Update on Peanut Disease 2016
Though still approximately 6 weeks away from the general start of the planting season, there are issues regarding management of peanut diseases and nematodes affecting peanut that deserve attention now.
- Choosing the right variety. Most of our acreage will be planted in ‘Georgia-06G’ and this continues to be an excellent variety. Seed for ‘Georgia-12Y’ is generally unavailable; however I encourage growers who are concerned about white mold to plant some if they can. If you have root-knot nematode problems consider planting at least some acreage in ‘Tifguard’ or ‘Georgia-14N’, remembering that Georgia-14N is a later-maturing variety. Use the 2016 version of ‘Peanut Rx’ to determine the predicted risk to tomato spotted wilt, white mold and leaf spot diseases given the variety planted and production practices. With this information you can make a better informed decision on the disease management program.
- Decisions regarding nematode control are critical now. Growers who anticipate a problem with peanut root-knot nematodes and who plan to applpy a nematicide will likely use Telone II or Velum Total. Most of our acreage in Appling County is a cotton/peanut rotation, so peanut rootknot nematode is not a huge problem. However, it is likely that some have dealt with this pest. The primary consideration in choosing between a resistant variety, Telone II and Velum Total is the size of the population of nematodes in a field. The economic threshold number is 10 per 100cc soil. Velum Total (18 fl oz/A) is generally recommended where a grower would have used Temik 15G, 10 lb/A at-plant, which would coincide with “low-to-moderate” nematode populations. Defining “low-to-moderate” populations is unsettling, but I would say anywhere from 10 to 100 root-knot nematodes per 100cc soil in a FALL-collected sample. As numbers increase beyond 100 per 100cc soil, a resistant variety or Telone II becomes increasingly important. Also, given that the root-knot nematodes are generally “clumped” in a field, it is likely that even a field described as “low-to-moderate” will have significant “hot spots” in it. Telone II should be applied in-row at 4.5 gal/A in-row 10-14 days ahead of planting with special awareness of soil conditions during this El Niño season. The possibility of frequent rain events could make fumigation challenging. An insecticide for management of thrips is still required when Telone is used but not when Velum Total is applied. Velum Total should be applied at 18 fl oz/A for peanuts and the product can be mixed with other fungicides and inoculants without concern. Whether choosing Telone II or Velum Total, accurate calibration and precise application are critical for maximum success. Growers should ensure that equipment is properly put together and tested for calibration.
- By now, most growers are aware that Tilt-Bravo will be generally unavailable this season and the issues concerning sale of peanuts treated with propiconazole (the active ingredient in Tilt) to the European market could affect other products as well. For example, it is not clear how Artisan, a combination of flutolanil and propiconazole will be sold this season; however, Convoy (flutolanil alone) will be readily available. Syngenta will likely recommend a tank-mix of Bravo and Alto to replace Tilt-Bravo; products like Priaxor will also perform well in this early-season spot. As we move beyond planting, additional discussion regarding leaf spot management will be proposed.
- White mold is of special concern this year, both because of anticipated short-rotations and because of the severe outbreak we had last year. Growers are reminded that early-season applications of Proline and, perhaps, Elatus can help to manage this important disease. Banded applications are typically made approximately 3-5 weeks after planting. NO FUNGICIDE PROGRAM CAN MAKE UP FOR SHORT ROTATIONS. However, using the right products at the right time sure can help.
What about AgLogic 15G?
By know you have likely heard something about AgLogic and it being a replacement for Temik. Here is what we know about AgLogic:
AgLogic is labeled for use in soybeans, cotton, peanuts, sugar beets, drybeans and sweet potatoes.
I do not know the price.
We (UGA) have not tested it. However, we do expect it to perform very similar to Temik 15G, but, again, have not tested it.
It will be in short-supply this year.
Growers who are able to get a hold of some will be required to take a 20-question test with the dealer who will sell them the product.
Update On El Nino Weather
The climate of Georgia this winter has been strongly influenced by El Nino, which is related to cooler and wetter conditions than usual in the Southeast in the winter and spring when an El Nino is occurring. While December did not follow the pattern this year, with much above temperatures, the rest of winter has settled into a more typical El Nino regime. This is expected to continue through spring, which may mean wet conditions in the fields for the next few months. This may lead to delays in planting which could hurt yield, according to the peanut planting date tool at www.agroclimate.org.
El Nino is already starting to diminish and is expected to return to neutral conditions by May or June before swinging to the opposite phase, La Nina, later this summer. La Nina is associated with dry and warm conditions, which could hurt crop development later in the growing season, but could help with harvest. The only exception is in areas that are hit by tropical storms, which are often more numerous in La Nina years. If a La Nina does develop, next winter is likely to be warmer and drier than usual, leading to the possibility of drought returning to the Southeast in 2017.
Dr. Bob Kemerait, UGA Plant Pathologist
Pam Knox, Agriculture State Climatologist