Category Archives: Uncategorized

Sweet corn IPM Scouting – Week Ending July 20, 2018

Moth trap monitoring

We are monitoring corn earworm and fall armyworm moth activity levels on sweet corn farms in 17 different counties in Virginia. Moth Trap Catch Data are being recorded by: Kuhar Vegetable Entomology lab (Montgomery Co.); Phil Blevins (Washington Co.); Chris Brown (Franklin Co.); Jason Cooper (Rockingham Co.); Ursula Deitch (Northampton Co.); Helene Doughty (Accomack Co.); Roy Flanagan (VA Beach); Bob Jones (Charlotte Co.); Kenner Love (Page and Rappahannock Co.); Laura Maxey Nay (Hanover Co.); Steve Pottorff (Carrol Co.); Stephanie Romelczyk (Westmoreland Co.); Beth Sastre-Flores (Loudoun Co.); Laura Siegle (Amelia Co.); Rebekah Slabach (Halifax Co.); and Mark Sutphin (Frederick Co.). Data are posted weekly.

Trap Catch

Below are some trap catch results (moths per night) for some of the locations around Virginia for this week. In summary, we are observing a slight drop off in corn earworm moth activity at most locations, except Amelia County, which posted the highest corn earworm activity this week.  Very little fall armyworm activity has been observed at this point, and numbers are so low that they are not presented.

 

Sweetcorn IPM Scouting in Virginia – Week ending July 13, 2018

We are monitoring corn earworm and fall armyworm moth activity levels on sweet corn farms in 17 different counties in Virginia. Moth Trap Catch Data are being recorded by: Kuhar Vegetable Entomology lab (Montgomery Co.); Phil Blevins (Washington Co.); Chris Brown (Franklin Co.); Jason Cooper (Rockingham Co.); Ursula Deitch (Northampton Co.); Helene Doughty (Accomack Co.); Roy Flanagan (VA Beach); Bob Jones (Charlotte Co.); Kenner Love (Page and Rappahannock Co.); Laura Maxey Nay (Hanover Co.); Steve Pottorff (Carrol Co.); Stephanie Romelczyk (Westmoreland Co.); Beth Sastre-Flores (Loudoun Co.); Laura Siegle (Amelia Co.); Rebekah Slabach (Halifax Co.); and Mark Sutphin (Frederick Co.). Data are posted weekly.
Below are some trap catch results (moths per night) for some of the locations around Virginia for this week (note we do not have data for all locations yet).  In summary, we are observing the highest corn earworm activity in the eastern portion of the state including Virginia Beach and Exmore on the Eastern Shore.  Pest pressure is considered high in those locations.  Above threshold trap catch of corn earworm is also being observed on some farms in the southwest region of the state (Franklin County and Montgomery County).  Very little fall armyworm activity has been observed at this point.

Region County        Field                      CEW/night     FAW/night
Eastern Accomack Painter
Eastern Accomack Painter
Eastern Virginia Beach Northridge    3.4                       2.9
Eastern Virginia Beach Pungo            4.3                          0
Eastern Virginia Beach Creeds           5.9                       0.1
Eastern Northampton Capeville         1.0                        0
Eastern Northampton Cheriton          1.9                        0
Eastern Northampton Eastville           0.7                        0
Eastern Northampton Exmore            7.4                        0
Eastern Westmoreland Field                0.2                       0
Central Amelia Field
Central Hanover Wiblin
Central Hanover Haynes
Central Halifax
Central Halifax
Central Charlotte
Northern Loudoun Field1                    1.0                         0
Northern Loudoun Field2                    <.2                        0
Northern Loudoun Field3                    <.2                        0
Northern Rappahannock
Northern Page
Northern Frederick Field1                     0.3                      0
Northern Frederick Field2                     0                         0
Northern Rockingham
Southwest Montgomery Whitethorne   0.0                    0
Southwest Montgomery Homefield       0.0                    0
Southwest Montgomery Wall                  2.0                    0
Southwest Franklin Wirtz                         1.4                    0
Southwest Carroll
Southwest Washington Abingdon

Walk Your Fields

For greater soybean yields, one of the best things that you can do is walk your fields.  Many problems reveal themselves during the summer.  Actions taken or not taken can be very noticeable.  By walking fields, we can see what’s working and what’s not working.  Certain problems can be solved, some cannot.  For those that cannot be solved this year, we can do better next season by understanding why we have the problem.  Therefore, a review of how to diagnose your crop will likely beneficial.

