UK Soybean Cyst Nematode Analysis Services Being Suspended Indefinitely

Due to imminent personnel changes in the UK Soybean Cyst Nematode (SCN) Laboratory, SCN analysis services will be suspended, indefinitely, effective January 1, 2014. Services may resume at a later late, but this has yet to be determined. In the meantime, all Kentucky growers who desire to have soil tested for SCN are encouraged to use the services of the University of Missouri Plant Nematology Laboratory.  I have great respect for this lab:  I trust the results they generate, they are accustomed to receiving out-of-state soil samples, and they are very easy to work with. The cost per sample for an SCN egg count is $15.00. That lab also offers HG (race) testing services, if needed, for an additional fee.

Note:  Samples received by the UK SCN Laboratory after January 1, will be returned to sender and will not be processes; no exceptions can be made. Please pass this information on to anyone who might be impacted by this decision.

Below is the website for the University of Missouri Plant Nematology Laboratory. Please note it will be necessary to use their sample submission form, which is available via a link on the Laboratory’s website.


http://soilplantlab.missouri.edu/nematode/

Early Bird Meetings this Week

Chad Lee, Extension Agronomist, University of Kentucky

The Early Bird meetings are this Monday, Tuesday and Wednesday (Nov. 18, 19 and 20, 2013). The meetings are located at Morganfield (Monday), Sedalia (Tuesday) and Hopkinsville (Wednesday). Even with tornado damage in the Union County area, turnout is respectable at the first of the three meetings. Topics include the latest research results on disease management, weed management, soil fertility, proper grain storage, insecticides and the challenges of looming high rents and lower commodity prices.

Each of the three meetings starts at 8:30 am and ends with lunch, which is sponsored by the Kentucky Corn Growers Association, Kentucky Soybean Board and Kentucky Small Grain Growers Association.

Click here for more information about the meetings.

2013 Kentucky Corn Yield Contest Deadline Delayed

Chad Lee, Extension Agronomist, University of Kentucky

The 2013 Kentucky Corn Yield Contest deadline has been delayed until November 29, 2013. We have several farmers who still need to harvest corn and want to enter the contest. Corn harvest across the state has been delayed this year and that prompted the extension of the deadline.

This Kentucky deadline does not change the NCGA Corn Contest, which has a deadline of November 22, 2013.

Kentucky Corn Contest Form
NCGA Harvest Report Form

2013 Hybrid Corn Performance Test

Chad Lee, Extension Agronomist, University of Kentucky

The 2013 Kentucky Hybrid Corn Performance Test is available online as a pdf file. A website with links to individual tests is here: http://www2.ca.uky.edu/cornvarietytest/2013/Results.html

The test includes hybrids in the early, medium and late maturities as well as a white corn test. Yields from five locations across Kentucky are reported this year. Yields were excellent. The average yield was 181.8 bu/A for the Early Test, 186.8 bu/A for the Medium Test, 203.5 bu/A for the Late Test and 156.3 for the White Test. 

Corn Numbers on Food vs. Fuel

Chad Lee, Extension Agronomist, University of Kentucky

There is a lot of recent discussion about corn for food versus corn for fuel. Here are some numbers on corn in the United States that seem to be lost in this discussion

Based on 2011 estimates, corn for direct food consumption was about 5 to10% of total U.S. production. Fuel ethanol was 38%, feed and residual was 38%, and exports were 14%. (Source: USDA-ERS Yearbook).

Corn Knocked Down from High Winds

Chad Lee, Extension Agronomist, University of Kentucky

Corn downed by high winds on October 31, 2013.
Image courtesy Eric Baker

October left with a blast. High winds across the state blew in odd directions and over some corn fields. We knew this was going to be a risk this fall. The heavy ears, shallow roots and slow drydown all created a risk for downed corn. The high winds also brought rains, meaning that harvest will not resume for several days. What can we do now?

We can start by inspecting fields. Identify the fields where corn is down and fields where corn is standing. If corn is standing, check stalk strength with the grab test. (Grab the corn stalks at shoulder height, pull or push about 18 inches off center and release. If the corn stalks remain upright, stalk strength is good. If not, stalk strength is weaker.) Identify the grain moisture in all fields.

Freeze Damage to Soybeans and Harvest Options

Chad Lee, Extension Agronomist, University of Kentucky

Freeze Damaged Soybeans. Image courtesy of Curt Judy

The freezing temperatures wilted leaves and killed soybeans in some fields across Kentucky. Now that temperatures have warmed up again, we can better determine how to manage the crop from here.

The vast majority of soybeans were done growing and seeds were in the process of drying down. Those plants were at full maturity where the leaves had dropped, the pods were brown or tan and the seeds were yellow instead of green. Seed moisture was less than 20%. For those soybeans, the freeze events delayed drydown a little but did not harm the plants or the yield.

