CROP WATCH
As we quickly march into the end of summer and the growing part of the growing season enters its final month we realize that in about two months we will get to measure the success or failures of the different decisions we have made. Once we get to see the results we will begin to make plans for the 2017 season and for most we hope they begin the cycle again.
The soybean plants in most fields are too tall or too tangled to think about making any new pass. In corn most fields are in the dent stage and nearing black-layering.
In just a few weeks the many field tours will be conducted by different groups trying to get a firm handle on how the yields for both major crops will turn out. This is always a time when we either agree with them or wonder what they are drinking.
Locally we all know what the challenges during the season were, first it was too cool and/or too wet for weeks, then it was too hot and too dry, then once it began to rain it stayed too cloudy and so on.
We know the warts of our own crops and the negative factors in our own areas. Of course there will be states and regions where everything purred along and the crops look great from the road and air, so personal field and farm records may be set.
But what about state and overall summaries? We want the overall production to be lower, but our own to be all time highs.
Corn
After watching the fields closely and then walking the fields in Iowa, Nebraska and Missouri in the last week or so I recognize there will be some very good yields. However in mid-July after returning from Chicago one could look at the corn fields and see a slight, barely discernible yellowing in the plants.
Then in the past two or three weeks we have seen more of the leaf tissue began to turn a coppery or brownish color to the point that the plants are dying from the top and bottom again. It is not happening as early as it did in 2012 or 2014 when most of the corn was dead by the Farm Progress Show time, but it is sure earlier than a decade ago when the corn stayed green until it froze.
Let’s see what sort of explanation is given this year as to the early death of these early dying fields. Will we see the shallow kernel fill, light ears and bad stalks or will things be different?
Watch for the fields that remain green the longest, and then quiz the grower to see that they used or did to maintain plant health longer into the season. They typically will not have a silver bullet type explanation but will instead have more of a systems approach that needs to be copied by others.
I don’t know if many growers have done a close autopsy on any corn plants yet, but what they may want to check on is if their shanks remain white, firm and healthy or if they are brown, mushy and slimy. I have been in fields where a high percent of the shanks are the latter. This is what led to the heavy populations of volunteer corn plants in many soybean fields. It was great for FOP and DIM herbicide sales though.
Soybeans
There were big changes in many bean fields in that SDS became more visible. The soybeans are still 10 to 14 days behind in development, so the yellowing leaves from this disease is still visible below the top of the canopy with the majority of the symptoms still waiting to become highly visible in about 10 days.
Based on experience we have learned that we can make careful observations of the plants in those fields in late May thru mid June of the slight yellowing that appears in lower and poorly drained areas and see how eventually those fields typically explode with the SDS yellow/brown mottling in late August.
Where the loss will come from is the leaf loss means the plants are no longer able to form the sugars needed to fill the pods. More of the pods will be dropped or only partially filled.
What has confounded bean growers with the problem this year is that many of them spent money and time implementing all the steps and using all the different products that were supposed to prevent the problem.
There are growers who planted in late April when the ground was cool and saturated and there were growers who planted in mid-May when the ground was the same way and both now have similar SDS problems.
Two solutions for 2017 that deserve to be looked at would be using a biological product that have Fusarium fighting ability, like Pseudomonas fl. an in-furrow liquid mineral product that used copper and manganese to fight the slime molds causing the problem. There is currently research data on that mix.
Varieties, often going back to parental or grandparental lines and their characteristics need to be examined. Recognize that no university breeder has researched why the original herbicide resistant parent was so susceptible to the causal fungus. This insight could be very helpful.
Crop scouts are also seeing a high incidence of Frog Eye leaf spot. In both Illinois and Kentucky they found strains of Cercospora that had become resistant to the different strobe fungicides. Is that the case here? We will have to see if any lab work was done on this in the northern Midwest.
Insects
The heavy aphid populations never developed to the high levels seen two and three years ago. There are fields with enough bean leaf beetles to spray yet. Look for the nice round holes as opposed to the ragged holes that grasshoppers leave.
In Minnesota the problem they are researching now is they have discovered populations of aphids that have apparently developed resistance to pyrethroids. They still have to find out if it a broad resistance to all member of the class or only certain ones. With insects that create many generations per season their ability to develop resistance has been well proven.
Late rootworms
In scouting corn fields for late CRW beetles the populations now remain quite low. This is likely because there are no longer supplies of pollen or corn silks that serve as good sources for them. Instead they are flocking to ragweed and waterhemp areas where those weeds are producing large amounts of pollen. Will those pregnant (gravid) females lay eggs close to those week patches, fence lines, or ditches or will they move back into corn to lay their eggs? Past history says if those patches are in SB fields they will consider it a good laying spot.
A new website
After having been invited to both attend and present at several medical conferences and interacting with different health specialists, of the environmental and functional MD type, in recent years where all factors including exposure to heavy metals or other compounds related to the problem are examined, Carol and I decided we needed to have a website constructed where we could present different pieces of ag information to people as well as providing health promoting news and products.
You can find this site at www.CentralIowaAg.com . For the health related items go to the Health Solutions Store and Healthy Living. We believe that nutritious food and healthy soils are 100 percent related to good human health, so will try to share some of the information we have gathered and learned.
Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143.