A few years ago, I published “Troubleshooting The Soybean Crop“.  Although a little dated, most of the information is still good.  This publication will guide you through how to go about diagnosing problems, includes a vegetative- and reproductive-stage outline with lots of photos, and also includes a sample crop scouting and diagnostic form.  You can download a view a PDF copy, or contact me – I still have a few hard copies left.  By following some general guidelines, one can become quite good at diagnosing problems.  Below is a summary.

First, document everything!  Memories tend to fade.  We often forget or overlook details. You can document by taken notes (many phone apps or iPad/tablets work well for this).  Make a recording.  Take pictures – this is especially useful when you need help – and send those photos to others.

PRELIMINARY FACT FINDING.  You can obtain plenty of information before you even get to the field.  Although I call this preliminary (as if you’ve not seen the problem), you may need to go back to the office to refresh your memory of what you did.  Information that can be acquired beforehand or back in the office includes:     

  • Cropping History
  • Equipment
  • Soil Information
  • Weather
  • Pest Management Information
  • Tillage and Other Cultural Practices

THE FIELD VISIT

  • Take all materials and equipment needed (e.g., phones, paper, shovel, plastic bags, soil probes, etc.)
  • Windshield/Whole Field Investigation
  • Above-Ground Inspection
  • Take Appropriate Plant or Soil Samples
  • Equipment Check
  • Interaction with Others
  • Document Everything!

ANALYSIS OF DATA AND FINDINGS

  • Patterns
  • Look-Alike Symptoms
  • Interacting Factors/More Than One Problem

DRAWING A CONCLUSION. Review the facts and data.  Eliminate unlikely causes.  Validate likely causes.  You may be able to drawn a conclusion in the field, but lab analysis may be needed.

FOLLOW UP. Revisit the field.  If you took corrective action, did it work?  Why or why not?

This is a very rough outline of the guide.  Again, if you want a hard copy of Troubleshooting The Soybean Crop, contact me.

Peanut iPiPE and Disease Advisories

Especially with all the wet weather we have been having in much of the region, it is time to start thinking about peanut diseases. We do not typically see a lot of disease until the canopy closes, but once the vines are touching the environment within the canopy becomes favorable for disease development. Leaf spot programs should be applied beginning at early beginning pod then according to a calendar-based (usually 14 day intervals) or advisory based program. The leaf spot advisory for Virginia can be found at https://webipm.ento.vt.edu/cgi-bin/infonet1.cgi. Some keys to a successful leaf spot fungicide program include:

  1. Make the first application at the appropriate time (not too late).
  2. Apply fungicides regularly before leaf spot outbreaks are observed (once disease is present it is difficult to slow down the epidemic).
  3. Stick to a regular calendar-based program or utilize leaf spot advisories.
  4. Be mindful of fungicide resistance management (rotate chemistries and/or tank mix with chlorothalonil).
  5. Scout for soil-borne diseases and utilize fungicides with activity against both leaf spot and other target diseases (e.g. for both late leaf spot and southern stem rot control use a product such as Provost, Elatus, Priaxor, etc.).

Data are currently being collected to improve both leaf spot and Sclerotinia advisories and to develop a southern stem rot fungicide advisory for peanut. This is being conducted through the Peanut iPiPE program. The Integrated Pest Information Platform for Extension and Education (iPiPE) is a program that allows farmers and extension agents to share information with each other through the internet.  iPiPE works by allowing users to enter pest data such as presence and severity of diseases or insects. This data will be shared with everyone in an effort to create a more precise system of pest monitoring and management. The Plant Pathology program at the Virginia Tech Tidewater AREC is leading the Peanut iPiPE and using it to improve disease advisories based on observations of disease onset in peanut fields throughout the region. Two undergraduate interns are currently scouting for peanut diseases in the region, and they will enter disease observations into the iPiPE database.

