Today at the NIARC corn was side-dressed with nitrogen by Dave Lindgren and Darin Joos from variety testing. Also on hand were Nick Tinsley and the entomology crew that is making their northern Illinois swing cutting borders in their studies. Despite all the advances in plot work, borders are still put in the old fashioned way, lots of help and a sturdy  hoe!

Lisa Gonzini, research specialist with the University of Illinois department of Crop Sciences had an early start to her day in an attempt to travel from campus to the NIARC to make post herbicide applications before the wind speed picked up. Even though the weather prediction was a calm day until mid to late afternoon we clocked winds of near 13 mph by 9:30 am. Lisa and the rest of us will be finishing spraying on another day.

For most farmers planting date is dependent on spring weather. In effort to quantify the change in corn yield we have a long term study at the NIARC varying planting dates. This year our planting dates were

• March 29^th
• April 19^th
• May 9^th
• May 29^th

This study has two hybrids, a full season and a shorter season, and will also include a fungicide treatment on each planting date.

Stephanie Porter sends a weekly summary of diseases and plant injuries diagnosed from samples submitted to the University of Illinois plant clinic. Visit the plant clinic site to learn all that they have to offer

http://web.extension.illinois.edu/plantclinic/

In this week's report several corn seedling samples had been diagnosed as chemical/herbicide injury. I noticed several examples of herbicide injury at the NIARC as well. Dr. Aaron Hager recently shared that the increased observation and inquiries from herbicide injury appears to be statewide.

From Aaron's article; "Many postemergence corn herbicides routinely cause some corn injury," said Hager. "Some growers, however, have the impression that this year there is a bit more injury than usual.

Hager said that several factors can affect the sensitivity of corn to injury from postemergence herbicides, including:

• Hybrid: Hybrids have varying sensitivity to herbicides labeled for use in corn. For example, some corn hybrids are sensitive to specific ALS-inhibiting herbicides and tend to exhibit considerable injury following herbicide application. Many corn herbicide labels (especially labels of postemergence corn herbicides) carry warnings that certain corn hybrids could be sensitive to the active ingredient.

• Environmental conditions: High air temperatures and relative humidity levels favor rapid absorption of foliar-applied herbicides, but some environmental conditions can induce crop stress, slowing the rate at which the crops metabolize the herbicide and leading to increased herbicide-related injury. For example, cool air temperatures and wet soil can induce crop stress.

• Spray additives: Crop response may be enhanced when spray additives are applied with a postemergence herbicide or tankmix combination because of the increased rate of herbicide absorption into the plant. Be sure to read all label suggestions and precautions related to spray additives that should be either included or avoided when applying herbicides postemergence.

• Contamination: Herbicide residues from prior applications may be applied inadvertently with the postemergence corn herbicide. These residues, either alone or in combination with the postemergence corn herbicide, may enhance the amount of corn injury. The type of contaminant and the dose at which it is applied affect the severity of the corn response to spray contamination."

Dr. Hager's article can be read in its entirety here

http://web.extension.illinois.edu/niarc/news/news27443.html

What can producers do when they notice herbicide injury to the crop? Inmost instances the only option is simply to wait and see if the corn successfully metabolizes the herbicide and re-starts its growth. With our recent favorable weather this should happen in most situations but we should keep an eye on those areas of the field and make a mental note to prevent it from recurring in future crops. Careful selection and matching of herbicides and hybrids coupled with pesticide placement should remedy most issues.

It is not normal for my drive home to be this exciting. Wind gusts reaching 45 mph on Thursday evening relentlessly moved Northern Illinois precious topsoil. Momentary visibility was greatly reduced, I stopped to take this picture just west of Newark. Hopefully the moisture we are supposed to get over the weekend and future crop growth that will provide more ground cover that will make this an isolated event in 2012.

Hang on to your hat, your clipboard, or anything you are trying to carry today. If you don't; it will most certainly end up in your neighbor's field. Windy conditions are preventing us from any applications at the NIARC today; farm foreman Dave Lindgren is planting our remaining fill areas with soybean. For farmers who still have soybean to plant the questions we are hearing include

