Peanut Weed Control and Hot Weather
A few things to think about in regards to peanut weed control given the current weather conditions:
1) Rainfall events on Mother’s Day Weekend (May 9-13) caused some Valor related peanut problems in many areas of south Georgia. Since I have addressed this issue numerous times in other blogs, I feel no need to bloviate any further. But, this problem should not be a surprise to anyone who has ever used Valor in the past. Valor injury will almost always happen when rainfall events occur from cracking up until about 2-3 weeks later. Historically, this injury has been cosmetic only and not resulted in reduced peanut yields.
2) Cracking/EPOST applications of paraquat mixtures or solo applied Storm or Ultra Blazer should be delayed as late as possible in peanut fields suffering from Valor injury. I would argue that if Valor injury has occurred, then good weed control has also occurred and a cracking treatment might not really be needed. Paraquat treatments can safely be applied in peanuts up to 28 days after cracking.
3) Common paraquat mixtures include paraquat + Storm or Basagran + Dual Magnum or Warrant or Zidua. I have no preference between Dual Magnum, Warrant or Zidua. There is no need for additional adjuvants with Dual Magnum mixes but a NIS (0.25% v/v) should be used in Warrant or Zidua + paraquat tank-mixes. FYI, I am not a huge fan of paraquat + Dual Magnum or Warrant or Zidua without any Basagran/Storm due to greater injury potential that might reduce yields (especially under these lava-like weather conditions). Also, paraquat without Basagran/Storm is not very effective on smallflower mg
4) It is very hot and very dry right now. Non-irrigated growers who were planning on using paraquat tank-mixes after peanut emergence might want to re-considering their options. Why? Rainfall/irrigation is critical in helping peanut plants recover from paraquat injury. I do not think that irrigated growers need to worry about this issue since they can help the peanut plants recover from paraquat injury with well-timed irrigation events.
5) When paraquat + Storm/Basagran + Dual/Warrant/Zidua mixtures are applied in peanut, there is no need to be a great ID’er of weeds since these mixes control just about everything (small grasses and small broadleaf weeds). But, if a non-irrigated grower decides to go with something other than paraquat mixtures (which is fine), such as Ultra Blazer or Strongarm or Cadre or 2,4-DB, they better know what is in the field since these herbicides are not as broad spectrum. I am not comfortable with very early applications of Cobra unless the peanut plants have reached the 6 true leaf stage.
6) No matter what I say or do, if it don’t rain, it don’t matter! (That’s a famous quote from former UGA Extension Peanut Specialist, Dr. John Baldwin)
UGA Weed Specialist Dr. Eric Prostko
Downy Mildew Alert
Downy Mildew has been found on cucumber in Echols and Colquitt Counties; and on watermelons in Decatur county.
Watermelon: Rotation (foliar application) with Orondis Opti;
Please do not use Orondis Opti or Bravo after fruit set.
Other cucurbits: Orondis opti;
If Orondis was used as a soil application, please do not use it as foliar (use restriction according to the product label).
Bhabesh Dutta – UGA Vegetable Pathologist
Peanut White Mold and Hot Weather
White mold on peanuts could be ignited EARLY because of the hot. I recommend all growers start their white mold program aggressively, even if it is only adding tebucoazole to early leaf spot sprays. There are other good options as well. Important to not get behind. Dr. Bob Kemerait – UGA Peanut Disease Specialist