Harvesting very green corn for silage this season

Chad Lee and Carrie Knott, Extension Agronomists, University of Kentucky
Donna Amaral-Phillips, Extension Dairy Nutritionist, University of Kentucky

Farmers are chopping silage at the normal time on the calendar and commenting on the very green corn in the fields. Silage corn was planted late this spring and that delays corn development. The summer was cooler and cloudier than normal, which also delays corn development. Finally, there is a lot of biomass in the corn this year, so drydown may take a little longer. Corn chopping may need to be delayed several weeks this season to get corn to the proper moisture.

Wheat Drill Calibration Tables

Chad Lee, Extension Agronomist, University of Kentucky

As producers gear up for wheat planting, calibration of the seeder is extremely important. Below are two tables to use as quick references in the calibration process. Most producers are using drills with 7.5-inch row spacing. The first table calculates how much seed to collect in 50 linear feet from one row of the drill. Target populations of 30 and 35 seeds per square foot are used for the calculations. The needed seed weights are listed as ounces (oz.) and as grams.

Insect Considerations for Wheat Planting Decisions

Doug Johnson, Extension Entomologist

As I travel around the countryside, I see plenty of emerging corn in fields that will likely be planted in wheat. This “Green Bridge” could lead to problems with certain insects important to wheat Production. The insect pests we need to consider have not changed from previous years, but their relative importance may have changed from last year. Fall armyworm (FAW), Hessian Fly (HF), cereal aphid complex (CAC), and wheat curl mite (WCM) are annual threats. In most years, only the CAC is of major concern. In 2012 the FAW was a considerable problem in west Kentucky, not only in wheat,but also in many forage grasses.

Good Corn Yields Despite Nitrogen Losses

Chad Lee, Extension Agronomist, University of Kentucky

Excellent seed fill,
even though N deficiency is evident.

Corn in most fields across the state displayed nitrogen (N) deficiency before black layer was reached. Those losses were expected this season as we experience more rain. Normally, we expect yield losses to occur when the corn crop runs low on N before the seeds are done developing on the cob. However, walking some of these fields reveals that corn yields should be very good despite the apparent lack of N.

Stink Bugs Could Still be a Problem in Soybeans

Doug Johnson, Extension Entomologist

Because of delayed planting and a cool summer, Kentucky soybean producers are likely to have considerable acreage of late maturing soybeans. This probably causes most folks to be concerned with frost. However,this extended maturity may also set up fields for additional damage by stink bugs. Producers and consultants should remain watchful as long as pods are still filling.

Great Corn Harvest but Compaction Nipped Some Yields

Chad Lee, Extension Agronomist, University of Kentucky

The ear on the left is on a plant with
roots limited by compaction and the
other is on a plant with no compaction.

The corn yields being reported are excellent to date for Kentucky. With the wet weather at planting, we all were very concerned about compaction problems. The continued wet weather helped a lot of corn roots break through compaction. We dodged a disaster, but corn yields were dinged by the compaction. I walked a field yesterday where we think we may have lost as much as 75 bushels per acre to compaction.

That's the bad news. The good news is that the field went about 250 bushels per acre. That's an excellent yield in most fields and especially in a field with some compaction.

Maximize Wheat Yield Potential Despite Late Planting Dates

Carrie Knott, Extension Agronomist-Princeton, University of Kentucky

For most areas in Kentucky, this spring and summer has been unseasonably wet and cool. Since April rainfall across Kentucky has been almost 6 inches above normal and the daily high temperatures have been almost two degrees Fahrenheit cooler than normal. These unseasonably wet and cool spring and summer conditions delayed corn planting. This year on May 19 only 56% of the corn was planted as compared to 75% for the five-year average. This will likely delay corn harvest. As of September 1 only 1% of corn was harvested as compared to 12% for the five-year average. Wheat producers need to be prepared for delayed plantings this year due to delayed corn planting, development and harvest.

Stalk Strength and a Longer Drydown for Corn

Chad Lee, Extension Agronomist, University of Kentucky

My colleague, Bob Nielsen at Purdue, wrote an excellent article on corn yield potential at later growth stages. The quick points from Bob's article are: corn in the dough stage is at 50% of its yield potential. When every kernel is dented, corn is at 60% of its yield potential. Corn at half milkline is at about 88% yield potential. As we have gotten drier in some areas of Kentucky, our corn that is not at blacklayer is losing yield potential. But, we started out at very good yield potential, so overall yields should be very strong.

Brown Marmorated Stink bug…….. Let’s Not Forget About This One!

Doug Johnson, Extension Entomologist

I have just been reminded by my colleague in Lexington that Brown Marmorated Stink (BMSB) continues to move and build in numbers in KY. BMSB was recently collected from soybeans in Fayette Co. KY., still in very low numbers, but in fact they are beginning to utilize one of our major field crops as host/food source. If our sister state of VA is any indication, we can only expect that this will get worse.

