Wednesday, September 22, 2021

Defining IPM

David Jordan
DAVID JORDAN
North Carolina State University

As we move into the season, we often think in terms of preventive treatments versus reactive treatments to address agronomic issues and pests. In reality, we use both approaches. This is in part based on logistical constraints and the ability to be timely with inputs to correct a problem.

We also may need to incorporate effective practices that prevent or minimize a problem because we may not have a corrective tool once something develops. The ability to address issues rapidly and completely is important to protect peanut yield.

If we are unable to do that, we better do something ahead of time that keeps the issue from exploding and causing yield and financial loss.

I recently read a letter to the editor in the periodical Science titled, “Stay True to Integrated Pest Management.” The discussion was not specific to peanuts. However, the letter seemed to say that using insecticide seed treatments was not consistent with the goals of IPM.

This got me thinking about how we decide if a practice should be defined as a principle of IPM, which is important because I think managing pests using IPM principles is critical and because I teach an IPM course at N.C. State. We often think of IPM with respect to monitoring pest populations during the crop cycle and then treating based on economic thresholds that are established. Thresholds are based on pest numbers or levels of injury caused by the pest in relation to the impact on yield, crop price and cost of the treatment.

This is a core component of IPM. But knowledge and monitoring occurs well before the crop is planted, especially with peanuts. What happened in the field years ago needs to be considered. Effective fungicide seed treatments are essential in protecting peanut seedlings from pathogens and the diseases they cause to get an adequate stand. There is no substitute other than an in-furrow application of fungicide. Our stands will be low if we do not treat, even when seed quality is good.

We also know in North Carolina that if an insecticide is not applied to suppress thrips, we will get a yield hit in most fields. One can certainly wait until peanuts have emerged to apply insecticide, but a more effective way from a logistical standpoint is to apply a systemic insecticide in the seed furrow at planting.

For both seedling disease and thrips, we know fields will exceed the economic injury level if a control practice is not used. An effective way to suppress these is to use a preventive treatment as the crop is being planted.

Even deciding to use a resistant variety for a disease is done when we plant and not after the peanuts emerge. This, too, is a core component of IPM because we are using knowledge from the past and making a decision based on the economic impact.

We also have to take into account the yield of a resistant variety versus a susceptible variety if the pest is either controlled in some other way, in the case of a susceptible variety, or the pest does not develop, as in the case of a resistant variety. What is the financial impact in both of these scenarios? Because we don’t automatically plant the resistant variety does not mean we are ignoring IPM principles.

And of course, we would have major yield losses in peanuts if we did not use preplant incorporated or preemergence herbicides. We also know our weed populations will be high enough in most fields to justify herbicide use, and practical knowledge informs us that relying only on postemergence herbicides is not always, and in fact seldom, completely effective. There is nothing wrong from an IPM standpoint with using herbicides in a preventive manner.

There are many risks to peanut yields, and we have many tools to address these risks. The more we know about the history of fields and production in those fields, the more effective we can be with IPM. Preventive treatments are just as much a part of IPM as the reactive treatments. IPM depends on our knowledge of the pest both historically and contemporarily and the availability and effectiveness of the tools at our disposal.[divider]

Water Efficiency In Prolonged Drought

emi kimura
EMI KIMURA
Texas A&M AgriLife
Extension Peanut Specialist

Peanut has a shorter rooting depth than cotton and grows in sandy soils with low water-holding capacity. It requires approximately 20 to 30 inches of water (irrigation and rainfall) per growing season depending on weather conditions. Most of this water requirement will need to be supplied by irrigation, especially for West Texas peanut growers currently under the drought conditions.

With the prolonged drought across the Southwest peanut growing regions, it is critical to estimate realistic yield goals that match irrigation capacity and water quality. As water demand of peanut is higher than other crops typically grown in the regions and if irrigation water is limited, it is advisable to plant fewer acres and irrigate adequately than providing limited water to larger acres. The latter approach will not only reduce yield potential, but also increase disease susceptibility, weed pressure and lower the peanut grade.

Under limited water availability, irrigation management becomes very important. Water demand differs at each developmental stage. In general, water use is low in the early season. It is at its peak during the reproductive period, requiring approximately 2 inches of water per week. Adjust the weekly amount based on the transpiration and evaporation.

Planting Spanish and Valencia type peanuts may help in spreading irrigation water out over the season because these peanut types are early maturing compared to runner and Virginia peanut types. Many Southwest producers are already splitting pivots into two or more crops to further improve water-use efficiency.