Should I
1.Wait for rain before planting
2.Plant deep
3.Plant at normal depth and wait for rain
Dr. Emerson Nafziger addressed this topic and shared the following comments. Under favorable conditions most soybeans can successfully emerge from planting depths of 2½ inches. However, planting deeper than two inches increases the risk of the seedling being sealed off prior to emergence with a heavy rain event. If you need to plant as deep as 3 inches to reach moisture you may reconsider. While hard to do as we move closer to June, the best case scenario is for soybeans to emerge with little or no rain between planting and emergence, both from a disease standpoint and from the standpoint of crust formation. Dr. Nafziger's entire article can be found here
http://web.extension.illinois.edu/niarc/news/news27423.html
Yesterday a producer was questioning the economic threshold for Bean leaf beetles. While absent in most early season sweeps I have made at the NIARC, feeding had obviously taken place on this producers no-till field. Dr. Mike Gray provided an updated threshold that accounts for higher commodity prices. From Dr. Grays article; "For 30-inch row beans (population of 150,000 plants per acre) with 8.6 plants per foot of row, this estimated threshold is equal to 17.2 to 25.8 beetles per foot of row. This adjusted threshold is lower than the threshold suggested in 1995, but a large number of beetles still have to be present for a rescue treatment to be warranted."
The entire article can be found here
http://web.extension.illinois.edu/niarc/news/news27414.html

Like most farmers, NIARC farm foreman Dave Lindgren and I had collective sighs of relief as we finished planting our final plot last night. We cannot put the planter away just yet because we have several date of planting studies that stretch into the last week May and the first week of June. We will also be planting late corn and pumpkins to serve as a trap crop for Corn rootworm beetles. We have corn on our site ranging from VE to V3, this weeks projected temperatures in the nineties should be very beneficial to the emerged crops. Dr. Larry Bledsoe from Purdue University shared that the Western corn rootworm hatch has taken place, the earliest hatch date in 17 years.

At the NIARC we planted our last corn trial and will finish all planting in a few days. Today the plant diseases group was at Shabbona planting their study; also pre-emergent herbicides were evaluated at the V2 stage in our corn. Our trials are almost grass and Lambsquarter free. Our researchers have even suggested bringing more seeds of those weeds to plant for future years. No such problem with Giant ragweed, our most challenging weed. It continues to emerge and survive in several of our treatments. One study of interest this year is the return of a plot that was in Switchgrass for several years to corn and soybean production. We are looking at challenges producers may face if they attempt to bring acreage in perennial grasses back into production. The plot has received a glyphosate burn-down and is planted (in both corn and beans in 30"rows) but as the picture illustrates, the Switchgrass is far from dead. We will keep you abreast on what we learn from this study.

Good weather, good progress! The final three soybean studies were staked out today and I picked up our starter fertilizer for our final corn study to be planted. The end of planting is within sight! Our weeds researchers will be back tomorrow at the NIARC to apply herbicides to our V2 corn. Be cognizant of the growth stage of the corn and the weeds you are trying to control with your post herbicide applications. Dr. Aaron Hager has been receiving calls from across the state sharing incidents of herbicide injury to corn. Aaron posted the following article in today's Bulletin.

http://bulletin.ipm.illinois.edu/article.php?id=1643

Before I finish, this past weekend my wife and I had the opportunity to attend the University of Illinois graduation ceremony. It was a very inspirational and exciting day to watch our future co-workers, leaders and scientists accept their diplomas. Congratulations to all the new graduates (including my daughter) and their parents!

Last evenings best performance may have been the Lightening "light" show courtesy of Mother Nature. The quick moving storm did not yield enough rain to keep us out of the field. Today at the NIARC soybean pre-emergence herbicides were applied in one study, 0-12 inch and 12-24 inch soil samples were collected prior to fertilizer applications in another study. Dr. Brian Diers soybean germplasm evaluation trials were also planted this afternoon. While staking out the location for the final date of planting in our corn study, I noticed our earliest planting corn is rebounding from earlier cold temperature damage to its leaves. A quick reminder to stay alert for Black cutworm damage came from an unexpected phone call. My brother shared that the Indian corn that he had started in his hothouse and transplanted in his garden had been "cut off at the soil line". I didn't get the chance to confirm my diagnosis but am fairly certain Black cutworm is the culprit. Be alert if you have high risk fields.

With almost 90% of the corn planted in Illinois we are playing catch up at the NIARC. Replicated studies planted with a four row planter and different treatments is a slower process when compared to planting with a 12 row (or larger)planter across large fields! Activities at the NIARC yesterday included the Variety testing team who planted their soybean variety trial; the entomology researchers pulled in at 8:30 pm and got an early start this morning to plant their soybean studies as well. Lyle Paul shared his expertise in designing and spraying a pre-emergence herbicide trial. Expect lots more action today, I'm off to the fields!

