Soybean. Fungicides: Efficacy and Economics

Wheat Corn Soybean Fungicides: Efficacy and Economics HEATHER KELLY, EXTENSION/RESEA RCH PLANT PATHOLOGIST DANNY MORRIS, AREA FARM MANAGEMENT SPECIALIST UNIVERSITY OF TENNESSEE

Disease Pyramid Factors needed to result in yield loss due to disease PEST 1. Pathogen influenced by field history, location, etc. 2. Environment promotes disease development 3. Susceptible host variety 4. Time all 3 factors have to occur at a critical time/growth stage For yield loss to be an issue

Image from southernstates.com F6-F9 Scout for leaf diseases - infections begin on lower leaves (news.utcrops.com) F 10.5.1 Spray for Scab fungus infects through the blooms (use www.wheatscab.psu.edu for risk)

bu/a Wheat 2013-2017 Fungicide Trials 7 6 5 4 3 2 1 0 1.3 Yield (bu/a) above Non-treated check 1.7 4.6 4.6 early early+bloom early+flag flag bloom Fungicide Timing # treatments 17 2 13 35 59 5.8

Top Yield Robbing Diseases in Corn Upper side of leaf Grey Leaf Spot Lower side of leaf Southern Rust news.utcrops.com For in season disease updates

Corn Growth Stages Image from aganytime.com, adapted from Univ. of IL agronomy handbook, 1999

Average Corn Yield Response to Fungicides (bu/a) Summary Data from 15 states and Ontario, Canada 2010 n=160 2011 n=57 2012 n=343 2013 n=425 2014 n=462 Avg n=1447 Early (V5-V8) 3.4 2.1-1.1 0.1 2.3 1.0 Standard (VT-R2) 4.5 0.4 4.9 4.5 7.6 5.4 Double (V5 + R1) 7.4 4.5 3.0 3.7 4.9 4.4

2014 National Corn Disease Data Standard fungicide timing (VT-R2) observations Less than 5% final disease on non-treated control (n = 86): +3.0 bu/a More than 5% final disease on non-treated control (n = 121): +11.1 bu/a

Soybean Best timing for fungicide application - growth stage R3 (beginning pod ~0.25 inch long pod at one of 4 uppermost nodes on main stem) Fungicide response factors: Variety Field history Disease pressure/environment

Soybean Variety Disease Trials o County Standard Trial (CST) varieties are evaluated in small, replicated plots at o Multiple locations (varying disease pressures) o With and without fungicide application at R3 o Disease rating data: Frogeye Leaf Spot, Target Spot, Stem Canker, Sudden Death Syndrome, Charcoal rot, Cercospora Leaf Blight, and Soybean Cyst Nematode o 2013 2017 data in searchable database @ http://search.utcrops.com/disease/ o Larger database is being build by group of specialists http://search.utcrops.com/ o PDFs also available @ UTcrops.com

2017 Variety Disease Data -Field history and yearly environment affects Average 5.2 1.9 1.2 http://search.utcrops.com/ Average 2015 yield 2016 (bu/a) 2017 response 2015to 2016 fungicide 2017 2015 2016 2017 Disease pressure Severe RECM JAX Severe-Moderate WTREC Moderate-Low MG III MG III 5.2 4.5 3.8 3.2 7.6 2.8 - - - 3.8 2.8 - MG IV E 6.1 5.0 3.9 3.4 5.1-1.4 3.5 1.9 - MG IV E 3.9-1.4 - MG IV E - LL - - 7.0 - - 0.6 - - - LL MG IV E 7.0 0.6 - MG IV L 7.5 6.6 4.1 5.0 6.2 2.8 4.6 4.4 0.9 MG IV MG L - LLIV L 5.6 4.84.1 8.4 2.8 3.5 5.5 0.9 2.7 - - 1.5 MG V LL MG IV 7.5 L 6.98.4 4.2 2.7 5.2 8.8 1.5 3.8 - - - Average MG V 6.4 5.34.2 5.2 3.8 4.1 6.7-1.9 4.1 3.5 1.2 5.6 4.2 2.9

http://search.utcrops.com/ 2017 Variety Disease Data Example scenario Should I spray a fungicide on my soybeans? What s the variety and field history? Seeing any disease? AgriGold G4835 RX variety, have it in multiple fields with different histories Based on variety trial data, spraying a fungicide at R3 protected: 6.5 bu/a in severe disease pressure location 0.9 bu/a in moderate disease pressure location 1.9 bu/a in a low disease pressure location (after wheat) Across all locations, average of 3.1 bu/a fungicide response

