Peanut Pointers

Jason Woodward, Texas Agri-Life Extension Plant Pathologist

As the 2014 season unfolds, final decisions need to be made as it relates to the placement of varieties and, more importantly, market types. When it comes to planting early, peanuts are a little more forgiving than other crops, such as cotton. However, efforts should be made to plant under the most favorable conditions.

It is always important to use high-quality seed and check for splits and immature kernels. Planting should occur when soil conditions are favorable for rapid germination of the seed and development of the plant. Recent studies have shown that planting densities can be substantially reduced for all market types, but differences in seed size and seed count may need to be addressed when calibrating vacuum planters. Adjustments in planting depth should be made based on soil type, planting date and moisture conditions. Overall, late planting dates generally lead to reduced yields and lower grades, as well as increasing the risk from freeze damage and late-season drought.

Market types requiring more time to mature, as is the case with most runner and Virginia varieties, should be planted by the middle of May. Spanish and Valencia varieties, which mature earlier, can be planted as late as June 1 in the High Plains or later in Central and South Texas; however, late planting dates may increase the risk of losses due to tomato spotted wilt. Properly preparing beds can help in stand establishment. If soils are extremely dry, preplant irrigation should be applied as opposed to dry-planting followed by irrigation, as this may impact the viability of rhizobia found in inoculants and subsequent nodulation.

David Jordan, North Carolina State University

Weed management is one of the most important tasks during the month of May. In conventional tillage systems, incorporating a dinitroaniline herbicide, and in some cases a chloroacetamide herbicide, is recommended.

In reduced tillage, the DNA herbicides will have limited effectiveness if placed on the soil surface. Metolachlor, of which there are several formulations, dimethenamid (Outlook) and acetochlor (Warrant) applied preemergence with flumioxazin (several formulations) are available and recommended. Depending on rainfall, these herbicide combinations may provide excellent control well into the season, or they may be only partially effective.

Applying paraquat within the first three weeks after peanuts emerge will help clean up escapes and take pressure off of herbicides such as Storm, Ultra Blazer, Cobra, Cadre and 2,4-DB. With paraquat, always include at least 0.5 pints per acre of Basagran. In weedy fields, including additional chloroacetamide herbicides can be very helpful. Chloroacetamide can also be applied with Storm, Ultra Blazer, Cobra, Cadre and 2,4-DB to “shore up” weed control as you move later in the season.

During the first month of the season, there may be a need to apply acephate (several formulations) to control thrips, and most folks are going to want to apply this insecticide along with herbicides. Certainly the timing works out in most cases for tankmixtures to be effective. However, if you see thrips damage, but don’t think it is time for postemergence herbicides, you should apply the acephate as soon as needed and then come back with herbicides. Eliminating thrips feeding and injury to peanut needs to be done as soon as possible, especially in the V-C region where crop development is essential for optimum yields. We can’t afford delays in crop development.

Keys in May and June are getting adequate stands established, minimizing thrips injury and keeping fields weedfree. If you are able to achieve an adequate number of plants, at least four to five per row foot, that are growing vigorously, you’ve given the peanut crop an excellent chance to yield well in the fall. There is a lot of time left in the season, but this is a great start.

Glendon Harris Jr., University of Georgia Extension Agronomist

The application rate and timing recommendation for calcium in peanut have not changed, despite the use of larger-seeded varieties. One thousand pounds of gypsum still works on the large-seeded varieties, and for timing, it’s still lime at planting and gypsum at bloom time.

What has changed is the number of sources for calcium. Lime is still a mined product that is either dolomitic or calcitic, and either product is usable. It does not have to be high-calcium or calcitic lime to provide calcium in peanuts. However, it does have to be applied at planting to provide enough time to leach down into the pegging zone to become available to developing pods.

Calcium sulfate, or gypsum, is now available from many different sources. It may be mined or it may be a by-product of phosphorous fertilizer mining in Florida. It can also be a product scrubbed from smoke stacks or created from citric acid production. All these products work just fine as sources of calcium for peanut applied at bloomtime. The calcium in gypsum is more soluble than that in lime and will move quickly through the soil profile. Applied any earlier, gypsum may move beyond the pegging zone and out of the reach of developing pods.

Another emerging source of calcium is applied through the pivot. Calcium chloride, which goes by the trade name “Hi-Cal,” and calcium thiosulfate, which is known as “cats” or “Thiocal,” is the most soluble form of gypsum available. A product applied through the pivot is put out with so much water and force that it is considered “soil-applied.” Products applied to the leaves, or foliar-appled calcium, are not recommended because they do not provide near enough calcium and the material does not translocate through the peanut plant.

Whatever product you use, remember that calcium, with the right rate and timing, is a critical component of peanut production.

Kris Balkom, Auburn University Agri-Program Associate

Since we are still in the first of May and the beginning of planting for some, I would like to point out a few things during planting season. You have all heard and know the recommendations about soil temperature for planting peanuts, along with seeding rates. If conditions are favorable for planting, I would recommend planting as early as possible this year. This is due to the fact that we are predicted to be in an El Niño weather pattern, which means a cooler, wetter fall and winter. Therefore, we need the crop planted early so that we have plenty of time to allow it to mature where it can be harvested before the rainy weather sets in.

If El Niño comes to fruition, we don’t need to be planting way out in late May and early June. Last year, we also experienced some cooler weather during planting season. This delayed thrips flights, which put a lot of pressure on the crop. Our weather has been very similar this year so be on the lookout in case you need to make a late foliar application for thrips over the top.

Also, I saw more tropical spiderwort in Alabama last year. If you had this troublesome weed and that land is going to peanuts, I encourage you to be proactive and use Strongarm and/or Dual in your herbicide program to battle against this prolific weed.