Peanut Pointers: April 2022

Maximize Planting Potential

Moving into April, some farmers are preparing to start planting in the southwestern part of Georgia. With planting season about to start, there are several things I’d like to revisit in hopes to minimize potential issues at the outset. First, soil samples to detect pH issues or fertility deficiencies should already be submitted. Otherwise, do so immediately. These issues need to be fixed prior to planting. Last year we observed peanuts with zinc toxicity because of low pH. 

Second, proper field preparation is key to establishing an adequate stand. It does not matter if you are practicing conventional or reduced tillage, seed beds need to be weed free and clean enough to allow seed to be planted at the proper depth for good seed-to-soil contact. 

Keep in mind, the soil environment influences germination and emergence. Seed needs to be planted in soil that maintains a 68-degree daily average in the top 4 inches for three consecutive days and has enough moisture to adequately germinate the seed. Anything less could result in poor stands. 

Seed is another important factor for ensuring proper stands. Growers need to ask or test for the germination percentage of each lot they are planting. This will allow for adjustment of seeding rates as needed. Buying points and growers need to store seed properly to ensure it is not subjected to significant spikes in temperature and humidity. Improper storage and handling of seed can result in decreased germination. Another important rule regarding seed is to adhere to the “first in, first out” rule to distribute or plant the oldest seed first.

Lastly, I caution growers to only apply university tested and recommended products in furrow with the seed. These are inoculants, fungicides and insecticides. I have been asked several times this year about applying biologicals, bio-stimulants and fertilizers in furrow with the seed. In using biologicals or bio-stimulants, I would ask for university data and recommendations to back up the use of the product. So far, I have not observed any negative reactions with biological products, but I have also not observed consistent benefits either. 

Based on our recent research, the use of in-furrow fertilizers causes significant reductions in germination and/or emergence and is NOT recommended for use in peanut. 

I hope peanut growers have a great year. Remember to reach out to your county Extension agent if you have any questions or need help.

Take Soil Samples And Temperature Readings

2021 was a relatively good season for Southwest peanut and cotton growers, except for a few acres where planting was not possible due to the prolonged wet field conditions through June. This means that the high-yielding peanut or cotton crops removed nutrients from the soil to support the good production. Because of this, soil testing at the fruiting zone will be important as soil nutrients need to be replenished to support this year’s crop. A fertilizer program can be refined only by testing soil and water to estimate residual nutrients. 

After crop emergence, it is recommended to take soil samples at the pegging zone, which can help estimate the amount of calcium fertilizer necessary for optimum yield. When input costs are skyrocketing, soil testing results can reduce the risk of wasting fertilizer. Over- or under-application of fertilizer can be a very expensive mistake, especially in 2022. 

Understanding the soil temperature in the top 4 inches is critical to determining the best time for peanut planting. Although peanut seedling emergence is not as challenging as cotton due to the large seed size, seeding into cold soil can slow the seedling emergence and increase chances of getting soil-borne diseases. Optimum soil temperature for peanut germination is at least 68 degrees Fahrenheit for three consecutive days without a cold front in the forecast. 

In 2020, cold snaps and dry soil conditions slowed germination of peanut and cotton. The longer seeds stay in the soil, the more susceptible they become to soil-borne and seedling diseases. Using online resources for checking the soil temperature is a good option; however, confirm the actual soil temperature in your fields with a soil temperature probe. Soil temperature can vary widely depending on the soil texture, amount of residue in your fields, topography and other factors. 

Establishment of a good stand is the first step for successful peanut production for 2022 growing season. 

Watch For These Early Problems

As we move into April with an eye toward May, several key elements of peanut production come to mind. First, is seed quality where we need it to be? Generally, in the Virginia-Carolina region, seed quality is good, and thus far, we have not experienced issues with the performance of fungicide seed treatments. Obtaining four to five plants per foot of row is critical to optimize yield, which requires about four to six seed per foot of row when considering 80% germination. 

Planting date is also an important consideration. In North Carolina, we generally have our greatest yield when we plant in the middle of May. In doing so, we often avoid the highest infestation of thrips, which can also help us minimize tomato spotted wilt. 

Given that we will not have chlorpyrifos (Lorsban) to suppress southern corn rootworm, we are encouraging growers with high-risk fields to consider planting early — late April to the first week of May. This can result in peanuts having shells that are more developed and with less chance of puncturing when larvae feed on pods. We suspect that about 25% of peanut acreage in North Carolina carries some risk to damage from southern corn rootworm, but a reduced percentage is at high risk for yield loss. 

