Tuesday, September 30, 2014

My Soybeans had White Mold, Now What?

Many farmers in Northern Illinois, Iowa, Wisconsin, Michigan, and Minnesota are all too familiar with the significant yield loss that white mold can cause to soybeans.  However, many found white mold in their fields further south for the first time in 2014, due to the cooler temperatures.  Actually, a soybean plant showing white mold symptoms was found as far south as Arenzville, IL. 

According to the Illinois State Climatic Data Center, this summer was the 29th coolest on record.  " Daytime highs were much cooler than average while the nighttime lows were near-average." - more on this article can be found at:  Illinois and Global Temperatures for June-August

White mold or Sclerotinia stem rot is caused by Sclerotina sclertiorum and actually has a fairly wide host range.  If your soybeans appeared to affected this year, you now are aware that this fungus has somehow made its way to your field and has survived in the soil as fungal survival structures called sclerotia.  If environmental conditions are right (soils 40 to 60 degrees), these sclerotia will send up mushrooms called apothecia, which can release millions of spores that can infect senescenced flowers at bloom. 

Soybean infected with white mold.  If the canopy is humid, white mycelium will form on the outside of the stem.  Black sclerotia will form within the white mycelium or inside the stem.  (Picture provided by Jim Hughes)
Field infected with white mold (Picture provided by Jim Hughes)

START BECOMING CONCERNED ABOUT WHITE MOLD IF TEMPERATURES ARE BELOW 85 DEGREES WHEN SOYBEANS START TO BLOOM (R1 GROWTH STAGE)!

1.) If you have NOT ever had white mold in a field:  scout for the apothecia (mushrooms of white mold) before soybeans bloom on the soil surface.

2.) If you have had white mold in a field:  spray fungicide at soybean growth stages R1-R3 to SUPPRESS or CONTROL THIS DISEASE before infection takes place (if canopy conditions are cool).  Fungicides will only be effective if the are applied at the correct time, with good coverage within the canopy!  Fungicides will not offer total protection (0 to 60% disease reduction). 
Fungicides for soybean foliar diseases:
https://www.extension.purdue.edu/extmedia/BP/BP-161-W.pdf

Some herbicides (Cobra or Phoenix) do not have an effect on this fungal pathogen, but may help to reduce the incidence of white mold by reducing crop canopy or delaying/reducing soybean flowering time.

3.) If you find white mold in a soybean field:  IT IS TOO LATE TO APPLY A FUNGICIDE.  KEEP RECORDS OF FIELDS THAT HAVE WHITE MOLD FOR FUTURE YEARS.

What puts a field at risk to have white mold?

A.  The white mold disease pathogen has to be present in order for soybeans to become infected.  HARVEST INFECTED FIELDS LAST, SO THAT THE COMBINE DOES NOT SPREAD THE (SURVIVAL FUNGAL STRUCTURES) TO OTHER FIELDS.  CLEAN COMBINES!

B.   What is the rating of your soybean for white mold?  Check to see if your soybeans have a good rating (higher number) for white mold.  No soybean variety is completely resistant to white mold!

C.  The white mold disease pathogen will only infect under cool conditions.  If temperatures are above 85 degrees when soybeans bloom, infection most likely will not take place.  

D.  Factors that increase canopy closure, will cause fields to be more at risk for infection because this will allow for cooler, humid conditions for disease developmentThe factors that increase canopy closure are early planting, narrow row spacing, higher plant populations and higher soil fertility.  There are arguments as to whether row spacing causes a higher risk for disease development.  From experience and what I have read, I don't think that row spacing is a factor, because spore dispersal is still possible within various row spacings.
White mold infection that was intensified by a higher planting population (200,000 plants per acre) (Picture provided by Dennis Mueller)
E. A minimum rotation of 2 to 3 years to a non-host crop (corn or small grains) is required to help reduce the fungal survival structures within the soil.  But, keep in mind, that I visited a field this year with a high incidence of white mold that had previously been in corn for 5 years!

