, which requires young farmers to have some experience, the rules for TIP say nothing about that. "I guess it's pretty much self enforcing. The land owner isn't going to lease to someone without experience," he said.

Already, the new CRP program is attracting interest.

"Our member groups are getting calls -- more from beginning farmers than landowners, but some landowners," Hoefner said.

Hoefner said he thinks the typical beginning farmer using this program will be one who is already farming and is looking to add more acres to the operation. He thinks retired or retiring farmers with CRP land who still live in their rural community will be the most likely landowners to use TIP.

If the CRP was already supplementing that farmer's retirement income, "two more years is good. Its nothing to sneeze at," he said.

For the young farmer, USDA offers a few perks as well. USDA is required to offer the beginning farmer a chance to sign up for the Conservation Stewardship Program or Environmental Quality Incentives Program. And, if the young farmer wants to enroll buffer strips on that farm into the continuous CRP, the normal one-year requirement for enrolling in that program is waived. Young farmers interested in farming organically can get one year of credit towards the three-year transition to organic certification, if the land meets organic qualifications.


17.05.2010 um 10:32 Uhr

Iran agrees to send uranium to Turkey, report says

Iran has agreed to ship its low-enriched uranium to Turkey, state media said Monday.

Western nations had been asking Iran to send the low-level uranium out of the country to be enriched elsewhere, but the country had resisted until now.

On Sunday, Turkish Prime Minister Recep Tayyip Erdogan announced he was heading to Iran to join nuclear talks in Tehran involving Brazilian President Luiz Inacio Lula da Silva and Iranian President Mahmoud Ahmadinejad.

The meeting in Tehran sought to reach a breakthrough in the showdown over Iran's nuclear program, according to Erdogan.

The last-minute trip followed a "signal" from the talks, which are intended to resolve the dispute over Iran's nuclear energy program, Erdogan told reporters before departing. Erdogan indicated the signal involved Iran's agreement to swap its low-enriched uranium for nuclear fuel, CNN Turk reported.

Erdogan said he hoped an agreement in Tehran would stop the U.N. Security Council from its negotiations on tougher sanctions on Iran.

"The Security Council was contemplating a step in the direction of sanctions as of yesterday," Erdogan said. "As a part of our talks, this has been postponed. Now with this step we are going to take, I hope that we will have the opportunity to overcome these problems."

Iran's official Islamic Republic News Agency made no mention of the nuclear issue in reporting earlier that Lula was sitting down with Ahmadinejad. But French President Nicolas Sarkozy and President Dmitry Medvedev of Russia both have said they back Lula's efforts to resolve the long-running, high-stakes stalemate.

"This could be the last chance before the U.N. Security Council makes the already known decisions," Medvedev said, referring to the U.N. decision on imposing sanctions against Iran.

Sarkozy said earlier that he had spoken with Lula by phone to assure him that Paris supports his efforts to resolve the impasse.

The United States and many other countries believe that Iran intends to develop nuclear weapons. Iran says its nuclear program is for peaceful purposes.

On Saturday, Turkish Foreign Minister Ahmet Davutoglu left for Tehran to join the Iran-Brazil talks. Erdogan said Sunday the anticipated signal from Iran was received and he was changing his schedule to travel to Tehran, postponing a planned visit to Azerbaijan.

Erdogan's statement indicated an agreement in which Iran would send most of its low-enriched uranium to be turned into fuel rods suitable for Turkey's nuclear power reactor that makes medical isotopes.

"After our high-level meeting in Tehran, I believe we will have the opportunity to start the process regarding the swap," Erdogan said. "We said that we will go to Tehran if the swap takes place in Turkey, and we received news that the text includes a reference to this. That's why we are going. Otherwise we wouldn't have gone."

Turkey and Brazil have been working on a joint offer based on the nuclear swap deal offered previously to Tehran. Both countries are temporary members of the U.N. Security Council and have been working toward a diplomatic solution that does not involve sanctions.

Lula is in Iran ahead of the Group of 15 developing nations meeting in Tehran. The group actually has 17 members -- Algeria, Argentina, Brazil, Chile, Egypt, India, Indonesia, Iran, Jamaica, Kenya, Malaysia, Mexico, Nigeria, Senegal, Sri Lanka, Venezuela and Zimbabwe.

Lula also met separately with Iranian Supreme Leader Ali Khamenei on his trip, according to Iranian media reports. State-run Press TV reported Khameini emphasized to Lula the need for relations between independent states such as Brazil and Iran in order to reduce the influence of superpowers such as the United States.

"The only way to change the oppressive relations in the world today is through the formation of closer ties between independent states," Khameini said, according to Press TV. "Superpowers have defined vertical relations in the world which places a superpower at the top. These relations must be changed and their change is possible."