2017 Fungicide Trials Conducted at 2 to 3 locations Fungicides applied at R3 growth stage Verification 5 highly effective fungicide combinations evaluated across 3 cultivars, varying in disease susceptibility Make Your Own Mix Fungicide combinations compared to pre-mixed fungicide across FLS susceptible cultivar

Verification Trials 2017 Across all locations, all products significantly protected yield, regardless of cultivar, but analysis by location showed No effect on yield from cultivar or fungicides at low disease pressure location (wheat-beans) Yield (bu/a) Yield FLS Suscept. (bu/a) Response Cultivar -at Mod-Severe Yield Pressure (bu/a) Location FLS Resistant Cultilvar - AG4934, Severe Disease Pressure AG4632, Severe Disease Pressure Priaxor+Tilt Topguard EQ Quadris+Tilt+Topsin a 57.1 Acropolis Quadris Top SBX a 55.9 Quadris+Tilt+Topsin a 55.8 Acropolis (domark+topsin) Priaxor+Tilt a 53.7 Topguard EQ (quadris+topguard) Quadris Top SBX a 53.4 NTC b 46.3 NTC Table 4 in report Table 3 in report Priaxor+Tilt Topguard EQ NTC bc Quadris Top SBX c Quadris+Tilt+Topsin d Acropolis 45 50 55 48 60 50 52 54 56 58 4560 62 5064 55 60 abc ab a b 49.4 b 52.8 b 52.6 b 52.1 b 51.3 a 57.0

Fungicide Trials make your own mix 2016 Jackson - Yield (bu/a) Quadris+Domark a 53.3 Quadris+Tilt (6+3) Quadris+Tilt (4+4) Quadris Quadris+Tebu Star ab 52.0 ab 51.3 ab 50.4 b 49.8 Non-treated Check c 46.3 42.0 44.0 46.0 48.0 50.0 52.0 54.0

Fungicide Trials make your own mix 2017 Yield (bu/a) - across 2 locations Quadris+Topguard Quadrist+Tilt+Topsin Aproach Prima Quadris+Proline Quadris+Domark Quadris+TebuStar Quadris+Tilt NTC * * b 48.6 a 52.8 a 55.2 a 55.0 a 54.3 a 54.3 a 53.9 a 53.9 * Phytotoxicity noted Significantly lower FLS ratings than non-treated 44.0 46.0 48.0 50.0 52.0 54.0 56.0

Resources for fungicides: UTcrops.com Fungicide efficacy tables Diseases listed across the top Products listed down the left, grouped by fungicide MOA Each product rated from Poor to Excellent

Economics of Fungicide Applications - Review economics of fungicide applications in the following crops: Wheat Corn Soybeans - Various scenarios for each crop - Break-even charts for each crop

Economics of Wheat Applications - Evaluate applying an early applied fungicide versus spraying at bloom - Targeted disease is septoria and head scab (Fusarium Head Blight/FHB) - Early application is tebuconazole and bloom application is Prosaro

Fungicide Application in Wheat Wheat Scenario: Apply full rate of tebuconazole early Benefit Yield Increase (bushels per acre) 1.30 Price per bushel $ 4.50 Gross Revenue Gain from Fungicide Application $ 5.85 Expenses Chemicals: Tebuconazole (Early Application) $ 2.65 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 7.72 Net Gain from Fungicide Application per Acre $ (1.87)

Fungicide Application in Wheat Wheat Scenario: Apply full rate of Prosaro at bloom Benefit Yield Increase (bushels per acre) 5.80 Price per bushel $ 4.50 Gross Revenue Gain from Fungicide Application $ 26.10 Expenses Chemicals: Prosaro (Bloom Application) $ 12.46 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 17.53 Net Gain from Fungicide Application per Acre $ 8.57