F.  There are also mixed feelings on the effect on tillage, when it comes to the prevention of white mold.  Deep tillage (8 to 10 inches) can help to bury fungal survival structures in the field; however another tillage pass could also bring fungal survival structures to the soil surface and increase disease incidence. Some say that fungal survival structures will degrade faster within no-till soybeans.

G.  Some weeds and cover crops can make conditions more favorable for white mold infection.

H.  There has been limited research done on biological controls that help to reduce or biodegrade the survival structures (sclerotia) of white mold within the soil.  The most popular biological control is Coniothyrium minitans (Contans or KONI).  Most of these biologicals should be incorporated (within 2 inches) of the soil at least 3 months before white mold infection.  Studies have shown up to 95% reduction of sclerotia or reduction of disease incidence up to 10 to 70%.  But, keep in mind, if you have a heavy amount of disease inoculum in your field, you will never be able to completely free the soil of the fungal pathogen that causes white mold. 

Control of white mold within soybeans requires an integrated approach or the implementation of many different management strategies (listed above).










Monday, September 29, 2014

A Note from Tom Burrus About Grain Outlets for Agrisure Viptera Products




 Dear Folks,


Since Agrisure Viptera is not approved in China, the grain from those products need to be channeled into the correct elevators who don’t sell to China.

Now growers can call 844-203-3003 for advice as to who is buying this grain closest to their farms.

There are currently 1100 elevators in Illinois taking this grain and the number is still growing.

Good luck as you try out the number this week.  Hopefully growers will find more outlets and we can better utilize our Catalyst 4685 and 7893 products. 

Good luck,
Tom

The Sun was Shining on Catalyst 7893 in the Burrus Preview Plot near Columbia, IL

Friday, September 26, 2014

Urgent – Carefully Monitor Non-GM Corn for Purity This Season


Burrus has received some customer reports related to non-GM harvest issues.  Simply stated, the type of “border harvest” needed to reach an acceptable non-GM purity has been atypically wide in 2014.  In one case, the grower had to shave off 4 to 5 times the border area commonly needed.  Such issues apparently are occurring in proximity to neighboring GMO corn. 
               
What should you do?  Because the issue appears to be pollen drift into non-GM fields, Burrus strongly recommends that non-GM growers harvest outer rows and deliver that corn until they eventually hit acceptable purity.  We simply cannot predict where that line is in each field, but sampling each field should paint the needed picture.  Burrus also strongly recommends that growers not toss everything in the bin before conducting the step above.  If contamination truly was exceptional (for reasons listed below in this article), the risk of contaminating or losing the non-GM premium on an entire bin of corn is simply not worth the additional corn in storage.  Pick and deliver until you hit purity, then start thinking about storage.

Why do growers have to go deeper into fields before they reach acceptable purity?

1.) How much GM pollen has been present in 2014?  In a July 2014 report, the USDA Economic Research Service stated that herbicide tolerant crops represented 89 percent of US corn acreage.  Corn with at least one insect trait represented 80 percent of US corn acreage.  In total, 93 percent of the US corn acreage consisted of some kind of traited product.  Increase the relative number of GMO corn near a non-GM field, and the "contamination risk" of pollen contamination increases as well. 

                
2.)  There must be a relatively smooth “nick” between the undesired/donor/GM corn and the non-GM crop. “Nick” refers to pollen being present when silks are present.  In Illinois, it often takes about 8 days to go from 50 percent planted to 75 percent planted (USDA – NASS), but in 2014, growers were able to complete planting in about 5 days.  In addition, alot of similar maturity corn was planted at the same time.  It usually takes about 8.5 days for Illinois corn to go from 50 to 75 percent silk.  In 2014, silking occurred within 5 days.  In other words, many of the same corn maturities began to silk and shed pollen at the same time.  GMO corn was eager and much more able to provide contaminating pollen in a “timely fashion.”


3.)  Environmental factors, such as cool conditions, increased the viability of pollen.  Corn pollen can last for a while (hours) before it “must” come into contact with silk, but it doesn’t last forever.  Cool conditions increases the viability of pollen, which provides more opportunity for contamination.  

