They are getting worse. Maybe it was the dry fall, but as I was harvesting I saw more pod feeding that I have ever seen before. I don’t think we scout much after about mid-July so we probably missed the increasing levels of these late season insects on soybean. Late season insects I saw were grasshoppers, bean leaf beetle and (more widespread than I have ever seen) the brown marmorated stink bug.
Check these pictures of bean leaf beetle pod damage and of the adult brown marmorated stink bug to see if these images remind you of what you saw at or just before harvest. I had them crawling on the combine and on other surfaces around soybean harvest
Variety and hybrid selection matters — choose a variety with excellent protection from disease. Did you see frogeye in soybeans this year or gray leaf spot in corn? Comb through your company seed trail yield data and look through the seed catalogs. And as quickly as it is posted look through any unbiased yield data you can find, including OSU’s corn and soybean performance trials. Watch for the print edition of the trials here in the OCJ later this year or online in the C.O.R.N. newsletter at http://corn.osu.edu.
Did Soybean cyst nematode hurt yields this year? Probably, as we have been conducting the soybean surveys across Ohio the past three years, we have found more SCN than you expected. So from Anne Dorrance and Terry Niblack our OSU Plant pathologists we get these suggestions from a recent C.O.R.N. newsletter: http://corn.osu.edu/newsletters/2015/2015-34/sampling-for-soybean-cyst-nematode-2013-it2019s-time.
- This year’s early harvest provides the perfect opportunity to take a look at the SCN populations in your fields. We know that the state is now “polluted” with SCN, fortunately most of those fields are at very low levels, which is where they should be kept. However, there are some surprising locations where individual fields are getting or have gotten into trouble with very high populations.
- SCN is picky about what it feeds and reproduces on, but it does like a few weed hosts and cover crops as well as soybeans. If you have SCN in your fields, it is important to also control winter annuals such as purple deadnettle, but also avoid cover crops such as several of the clovers, cowpea and common and hairy vetch.
- So it is time to sample! We recommend sampling in the fall because in most cases this is what the population will be in the spring. With the warmer weather this year and hopefully no frozen ground, there should be ample time to collect and process the samples in plenty of time for spring planting. Processing of samples does cost time and money, so here are a few thoughts on how to sample or how to target your sampling to get the best information for your money. Through funds from the soybean checkoff, we have completed several targeted surveys over the past five years. My group tended to target those fields where yields were stuck or below 30 bushels per acre. Or when we sampled we hit those pockets in the field where the soybeans tended to be shorter or where they matured earlier and always yielded less that the rest of the field. We were able to detect SCN in almost all of these situations, so these are the ones that should have the top priority for sampling.