What is in this article?:
- Disease control still critical in peanut production
- Need-based point system
- Many products out there
• All peanut diseases are still relevant, and to ignore any one of them would be a mistake.
• Many fungicides are now available for leafspot, and that’s probably the disease growers should be most concerned about.
• As far as leafspot resistance, the best variety bets are GA-07W, FLA-07 and Tifguard.
Need-based point system
The Peanut Rx program, explains Hagan, is a need-based, point system that allows growers to use some of the name-brand products but reduces the total application costs.
“We’ve had very good luck using these programs in trials. The four or five-spray programs with a resistant variety have worked very well in comparison to the seven-spray program. The main sprays you cut out with the Peanut Rx program are sprays of chlorothalonil. If you’re talking about a generic chlorothalonil, you’re talking about $5 per product per application, and if you’re talking about Bravo Ultrex or Bravo WeatherStik, you’re talking about $7 or $7.50. You’re probably going to save no more than $15 per acre when shifting to this program, but it is an option. The other option is to go the generic route.”
As far as leafspot resistance, the best variety bets, says Hagan, are GA-07W, FLA-07 and Tifguard. “These varieties give you added security as far as slowing down leafspot. That’s especially helpful if we have a tropical storm or hurricane that keeps you out of the field for a couple of weeks.”
(For a look at how growers figure the value of peanut variety resistance see http://southeastfarmpress.com/peanuts/placing-value-disease-resistant-peanut-varieties-0).
If you were going to look at a prescription program where you use reduced fungicides for leafspot control, you’re probably better off using one of those varieties as well, he says.
“These varieties give you an extra margin of safety over Georgia Green. Basically, from our standpoint, looking at diseases, GA-06G is every bit as susceptible to white mold and leafspot as Georgia Green.”
Looking at leafspot ratings at the plant breeding unit in Shorter, Ala., the highest came in for Georgia Green and the lowest for Tifguard, with many of the other varieties falling somewhere in between, he says.
“A grower might have a problem with white mold if he has a history of soybean production, or he’s back for the third time with peanuts, or he has had some history with vegetables in the field, especially if it becomes hot and dry at pegging time.”
One way to suppress white mold is to plant later, says Hagan. “Down in the Wiregrass region of southeast Alabama and in other areas, growers are wanting to move their planting dates earlier to give them a little more flexibility at the end of the season with harvest operations. With those late April to early May planting dates, they’re more likely to run into problems with white mold because the peanuts have been setting their pods in late August and early September, when temperatures are really hot, particularly at night.
“If we plant in the middle of May to the end of the month, then the peanuts are maturing in late September up until the first of October, the soil temperatures will be dropping, and the risk of white mold will go down on its own.”
As for varieties, Georgia Green and Georgia Greener tend to have more issues with white mold than almost all of the others, he says.