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2004 Crop Production Considerations. Todd Vagts ISU Extension Crop Field Specialist. Talking Points. Rotation changes? Corn – Soybean Yield Comparisons Soybean Yield Plateau? Pest Considerations Soybean Corn. The Rotation Decision?. Traditional Corn-Soybean Corn-Corn-Soybean
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2004 Crop Production Considerations Todd Vagts ISU Extension Crop Field Specialist
Talking Points • Rotation changes? • Corn – Soybean Yield Comparisons • Soybean Yield Plateau? • Pest Considerations • Soybean • Corn Todd Vagts
The Rotation Decision? • Traditional Corn-Soybean • Corn-Corn-Soybean • Continuous Corn • Problems and Considerations Todd Vagts
Why Corn-Bean Rotation • Higher Yields (?) • Rotation Effect… • Lower fertilizer costs (?) • Less pest problems (?) • Weeds, insects, disease • Less crop residue to manage • Farm program (?) Todd Vagts
-7% -10% (1998-01) Todd Vagts
CS | C (1) | C (2) | CC CS | C (1) | C (2) | CC Todd Vagts
-9% Todd Vagts
2nd Year Corn • Potential 7 to 10 percent yield reduction compared to 1st year corn • Additional 2 to 4 percent yield reduction with 3 or more years of corn Todd Vagts
Rotation Yield Gains and Losses • 2nd Year Corn • 8% Yield reduction X (149 bu/A) = 11.9 bu • 11.9 bu/A X $2.48 = $28.56 (Disadvantage) • Soybean following 2nd Year Corn • 6% Yield Increase X (43.9 bu/A) = 2.6 bu • 2.6 bu/A X $6.04 = $15.70 (Advantage) Todd Vagts
Costs to Corn-on-Corn2nd year corn and 3rd year soybean Corn Yield Reduction Soybean Yield Gain -$28.56 + $15.70 = -$12.86 Todd Vagts
Nutrient Requirements Todd Vagts
Nutrient Costs Todd Vagts
Costs to Corn-on-Corn2nd year corn and 3rd year soybean Corn Yield Reduction Soybean Yield Gain Fertilizer Cost -$28.56 + $15.70 + -$12.00 (2 years) = -$24.86 (2 year) Todd Vagts
Yield and Rotation • Yield benefit to rotation most evident in lower yield environments (25%) • Yield benefit declines under high yield environments for both corn and soybean (15% or less) • Corn-Soybean rotation maximizes corn yield but not soybean yield • The Corn Soybean Rotation Effect, Joe Laurer Paul Porter and Ed Oplinger. University of Wisconsin. Todd Vagts
5-Year Average Soybean Yield Todd Vagts
5 Year Average Yield Todd Vagts
Greater Advantage to Corn “High corn yields relative to soybean yields” Todd Vagts
Yield Trends 1971 - 02 Iowa Calhoun County Todd Vagts
Yield Trend - 1997 - 02 Calhoun County Iowa Todd Vagts
6-Year Yield Trends Iowa 1997 – 02 1987 – 92 1977 - 82 Todd Vagts
6-Year Yield Trends Calhoun County 1997 – 02 1987 – 92 1977 - 82 Todd Vagts
Yield Trends for Iowa 6 Year Increments Todd Vagts
Yield Trends for Calhoun County 6 Year Increments Todd Vagts
Have Soybean Yields Reached a Plateau? • For Calhoun County, when compared to similar time periods in the past – No • Answer is more difficult to determine for the state Todd Vagts
Economics Todd Vagts
Shift Acres from Beans to Corn?2/09/04 R. Wisner ISU Econ. • Dec. corn futures $2.83 Less basis, N. Iowa 0.35 Harvest hedge price 2.48 • Nov. soybean futures $6.49 Less basis, N. Iowa 0.45 Harvest hedge price 6.04 Todd Vagts
