Archive for the ‘Crop/Pest Observations-2011’ Category

Aug
31

How Much Time do we Need to Finish out 2011 Corn and Soybean Crops?

by Greg LaBarge, Fulton County

With Labor Day around the corner and some pretty green crops covering all but a few fields in the region, the question becomes how much more time do we need to finish out our corn and soybean crop? The short answer is we need about another 30-45 days to get the majority of the acres to physiological maturity. The last CORN newsletter provided some hope via Jim Noel that we could expect a normal frost date.

Dates in fall by which the chance of the first 32 degree F temperature will have occurred is 50%.

The graphic below shows historic dates for a 50% chance of first Temps below 32 degrees. Thus a normal frost date of 10/10 to 10/15 would be a good thing and November 1 would be even better.

The answer about where your fields are at is in the growth stage of the crop.  Staging is not a difficult as it sometimes seems and hopefully a couple of hints here will help you in a look at your fields and days to harvest.

Soybeans are generally in an R5 stage approaching R6. During the pod set and pod fill stages you want to focus on the top four nodes on the plant.

Soybean Late Reproductive Stages:

  • R3 is initial pods set and there will be a pod 3/16 of inch long at one of the four upper nodes on the plant.
  • R4 is full pod and one of the four upper nodes will have a 3/4 inch long pod  when this stage is reached.
  • R5 is beginning seed where a bean in one of the pods is 1/8 of an inch long at one of the four upper nodes or basically when the pod is a full size but the bean is not noticeable.
  • R6 is full seed where the green bean fully fills the pod cavity in one pod at one of the four upper nodes.
  • R7 is the next to last stage or beginning maturity. At this stage a mature pod at any node on the plant indicates this stage. Typically the middle of the stem has the most mature pods.
  • R8 is full maturity.
  • Note a field is considered at the given stage when more than 50% of the plants reach that stage.

To reach the R7 stage from the stages listed above requires approximately the following number of days.

Current Stage Number of Days to R7

R3

55

R4

45

R5

35

R6

20

R7

10 days to R8

R8

5-10 days to 15%

For Corn we also have the late reproductive stages to take a look at:

  • R3 is milk stage where the ear has the look of an ear of sweet corn.
  • R4 is the dough stage where the starch are solidifying.
  • R5 dent stage where the top of the kernel is depressed.
  • Between R5 and R6 is the half milk line stage. Where the starch line has moved half way down the kernel.
  • R6 black layer when a kernel is plucked off the ear and you see a black layer where the kernel was attached to the ear.

Corn stages are across the board due to the planting dates and hybrid maturity so it is hard to generalize.

The table below shows approximate days to R6.

Current Stage Number of Days to R6

R3

43

R4

37

R5

23

Half milk line

12

R6

0

The number of days are approximate and depend upon actual temperatures for the period. For those hybrids or varieties in the earlier stages it would be worthwhile to check progress a couple of times as we move further into fall.

Aug
12

Soybean Aphid Numbers Building-Time for Scouting

Soybean Aphid Population-Southern Henry County 2011

by Greg LaBarge, Fulton County

Friday afternoon I was in Archbold, Wauseon, Custer (OARDC Branch) and Holgate. I stopped at 19 different soybean fields along the way and found soybean aphid in all but 2 fields. All but two field had soybean aphid that were easily found. Number would be 3-70 per plant with many in the 20-50 range. Greatest numbers were in Fulton County but there was a hot spot in Henry. See picture to the left. Aphids were on the OARDC Branch as well. Soybeans are in R3-R4 stages generally. Did not see lady beetles.

Threshold number for aphids remain a rising population reaching 250 aphids per plant. Sample several areas in the field with at least 30 plants per 20 acres to come up with that average. The type of infestation pictured would near 250 but remember we are talking about average infestation for multiple plants not just a single plant 250. We need to be concerned with aphids until we reach R6.

Some scouting keys:

  • At this point look at the growing point and leaf below the growing point.
  • The picture to the left is more than 250 aphids.
  • A colony that covers all sides of the stem for 1 inch is 250-300 aphids.
  • A speed scouting method has been tested in the west. A copy of the sheet from Minisota can be found at: http://www.soybeans.umn.edu/pdfs/2007/aphid/speed_scouting_2007.pdf

They are easily controlled with insecticides but keep in mind in you have bee hives in the 1/2 mile of your field to notify the beekeeper on your intent to spray.

