How Will The Western Bean Cutworm Over Winter?

2010 brought a new observed level of the Western Bean Cutworm to NW Ohio corn production. Defiance and Fulton Counties each caught over 400 WBC moths in their respective four traps during summer monitoring and each county located at lease one field with WBC larves in the corn ear. However, 2010 corn fields did not reach economic thresholds that would warrant rescue treatments.

Since 2006, WBC has increased in numbers here in Ohio to the point where NW Ohio might expect the insect to complete its life cycle by over wintering rather than only moth flight migrating to Ohio during the growing season.

How do they survive the winter? Large larvae (6th or 7th instar) emerge from the ear and fall to the ground, burrow 3 to 6 inches into the soil, and construct an earthen overwintering cell (Figure). They spend the winter inside this cell in a pre-pupal stage. Larvae pupate in late May followed by adults crawling up through the soil with emergence starting in early July.

OSU Ext Factsheeet: http://ohioline.osu.edu/ent-fact/pdf/0040.pdf

reference: http://tinyurl.com/37asbqe (Univ. of Nebraska, Lincoln)

Dry Soils Impacting: Tillage and Soil Sampling

Moderate rainfall yesterday and overnight gives promise that area farmers might find relief to hard, dry soils. The Defiance Memorial Airport NOAA weather station reports 0.75" of rainfall during November 16 & 17, 2010. Farmers are reporting machinery repairs every 3-4 days or every 50-60 acres from excessive wear and tear on tillage tools.

An area farmer shared that "Replacement bolts, shanks, etc quickly add up to $1,200 each week. A small bag of high grade bolts seem to cost more this fall and they don't last long. The deep shanks bend and bow to follow the cracks in the soil rather than busting through."

Private consultants and farmers collecting soil cores are also feeling resistance. Power augers and hand probes are bending and worn and need maintenance and replacement more regularly.

Agronomists and farmers should anticipate that soil test results reported from very dry soil samples collected may have drought induced lower pH and potassium levels this fall. OSU and Purdue Ag Answers addressed this effect in an October 2010 article: http://www.agriculture.purdue.edu/aganswers/story.asp?storyID=6109

Crop Development as of July 16- Fulton County

I finally got a chance to go through my normal Fulton County survey route on July 14 and 15. I headed across County Roads L & B from boarder to boarder. I looked for insect and disease as well as crop development. Here is what I saw

Corn

This year there are 40 corn field on the route and 67% are in the R1 stage where pollination is occurring. The other 33% of the fields are in late vegetative stages V7 to V13. Most of the corn seems in pretty good shape but there are areas particularly west of 66/south of 20 and the south east corner that are under moisture stress.

Diseases are minimal to nonexistent. A little bit of rust. I have heard reports of gray leaf spot but did not see any. Areas of southern Ohio have been seeing a greater amount of gray leaf spot in 2010.

Insects we did find the first larval feeding of western bean cutworm in corn early in the week and have confirmation from OSU Entomologist. The infestation levels are low but it does indicate that this pest has advanced in from the west. For 2010 it more of a novelty and academic observation. At season end we will have a better idea of the extent and based on experiences from other areas help discuss management changes for 2011. You can also find European corn borer feeding as well but at fairly low numbers in non bt hybrids.

Soybeans

Soybeans have improved dramatically over the past two weeks. Rows have closed in and we are entering the flowering stages even pod set in some cases. There are 46 soybean fields on the route. Forty three percent were in vegetative stages and had not begun to flower. About 47% of the field were in R1 (a flower at any node) or R2 (flowers at the two top nodes) stage. Nine percent were in the R3 stage with pods setting on the upper nodes.

Disease were not a concern here as well. A little bit of brown spot could be found but that was basically it.

Insects were at very low levels. There was a little foliar Japanese beetle feeding but a extremely low levels. Soybean aphids were found in three fields in the southeast corner of the county with levels were less than 5 per plant.

Tips for th eapproaching wheat harvest

Wheat is ahead of schedule and likely will see some area harvest in the next 10 days. Reports from other areas of the state are indicating an average to below average year and test weights ranging from 49 to 59 pounds per bushel and an average of 54. Head scab and associated vomitoxin levels rate from very low near zero to 9.1 regionally.

While the local survey showed some scab our number tended to be lower than other parts of the state. We also seemed to have a high incidence of glume blotch which reduces yield but does not produce toxins. (see previous article)

As we approach harvest I think we can maximize yield with some good harvest practices. I found an excellent reference from Kentucky. The highlights of the article are:

1. While we tend to harvest once wheat reaches 13-15% moisture we can capture more yield by beginning harvest at 20-24% moisture and doing some drying. The amount of drying depends upon the equipment available. If you have a high speed dryer moisture of 21-24% can be harvested, with a bin dryer with heat and stirring we can harvest15-20% and bin dryers without heat 15%. We also need to be aware of temperature. Heat above 140 degrees F affect milling quality and heat above 110 affects seed germination, so stay below these temperatures. Field trials have shown a 1.7 bushel yield loss per acre when wheat dries naturally from 23% to 13% moisture.
   
2. Adjust cylinder speed, concave clearance, screen opening and fan speed by manufacture's recommendations. If you have a field with high levels of head scab raise the cylinder or fan speed to blow out light weight kernels. If you have glume blotch you will not necessarily need to blow out the kernels but will have a lower test weight. Kernels on the ground equal to 20 seeds per square foot is equivalent to 1 bushel per acre yield losses.
3. Avoid over dry to below 13.5% which cost in excess energy usage and loss of weight of grain.

There are a number of potential adavtages to harvesting wheat and drying.