This approach will help to provide adequate water to peanut production. Other factors that can improve water-use efficiency for peanut production include maintenance of irrigation equipment, monitoring in-season soil moisture and checking water salinity.[divider]

Planting Decisions

Scott Monfort
SCOTT MONFORT
University of Georgia

Growers are beginning to make plans on when to start planting. I have already received several calls from growers asking about planting in the first part of April if the soil temperatures and moisture are perfect for planting. In answering this question, there are several key things I would have growers consider.

The first thing for growers to consider is the risk for tomato spotted wilt virus. Remember, planting in April presents a higher risk compared to mid-May. This does not mean growers do not need to plant in April.

It just means they also need to adapt other strategies for reducing TSWV, such as applying Thimet insecticide, planting good quality seed, using a proper seeding rate, planting in twin rows and at the proper plating speed, applying an in-furrow fungicide and planting into good soil moisture at the proper temperature.

Available moisture is another key factor to consider when deciding about April planting. In recent years, growers have had adequate moisture in late April but waited until May due to soil temperatures being 65 degrees F instead of 68 degrees and/or they wanted to reduce their risk for TSWV. The problem is it turned off dry in early May, and they had to wait on rain until late May to early June, which reduced overall yield potential.

If a grower does not have irrigation, but has adequate moisture in late April and a soil temperature of 65 degrees or higher, with an unfavorable forecast for rainfall in the next week to 10 days, then it would be advisable to go ahead and plant.
This does not mean everyone should be planting in early to mid-April.

The risk of TSWV is still very high on early plantings, even if everything else is done to lower the risk. Call your local county agent for more information or if you need further assistance.[divider]

Seeding Rate Recommendation

Kris Balkcom
KRIS BALKCOM
Auburn University

Now that we have entered the month of April, planting is just around the corner. Everyone knows that there always seems to be a cold spell around Easter. Since the holiday is early in the month this year, we should be confident enough that there’ll be consistently warm temperatures for early planting by the end of the month.

I am sure you haven’t forgotten the weather challenges we have faced two of the past three planting seasons. The earlier start gives us a longer window of opportunity to achieve our highest goal. With a forecast of warmer temperatures and having higher quality seed this year, there is no reason not to get an early start.

Having high-quality seed coupled with good planting conditions brings up the topic of seeding rate. I have heard many times of producers planting higher seeding rates than our recommended six seed per foot of row. Because of this, I felt like we needed to reassess our recommendation to see if it is still correct for current varieties.

Our standard seeding rate has always been based on 36-inch row peanuts at six seed per foot of row. This is what we recommend at planting to ensure that you get four plants per foot to achieve maximum yield. If you are on 30-inch rows, it would be five seed per foot.

seed totesThe seeding rate depends on the type of seed you have and the quality of that seed. If you have poor quality seed or a lower germination seed, then you would need to use a higher seeding rate.

To confirm our seeding rate recommendation, we had a test this past year where we planted different rates to see if we could come up with a yield difference. We planted at 3.5, 4, 5.5, 6, 8 and 10 seed per foot of row.

All of the various rates yielded well in this test at more than 6,200 pounds per acre. The lowest three were 5.5, 4 and 8 seed per foot, which yielded the least amount. The three highest rates were 10, 6 and 3.5. However, there was no statistical difference between these top three rates, even though there was a slight numerical difference in yield.

We will continue to look at seeding rate research, but we still feel that the recommendation of six seed per foot of row is adequate for achieving a good stand and an opportunity for maximum yield when you have good quality seed and favorable planting conditions. [divider]

Georgia Peanut Commission To Hold Referendum

georgia peanut commissionThe Georgia Peanut Commission will hold a referendum March 15 through April 16, giving peanut producers an opportunity to vote on reaffirming the commission. State law mandates a referendum be held every three years. Georgia peanut producers invest $2 per ton to fund the commission and its research, education, promotion and communication programs.

The last referendum in 2018 passed with a 94.02 percent reaffirmation.

“I urge all peanut producers to vote in this referendum. Research, education, and promotion continue to be the core focus of the commission,” says Armond Morris, GPC chairman. “It is extremely important for growers to continue to focus their efforts on supporting research and promotional efforts through their checkoff dollars. One way for farmers to do that is by continuing their support of the Georgia Peanut Commission.”

GPC Executive Director Don Koehler urges producers to contact him by email at don@gapeanuts.com or 229-386-3470 if they have any questions about the commission’s activities or the referendum.

Peanut producers who do not receive a ballot may obtain one by calling the commission. The commission requests that anyone who receives a ballot but is no longer farming to write, “no longer producing” on the certification envelope and return it to the commission. This will assist the commission in updating its mailing list. The commission’s address is P.O. Box 967, Tifton, Georgia 31793.

The Certified Public Accounting Firm of Allen, Pritchett, and Bassett will count the votes.

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