Disease and pest observations can be easily uploaded to the database through a mobile phone app or the online platform. We are encouraging anyone who scouts peanuts to help us collect disease observations. To become a participant, you can request an iPiPE account by visiting the iPiPE platform (http://www.ipipe.org/). Detailed information on the iPiPE platform and a user guide for the mobile app can be downloaded below. Alternatively, you can email disease observations to Dr. Hillary Mehl (hlmehl@vt.edu). In addition, if you are located in southeastern Virginia or northeastern North Carolina and are interested in having your peanut crop scouted for diseases by our iPiPE interns, please contact us.

Peanut iPiPE Stakeholder Card 2018

Peanut iPiPE Users Guide 2018

For more information or questions regarding the Peanut iPiPE contact Dr. Hillary Mehl (hlmehl@vt.edu).

 

 

 

Plant bug scouting report – Week 2

A team led by graduate student Seth Dorman scouted 34 VA fields for plant bugs this week. Plant bugs were found in all but 4 fields, 6 fields were over threshold. Prior to bloom, fields require treatment if you find 8 plant bugs in 100 sweeps AND less than 80% square retention.

Nymphs are increasing in number. Young nymphs are small (aphid-sized) and thus, can be harder to scout for. They will be captured in sweep nets – be mindful when checking the bottom of the net. I recommend sampling with a black beat cloth later in the season to help identify nymphs in blooming cotton.

I will continue to provide updates and recommendations as cotton begins to bloom in our area. My thanks to Seth Dorman and team for their continued effort.

Start scouting cotton now for tarnished plant bug

Black squares and missing squares are a sign that plant bugs have fed in your field. Scout to determine if they are still active.

Tarnished plant bug (TPB) has begun its annual migration into Virginia cotton. PhD student Seth Dorman scouted VA cotton fields this week (image below) that were over pre-bloom thresholds (indicated in red).

Plant bugs can be found in every VA cotton field from the first square on, but it does not pay to spray unless they are causing damage. Use thresholds when determining what fields to treat and use a sweep net to sample multiple places in a field since populations are not evenly distributed. Prior to bloom, fields require treatment if you find 8 plant bugs in 100 sweeps AND less than 80% square retention. Adults are highly mobile and can reinfest quickly following applications. It may be tempting to spray only later in the season. If you are above threshold, this decision will lower your yield.

Impact of different spray timings on yield. Spraying at any point in the season yielded higher than unsprayed cotton. Thresholds are as effective as weekly sprays and will save you money. The damage potential in late-plated cotton is higher.

Important considerations for this season include:

1) Late-planted cotton is at higher risk. This picture from last season shows that losses in late-planted cotton (Jun 1) are much greater than in early-planted cotton (May 1).

Effects of different spray timings on lint yield are much more apparent in late-planted cotton. Spraying for plant bugs at threshold will save money and increase yield regardless of planting date.

2) Spraying at threshold is as effective as weekly sprays and costs less money. Spraying only early (pre-bloom) or only late (>5th week of bloom) are the least effective spray timings.

3) Rotate insectides. Some populations in the Suffolk area are surviving high doses of acephate and bifenthrin. If your cotton is squaring, thrips treatments are no longer needed and acephate should be left out of the tank. I recommend using a neonicotinoid product pre-bloom (clothianidin, thiamethoxam, or imidacloprid). Check the label and use the highest allowable rate. Neonicotinoids will not provide adequate control after cotton has bloomed.

Seth’s team will continue to scout VA cotton counties and we will post distribution updates and management recommendations as the season progresses. I would like to thank Seth for his hard work on this problem. If you have concerns, please contact me.

Flooded Soybeans – How Much Damage? What to do?

Rainfall across the state resulted in in saturated soils and sometimes flooded soybeans or fields to be planted in soybean.  Although fields are drying out, more rain is expected this weekend.