Stripe rust of wheat has been a topic for several weeks in the Illinois Bulletin. The disease was initially reported in southeastern Missouri and Arkansas. It then progressed into southern and central Illinois and this week was identified by Norman Smith on susceptible germplasm in the wheat variety testing trials at the NIARC. Stripe rust symptoms first occur as chlorotic linear streaks on the leaves. Later on, yellow to orange pustules will develop in a linear fashion ("stripes") within these chlorotic streaks. While most commercial varieties appear to have adequate resistance to the disease, now would be the time to scout. Most wheat fields in northern Illinois have started to flower (Feekes 10.51) If Stripe rust is present fungicides registered for control of Fusarium head blight (scab), such as Caramba, Prosaro, and tebuconazole products (e.g. Folicur and others), would be the products to apply for protection against stripe rust if needed. In addition to suppressing Fusarium head blight, these products have excellent efficacy against stripe rust, and their labels allow applications during flowering (unlike other products that may not allow applications past Feekes 10.5 - heading).
http://bulletin.ipm.illinois.edu/article.php?id=1608
http://bulletin.ipm.illinois.edu/article.php?id=1620
Today at the NIARC the oat testing trials were treated with a herbicide, and we hope to plant date of planting studies in both corn and soybean.

Rainfall in northern Illinois for the preceding four days has ranged from less than ¼ inch to 5+ inches. While standing water is not currently an issue at the NIARC it is for others in our area. Flooded and saturated soils cause anoxic conditions (limited oxygen) for the plants and importantly, the root systems.

Dr. Bob Nielsen at Purdue authored an article on the "Effects of Flooding or Ponding on Young Corn", the 2011 article can be found in its entirety at the following URL

http://www.agry.purdue.edu/ext/corn/news/timeless/pondingyoungcorn.html

Excerpts from the article shared the following generalizations. I'm careful to state "generalizations" because I am one who has been burned by a recommendation that I once made on a ponded field, stating with almost certainty that the corn would not survive. In fact, the water receded and the field dried comparatively quickly, the corn survived and yielded in the 160's. I am reminded of this annually whenever I interact with the farmer. So, there are few absolutes but;

• Plants that are completely submerged is at higher risk than those that are partially submerged.
• The longer an area remains ponded, the higher the risk of plant death.
  • Most agronomists believe that young corn can survive up to about 4 days of outright ponding if temperatures are relatively cool (mid-60's F or cooler); fewer days if temperatures are warm (mid-70's F or warmer).
  • Soil oxygen is depleted within about 48 hours of soil saturation. Without oxygen, the plants cannot perform critical life sustaining functions; e.g. nutrient and water uptake is impaired and root growth is inhibited.
• The greater the deposition of mud or old crop residues on plants as the water subsides, the greater the stress on the plants due to reduced photosynthesis.
  • Ironically, such situations would benefit from another rainfall event to wash the mud deposits from the leaves.
• Corn younger than about V6 (six fully exposed leaf collars) is more susceptible to ponding damage than is corn older than V6.

The survivability of the seedling can be determined by examining the color of the growing point of the corn plant. The radicle (root) and coleoptile (shoot) should appear white or cream colored. Surviving plants usually resume growth within three to five days after the water recedes.

If you are of a certain age you may remember the opening lyrics to the Mama and Papas 1966 song. While some moisture was appreciated we are anxious to continue with planting activities. While the NIARC missed many of the weekend rains that traveled across northern Illinois we received 1+ inches Sunday night. A snapshot at the NIARC has our second planting from our corn date of planting (April 19th) study emerged. Our wheat is also heading, along with an estimated 87% of the Illinois winter wheat according to today's NASS report

Three consecutive days where we have reached 80 degrees  have been beneficial to the planted corn at the NIARC. This is especially true on behalf of our earliest planted corn (March 29). This corn emerged on April 16th and over the next 13 days was exposed to seven freezing or near freezing events resulting in some tissue damage on the leaves. Corn normally makes the transition to its nodal root system near V3 and is no longer dependent upon the kernel reserves to sustain its growth. Prior to this stage the seedling is particularly susceptible to a number of issues including insect damage or disease. Expediting the transition from seedling stage to V3 is beneficial to the plants. This is accomplished by accumulated GDD's.

Based on catches of Black cutworm adults across Illinois initial projections for BCW cutting dates have been posted by Kelly Estes, State Survey Coordinator at the University of Illinois. Corn fields most likely to exhibit damage are those that were overgrown with grasses or winter annual weeds during adult egg laying. Weeds that are attractive to egg-laying moths include chickweed, shepherd's purse, peppergrass, and mustards such as yellow rocket. Winter wheat is also a likely host. I'm encouraging farmers in northern Illinois to be diligent and scout as we near the projected May 20th date for NE and NW Illinois.  More information on the Black cutworm can be found in this fact sheet.