Break-even Points for Wheat Fungicide Application Break-even Scenarios for Wheat Wheat price Application cost ($/A) ($/bu) $ 10.00 $ 12.00 $ 14.00 $ 16.00 $ 18.00 $ 20.00 $ 22.00 $ 24.00 $ 4.00 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 $ 4.25 2.4 2.8 3.3 3.8 4.2 4.7 5.2 5.6 $ 4.50 2.2 2.7 3.1 3.6 4.0 4.4 4.9 5.3 $ 4.75 2.1 2.5 2.9 3.4 3.8 4.2 4.6 5.1 $ 5.00 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 $ 5.25 1.9 2.3 2.7 3.0 3.4 3.8 4.2 4.6 $ 5.50 1.8 2.2 2.5 2.9 3.3 3.6 4.0 4.4 $ 5.75 1.7 2.1 2.4 2.8 3.1 3.5 3.8 4.2

Fungicide Application in Corn - Evaluate fungicide response in corn based on summary data from 15 states and Ontario, Canada - Look at early application (V5-V8) versus standard application at (VT-R2) Evaluate applications in high disease pressure versus low disease pressure Main diseases include southern corn rust and grey leaf spot

Fungicide Application in Corn 15 State & Ontario Study Corn Scenario: Southern Rust and Gray Leaf Spot; Early Application (V5-V8) with full rate Benefit Yield Increase (bushels per acre) 1.00 Price per bushel $ 3.60 Gross Revenue Gain from Fungicide Application $ 3.60 Expenses Chemicals: Stratego YLD (Early Application) $ 11.48 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 16.55 Net Gain from Fungicide Application per Acre $ (12.95)

Fungicide Application in Corn 15 State & Ontario Study Corn Scenario: Southern Rust and Gray Leaf Spot; Standard Application (VT-R2) Benefit Yield Increase (bushels per acre) 5.40 Price per bushel $ 3.60 Gross Revenue Gain from Fungicide Application $ 19.44 Expenses Chemicals: Stratego YLD (Standard Application) $ 11.48 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 16.55 Net Gain from Fungicide Application per Acre $ 2.89

Fungicide Application in Corn National Corn Disease Data Corn Scenario: Standard Application (VT-R2) less than 5% of final disease on non-treated control Benefit Yield Increase (bushels per acre) 3.00 Price per bushel $ 3.60 Gross Revenue Gain from Fungicide Application $ 10.80 Expenses Chemicals: Stratego YLD (Standard Application) $ 11.48 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 16.55 Net Gain from Fungicide Application per Acre $ (5.75)

Fungicide Application in Corn National Corn Disease Data Corn Scenario: Standard Application (VT-R2) more than 5% of final disease on non-treated control Benefit Yield Increase (bushels per acre) 11.10 Price per bushel $ 3.60 Gross Revenue Gain from Fungicide Application $ 39.96 Expenses Chemicals: Stratego YLD (Standard Application) $ 11.48 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 16.55 Net Gain from Fungicide Application per Acre $ 23.41

Break-even Points for Corn Fungicide Application Break-even Scenarios for Corn Corn price Application cost ($/A) ($/bu) $8 $10 $12 $14 $16 $18 $20 $22 $24 $3.00 2.7 3.3 4.0 4.7 5.3 6.0 6.7 7.3 8.0 $3.25 2.5 3.1 3.7 4.3 4.9 5.5 6.2 6.8 7.4 $3.50 2.3 2.9 3.4 4.0 4.6 5.1 5.7 6.3 6.9 $3.75 2.1 2.7 3.2 3.7 4.3 4.8 5.3 5.9 6.4 $4.00 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 $4.25 1.9 2.4 2.8 3.3 3.8 4.2 4.7 5.2 5.6 $4.50 1.8 2.2 2.7 3.1 3.6 4.0 4.4 4.9 5.3 $4.75 1.7 2.1 2.5 2.9 3.4 3.8 4.2 4.6 5.1