4.) Getting pollen to travel far requires the correct environment as well.  Most corn pollen drops relatively close to the plant from which it originated (some resources say about 99 percent falls within a couple dozen feet of the plant).  However, this does not mean all corn pollen falls within that distance.  A percentage or two of that pollen will always drift further.  The distance this pollen moves can total an additional several feet to several dozen feet.  The microenvironment, wind in particular, will determine how far pollen drifts.  The 2014 storm events allowed pollen to really move around! 

– and you get increased GM contamination risk to non-GM corn in 2014!
(Matt Montgomery, THE Burrus Sales Agronomist)

                

Wednesday, September 17, 2014

Can the Woollybear Catepillars Predict Winter Severity?

There has been talk that this winter may be harsh and many of my Facebook friends have been talking about seeing dark woollybear catepillars and afraid that this may mean there could be a nasty winter headed our way!

Rhonda Ferree, University of Illinois Extension, Horticulture Educator commented on my Facebook page and said that she had written an article about woollybear catepillars and winter prediction in the following article:  Woolly Bear Caterpillars and Weather Predictions


In this article, she says the following: 
"According to superstition, the amount of black on the woolly bear's bristle coating forecasts the severity of the coming winter. Ferree says, "It is the relative proportions of the black and reddish-brown portions of the caterpillar that are supposed to predict the winter." The longer the black segments on the ends of the caterpillar, the harsher the coming winter.

One of the problems with trying to forecast the winter using these insects is that the tiger moth has similar caterpillars as its larval stage. Unfortunately, there are about 260 species of the tiger moth and each species has a different color variation. Plus the caterpillars shed their skins or molt six times before reaching adult size, and their colors change with each molt.

According to Donald Lewis, Entomologist from Iowa State University, there is some year-to-year variation in the amount of black hair on these caterpillars, but the differences are caused by age and wetness. Older caterpillars have more black than young ones and caterpillars that fed and grew in an area where the fall weather was wetter have more black hair than caterpillars from dry areas. (IT HAS BEEN A WET FALL!) SKP

If they are going south, it is going to be a harsh winter. If they are headed north, it will be a mild winter. Rhonda was driving east and west, so she doesn't know what that means! If you don't believe woolly bears can predict the weather, you might instead want to look at pig spleens, groundhogs, hornets, persimmon seeds, or read what "The Old Farmer's Almanac" says. You can watch the weather forecasters using their high-tech equipment. Or, you can just wait and see what winter has in store for us." - Rhonda Ferree

So, I took a Facebook poll.  I asked my Facebook friends what color of woollybear catepillars that they were seeing in their "neck of the woods" and here is what they said:

Picture provided by Bridget Hill
  "He says (picture above) it's going to be mild at times and harsh at others... Lol" -Bridget Hill

Picture shared by Kaitlynn Bissonnette, University of Illinois Plant Pathology Graduate Student
"That picture (above) was from last year. But I have seen all colors in the field so far this year." -Kaitlynn Bissonnette

"You will have to cut a persimmon seed in half to get you the real scientific winter prediction." -Raymond Elder

"There are a ton of black ones at my house!" -Carrie Gordon

"I have seen dark ones crossing the country roads." -Jaynen Kates 
(Hmmmm, I should of asked her which direction they were headed!)

"85% of what I have seen so far this year have been black, a few tan, orange and two white." -Jeff Knodle

"All we have seen have been black and dark brown and maybe a couple sorrel" -April Eddington

(Sorrel? - I think she is an art teacher!)


Shannon Hadley Tester's photo.
Picture taken by Shannon Tester

"This is what I have seen (picture above)." -Shannon Tester

"I have seen black, brown, orange, and white." -Kristy DeLuka


Wendi Slightom's photo.
Picture taken by Wendi Slightom

"This is what we have (picture above) at my house. Very dark ones!" -Wendi Slightom

"Mine are very dark also." -Doris O'Malley

Picture taken by Melissa Cauble, Montgomery County Soil and Water Conservation District



Picture taken by Monte Epley
So, what is your winter prediction?