Early Season Peanut Tips From Jay Chapin

Weeds

Killing small weeds is the top priority right now and of course pigweed is at the top of the weed list.  If we can catch pigweed 3” and Texas panicum in the small 2-blade stage we can really do a job with paraquat.  The standard paraquat rates are 12 oz for 2-lb material and 8 oz for 3-lb formulations.  Always add surfactant to paraquat unless Dual is in the tank mix.

If lots of grass is the major issue (especially Texas panicum or goosegrass) and pigweeds have not flushed, it is often worth it to kill the grass first (Select, Poast) and come back in a day or two with paraquat for sicklepod, etc.  Otherwise, any grass that escapes paraquat will be much tougher to kill with the Select.  If pigweed is flushed, you have to go ahead and kill it first and then fight escaped grass after it comes out of paraquat injury.

Which Paraquat “Safener”?

Whether to add Basagran ½ pt, Storm 1-1.5 pt, ENC or substitutes to paraquat depends on the weeds peresent.   There is no absolute choice that fits every situation.  ENC lightens paraquat injury but doesn’t bring anything to the table on morningglories or other weeds.  That’s still a good solution for small pigweeds, small grass, and sicklepod.  A few morningglories can be handled later with Cadre and 2,4-DB.  Basagran reduces paraquat injury and helps slow down morninglories and yellow nutsedge, prior to Cadre allocation.  Storm (Basagran + Blazer) controls morningglories even better, can get some marginal 5”-sized pigweed, and picks up croton and sida.

Add Dual to Paraquat?

The justification for post-emergence Dual (or Warrant) is residual control of pigweed.  If there is already a major pigweed flush it shows that Valor is not holding up for whatever reason and it makes sense to get Dual out with paraquat to reduce the next flush after paraquat control.  If no or few pigweeds have flushed it is usually better to save the Dual or Warrant for later Cadre application timing to extend residual pigweed control after the Valor plays out.  Dual is labeled for two full 1.3 pt applications under extreme pigweed pressure.  Do not use surfactant with paraquat or Cadre when Dual is added.  But both paraquat and Cadre require surfactants when used with Warrant.

TIMING

The biggest issue with post emergence pigweed control is TIMING!  Small pigweeds don’t get seen in time or when they are seen in time the sprayer might get there four days later.  Pigweed can grow an inch a day and a 6” pigweed will get burnt to the ground but come back to life.  You can’t windshield pigweed control decisions.

Thimet Did Not Go Out

We have had the usual annual calls about Thimet application issues.  Where it is known that it failed to go out on an entire field area or significant portion of a field, the best policy is to treat 2-3 leaf peanuts (about 14 DAP) preventatively before any thrips stunting is noticed.  Foliar Orthene (acephate) rates for the various formulations are: 75S: 12-16 oz, 97: 8-12 oz, 97: 9-13 oz.  From what I have seen so far, both Thimet and Admire Pro (or generic imidacloprid) are standing up well to thrips pressure.  Imidacloprid usually does a little better, but the major problem with Thimet is stopped tubes.

It’s Getting Late, I’ve Run Out of Moisture, Should I “Dust-In” Peanuts?

Probably not, and certainly not on new peanut land.  Inoculant is too important on new land to not have a chance to survive in decent soil moisture.  Even on rotated land where we can usually get by without full inoculation, they won’t germinate until it rains anyway.  Odds are it will only cost a couple more days after a rain to get them planted.

Inoculant Did Not Go Out, What Now?

If the land has been in peanut within the past three years, it’s more likely than not that there is enough residual bacteria (Bradyrhizobium) out there to carry the crop.  Don’t borrow trouble yet, give them a chance to make it on their own.

If it is new land and you know that no inoculant went out, just plan on feeding N (120 – 150 units).  They should be OK for the first 30 days and we don’t want to go too early and lose most of the N before they can use it.  If you can make two trips, spread 50-60% at 30 DAP and the rest by about 60 DAP.  If you can only go once, put it all out about 30-35 DAP.

If it is new land with partial application failure suspected and you don’t know how many rows or what area is lacking how much of the inoculant, the best option is usually to wait for the first signs of deficiency (yellowing) to show up and go from there.  It might be that only part of a field needs supplemental N.  If there is going to be a problem, it will show up by 45 DAP.  See page 12-13 of 2015 Peanut Production Guide for details of how to evaluate nodulation at 45 DAP.

Volunteer Peanuts in Peanuts

It’s certainly not a recommended practice for sustained high yield, but some peanuts do get planted behind peanuts.  The two major short term issues of volunteer peanuts are leaf spot control and digging problems.  The best solution for both of course is plowing under the volunteers to start with.  Otherwise volunteers must be killed with Ignite / Libery at planting.  Volunteers that come up later in the middles have to be controlled either with hooded Ignite / Liberty or glyphosate 5 gal/100 gal.  The other option is a sweep cultivator.  Too many volunteers in the middle can make a mess at digging.

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