This page contains a Flash digital edition of a book.
White Mold Poses Significant Threat To Soybean And Dry Bean Yields

white mold when evaluating their ‘dis- ease watch list’ for 2012. White mold, also known as Sclero-


tinia stem rot, was first discovered in the United States in the late 1800’s on tomatoes. Since then, the pathogen has been found on hundreds of other crops and by 1992 it had established itself as a wide-spread problem in ge- ographies where climate provided opti- mum condition

for disease

proliferation. When left untreated, white mold can

cause yield loss or total crop loss de- pending on the infected crop and with the added challenge of lingering in the soil for up to 10 years. The reason behind the rapid increase

of white mold has yet to be determined, but it is thought to be related to changes in cultural practices that pro- mote a greater canopy density. The in- crease in white mold is also believed to be influenced by changes in the genetic base of current soybean and dry bean varieties, or changes in the white mold pathogen. In the Northern U.S., it may be related to wet climate cycles that have persisted year after year. “The optimal climatic conditions

throughout North Central states can make white mold a serious threat for our growers,” says Dr. Sam Markell, Extension plant pathologist at North Dakota State University (NDSU) in Fargo. “Combine that with the lush, dense canopy that you find with many high producing varieties of soybeans and you just have a great environment for the disease.” Fostering conditions of white mold White mold typically rears its ugly

head in late-spring and early summer around the time that both soybeans and dry bean plants begin to bloom. The disease thrives in cool tempera- tures ranging between 59 and 75 de- grees Fahrenheit and moisture-rich soil conditions caused by heavy spring rains. Combined with a dense crop canopy that can stay moist until the late morning hours, Markell says the environment can become “a perfect storm" for the disease to infect throughout a field. Infection occurs when ascospores, released from the white mold pathogen land on senesc- ing flower petals, then germinate and form mycelium. “The spores are generally unable to

infect the plants directly, but can eas- ily digest the senescing flower petals,” Markell says. “Shortly after the infec- tion occurs, the fungus will form a le- sion, causing significant damage to the plant and disrupting nutrient uptake.” Portions of the plant stem, above the

area or infection, die and dry up. The disease then hollows out and shreds the stem at the spot of the lesion. At this point, the plant is non-productive, if not dead, resulting in significant yield loss for that season and sclerotia in the soil for years to come. Land grant universities across much

of the Midwest and Northern regions are placing greater attention on the disease. Many are completing yield im- pact studies to determine the changing significance of the issue across varying


oybean and dry bean growers across the Midwest and North Central U.S. need to prioritize

geographies. The results have shown that yields can be reduced by 10, 20, 30 and even as high as 50 percent de- pending on disease severity, conditions and control practices. With a low end reduction of just 20 percent on an ex- pected 60 bushel per acre crop means 12 bushels will never be harvested. And at $12 per bushel as an average soybean price, that quickly equates to $144 an acre eliminated from a grower’s profit potential. “A grower only has to look back as far

as the 2009 season to see the eco- nomic impact white mold can have on a crop,” says Markell. “There is tradi- tionally a white mold outbreak at some point and on some crop in North Dakota due to our climate. But in 2009, growers as far South as Iowa and Illinois experienced white mold pressure and the severity it can have on yield.” Iowa State University reports about

the 2009 white mold outbreak pointed to losses totaling more than $10,000 per field for soybeans alone. In North Dakota, growers saw significant yield reductions in soybeans and total crop destruction in some dry bean fields. Markell adds that the 2009

epidemic was an eye-opening experi- ence for a lot of growers, and with a re- peat in 2010 of high white mold pressure in certain geographies, he says every soybean and dry bean grower should have the disease on their radar. He continues by saying that there is still plenty of white mold inoculum in the soil, making it neces- sary to take precautions to minimize the disease risk for the 2012 crop. Minimizing white mold risk David Feist, project development

leader with MANA Crop Protection, re- minds growers that white mold is not your typical disease where traditional management practices and generalized inputs are guaranteed to work as nor- mally expected. “White mold will persist in the soil for

years and germinate when it comes in contact with a sensitive host crop like soybeans, dry beans, alfalfa or clover. Weeds like pigweed, ragweed and lambsquarters also provide a haven for white mold to survive, season after season. Unfortunately, there is no sin- gle factor that will prevent white mold from developing,” Feist says. “Relying on a preventative approach to get ahead of the problem is the best de- fense strategy.” In recent years the industry has

struggled with full-scale solutions for white mold due to limited crop protec- tion tools that could zero-in on mas- tering control. The good news is that MANA Crop Protection has prioritized white mold as a critical focus for tech- nical development - bringing a new-age tool to the rescue. Incognito™ 4.5F fungicide is

the company’s recent solution for ef- fective management of white mold in soybeans, dry beans and other crops. While providing superior protection against white mold, Incognito also de- livers broad-spectrum control over a range of other diseases like Frogeye leaf spot, Brown rot, Anthracnose, Stem and Pod Blight, scab and rusts. Specific to white mold on soybeans,

CONTINUED ON PAGE 16 January 20, 2012 / MidAmerica Farmer Grower•9 March 2, 2012 / MidAmerica Farmer Grower • 13


TRACTOR SALES 2611 West Main Vandalia, IL 800-878-8831 618-283-2893


TRACTOR SALES 18017 St. Rose Rd. Breese, IL 855-526-4900 618-526-4900


TRACTOR SALES 307 E. Jourdan Newton, IL 800-428-9271 618-783-8461

B95B $59,500

2008 NH CR9070 S/N: HAJ111459

Stk #: 013773, 805 Hours, 692 Separator Hours, 463 hp, 4WD Drive, 4wd, Yield and Moisture, Ext. Wear Augers, Duals $245,000

1981 Versatile 875 5300 hrs. $25,000

Case 34’ 330 turbo disc $49,500

2009 T8010 $118,000

Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36