Peanut Thoughts from North of the Border. David Jordan, Crop and Soil Sciences North Carolina State University

Transcription

1 Peanut Thoughts from North of the Border David Jordan, Crop and Soil Sciences North Carolina State University

2 Information and Updates Peanut Notes Peanut Information Series Field days County production meetings Risk Management Tool

3 Topics 2019 survey Heat units in Sep and Oct ph Weed management Harvest survey from 2018

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6 Average heat unit accumulation from Lewiston-Woodville, NC M 15 - J 15 J 16-J 15 J 16 - A 15 A 16 - S 15 S 16 - O 15 O 16 - N 1 Ten-year average ( ) 2018

7 Influence of soil ph on peanut yield presented as percent of maximum yield Data are pooled over 3 years Y = x x , p = , r 2 = 0.60, SE of mean, Soil ph

8 Estimated economic return on investment in lime for peanut in a single season (not prorated) Adjustment with lime Dolomitic lime Economic return on lime investment ($/acre) Rate Cost ph tons/acre $/acre 4.5 to to to

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11 4 of 125 populations with suspected resistance to PPO herbicides One population with possible resistance to glyphosate and herbicides that inhibit ALS, PPO, and HPPD

12 Weed Control in Peanut Overlapping residuals has been a component of success Intensive weed control early in the season is important Controlling weed escapes later in the season is just as expensive and less effective than upfront PPI/PRE herbicides Spraying large Palmer amaranth multiple times with PPO inhibitors later in the season most likely hastens development of resistant populations

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14 Weed Control in Peanut Effective PPI and PRE herbicides need to be supported with early POST applications of Gramoxone plus Basagran with residual herbicides Warrant, Outlook, Zidua, or Dual materials are effective residual herbicides applied with Gramoxone plus Basagran

15 Thrips Control in Peanut Effective systemic in-furrow insecticides often need to be supported with early POST applications of acephate Warrant, Outlook, Zidua, or Dual materials are effective residual herbicides applied with Gramoxone plus Basagran These combinations are often applied with acephate for thrips and weed control

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17 Current Knowledge of Co-Application for Thrips and Weed Control Many studies with Dual materials mixed with Gramoxone plus Basagran plus Acephate Some work with Outlook, but this herbicide is used less frequently Some work with mixtures of Warrant or Zidua mixed with Gramoxone plus Basagran plus Acephate

18 One Day after Treatment Paraquat plus bentazon Paraquat plus bentazon plus pyroxasulfone

19 One Day after Treatment Paraquat plus bentazon Paraquat plus bentazon plus dimethenamid-p

20 One Day after Treatment Paraquat plus bentazon Paraquat plus bentazon plus acetochlor

21 One Day after Treatment Paraquat plus bentazon Paraquat plus bentazon plus S-metolachlor

22 Two Weeks after Treatment Paraquat plus bentazon Paraquat plus bentazon plus pyroxasulfone

23 Two Weeks after Treatment Paraquat plus bentazon Paraquat plus bentazon plus dimethenamid-p

24 Two Weeks after Treatment Paraquat plus bentazon Paraquat plus bentazon plus acetochlor

25 Two Weeks after Treatment Paraquat plus bentazon Paraquat plus bentazon plus S-metolachlor

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29 Injury from Southern Corn Rootworm Data are from 25 trials during Scarring (%) Yield loss threshold, about 25% scarring Non-treated Prevathon Lorsban

30 Injury from Southern Corn Rootworm Data are from 25 trials during Pod yield (lbs/acre) Yield loss threshold, about 25% scarring Non-treated Prevathon Lorsban

31 Pyrethroid resistance in corn earworm Presence of tobacco budworm Points to: Use of more effective but certainly more expensive chemistries to control the foliar-feeding insect complex

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33 How many days from digging? Assume soil is in good shape, no hurricanes and little to no leaf spot Write the number on the survey sheet

34 Number of Growers from All States Stating that Peanut will be at Optimum Maturity in a Certain Number of Days Based on the Pod Blasting Sample Percent of Growers Days to Optimum Maturity Based on Pod Blasting Samples

35 Peanut Yield (percent of maximum) and Digging Date Data are pooled over varieties and seeding rates 100 Planted May Sep 8-9 Sep Sep Oct Sep 7 Sep 18

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37 Percentage of Farmers Practice NC SC VA Prohexadione calcium Guidance Both