April's Ag Advice By April Borders Just wanted to give you a quick update on how things are going so for this summer.
Winter wheat is about all harvested and I think that as harvest was happening we could see light at the end of the tunnel created by fusarium head blight. The range of mycotoxin being reported in samples ranged from 0 to 168 ppm of vomitoxin. Remember the tolerances are between 1-10 ppm. So there were some extremely high levels out there.
There were some questions about saving seed from fields with scab that have been tested with low vomitoxin levels (1 to 2 percent). The recommendation is that if the visual observation of scabby or fusamium damaged kernels is low, producers could use it for seed, however producers should use a seed treatment like Vita-vox, Raxel, or Raxel-Xtra to prevent seeding problems. But the overall rule of thumb should be: If in doubt � throw it out!
If you are worried about using the seed or the straw for livestock feed, you should have it tested to find out the mycotoxin levels. Samples can be sent to Veterinary Science Diagnostic Lab, Van Es Hall, NDSU, Fargo, ND 58105. If you need to call them their phone number is 701-231-8307. They have indicated they would like a straw sample about the size of a shoe box plus some. If you are sampling bales you need to send 10 to 12 core samples from the bales. You should be submitting a sample that is representative of the whole field as there is variability if infection is throughout the field. The cost for running the test is $60 per sample.
Producers should be out scouting for soybean aphids. There are fairly high numbers of aphids in several fields that I have scouted while we are just starting to see aphids in others fields. We are also seeking leafhoppers in the fields. Don�t confuse the leafhopper for the soybean aphid. From now to R5, growers need to be scouting for soybean aphids and should be prepared to treat.
Asian soybean rust is still staying in the south and the hurricane systems may still play a part in the movement of the disease into our area. We will have to wait and watch. Dr. Marty Draper, Extension plant pathologist said, �There are still a lot of unknowns out there but we are about 2-3 weeks away from being home free from getting the disease.�
Latest reports of Asian soybean rust detection have been in Mississippi and Georgia. Rust has also been found in Florida and Alabama.
Corn is tasseling and silking and looking pretty good. We sure could use some rain though. There are reports of short, waist-high corn tasseling, as well as uneven flowering within fields. A lot of growers are concerned about the impact of drought stress during corn pollination. This stage in corn development is the most sensitive stage to stress conditions. Sometimes the stress can cause a delay in silk emergence. The length of this delay is such that little or no pollen is available for fertilization when the silks finally appear.
Each potential kernel on the ear has a silk attached to it. Once a pollen grain �lands� on an individual silk, it quickly germinates and produces a pollen tube that grows to fertilize the ovule in 12 to 28 hours. Within 1 to 3 days after a silk is pollinated and fertilization of the ovule is successful, the silk wills detach from the developing kernel. Keep in mind that silks can remain receptive to pollen up to 10 days after emergence.
Unusually long silks are being seen this year, these long silks that are still �fresh� are a symptom that pollination has not been successful. Unpollinated silks continue to elongate for about 10 days after they emerge from the ear husks before they finally deteriorate. During this period, silks become less receptive to pollen germination as they age and the rate of kernel set success decreases. If you observe unusually long silks in drought stressed fields it may be an indication of pollination failure. Sampling several ears at random throughout a field will provide an indication of the progress of pollination.
For more information contact the Clay County Extension Service at 677-7111.