In any given year, we are not sure of how many SCR adults will enter a field, or the duration of the infestation across the growing season. In addition, we do not know how much rain will occur and how frequent it will be. Both of these can affect the length of time larvae survive in fields and feed on peanuts. With that said, we need to adjust practices to minimize risk in high-risk fields. To figure out risk for fields, refer to 2022 Peanut Information to see the risk index for southern corn rootworm. 

In short, fields that are finer-textured in nature that are poorly drained present our greatest risk. Moreover, if those fields are irrigated, the risk can be high. For these fields, planting early is the best option to hedge your bets against damage, that is, if you absolutely need these fields for peanut production. 

If you decide to plant early, regardless of risk to southern corn rootworm, you will need to stay on top of thrips management to avoid injury from this insect and also to minimize incidence of tomato spotted wilt. Our recommendation for early planting is to establish five plants per foot by planting six seed and applying an effective, systemic in-furrow insecticide. Phorate (Thimet), AgLogic and imidacloprid products can provide good suppression of thrips. Early planting can result in peanuts emerging during the peak thrips flight. If there is an inkling of concern over performance of systemic in-furrow insecticides, applying acephate in the first three weeks after peanuts emerge can be extremely helpful. 

Be on the watch for less than ideal performance by imidacloprid products. We have seen these products perform inconsistently over the past five years in trials that Rick Brandenburg and Brian Royals have conducted across North Carolina. If injury is observed, the sooner acephate is applied, the more quickly peanuts can recover. 

Finally, in North Carolina, we have about 30% of our peanut production in reduced tillage. It is critical to have clean seedbeds when peanuts are emerging. Winter and summer weeds need to be controlled to give peanuts time to become established without interference from weeds. Keep in mind some winter weeds and emerged summer weeds are resistant to glyphosate. A mixture of glyphosate with 2,4-D applied one month before planting is a good start. Paraquat applied close to planting and before peanuts emerge is essential in controlling glyphosate-resistant biotypes. As all of you know, establishing an adequate stand of peanuts in a clean seedbed in May goes a long way toward realizing optimum yields in the fall.

Reduce Your TSWV Risk

Here are a few thoughts as planting season draws closer. Experience teaches us that we don’t seem to forget things when it comes with a cost. Last planting season, we had a cool spring, which brought on late thrip flights. I wish this was something that we as researchers could scientifically predict. 

Many of us seem to have forgotten about Tomato Spotted Wilt Virus after we got Georgia-06G some 16 years ago. However, we have been seeing more TSWV in recent years. I encourage everyone to use the Peanut Rx guide to help lower your risk or at least weigh your options as a producer based on the choices you have. 

We have said before, and our research last year still proves, that Thimet 20G is the best product for reducing TSWV. I know many don’t like to use a granular product, but the data is what it is. Thinking back on research data, before we had resistant cultivars, we only had the cultural practices to help reduce TSWV. As listed in Peanut Rx, these are planting date, plant stand, at-plant insecticide, twin rows and reduced tillage.

Our highest yields are from earlier planting dates such as the end of April or first week of May. This is true if we dodge TSWV and do our due diligence to battle against diseases. We know that planting mid-May seems to be the least risk of TSWV; however, we also must have moisture to germinate seeds. Therefore, we must manage as best we can and try to reduce risk. Start planting with a variety that has a high level of TSWV resistance such as Georgia-12Y or TifNV-HighO/L. 

Now we know the earlier we plant, the lower the leaf spot pressure, but white mold risk increases. Georgia-12Y helps because this variety has the lowest white mold rating. I would still encourage you to use an at-plant insecticide regardless of variety when planting early. 

Also, plant nematode-susceptible fields first. TifNV-HighO/L has significant TSWV resistance, which would allow you to plant early. The sooner you plant those fields, the better so that harvest can happen before nematodes build up and peak in the fall. 

This year is full of challenges because of high costs and limited supplies of products we use, not to mention the second La Niña year in a row. Because we have been experiencing drier conditions, let’s conserve as much moisture as we can and make the best decisions possible this planting season. I know I don’t have to tell you, it will only be 365 days before we have the chance to do it again.