Other Insects found:

Spider mites: Are found in southern Henry who in the SW have missed rains. Generally along the edge but edge in areas have totally bronzed plants.

Bean leaf beetle: Beetles are being seen again.

Green Cloverworm, grasshoppers, white flies, Japanese beetle and potato leafhopper were amoung the other insects seen.

Aug
9

Western Bean Cutworm Update August 9th

Three Western Bean Cutworm Feeding on a single ear -2011

By Greg LaBarge, Fulton County

WBCW moth flights dropped off to very low numbers last week as we expected. The larvae stages might be seen in areas fields. The picture to the left was taken near Delta with numerous larvae on single ears in some cases. As you can see they are different sizes even on the same ear. The hybrid was a non-gmo in a test plot area where we identified egg laying back on July 21st.

The larvae can be found feeding on the end of the ear but often borer through the husk  leaving a hole in the

WBCW boring under the husk-2010

husk. See the picture below and to the left from 2010.

If you see feeding activity anywhere in northwest Ohio we would be interested in knowing. Give me a call 419-337-9210 or labarge.1@osu.edu.

Aug
9

Yellow Flash in Soybeans

By Greg LaBarge, Fulton County

Overlap areas whether in the middle of the field or in the headlands for some soybean fields has shown an interesting coloration. Often when we see yellowing beans in a field we think of micro nutrient deficiencies such as manganese. Those appear as areas in the field circular or semi circular areas. The linear patterns and location of yellow patches being seen happen after applications of glyphosate about 3 weeks ago. The areas where sprayers were turned on and off  are most pronounced.

Yellow flash is the name given to this phenomenon. This has been noted in other areas of the midwest in previous growing seasons. The conditions leading to this tend to be:

  1. Rapid soybean growth after application
  2. Sprayer overlap or other application conditions that lead to higher product application.
  3. Areas prone to micro nutrient deficiencies primarily manganese or iron.

The yellowing is a by product of the level of AMPA in the leaf which is a breakdown product of glyphosate which reduces chlorophyll levels in the newly developing leaf give the yellow appearance.  If you want more information, Dr Mark Loux has a couple of links posted at http://corn.osu.edu/newsletters/2011/2011-26/yellow-soybeans-in-response-to-glyphosate-applications

Jul
29

Western Bean Cutworm Update July 29th

by Greg LaBarge, Fulton County

Trap Counts for local traps appear to have peaked during the week. Two of the three traps showed a decline while third trap had big numbers of 35-40 per day early in the week but dropped of to just 3-5 per day by weeks end. The week did not yield any big finds of eggs or larval damage, in fact it was more difficult this week to eggs or larvae than it was during the week of July 18th. In fact there is a lot of speculation that the extreme heat has set this insect back this year.  Refer to last weeks article for scouting information.

Jul
22

Western Bean Cutworm Status as of July 22

By Greg LaBarge, Fulton County

The week of July 22 saw a dramatic increase in Western Bean Cutworm Moth captures in traps across northern Ohio. Also found were eggs and first instar larvae.

There were a wide range of counts for the week. Bruce Clevenger, Extension Educator in Defiance County saw counts of 0-154 for the week on 7 different traps. A report for a local farmer was 204 for the week. The figure to the left are trap counts from three locations I have. The 2011 trap counts are peaking in a similar pattern to 2010.  In 2010 there was a dramatic decrease from July 26 to July 30 counts. We will check traps mid week to see if counts have dropped off.

On Thursday (July 21) Dr Andy Michel, Extension Entomologist and I were out in eastern Fulton County. We stopped at eight fields and found egg masses or larvae in five fields. In order to find these we had to look very hard, only finding a couple of egg masses or larval hatches in each field. Based on what we saw on Thursday we may find some larvae in many fields but very light infestations overall. Also we discussed the heat and it is generally felt this will be a deterrent to higher egg laying by female moths. Scouting next week will give us a true picture of the potential for infestation.

Peak flight and corn size are important to targeting scouting. Focus scouting on corn which is pretassel, the V9-V10 stage (around waist high). Also keep in mind genetics. You may find eggs and larvae in a field, but if you have  transgenic hybrids with the Cry1F gene will offer adequate to near-complete control of WBCW. These include Herculex I and Herculex Xtra, as well as SmartStax.  A new gene, Vip3A from Syngenta also offer control of WBCW.