• Reduce potential for weather losses from sprouting and/or storm shatter or hail.
• Higher test weights. Test weights seem to go down when wheats goes through wetting drying after initial dry down.
• Potential for double cropped beans.

The full article from Kentucky on wheat harvest and drying is worth a quick read.

Head Scab Low in Northwest Ohio

If you have been following the news you may have heard about high levels of head scab and potential for vomitoxin issues in wheat. The best summary of the statewide information can be found in our Crop Observation and Recommendation Network Newsletter. Locally in the afternoons of June 17 and 18 I made scab head counts on 10 fields in Fulton(6) and western Lucas County(4). The range of head scab was 15% on the high end to 0% on the low end with an average of 3.6%. Our later flowering date coupled with a dry stretch at that time around Memorial Day gave us the right conditions to miss out on the higher infection rates that others are seeing.
Slight adjustments to the combine to blow out light weight kernels should help us avoid vomitoxin issues at the elevator.

I saw a higher incidence of wheat glume blotch than head scab in many fields. This was particularly true on our high sand areas of fields with low organic matter. While this disease may cause lighter weight kernels, it does not produce a toxin.

Decision Tips for a Late Planting Season

As farmers wait for another planting window, there are a number of decisions that need to be made in order to be ready to finish planting. If you participate in the Federal Crop Insurance Program there are a set of decision to make that affect coverage for 2010. Other common questions are: If you do not have your entire corn crop planted do I stick with the plan or switch crops to soybeans? Do I need to change any production practices considering the later planting date?

From the crop insurance standpoint the best advice is to check with your agent before starting planting again. The last planting dates without affect crop insurance coverage were June 5^th for corn and will be June 20^th for soybeans. For many the last planting dates will affect decision for both crops. Many have both unplanted corn and up to 30% of their soybean crop unplanted. These unplanted fields are likely wetter fields and will take some time to dry.

After the June 5 and 20 dates are reached farmer have three options to consider.

First farmers can plant a crop but insurance coverage will be reduced by 1% per day for each day planting occurs after the final planting date for 25 days from the original coverage level. After 25 days coverage will be fixed at the 60% of the original coverage level.

The second option is to take a prevent planting payment which is 60% of the original coverage and plant no crop except a cover crop that could be grazed after November 1.

The third option is to take 35% of the prevented planting payment and plant an insured second crop after the late planting period for the first crop has passed. This becomes difficult if the crop we are talking about is soybeans since there are no viable alternative crops but soybeans could be an option to corn.

More information on:

Crop Insurance: Prevented Planting, Final Planting Dates, and the Late Planting Period

Crop Insurance/Cropping Decisions When No Crop Has Been Planted and a Farm-Level Crop Insurance has been Purchased

The description here provides an overall look at options but with several type of insurance available you need to check with your agents to know for sure what your coverage is.

The question of switching from corn to soybeans is an easier discussion. With a late June planting date we can expect approximately a 50% yield loss with corn over early May planting. Soybeans planted in late June will yield 65-75% of normal yield. Generally this information will lead us to switch to soybeans unless we are planting corn for silage.

Soybeans planted in late June do require a change of management strategy to maximize yields. Varieties of soybean plantings should be the longest season variety that will reach physiological maturity before the first killing frost. Generally, stay with the same planned maturity (unless it is earlier than 3.0). For northern Ohio, a 3.5 may be used until July 1. Planting rate should be increased when planting after June 15 to 225,000 to 250,000 in 6-7.5 inch rows. More details on planting decisions can be found in The Crop Observation and Recommendation Network (C.O.R.N.) Newsletter.

More details on the decisions can be found on the Ohio State University Extension Website at http://fulton.osu.edu or by calling the office at 419-337-9210.

Wheat entering heading and flowering stage

On May 20th most wheat fields in the Fulton County area were hitting the heading stages. The wheat head is starting to pop open the sheath of the flag leaf with the wheat head emerging. The beginning of pollination or anthesis happens in 3-10 days after heading. The most mature part of the head is the center with flowering proceeding up and down the head florets until complete. For a more detailed description of wheat plant development click here.

As heads emerge farmer may note the anthers getting caught in the sheath and the head is bent or appears stuck. This phenomenon has happened over the years especially with a cool spring. Some time it is accompanied by twisted flag leaves. The picture at the left is from the spring, 2000. Often the continued emergence of the head will cause the head to break free even though it may stay bent until harvest. Pierce Paul, OSU Extension Plant Pathologist recently comment on the issue.

Wheat Heads Trapped in the Boot – Pierce Paul

Wheat in Ohio is between Feekes 9 (full flag leaf emergence) and Feekes 10.5.1 (flowering). Reports are coming in from some field going through the head emergence growth stage (Feekes 10.1-10.5) of a fairly high incidence of heads being trapped in the boot. This is not an entirely unusual occurrence in wheat fields, however, incidence as high as 20 or 50% in some cases is alarming and causing some producers to be concerned. One of the main causes of this is cold temperature. Relatively warm temperatures allow the heads to emerge quickly and easily from the leaf sheath, whereas cold temperatures slow down this process and may even prevent the heads from emerging completely, leaving them trapped by the tip. Since May 1, we have had fairly cool conditions, with an average high of 66F and low of 47F.

Fields planted with varieties that are more sensitive to cold temperatures were the ones most affected. However, this does not necessarily mean that these varieties with automatically suffer a yield reduction. Once the heads remain green and healthy and water and nutrients still travel up the stem to the spikelets, these plants will produce grain. Yield will only be affected if the heads are distorted to the point of blocking or stopping the flow of water and nutrients to the spikelets.

The last issue of the Crop Observation and Recommendation Network had a couple of good articles on head scab potential. If the weather as currently predicted for next week happens we should have a low potential for head scab. Click here for head scab articles.