Update From Dan Anco Clemson Peanut Notes No. 181 2019

— Written By

Peanuts are ranging from about 90 days to 120 days, with activities spanning everything in between. Fungicides sprays are going out, insecticide is being delivered to worms in places, some fields are receiving Apogee growth regulator, and some of the earlier planted Virginia type fields are at a time to be getting their feet wet with pod blasting. Peanut seed size and maturity development varies from field to field. If a seed is currently small and match head size it would take about 15 or so days under good conditions to reach full size, with another 55 to 65 days for full maturity/weight gain. This probably varies some by cultivar and is a rough ballpark estimate.

Spider Mite Sighting

No bigfoot here… Had a report come in from Horry County today on spider mites. Dryland field without recent insecticide application. Fortunately it was noticed near the beginning of the episode, so there is time for intervention, though it is a challenging one nonetheless and can be expensive. Current legal options are pretty much limited to Comite II (2.25 pt) or Omite (4 lb), asking for a good rain, or also Microthiol Disperss sulfur. I do not have personal experience with this last sulfur one but it is labeled for 5 to 8 lb/ac and to repeat as necessary (attached is an article showing Microthiol Disperss to be effective against spider mites in grapes; always things that are different, but there is evidence of efficacy).

Traditionally, 2 applications of Comite or Omite (both are propargite) spaced 5 to 7 days can help to target spider mites currently present and those that hatch from current eggs. Depending on where in the field those applications occur, this may or may not agree with the label – consult your Extension agent or consultant. 20 gallons/ac is important to get good coverage. In strawberries, Portal has been highly effective and one application typically provides coverage. The sticker there is that it is not yet registered on peanut, but efforts are underway and hopefully it will be in the near future. All the more reason to be judicious with pyrethroids in dryland fields if mites are in or near your area. I do not recommend Danitol for spider mites, it is a pyrethroid. Previous notes have mentioned the effectiveness of the Microthiol in combination with fungicides for leaf spot, and this sulfur product is one of the few current options that can act preventatively as well. In my humble opinion, this value-added action would offset potential additional clean up time if a field is at risk.

Apogee combinations

Tank mix combinations save a lot of time and many products can be combined effectively. No surprise that just because we can mix it, not all mixes are equally helpful in the long run. Here is a recent note from David Jordan in NC about Apogee tank mixes with herbicides and fungicides.

Peanut/Row Crop Field Day is coming up in two weeks in Blackville on Thursday, September 5.

A link to the event with more details can be found here, and a slightly updated schedule is attached.

2019 Edisto REC Peanut/Row Crop Field Day

Inoculant benefits and nitrogen application following failure

Also attached is an article we put together on inoculant use and nitrogen application. Although we don’t really have alternative options, benefits of nitrogen application can be fairly variable.

Dan Anco

Extension Peanut Specialist and Assistant Professor

Department of Plant and Environmental Sciences

Clemson University – Edisto Research and Education Center

64 Research Road

Blackville, SC 29817

803-284-3343 x261 office

630-207-4926 cell

danco@clemson.edu

Clemson Extension