Scouting procedures were in the 2011-20 issue of C.O.R.N.:

Scouting for eggs and larvae should begin when adult catches occur on consecutive nights.  Inspect 20 plants in 5 random locations throughout a field.  Female moths prefer to lay eggs on the uppermost leaves which are still vertical in orientation, so those leaves should be inspected thoroughly. They also will be on the upper side of the leaf.

During winter meetings we shared a video on scouting for WBCW eggs and larvae from Purdue. To review that video click here.

If western bean cutworm eggs are found, please contact your County Extension Educator.

May
26

Heavy Rains throughout NW Ohio May 25-26 (Updated 5/26 9pm)

by Greg La Barge, Fulton County

Storm rainfall totals for the afternoon of May 26th added insult to injury with rainfall totals adding up to 3 inches to a small area of 8 inches in Defiance County for the period May 24th 9:32 am until May 26th 9 pm.

 

 

 

 

May 23 to 24 and the early morning on 25th allowed some planting progress throughout the area. Corn was the crop of focus and we currently for Fulton, Henry, Williams ( Report from Florian Chirra) and Wood County (Report from Alan Sundermeier) have made some planting progress. For Henry and Wood the northern part of these counties would be the focus area with planting progress. The further south the more likely that little if any planting has occurred.  The areas with planting seem to be in the 40-60% planted on corn and 10-15% planted on beans. Early emergence from May 5-12 planting generally are good although certain fields have crusting issues and emergence that is uneven.

Rainfall by noon brought all field activities to a halt. Doppler indicated rainfall showed 36 hour rainfall totals of 1 to 5 inches over a wide spread area.

May
16

Entering Critical Wheat Stages to Control Disease with Fungicide

by Greg LaBarge, Fulton County

We are entering the critical stages for protecting susceptible varieties from foliar diseases and head scab. For the best effectiveness we need to closely stage wheat and apply these products at the right time based on disease pressure.

Looking at local wheat field late last week we ranged in stages from Feekes 5 to Feekes 8. As we get into Feekes 8, 9 and 10 these stages are the critical stages as we discuss foliar diseases. Feekes 8 to 10 expose the flag leaf which provides the majority of the energy used to in grain fillThe stages are defined as:

  • Feekes 8- The last leaf (flag leaf) is just showing through the whorl of the stem.
  • Feekes 9 is where the last leaf (flag leaf) is fully out of the whorl with the collar region exposed.
  • Feekes 10 is the boot stage where the head is inside the sheath of the flag leaf.

A line drawing of the stages can be found at: http://ohioline.osu.edu/b827/pdf/Wheat_Management.pdf

At stage 8 through 10 we need to scout for the common foliar diseases we see in Ohio which are primarily powdery mildew and Stagonospora leaf blotch. With powdery mildew 2-3 lesion on the leaf below the flag leaf justifies a spray. For Stagonospora we only need 1-2 lesions on that leaf below the flag leaf to trigger fungicide use. A guide to fungicides for foliar diseases can be found at: http://www.oardc.ohio-state.edu/ohiofieldcropdisease/wheat/OFCDwheatfungicides.pdf

Besides foliar disease we are concerned about Head Scab (Fusarium Head Blight). This disease is a big concern due to the potential for formation of vomitoxins the contaminate the harvest wheat and lead to dockage or rejection of the grain at the elevator. Fungicides are available that can suppress this disease but timing is critical and the product must be applied after foliar spray timing. The best timing to insure the highest payback is during the early stages of flowering or Feekes 10.5. The wheat head starts to flower from the center of the head and progresses to the base and tip as flowering progresses. More details on the products, effectiveness  and other factors to consider in head scab treatment can be found at http://corn.osu.edu/newsletters/2011/corn-2011-11/fungicide-application-and-vomitoxin-suppression

Apr
28

Adjusting Corn and Soybean Management from A Wet April

by Greg LaBarge, Fulton County

We have gotten use to an April start to planting over the past several years. But in the late 80’s and into the 90’s we were often hesitant to start planting until we hit May 1. We are better equipped to handle a wet spring than we were 15 years ago. With increased planter sizes, multiple planters/drills on the farm 10 days of dry weather will change the landscape in a hurry for both corn and soybeans. Some recommendation from the last Crop Observation and Recommendation Newsletter will be helpful as we change some strategies. Here are a few highlights from that newsletter:

