Renewable Farming

Confirmed tests show Goss’s wilt emerging across Iowa

Crop consultant Bob Streit of Boone, IA has alerted broadcast media in Iowa and Nebraska to encourage farmers to scout cornfields for early signs of Goss’s wilt, a bacterial disease.

July 7, 2017 — Goss’s  hasn’t been widely expressed in the Midwest the past couple of years, but this season’s stormy, humid weather in much of the central Corn Belt has provided near-ideal incubation and spreading conditions. 

Bob tells us: “We found our first lesions about three weeks ago. The disease can be found on most corn plants that have reached the V9-V10 growth stage.”

Bob is alerting several news media, including radio, to get the word out for farmers to be alert: “We cut our first interview July 7 with radio station KRVN in Nebraska.”

The surest diagnosis method is to check tissue with the Agdia strip test kit, which you can take to the field and get  indications in minutes.  See also our earlier report on the broader need for full-season nutrition to stave off an array of bacterial and fungal diseases in corn, which have led to steadily earlier die-off of corn the past several years. In August and September, lesions like the ones in the nearby photo get very evident, but they’re not as noticeable in July.

Severe Goss’s wilt lesions on corn

Discussing the wider problem of early corn death from multiple diseases, Bob adds, “Many of our customers are having tissue testing done and realizing they need micros. WakeUP is going on with the micronutrients.”

WakeUP Summer blended with a foliar fertilizer solution enhances leaf coverage, absorption and translocation for improved yield performance. Veteran crop nutrition and disease scientist Don Huber often remarks at seminars, “Corn used to be one of our healthiest crops. Now it’s getting diseased and dying long before its normal maturity.”

Preserving corn’s lifespan well into the filling weeks has the potential to substantially more yield, such as 20 to 40 more bushels. Kernels deepen and test weights increase. That takes full-season nutrition, and often it’s possible only with careful testing of sap or tissue on a regular basis, then following up with foliars before the deficiencies impose severe drag on yields — and vulnerabilities to disease.

In past seasons, the Goss’s symptoms have been clear by early September. But they may not show uniformly in all parts of the field. Some fields have spots of infection, probably introduced by seed corn grown in soils carrying the dormant Goss’s bacterium. For example, here’s how a scouting drone might reveal that “pox” of diseased patches:

Goss’s wilt showing in patches across the field.
Note that the field on the right doesn’t appear diseased.