It’s difficult to know the long-term effect of flooding on soybean fields. Research is limited, but we do know that the fate of flooded fields will largely depend on 1) the development stage during which the flood took place; 2) the duration of the flood; 3) the temperature during and right after the flood; and 4) the drying rate after the flood.

Basically a flooded field depletes the roots of oxygen (O2), causing photosynthesis to slow.  After several days without O2, the plant may turn yellow, grown very slowly, and possibly die.  Other indirect effects of flooding can include reduced nitrogen-fixing bacteria (but they will recover), nutrient imbalances, and increased disease pressure.

For more detailed information, see a blog post that I wrote  in 2013 at the Virginia Soybean Update site.

In short, here are a few pointers for flooded fields.  If soybean have not yet been planted:

  1.   I don’t recommend tillage to dry the soil out for continuous no-till fields.  Tillage will destroy the soil structure that you’ve built since tillage was stopped.  The field is probably draining better than it ever was; tillage will just cause water to stand longer in the future.
  2. Bradyrhizobia japonicum, the nitrogen-fixing bacteria that helps provide soybean with that nutrient, is harmed by lack of oxygen caused by the flood.  Although the bacteria will recover, it may be prudent to add inoculant to the seed in areas that were flooded.

For flooded fields that have been planted:

    1.  Minimize any addition stress by staying out of the field.  Do not try to plant or replant too soon.  More damage can be done to the soil and more yield can be lost from planting into we soils than from planting too late.
    2. If soybean have not yet emerged and crusting evident, light tillage with a rotary hoe will help emergence.
    3. Evaluate the stand. If a stand reduction occurred, determine if it’s worthwhile to replant. Remember that after mid-June, every day delay in planting will cost you about ½ of a bushel in yield. The plants that remain are still higher yielding than seed that can now be planted, even if the stand has been substantially reduced.
    4. Stress such as herbicide injury can slow the crop down further. Still, weeds need controlling. But you may want to select herbicides (usually as tank-mix partners to glyphosate) that don’t cause a significant amount of burning.
    5. Finally, some will want to apply some type of foliar fertilizer to the crop to “kick-start” it back to health.  I see little advantage of this.  Remember that the real problem is lack of O2 to the roots and CO2 buildup in the soil; only after the roots begin to receive O2 will the recovery process start.Hopefully you haven’t experienced severe flooding (> 24 hours).  But if so, be patient and evaluate the field.  Then make good decisions on how to handle it.

 

 

New Crop Disease Management Resources

Though it has been around for several years, the Crop Protection Network (CPN) has recently added several publications on disease management in corn, soybean, and small grains that are relevant to growers, crop consultants, and extension personnel in Virginia and the surrounding region. These can be accessed at the CPN website cropprotectionnetwork.org. As stated on the website:

“The Crop Protection Network (CPN) is a multi-state and international partnership of university and provincial Extension specialists, and public and private professionals that provides unbiased, research-based information. Our goal is to communicate relevant information to farmers and agricultural personnel to help with decisions related to protecting field crops.

Extension specialists throughout the country (including myself) contribute to the publications and other resources posted on the website. An example of a recent publication on optimizing fungicide use for control of Fusarium head blight can be downloaded below. The CPN library includes over 30 publications on crop management, and additional publications are in development.

CPN-3001-Optimizing Fungicide Use for FHB

Wheat Disease Update – May 24, 2018

Fusarium head blight (FHB) risk for Virginia continues to be to high throughout the state due to recent wet, warm weather (http://www.wheatscab.psu.edu/). Most of the wheat is past the flowering stage and no longer at risk, but later flowering wheat may still need a fungicide application. Triazole fungicides including Prosaro, Caramba, and Proline are recommended. Do not apply fungicides containing a strobilurin since this can increase DON. For wheat that is past flowering, a fungicide application will not reduce FHB or DON contamination of the grain. Grain harvested from fields with signs and symptoms of FHB should be kept separate from non-infested grain.

For assistance with disease identification or management recommendations, contact Dr. Hillary L. Mehl, Extension Plant Pathologist (hlmehl@vt.edu).