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CROP WATCH

By Staff | Sep 18, 2009

September is half over with and forecasts are starting to hint of an early frost. While that sounded like a big threat a month ago, most of the crops have been pushed along by the cumulative stresses and leaf diseases to the point that it won’t matter much.

In fact several growers I work with commented that they had been gone a few days, came home, and thought there had been a frost. Thus we are now at the beginning of the harvest season and will have the chance to see if the inputs and decisions made during the growing season ended up being correct.

Things sure have changed from the summer of 2008 when corn was in the $6 per bushel range and everything was rosy. While many input companies and economists predicted new plateaus that would never see valleys again most seasoned growers took a more apprehensive view because they remembered 1973 and other years when markets were exploding.

Thus we are at the cusp of a season where there are many unknowns. The first year reports from the southern states on soybeans tell of great yields. However, cool weather and rain during their growing season meant 80 degrees with minimal stress while the same parameters represented 60 degree days and either too much rain or too little sun. Those were all negatives for us.

We want lots of bushels for our fields and poor results in all other sections of the country. In another four to six weeks we will all be much more knowledgeable about yields. Very high potentials during July may only be partially delivered in October and December.

This is the week of the Clay County Fair. Many rural Iowans and ag businesses recognize it as the biggest ag-related fair and use it as the premier event at which they can interact with their customers. It has always been fun to see the many displays representing either handicrafts, machinery or livestock. Hopefully many of you were or will be able to go.

Iowans lost a legend

Most Iowa residents may not know it, but one of the biggest and best scientists who worked with plants in Iowa for over 50 years, stood less than 5 feet tall. She was Dr. Lois Tiffany, professor of mycology at Iowa State University. I had the opportunity to take Botany 506 from her years ago and those lessons still stick with me. She would teach graduate and post-grad level courses from 7 a.m. until 10 p.m. and often did, without using any notes.

That never meant that we got by without taking loads of them. She made sure her students knew the differences between apoceiums, cleistoceiums and peritheciums and could distinguish urediospores from urediniospores or teliospores. She made learning fun and always explained how scientific facts and properties of each fungi related to something in the real world.

She died last week at the age of 85. From being born on a farm near Collins she reached great heights and was known as ISU’s Mushroom Lady and a member of the Iowa Academy of Science. A program to memorialize her will be held Saturday at the arboretum near Luther.

Leaf diseases, stalk quality

By now most growers have walked their fields and see a lot more tip-back than they are used to and were hoping for. It is typical this fall to find from 1 to 3 or 4 inches in many fields and those were kernels that pollinated and begun to fill.

Like most years pollination problems were rare, but the weather during the two weeks following pollination were not conducive to starch formation. In areas the identifiable causes included measurable nitrogen losses, delayed planting, too much residue slowed plant development, or hail ripped away leaf tissue.

All on that list were tough to manage around, save for nitrogen losses. Next year most growers who plan to plant second-year corn will most likely try to place their nitrogen as far away from the residue as possible.

We saw that growers who foliar applied nitrogen saw good green-up and growth beginning a few days after the application was made. It will be something they will have confidence in using in another year. There were differences in the products depending on source of nitrogen and the formulation procedure.

Many cropping newsletters have written about the explosion in leaf diseases that have caused the majority of fields to turn brown weeks ahead of normal. When that happens, and it did in 2008, expect stalk quality to be a major concern. I have found extremely soft stalks along Iowa Highway 3 and U.S. Highway 20.

Pilots have seen stalks collapsing already along I-80. With stalk anthracnose being present in many fields since the last part of July crop scouts have been dissecting stalks to find that many have been invaded and will be at risk during their dry-down period.

That means many growers who would typically like to let their cornfields dry as much as possible will have to agonize about harvesting early and paying the larger drying bill.

Scouting each field will be the best method of gauging what to do. We saw in 2008 that fungicide treatments typically helped greatly in improving stalk quality.

More farmers will likely be demanding more information about the hybrids they are choosing for 2010. They will assume nothing in their quest to avoid problems with leaf disease next year. If their current hybrids lodge yet this fall, there will be more unhappy campers.

Residue management

There are plus sides to keeping residue on the fields and many growers found out that there are negatives. Right now many growers are set up for similar problems in that the corn harvest moistures project to be quite wet through mid-October and most plants are quite tall.

Much depends on how warm the entire month of October is. If the residue isn’t managed properly it will be laying in the fields next spring ready to cause the same problems as this year. So growers need to be proactive in helping or causing the residue to begin the process of microbial degradation as soon as it is harvested this fall.

Thought it would be nice to wait until harvest was complete, it may be best to free up a person who can apply the right products to the residue. In cases sizing it and getting dirt on it will be helpful to the operator who plans to raise second-year corn.

Strip-till operators typically recognize the biological processes and organisms such as fungi and actinomycetes and help them along with applied nitrogen, sulfur and biological mix such as Z-Hume to start the degradation process.

No-till operations typically use residue managers to move the stover away from the row and do the job of absorbing rain drops and protecting the soil from erosion.

Soybeans

If you were to scout a soybean field that is still green and was sprayed more than a month ago, it would not be unusual to still find a few aphids present. Like always they are not following the rules that told them when to leave the fields.

Starting with 45-degree weather or colder, they were supposed to head to the trees to form the egg-laying generation. At a recent field day near Slater we saw aphid resistant plants that stayed quite clean of the insects this summer, while conventional plants next door still held several hundred per plant.

Good luck with getting final preparations done.

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