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Agronomic Implications of Soybean Rust Shawn P. Conley Ellsworth Christmas Purdue University Soybean Production Systems

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2005 Soybean Production Q & A Should I plant soybean earlier? Should I plant an earlier maturing cultivar? Should I modify my row spacing & seeding rate?

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Should I plant all corn in 2005? Will rust affect double crop beans more than the full season varieties? Can I tank mix glyphosate with a fungicide? 2005 Soybean Production Q & A

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Should I Plant Soybean Earlier in 2005?

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Floral initiation Photoperiod: Short day/critical value to initiate floral induction Temperature regulates when flowers appear

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Effect of Early Planting Date on Soybean Yield, Davis PAC, 1991 21%

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Effect of Early Planting Date on Soybean Yield, SEPAC, 1991 31% 21% 4%

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Effect of Early Planting Date Soybean Yield, SEPAC, 1992 24% 7%

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Soybean Yield Response to Planting Date 1991-94

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Should I Plant an Earlier Maturing Cultivar in 2005?

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Effect of Maturity on Yield -----------Grain Yield ----------- RegionM.G.Maturity200403-0402-04 229/1364.455.357.2 239/2167.658.959.6 329/0462.558.259.3 339/1465.162.763.3 349/2265.4** 439/1961.856.251.2 449/2864.857.452.7 2004 UI Variety Testing

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Implications for Early Variety Matured an average of 9 days earlier Average 4.5% yield loss 3 bushel yield loss @ $5.00 to $6.00 $15.00 to $18.00 for a fungicide application Risk assessment: 9 days vs. $18.00

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Should I Modify My Row Spacing and Seeding Rate?

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8% 3%

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Wheel Traffic Effect on Soybean Yield --------------Grain Yield --------------Estimated yield loss Center row Wheel track row Adjacent row 40 ft. boom 90 ft. boom ------------------------------bushel a -1 ------------------------------ 2 (VC)56.937.361.60.30.1 3 (V1)57.236.762.00.30.1 4 (V2-4)58.034.763.10.40.2 5 (V4-5)59.631.564.80.50.2 6 (V7-R1)61.826.967.20.60.3 2,459.625.467.60.70.3 3,559.824.868.00.70.3 4,660.722.969.00.70.3 Piper, Swearingin, Nyquist. 1989.

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Increased Income Compared to Increased Seed Cost for Solid Seeded Soybeans Seeding rate comparison Increased seed cost/A 2800 seeds/lb (140 k) Increased Income $/A $20/unit$25/unit$30/unit$5.00/bu$6.00/bu 200 to 30014.2917.8621.437.008.40 200 to 2507.148.9310.714.505.40 150 to 30021.4326.7932.1413.5016.40 150 to 25014.2917.8621.4311.0013.80 150 to 200 7.14 8.9310.716.50 7.80

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Increased Income Compared to Increased Seed Cost for Solid Seeded Soybeans Seeding rate comparison Increased seed cost/A 3200 seeds/lb (160 k) Increased Income $/A $20/unit$25/unit$30/unit$5.00/bu$6.00/bu 200 to 30012.5015.6318.757.008.40 200 to 2506.257.819.384.505.40 150 to 30018.7523.4428.1313.5016.40 150 to 250 12.50 15.6318.7511.00 13.80 150 to 200 6.25 7.819.38 6.507.80

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Should I Plant all Corn in 2005?

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Corn Yield Response to Tillage and Rotation from 1975 to 2004 in West Lafayette, IN (Chalmers silty clay loam) 1975-20032004Yield Gain for Rotation (%) Tillage systemC/SCCC/SCC75-032004 ---------Yield (bu/acre)--------- Moldboard176.4168.5213201 56 Chisel Plow176.9164.0209198 85 No-till172.5146.2207179 1816 T.D. West, T.J. Vyn, G. Steinhardt

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Corn Yield Response to Tillage and Rotation from 1997 to 2004 in Wanatah, IN (Sebewa loam) 1997-20032004Yield Gain for Rotation (%) Tillage systemC/SCCC/SCC97-032004 ---------Yield (bu/acre)--------- Moldboard188174230210 89 Chisel Plow189170234211 11 No-till184161224206 149 T.D. West, T.J. Vyn, G. Steinhardt

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Factors to Consider in Continuous Corn Yield loss (11 to 23 bushels in 2004) Higher tillage costs: No-till ineffective Associated higher soil erosion costs Higher optimum N rates ( 40 units N) Pest control may now be a wash T.D. West, T.J. Vyn, G. Steinhardt

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Will rust affect double crop beans more than the full season varieties?

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10 8 5 3 30 July June 28 26 24 22 21 20 19 18 Average Date For the Start of Wheat Harvest

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Average Indiana Soybean Development

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Increased Double Crop Risk? Vegetative versus reproductive stage Increased risk of early infection Multiple applications may be required Open canopy and airflow considerations? Yield potential versus increased risk?

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Can I Tank Mix Glyphosate With a Fungicide?

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Factors to Consider Drift and Nozzle Selection Droplet size and Pressure Herbicide: > 400 m and low pressure Fungicide: < 220 m and higher pressure Timing: Herbicide vs. fungicide Glyphosate: 4 to 6 for annuals; 6 to 12 perennials; up to 50% bloom Fungicide: R1 and later Label Issues: Tank mix partners? Vague Fungicides, Herbicides, and Soybean Rust, Do they Mix?

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Questions? conleysp@purdue.edu