C.O.R.N. Newsletter

  1. Author(s): Ed Lentz, CCA , Author(s): Steve Culman

    Some parts of Ohio have recently experienced heavy rains, especially the northern part. Producers in these areas may have concerns about nitrogen loss in corn fields. Nitrogen losses occur by two main pathways: denitrification (gaseous loss of N) and leaching of nitrate from soil through water leaving the tile line or into groundwater. There is no tool or test that can tell how much has been lost. An estimate can made on the loss potential, which is based on N source, time of application, soil temperature, and number of days that soils have remained saturated.

    Issue: 2015-17
  2. Author(s): Andy Michel

    Last week, Larry Bledsoe from Purdue University reported that corn rootworm hatch occurred on June 3 (seehttp://extension.entm.purdue.edu/pestcrop/2015/Issue11/).  With the exception of 2012, this seems to be in line with past few years.  The bad news is that these young larvae will start to munch on the developing corn roots.

    Issue: 2015-17
  3. Striped corn present in Wayne Co., 2015. Source: Rory Lewandowski
    Author(s): Peter Thomison , Author(s): Steve Culman

    I’ve received reports of corn plants exhibiting varying degrees of leaf striping (interveinal chlorosis) across the state.  There are several nutrient deficiencies (including sulfur, zinc, magnesium, and manganese) that result in leaf striping and some of these look similar. The severity of the striping may vary considerably within a field and may be associated with differences in soil pH, organic matter, compaction, tillage, temperature and moisture.

    Issue: 2015-16
  4. The first answer is we don’t know. The truth is that our soils, rainfall, temperatures, the year-to-year variation and cropping systems are different enough that any rate we tell you will be wrong.

    Issue: 2015-16
  5. Author(s): Peter Thomison

    Rainfall was mixed across Ohio over the past weekend. Although some areas of SW Ohio missed appreciable rainfall, many fields in NE and NW Ohio received up to 3 to 4 inches of rain resulting in localized ponding. If ponding and flooding was of a limited duration, i.e. the water drained off quickly within a few hours, the injury resulting from the saturated soil conditions should be minimal.

    Issue: 2015-15
  6. Author(s): Mark Loux

    While a variety of rainfall and soil moisture conditions can be found around Ohio, a shortage of rain following application of residual herbicides seems to be common.  We are hearing about weeds emerging early in the season even where residual herbicides were applied, which is an indicator of inadequate herbicide “activation”, or lack of downward movement into the upper inch or two of soil where weed seeds germinate.

    Issue: 2015-14
  7. Corn leafing out underground
    Author(s): Peter Thomison , Author(s): Pierce Paul , Author(s): Andy Michel

    According to the USDA/NASS (http://www.nass.usda.gov/) for the week ending May 24, corn was 87 percent planted, which was 21 percent ahead of last year and 17 percent ahead of the five-year average. Across the state, corn is at a range of growth stages. Some of the corn planted in early May is showing up to three leaf collars but in later planted fields, corn is still emerging. 

    Issue: 2015-14
  8. Purple Corn (Source: Glen Arnold, Putnam Co. 2012)
    Author(s): Robert Mullen , Author(s): Steve Culman , Author(s): Peter Thomison

    Corn seedlings often turn yellow (due to low nitrogen uptake and/or limited chlorophyll synthesis) or purple (reduced root development) under cool, wet conditions. Some hybrids are more likely to increase anthocyanin (purple pigment) content when plants are cool. Yellowing or purpling of corn plants at this stage of development generally has little or no effect on later crop performance or yield potential. If it's induced by environmental conditions, the yellow or purple appearance should change to a healthy green after a few sunny days with temperatures above 70 degrees F.

    Issue: 2015-14
  9. Author(s): Andy Michel

    For a couple of weeks we have been warning about the possibility of black cutworms based on adult catches reported by surrounding states.  We have begun to observe some minor feeding on corn, suggesting that the larvae are there and the worst of the damage is yet to come.  We have also received some reports of slug feeding—this is no surprise given the amount of early season rain as well as the more recent precipitation over the weekend.  As our crops are starting to emerge, these are prime sources of food for hungry cutworms and slugs.

    Issue: 2015-13
  10. Corkscrewed Corn
    Author(s): Peter Thomison

    Although corn stands are looking remarkably good across the state according to most observers, there are some localized reports of growers considering replanting. Most of these replant issues appear related to the consequences of planting in wet soils. 

    Issue: 2015-13