Louisiana feed grain crops… questions abound
Jul 24, 2007 10:27 AM,
David Lanclos
LSU AgCenter Specialist
Louisiana feed grain crops continue to improve with slight problems throughout the state — as can be expected for this time of year.
USDA acreage estimates have caused some concern among producers, especially those who have a portion of the 750,000 acres of corn. Storage is our number one concern right now.
And we need an end to rain so the crop can start drying. This excessive rain pattern we are experiencing is slowing the crop’s dry-down. I am getting reports that some corn will be ready to harvest by July 27.
Milo looks outstanding statewide. The concerns in this crop are much the same as corn. As the heads begin to mature, there is bird damage. There are additional concerns about sprouting due to excess moisture statewide.
Could this be detrimental to pollination? Usually, no, but in some isolated cases where there was rain every day during peak pollination times, there could be some problems. I expect these to be very minor, however.
Some producers and consultants have asked how to determine 30 percent moisture because they are very interested in using glyphosate as a desiccant for sorghum. They want to put it out before they start harvesting corn in a couple of weeks.
Logistically, this makes sense, but I want to err on the side of caution when it comes to determining 30 percent moisture. If you have a moisture meter that accurately reads moisture contents that high, take several heads across a field, thrash them and get a representative sample of seed.
A less scientific approach is to evaluate several heads and critically determine by feel on the lower portion of the heads. Squeeze the seed. If no liquids come out of the seed, you are going to be very close.
Black layer in milo is basically the same as it is in corn — you have reached physiological maturity and moisture is around 30 percent. The difference is it is much more difficult to see on the smaller seed.
Because the soybean crop ranges from R5.5 to V6 in most situations, the season is going to be long. We could develop some late-season problems.
A couple of things have caused some minor issues with the crop over the past couple of weeks. With the weather lately — primarily too much rain — the crop has slowed to a point where it needs a boost in some fields. In these isolated cases, I have recommended a nitrogen-based foliar feed, something I do not customarily do. In these situations, however, you sometimes need to get the crop growing again.
I am not saying the foliar feed necessarily increases yield, on a crop that is struggling to produce nodules properly and is not growing correctly, it can help jump start the crop.
Recently, Louisiana was granted a Section 24C for Syngenta’s new product Endigo, is a combination of Centric and Karate. In research trials it has controlled red banded stink bugs and other stink bugs very well. Early reports from consultants who have put some out have been positive.
The use rate is 4.0 to 4.5 ounces. It cannot be used consecutively in a field. In other words, if you use Endigo, the next insecticide would need to be another chemistry, such as Orthene.
Another label restriction is that you can not make more than two applications of the product in a given year.
Orthene is a great compound. I am glad we will have the opportunity to rotate these chemistries for the control of numerous pests in our soybean fields.
Often overlooked is the three-cornered alfalfa hopper. Over the past week, I have looked at several problems that were thought to be fungicide burning or herbicide injury. They were all previously sustained three-cornered alfalfa hopper damage.
These pests are showing up with a vengeance in some fields, and because they have not been controlled effectively, there will be some yield losses. In our St. Landry parish verification field, we had to spray early in the season — when the beans were still in the vegetative stage — to keep them under control.
Most of the damage I see now occurred several weeks ago. As the plant begins to fill seed, more symptomolgy becomes visible. You can expect overall yellowing of the trifoliates and eventually death where girdling has completely encompassed the petioles. Death of the plant can occur also when the main stem has been girdled.
You will notice adventitious roots emerging from the top of the girdled section, trying to compensate, but the plant is dead.
The threshold is one three-cornered alfalfa hopper per sweep.
Another topic that has generated much conversation over the past couple of weeks is that of fungicides and control of secondary diseases such as aerial blight which are flaring up due to the lack of air movement, thick canopies and excess moisture.
There is a tremendous amount of confusion in industry right now in terms of what has been recommended and the status of rust and other diseases. If you go to any number of Web sites that have links to the national map of where ASR has been positively confirmed, one thing is clear: the disease is spreading and severity levels are increasing.
The hot state over the past week has been Texas. So what does this mean for Louisiana? For the past several weeks, we have been recommending a mixture of a strobilurin and a triazole at R3 if that was the only spray that you were going to make. This is a solid recommendation because yield benefit is greatest with a strobilurin application at R3.
The water gets murky regarding what should be done before or after the R3 application. Several producers who have sprayed a fungicide — primarily a triazole — prior to or after R3 wonder if they have gained enough protection from the applications? In essence, yes, but we cannot guarantee anything.
As rust continues to be found, a more aggressive approach will be needed for later-planted beans. Producers can expect to spray twice if they are trying to protect a critical growth stage.
There are questions. Do the triazoles control other diseases? What is the difference between a curative and a preventive? What is the growth stage when we need to strop worrying about rust? All I can say is that we are working on these questions.
e-mail: dlanclos@agcenter.lsu.edu