Kudzu Bugs Found in Kentucky

Doug Johnson, Extension Entomologist and Garrard Coffey, ANR Agent, Whitley Co. KY

Summary: During the last week of August 2013, Kudzu bug adults and juveniles were collected from Kudzu along Interstate 75 and US Highway 25 E and W in Whitley, Bell, and Laurel Counties KY. Samples taken in Kudzu along US 25E in Knox Co. KY and Interstate 24 in Christian Co. KY did not capture Kudzu bug. This represents the first know collection of Kudzu bug in Kentucky.

GMOs and Corn Mycotoxins

Corn grain can be naturally contaminated by mycotoxins, natural toxins produced by fungi.  Though most Kentucky corn crops are free of mycotoxins, fumonisins are the most common threat.  These toxins affect a number of animal species, but horses and pigs are among the most sensitive. Aflatoxins are generally very uncommon in Kentucky, but when they occur, they can cause serious disruption to grain marketing.  Both mycotoxin families pose health risks to humans.  

Figure 1. Fusarium ear rot of corn, usually associated with fumonisin contamination.

Soybean Rust Risk for KY Still Very Low.

SBR is really taking hold in southern and northeast Alabama, and also in parts of Georgia, Florida and South Carolinia. However, there is limited activity in the Arkansas, Louisiana and Mississippi at this time. For example, a report I received today from Mississippi State University’s Dr. Tom Allen indicated that SBR is “hard to find” in that state. He attributed that outcome to rather dry conditions across much of that state during the last month. I see no immenent SBR risk for KY at this time. Thus, our risk continues to be very low. Most of Kentucky’s full season soybean crop is now out of the woods now in terms of risk – they are just too far along and SBR could not develop fast enough to hurt them -  but doublecrop beans still could be significantly affected if we were to find rust in the next couple of weeks (which is very unlikely in my opinion). 

 

We are continuing to monitor five sentinel plots for SBR. I will let you know if there are any changes to the status quo.

Addendum on corn stalk strength and disease

After my post yesterday about stalk strength, a seed company representative sent me images of substantial lower-canopy damage of southern rust in certain fields in western Kentucky (see figure).  I hadn't seen this level of damage in my own field visits this season, but this level of damage is certainly capable of affecting stalk health.  As explained yesterday, if leaf blighting occurs during grain fill, the corn plant often "cannabilizes" the stalk to fill the grain.  This can result in weaker stalks.  

Southern rust of corn causing foliar dessication. Note the dessication of leaves in the background.  This is a high level of leaf damage and will likely affect stalk strength in this part of the field. (Image from Bill Meacham)

The current forecast suggests that warm nights with dew will continue for a least a few days, so southern rust will likely continue to develop in some fields.  Again, this is another reason to watch fields for weakening stalks, and to consider this in scheduling fields for harvest.

Reasons to scout corn for stalk strength

Excellent yields are expected in many corn fields this growing season.  Along with that good news comes concerns over stalk strength.  Plants in many fields have heavy ears, along with shallow roots because of abundant rainfall.  Many of these plants could topple easily as they mature, especially if a late-season storm with high winds blows across the field.  Plus, several extended periods of cloudy weather during grain fill may have increased the risk of stalk weakness in some fields.  This is because, when the corn plant is filling grain, if leaves cannot meet the carbohydrate demand of the grain, the plant may “cannibalize” carbohydrates in stalks in order to fill the grain.

Similarly, infectious diseases may play a role in increasing stalk weakness, by depriving the plant of healthy foliage necessary to maintain stalk strength through crop maturity.  Gray leaf spot (Figures 1-2) is prevalent this year, although levels generally appear to be low to moderate.

Figure 1. Lesions of gray leaf spot, viewed by holding up to the sky. Some hybrids develop an obvious yellow border around these infections, as shown here.

Figure 2. Lesions of gray leaf spot in a highly susceptible variety. They are often described as "match-stick" lesions.

  

I have also observed scattered fields with significant damage from northern leaf blight (Figure 3).  Given the generally mild, wet weather this season, this isn’t surprising.

Figure 3. Lesions of northern leaf blight, with high levels of control by a strobilurin fungicide

Although southern rust has been present in Kentucky for over a month, some cool weather experienced in recent weeks has helped suppress disease activity.  This disease may still contribute to weakened stalks in some late-planted fields, but in general, it appears we have “escaped” widespread damage from this disease this year, especially if cool nights predominate.

Scouting for stalk lodging

Check for stalk weakness by walking the field and pushing plants about 1 ½ feet from vertical.  Those that fail to spring back exhibit lodging potential.  If 10-15% or more of the field show lodging potential, it may be wise to schedule that field for early harvest, before it is laid down by strong winds.