Thanks to Dr. Bob Kemerait for this update:
For many peanut growers, fungicide applications for the management of leaf spot and soilborne diseases begin in the month of June. As with disease management for all crops, initiating fungicide applications before disease becomes established is critical for the overall success of the program. Given that the majority of the peanut acreage in Georgia is planted in late April and throughout the month of May, important fungicide applications to consider in June include the following.
1. Where white mold (southern stem rot) is expected to be a problem, e.g., where peanuts are planted behind peanuts or where soil conditions have been unusually warm early in the season, growers may want to consider an early emergence BANDED application of Proline or Abound fungicides. Such are generally made somewhere between three and five weeks after planting. While these banded applications are needed in every field, they have been proven effective in both reducing severity of white mold season-long and also in significantly improving yields. NOTE FOR 2015: Weather conditions this far in 2015 have not been unusually warm so as to send a “red flag” for early season white mold control; however there have been some indications that the disease may be aggressive this year. For example, outbreaks of white mold were observed in sugar beets and wheat earlier this year in Tifton and lately on onions in east Georgia.
2. Until recently, conditions have not been favorable for leaf spot diseases on peanut as the weather has been dry for most growers. Rainfall over the past 10 days has creates conditions now more favorable for leaf spot; however since the crop is still young, growers still have ample time to protect their crop. Application of fungicides for management of leaf spot diseases typically begins somewhere between 28 and 45 days after planting, depending on the fungicide program being deployed and the use of Peanut Rx fungicide programs. Perhaps the most important concern this year with regards to leaf spot and peanuts is the availability of chlorothalonil. To follow up on early information, below are options growers may wish to consider for 2015 if they are unable to get the chlorothalonil that they need.
Peanuts and the short supply of Bravo/cholothalonil: What to do??
A. Replace 1.5 pt/A chlorothalonil with 15 fl oz/A Elast
B. Replace 1.5 pt/A chlorothalonil with 10 fl oz/A Topsin/thiophanate methyl, but ONLY one time!
C. Replace 1.5 pt/A chlorothanil with 7.0 fl oz/A Stratego (concern about resistance management…)
D. Replace 1.5 pt/A chlorothalonil with 3.5 fl oz/A Absolute (concern about resistance management…)
E. Replace 1.5 pt/A chlorothalonil with 5.5 fl oz/A Alto (better to mix 1.0 pt/A chlorothalonil with 5.5 fl oz/A Alto, or at least SOME chlorothalonil with the Alto!)
F. Replace 1.5 pt/A chlorothalonil with 5.5 fl oz/A Alto + 5 fl oz/A Topsin/thiophanate methyl
G. Extend chlorothalonil with 1.0 pt/A chlorothalonil with 1.0 pt/A Kocide
H. Extend chlorothalonil with 1.0 pt/A chlorothalonil with 5.0 fl oz/A Topsin/thiophanate methyl
I. Extend chlorothalonil with 1.0 pt/A chlorothalonil with 2.0 fl oz/A propiconazole.
3. Management of white mold (southern stem rot) and Rhizoctonia limb rot historically begins approximately 60 days after planting; however as mentioned above, management programs may begin now as early as three weeks after planting. Mixing tebuconazole (7.2 fl oz/A) with a leaf spot spray at approximately 42 days after planting (typically with 1.0 pt/A chlorothalonil and where other triazole fungicide programs are not used later) is an inexpensive and effective way to manage both leaf spot and white mold. The new Priaxor program from BASF also begins (for all disease control) approximately 45 days after planting. Use of generic tebuconazole products is very popular among growers because of the reduced cost of such programs. Tebuconazole remains an important fungicide in our arsenal to fight diseases in the peanut fields. However, growers should remember that programs including Abound, Artisan, Convoy, Fontelis, Provost, and Priaxor may be more effective and increase profits for the grower, especially when conditions are favorable for development of white mold.
4. Please remember that the Peanut Rx risk management tool is available for free on the APP Store (search “Peanut Rx”) and GOOGLE Play (search “UGA Peanut Rx”).
5. Peanuts and ELATUS: the label on Elatus fungicide from Syngenta is delayed and likely will not be here in time for the 2015 growing season.