2015 Spring..Managing Through A Wet Season. Wayne Flanary Extension Agronomist

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1 2015 Spring..Managing Through A Wet Season Wayne Flanary Extension Agronomist

2 Effect of planting date on corn and soybean yield in North Missouri Corn Soybean Yield Yield Planting as percent Planting as percent date of expected date of expected May 1 94 May 8 99 May 6 92 May May May May May May June 5 89 May June May June June 5 75 June June July 3 65 June July 10 54

3 Impact of tillage and planting wet soils?

4 Compaction Impact on Wet Soil Machine weight, tire size and tire inflation pressure Soil moisture plentiful, no impact however in dry years, yield loss Controlled traffic Reduce field operations Increase speed and decrease depth of field cultivator or disk

5 Suggestions for Moist Soil Conditions For no-till corn, plant populations may be improved by the use of seed firmers Surface soil drying can be enhanced by residue cleaning with row cleaners from the row area or by residue disturbance with rotary harrows in advance of planting. Chemical weed control is essential for system success. If rains have prevented timely burndown or residual herbicide application and certain problem weeds are beyond the stage for satisfactory chemical control, tillage may be required. Banding of starter fertilizer for corn is less beneficial with progressively later no-till planting. Achievement of a uniform planting depth and good closure of the seed furrow is essential (especially if dry weather follows planting into marginal soil moisture situations).

6 Should I consider switching from their normal full-season maturity hybrids to shorter-maturity hybrids? risk of the crop not reaching physiological maturity before a killing fall freeze risk of high grain moisture content at harvest estimate the GDDs remaining from a delayed planting date to the end of the season using longterm climate data and then choose hybrids with GDD ratings that should mature no later than the date you chose to define "the end of the season".

7 Heat Unit Concepts Related to Corn Development Commonly used terms for thermal time are Growing Degree Days (GDDs), Growing Degree Units (GDUs), or heat units (HUs) Daily accumulation of GDDs as the average daily temperature (degrees F) minus 50. Daily maximums greater than 86 degrees F are set equal to 86 in the calculation of the daily average temperature. Similarly, daily minimums less than 50 degrees F are set equal to 50 in the calculation. If the daily maximum temperature was 90 degrees F and the minimum was 72 degrees F, the GDD accumulation for the day would be (( ) / 2) - 50 or 29 GDDs. hybrids mature in fewer GDDs than expected when planted "late". Relative to a May 1 planting date, hybrids planted later mature approximately 6.8 fewer GDDs for every day of delay beyond May 1 (Nielsen et al., 2002).

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10 Corn-Planting-Affects-Crop-Management- Decisions/

11 Would Grain Sorghum be better choice for delayed corn planting? Alternative to corn as feed yellow endosperm sorghum varieties Suited to soils marginal to corn Limited market, have a contract in place Herbicides are limited compared to corn Bird damage Limited seed Field dry down may be slower Off-type sorghum plants to avoid risk of volunteer sorghum Limit to June 20 planting date

12 Cultural Practices Hybrid selection (maturity, yellow endosperm, chemical seed safeners) Planting depth one-inch Varies 13,000 to 24,000 seeds per pound and seeding rate 70,000 + Narrow rows Corn herbicides applied, risk of injury Nitrogen needs similar to corn but following soybean, nitrogen reduced Harvest 20% moisture or less

13 Calibrate planters using seed spacing 15-inch spacing at 70,000 plants 3.9 inches 30-inch spacing at 70,000 plants 1.9 inches Only 65 to 70% of planted seeds will emerge Since seed size varies, pounds per acre is not accurate

14 Grain Sorghum Labeled Herbicide Preemergence Atrazine Duall II Magnum/Cinch IntRRo 4L Lexar EZ Lumaz EZ Paramount Bicep II Magnum Bicep Lite II Magnum Cinch Lite ATZ Fultime NXT Verdict Linex Postemergence Aim 2E Atrazine Banvel/Clarity Basagran Buctril Paramount Peak Permit Starane 2,4-D amine 2,4-D LV ester Buctril/Atrazine Huskie Laddok S-12 Shotgun Yukon

15 Switching to Soybeans? Narrow rows Seed treatments? Hard to predict response so consider risks Seeding rates same for 30-inch and 15-inch Start with weeds killed before planting Marestail and Waterhemp If a July planting stay with Group III

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20 Soybean Seed Treatments? Poorly drained, no-tilled, continuous soybean and history of replanting Cool wet springs Post planting problems such as soil crusing, temporary flooding, soil compaction, poorly drained soils Low seeding rates SDS

21 Corn Herbicides Applied Labels have recrop intervals listed for different crops following herbicide application Families with long-lasting herbicides Pigment inhibitors Are soybeans are sensitive to herbicide family?

22 Group1 Site of Action Family Trade name 1 ACC-ase inhibitor fops 'dims' quiazalofop clethodim Assure II Select 2 ALS inhibitor sulfonylurea nicosulfuron Accent imidazolinone imazethapyr Pursuit 3 Mitosis inhibitor dinitroalinine trifluralin pendimethalin Treflan Prowl 4 Synthetic auxin phenoxy 2,4-D many benzoic acid dicamba Clarity 5 Photosystem II inhibitor2 triazine atrazine many 6 PS II inhibitor2 - bromoxynil Buctril 9 EPSPS inhibitor - glyphosate Roundup 10 Glutamine syn. inhibitor glufosinate Ignite 13 Carotene inhibitor - clomozone Command 14 PPO inhibitor diphenylether fomesafen Reflex - flumioxazin Valor 15 LC fatty acid inhibitor acetamide s-metolachlor acetochlor Dual II Magnum Harness 19 Auxin transport inhibitor diflufenzopyr Status 22 Photosystem I inhibitor bipyridillium paraquat Gramoxone 27 HPPD inhibitor triketone tembotrione Laudis - isoxaflutole Balance Flexx 1Herbicide group designated by Weed Science Society of America according to site of action. Group number is listed on most herbicide labels. 2 Groups 5 and 6 bind to the same target site, but at different locations on the protein.

23 Crops Planted with No Herbicide Use highest rates Use products that are most effective with hard to control weeds Add correct adjuvants, study the label Look for product combinations to create syngerism What has your dealer had success with?

24 Big Weeds

25 Marestail in Soybeans Roundup Ready soybeans is probably a tank-mix of glyphosate plus FirstRate. full labeled rates of glyphosate, adjuvants, including ammonium sulfate Other tank-mixes to consider with glyphosate for controlling marestail would include Classic and Synchrony herbicides. Some marestail may also be ALS resistant, in which case FirstRate, Classic, and Synchrony would also be fairly ineffective. Liberty herbicide has also provided fairly good control of large marestail as a burndown treatment or postemergence in Liberty Link soybeans.

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29 Before planting soybean and marestail escapes, start weed free Gramoxone plus Sencor (don't have to wait) Or gramoxone plus 2,4-D (have to wait) Liberty plus Sencor

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31 Nitrogen Losses in Corn NutrientManagement/

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35 Wayne Flanary Cell THANK YOU!