Disease Management

by | Mar 24, 2020 | Crop Watch

We are approaching the last week of March and all of a sudden nothing seems normal. The common opinion is that with bare shelves and people fighting over toilet paper we must have time traveled to an Iron Curtain country. We just got a letter from Big Tony down in Pergamino, Argentina where and he and wife are in their house with much of the population laying low and hoping things return to normal soon. Monday morning, we got a personal observation from a contact in the UK. Things are the same there with empty shelves. I have visited with quite a few very knowledgeable people with many years of being on the front line similar challenges. Is it real or a huge global hoax? I have to keep my opinion private.

In the Chat N Chew Café the Univ. or Illinois Ag Economists shared their thoughts on the market impact of this ‘pandemic’. This effect coupled with the effects of the Russian/Saudi oil squabble driving gas prices down, which is reducing ethanol demand, further complicates grain price predicting. They did a great job if untangling these different factors.

I missed Governor Reynolds talk on Saturday but earlier the Feds declare that Ag was a critically important cog in the economy. So her administration and those in other states would make sure  that our normal springtime activities like transporting fertilizer, machinery, livestock, feed and so on would continue like normal. We normally have that month long extremely busy season where spring fertilizer is being transported and applied, seeds are being delivered and planted, and weed control programs are being implemented. In addition, different groups are looking at the 2021 crop and suggesting locking down crop production inputs such as herbicides that might be tight in supplies.

Sports: For the first time ever since men’s and women’s college basketball became major spectator sports that we did not have the tournaments to watch, listen to, or even attend. They had first round games down in KC before things shut down. One group of BB prognosticators assembled their entire NCAA tournament brackets, looked at their many polls, and assumed the team from Lawrence was going to take it all. I looked into my crystal ball and saw they were matched against UNI again in the second round. The last time this happened UNI played a magnificent game and a #15 seed took down a #2 KU team. Karma says it was going to happen again on a late long three pointer.

The Hula Meeting

Just before most companies shut down their meetings and face to face meetings between employees and customers the scheduled meeting with David Hula was held in NW Iowa. The crowd was very acceptable in size. Mr. Hula’s claim to fame was his 600+ Bu/A corn yield achieved in the 2019 growing season. That yield achievement is above the theoretical potential which most crop scientists said was achievable for a perfect season and perfectly managed corn field.

Everyone was waiting for a moment or disclosure of some magic potion that he applied that really worked. But his was simply a systems approach where every preplanned addition contributed to the overall production. He did say his populations on his sandy or sandy loan soils in Maryland were in the 48k range using an older P hybrid that we saw a negative correlation with when populations were pushed beyond 36K.

I did not get the chance to ask what his Haney or other soil quality readings were. He is using biologicals but did not touch on which one or which combination. In comparison Jimmy   Fredricks of soybean yield contests will say he does not care about particular P or K levels, just give him good biological acidity in the soil and he will have enough nutrient release occurring. We are now seeing the official category that nutrient releasing biologicals are placed in is biostimulants. He was big on supplying Zn and testing the benefits of Co but has not looked at Ni yet.

Thus with 600+ Bu/A corn yields now achieved the champion growers can now aim higher. In reality the quest will be how to raise the whole farm yields while being selective on inputs and input dollars. Therefore, a high yield with any crop must be profitable to produce.

Cornell CRW Program

A few stories were being printed a few months ago about a new tactic being trialed in NewYork state with entomologists with Cornell Univ. What they were doing was applying PEN (persistent entomopathogenic nematodes) to fields the year before corn would be planted. The early season applied nematodes would build up in population in year #1 that corn was planted in the second year that the nematodes would devour the CRW eggs or larvae. In previous trials this treatment achieved the degree of control and higher yields than the traits were able to long term. They are placing more trials and have some hope it testing those PENs in the state.

Insect Pests

The ISU IPM newsletter this week was an excellent read. One item they discussed and is not brought up too often was the different insect spectrum that caused problems with soybeans when planted into a cover crop mulch. I saw this a few years ago in a crimped rye cover cropped bean field. With the protective and moisture holding mulch in place the slugs, millipedes and sow bugs (rolly pollies) were chewing on the cotyledons and nipping on the small seedlings. Supposedly the chlorypyrifos and pyrethroid insecticides can be effective in helping to control them, but have to come in contact with the insect to do so. The neonics have not been effective against those insects.

Lorsban Anyone

A season or two the ability to market the product known as Lorsban or Dursban was canceled when Dow did not submit a new info package to the EPA. The ability to produce and market the product was revived with the Trump administration in 2019. Now Corteva Ag Science decided that due to health concerns they will stop producing and selling the product.

It has been used the most in recent years to manage aphids and thrips in grain veggie crops while in soybeans two safer products (Sefina from BASF being one of them) being introduced if soybean aphids are a problem in that crop.

Disease Management

The sales of the reference book entitled ‘Mineral Nutrition and Plant Diseases’ by Datnoff and Huber is testament that more growers are slowly warming to the idea that diseases typically appear and become a problem in crops deficient in specific minerals. These deficiencies can be corrected with a combination of soil and foliar applied products or applications of manure that have been tested for mineral content.

For second year corn fields where the stalks remain untouched applying a mixture of microbes (like BioDyne 501), N and sugar which aids in faster residue degradation may be a wise move in that it should reduce the surviving disease inoculum this spring yet.

Back in 2003 and 2004 articles warning about over use and multiple applications of consecutive sole applications of Strobe fungicides were circulated. The reason was that single site of action  of members of that family left them prone to having resistance develop to them by different fungal classes. Since then we have seen those rules violated quite often as the same product, often with different names by different companies, were applied to the seed and then to the growing crop in-season. Whether the last mentioned multiple application or long term use of the same product is to blame the end result has been the same university disease specialists are now documenting resistance to the Qol or strobe fungicides.

The warning given is that your regular application of strobe at R3 may no longer control Frogeye leaf spot. The related Cercospora Leaf Blight and Septoria brown spot are still controlled by the strobes but no one can say for how much longer. You may wish to update yourself in case you see escapes this season.

Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or www.CentralIowaAg.com.