Returns to Corn Production • Corn/soy: Harvest hedge price $2.48 Less variable prod’n costs @ 149 bu./A. (5-Yr Ave. Yield Calhoun County) 1.21 Net/bu. 1.27 Net/A. over variable cost $189.23 • Corn/corn: Harvest hedge price $2.48 Less variable prod’n costs @ 136 bu./A. (91% of C/S) 1.60 Net/bu. 0.88 Net/A. $119.68 Corn, Corn, SB rotation Todd Vagts
Shift Acres from Beans to Corn? • Corn/soy: Harvest hedge price $6.04 Less variable prod’n costs @ 50 bu./A. 2.17 Net/bu. 3.87 Net/A. $193.50 • Corn/soy: Harvest hedge price $6.04 Less variable prod’n costs @ 38 bu./A. 2.86 Net/bu. 3.18 Net/A.(excludes aphid spraying cost)$120.84 Disease, Nematode, aphid problems Todd Vagts 2/09/04
Return to corn C/S Rotation $189 ($1.27/bu) C/C/S $120 ($0.88/bu) Return to soybean Low Yield $121 ($3.18/bu) High Yield $194 ($3.87/bu) Economic Summary Todd Vagts
Other Factor to Consider • Greater percentage of farm in one crop – increases risk • Corn requires greater input expenses Todd Vagts
Pest Management Considerations • Corn • Western Bean Cutworm • Grape colaspis • Soybean • Soybean Aphid • Bean Leaf Beetle • Cyst Nematode • Soybean Rust (?) Todd Vagts
EGGS LARVA ADULT Corn Pests –western bean cutworm • Eggs: Small, whitish, clusters that turn purple prior to hatch • Larvae: New larvae ¼” long and dark brown, lighten to pale brown as they mature. Full size is 1½” • Adults: White band along most of the leading edges of forewings Todd Vagts
Corn Pests –western bean cutworm • Injury: • Different from other cutworms; ear feeders • Economic damage may occur when multiple cutworms feed on an ear • Injury allows pathogens into the ear Todd Vagts
Corn Pests – western bean cutworm Todd Vagts
Insecticides for western bean cutworm Organophosphates (RUP) Lorsban® 4E Penncap-M® Carbamates Sevin® XLR Plus Pyrethroids (RUP) Ambush®* Asana® XL* Capture® 2EC Baythroid® 2E Mustang® Max Pounce® 3.2EC* Warrior® *Mite risk See “Integrated Crop Management”(http://www.ipm.iastate.edu/ipm/icm/) or product labels for correct application rates. Todd Vagts
Corn Pests – colaspis beetles • Description • Honey-brown leaf beetle • Fine tan & brown lateral stripes on grooved wing covers • Larvae are small, “C”-shaped, grubs Todd Vagts
Corn Pests – colaspis beetles • Grubs feed on roots • Above-ground symptoms may include stunting, wilting, purpling of the stem and leaves, and tip and leaf-edge browning • Damage extent unknown Todd Vagts
Soybean Aphid Todd Vagts
Where is it now?Spread of Soybean Aphid in the US, 2000-2003 • Spread to S & W continues • Outbreaks in 2003 primarily in western half of NC states • Treatment occurred in DE & MD in 2003 Todd Vagts Slide from K. Ostlie, Data from R. Venette, unpublished data
Soybean aphid Description • Very small, yellow aphid, 1/16 inch long • Distinct black ‘tailpipe-like’ structures on end of abdomen • Wingless and winged forms • Appear in colonies of adult females and offspring • Females give birth to live females Todd Vagts
(Buckthorn) (Soybean) Todd Vagts
How fast can a soybean aphid reproduce? [data generated in the lab by Ragsdale et al., Univ. of Minnesota] Life span (days) 22 15 12 3 (die) First babies (# days) 7 5 5 -- Total # babies 75 73 23 0 Doubling time (days) 2 1.5 2 dead Temp 68oF 77oF 86oF 95oF Todd Vagts Chris DiFonzo, Michigan State University