Corn. The focus is now planting. Planting date penalties are still minimal. The key thing will be to do everything right at planting. Avoid mudding in a stand since this tends to have a bigger penalty than planting date. Do the minimum amount of tillage to get an adequate seedbed. Plan to sidedress nitrogen. Whatever preplant N was planned can be substituted for minimum 30 lbs of starter N and then sidedress. If you have to preplant N, be sure to allow adequate time between anhydrous application and seeding (7 days, long if hot and dry) or be sure you are deep enough to prevent contact with the seed to avoid germination problems. P and K at planting are only needed if soil test levels are below critical levels. Plan to use your current hybrid mix up until May 20th and focus on longer season hybrids first. Soil tempertures have warmed to the mid 50-60’s. You can think about lowering seeding rates 3-5% over desired harvest population versus the 10 % rate suggested with early planting. Read the rest of this entry »

Apr
18

Updated Soil Temperatures Up To 4/17/2011

by Greg LaBarge, Fulton County

With snow flying this morning it is no surprise we are heading toward a later planting in 2011. There is a field here and there that was planted late last week. The weather outlook is not improving soon based on the forecast for the week. The good thing is we only will need 5-7 days of good weather to nearly get the corn crop in. With soil temperatures where they are we would essential be storing the seed in the ground so at this point it is good to have it in the bag.

Apr
11

Updated 2″ Soil Temps through April 10

by Greg LaBarge, Fulton County

With a couple of warm days, soil temperatures improved over the weekend. The bigger issue with getting our in area fields will be the rainfall.  In case you do not have a rain gauge out here are some rainfall amounts for April 1-11 from some area locations. Rainfall totals for the period were 1.08 inches at the Northwestern Research Station, 1.24 inches at Defiance, 1.75 at Lima, 1.29 at Wauseon, 1.08 at VanWert, 1.74 Montpelier, and 1.92 at Toledo Express Airport.

From a GDD accumulation standpoint for the period Wauseon has accumulated 50, Lima 61, Northwest Branch (Custar) 52,  and Ottawa has 52 GDD.

Apr
4

2011 Soil Temperatures Cooler Than 2010

by Greg LaBarge, Fulton County

We have a great weather resource in northwest Ohio to track soil temperatures and other data throughout the growing season. The OARDC Northwest Agricultural Research Station has a weather station that tracks a variety of weather data for the branch and the data is accessible on line next day. One weather piece that is useful is soil temperature data at 2 and 4 inches. It would be no surprise that soil temperatures are cooler in 2011 than our 2010 season. The chart to the left compares March of the two years. The average monthly soil temperature for 2010 was 41.7 while 2011 averaged 38.9.  Average 2 inch temperatures for April 3, 2010 were 53.9 and April 3, 2011 were just 38.3. Warmer air temperatures will change this relatively quickly but right now there would be no rush to put seed in the soil until temperature start to increase.

The OARDC weather website is linked off the following page http://agcrops.osu.edu/ohio-weather-and-grain-livestock/ohio-weather-radar/oardc

Mar
29

Attack Weeds with Multiple Controls to Prevent Resistance

Giant Ragweed

by Greg LaBarge, Fulton County

Currently northwest Ohio has background populations of weeds resistant to glyphosate and ALS products. The weeds of concern are maretails, giant ragweed and common ragweed. To keep these levels just as background levels of resistance and not widespread problems we need to put a sound weed control program in place.

There are not a lot of new chemistries with new modes of action we can deploy for the future. A recent article by University of Illinois Extension weed specialist Aaron Hager noted that “No new herbicide active ingredients are currently available for the 2011 growing season, and said he expects this “drought” of no commercialization of herbicides with unique sites of action to continue into the foreseeable future. More…” So we need to use a good mix of products and modes to keep our current lineup of products effective into the future.

Dr Mark Loux, Ohio State University Extension Weed Specialist, provides a four step system approach to weed control: Read the rest of this entry »

Mar
22

Corn Nematodes

by Greg LaBarge, Fulton County

Over the past 15 years, soybean cyst nematode have been something we have managed for in parts of northwest Ohio using rotation and resistant varieties in combination with testing to reduce population to minimize their impact on yield. “Corn nematodes” have become a topic of interest due to changes in production practices and surveys have shown higher population than previously know of in the state of Illinois. The buzz has caused questions about any effects here in Ohio plus the availability of seed treatment which control these nematode species have added to questions on this potential problem.

First we need to recognize “corn nematodes” are different from soybean cyst nematode in a big way. SCN is a single species while “corn nematodes” are actually a list of 28 species with 10-12 species considered important. The list at the right shows the common species of concern and sample levels associated with each. Some species are of greater concern and have a lower threshold while we can tolerate higher number of other species. Read the rest of this entry »