Iowa Crop Update For June 7 To June 12, 2016

 

The USDA Weekly Crop Progress Report showed that Iowa's corn crop is 99% emerged and has a good/excellent rating of 80% for the week ending June 12. The agency reported 91% of Iowa soybeans have emerged, 10% ahead of the 5-year-average. The good/excellent rating for Iowa soybeans are 81%, compared to the U.S. good/excellent rating of 74%. Sulfur deficiency and herbicide injury are two issues seen throughout the state over the past week, as side-dress nitrogen applications and postemergence herbicide applications continue. Read on for more information about your region's crop progress and field conditions from Iowa State University Extension and Outreach field agronomists.

 

 

Joel DeJong (Region 1): We had a dry, hot week in the northwest corner of Iowa this past week. Limited rain fell in the northwest corner Friday night, but the remainder stayed dry.  A lot of soybeans were planted on the Missouri River bottom during the past week, finally. Growth of corn was tremendous, but some showed problems from inhibited root systems (compaction, wet panting, etc.) during the three days with temperatures in the mid-90’s. Over the past week, I observed instances of herbicide injury in some fields, but it looks like most will recover OK. Stalk borer migration has begun, so check field borders in fields with corn hybrids that don’t have protection from Bt traits effective on stalk borers.

 

Paul Kassel (Region 2): Corn is stage V4-V8 in my region of northwest Iowa. The April 15-17 planting is V8 to V9 and is almost shading the rows in 30 inch rows. The late planted/replant corn is also looking good and is in the V4 stage. The soybean crop is also advancing. We are seeing the soybean crop in the VE-V2 stage. Farmers have been busy with side-dress nitrogen applications and post emergence herbicide applications.  

 

 

Brian Lang (Region 5): The first 5 weeks of corn growth is often referred to as the “ugly phase.” Corn fields often look uniform through V3 stage. If “ugly phase” corn had any problems with early root growth and/or premature rot of the mesocotyl from factors such as soil borne disease, soil insects, herbicide injury, fertilizer burn, etc., then unevenness will be increasingly noticeable as fields advance to V6 stage. Scout these uneven areas in the field to sort out why some the of the corn suffered significantly more stress in order to adjust management in the future. 

 

 

Michael Witt (Region 11): Corn is around the V4-V7 stage, on average, for west central Iowa. The crops are generally healthy with little nitrogen or other nutrient issues. Soybeans are ranging in maturity from V2-V4. Ninety-eight percent of planted beans have emerged across the area. Plants of all crops have been growing significantly this past week with the warm weather. There is adequate mid-to deep subsoil moisture, but crops could still use some moisture in the top layer. There is some plant curling and heat stress due to the abnormally hot temperatures of the last week. Herbicide spray damage has started across the area. This is mostly due to improper calibration of sprayer equipment, poor cleaning of equipment and tanks, improper mixing with surfactants and chemicals, or wrong chemical application. These issues have been mainly in corn with soybean spraying still going slowly across the area. Striped rust has been discovered in wheat crops in Iowa and across the Midwest. With rain forecasted early in the week, then a return to warm and dry conditions, crops and weeds will grow rapidly; proper crop scouting is essential for fields.

 

Clarke McGrath: In southwest and west central Iowa, corn spraying is about wrapped up. For fields yet to go, just take a minute to double check corn stage/size and compare to herbicide labels. We don’t want anyone to run into herbicide injury, as this corn is really growing quickly and might be pushing the upper limits of some product labels. Soybean spraying is getting started. Be sure to check weed sizes vs. herbicide rates so you can maximize herbicide effectiveness. I am getting calls on some pretty sizeable weeds in fields, especially ragweed and waterhemp.

 

 

Mark Johnson (Region 7): I had two calls last week wondering if what they saw was sulfur deficiency. One was eroded side hills on two fields, and the other was low organic matter areas of two fields. In both cases, there was no recent history of manure. With the side hill fields, the soil test levels for potassium were also low. They both were indeed sulfur deficiency and are being treated.

 

I had 2.5” of rain Saturday morning and some other areas in my area were similar, with parts of Warren County getting nearly double that, and some parts of my area getting far less. The photo below of rolled corn in Dallas County shows the need for rain that’s in the forecast for Monday night (June 13) and Tuesday (June 14).