Fungicide Applications in Soybeans - Evaluate fungicide applications in different maturity groups of soybeans - Look at the disease pressure of soybeans and how that impacts the economics of a fungicide application - Consider the potential impact that a variety s disease package has on fungicide applications - All data for soybeans comes from the 2015-2017 variety disease data testing conducted by UT Extension

Fungicide Applications in Group III Soybeans Soybeans Scenario: Varying Diseases; Application (R3); Maturity Group 3; Severe Disease Pressure Benefit Yield Increase (bushels per acre) 4.50 Price per bushel $ 9.70 Gross Revenue Gain from Fungicide Application $ 43.65 Expenses Chemicals: Sample Fungicide Treatment (Quadris Top SBX) $ 14.65 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 19.72 Net Gain from Fungicide Application per Acre $ 23.93 Soybeans Scenario: Varying Diseases; Application (R3); Maturity Group 3; Moderate Disease Pressure Benefit Yield Increase (bushels per acre) 4.53 Price per bushel $ 9.70 Gross Revenue Gain from Fungicide Application $ 43.97 Expenses Chemicals: Sample Fungicide Treatment (Quadris Top SBX) $ 14.65 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 19.72 Net Gain from Fungicide Application per Acre $ 24.25

Fungicide Applications in Late IV Soybeans Soybeans Scenario: Varying Diseases; Application (R3); Maturity Group Late 4; Severe Disease Pressure Benefit Yield Increase (bushels per acre) 6.07 Price per bushel $ 9.70 Gross Revenue Gain from Fungicide Application $ 58.85 Expenses Chemicals: Sample Fungicide Treatment (Quadris Top SBX) $ 14.65 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 19.72 Net Gain from Fungicide Application per Acre $ 39.13 Soybeans Scenario: Varying Diseases; Application (R3); Maturity Group Late 4; Low Disease Pressure [Soybeans Planted after Wheat] Benefit Yield Increase (bushels per acre) 3.18 Price per bushel $ 9.70 Gross Revenue Gain from Fungicide Application $ 30.85 Expenses Chemicals: Sample Fungicide Treatment (Quadris Top SBX) $ 14.65 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 19.72 Net Gain from Fungicide Application per Acre $ 11.13

Fungicide Applications in Soybeans: Comparison Between Resistant and Non-resistant Varieties Soybeans Scenario: Varying Diseases; Application (R3); FLS Susceptible Variety; Severe Disease Pressure Benefit Yield Increase (bushels per acre) 7.10 Price per bushel $ 9.70 Gross Revenue Gain from Fungicide Application $ 68.87 Expenses Chemicals: Sample Fungicide Treatment (Quadris Top SBX) $ 14.65 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 19.72 Net Gain from Fungicide Application per Acre $ 49.15 Soybeans Scenario: Varying Diseases; Application (R3); FLS Resistant Variety; Severe Disease Pressure Benefit Yield Increase (bushels per acre) -0.50 Price per bushel $ 9.70 Gross Revenue Gain from Fungicide Application $ (4.85) Expenses Chemicals: Sample Fungicide Treatment (Quadris Top SBX) $ 14.65 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 19.72 Net Gain from Fungicide Application per Acre $ (24.57)

Fungicide Applications in Soybeans: Comparison Between Resistant and Non-resistant Varieties Soybeans Scenario: Varying Diseases; Application (R3); FLS Susceptible Variety; Severe Disease Pressure Benefit Yield Increase (bushels per acre) 7.40 Price per bushel $ 9.70 Gross Revenue Gain from Fungicide Application $ 71.78 Expenses Chemicals: Sample Fungicide Treatment (Priaxor + Tilt) $ 16.25 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 21.32 Net Gain from Fungicide Application per Acre $ 50.46 Soybeans Scenario: Varying Diseases; Application (R3); FLS Resistant Variety; Severe Disease Pressure Benefit Yield Increase (bushels per acre) 4.40 Price per bushel $ 9.70 Gross Revenue Gain from Fungicide Application $ 42.68 Expenses Chemicals: Sample Fungicide Treatment (Priaxor + Tilt) $ 16.25 Application Costs (equipment, repair, fuel, & labor) $ 5.07 Total Expenses $ 21.32 Net Gain from Fungicide Application per Acre $ 21.36

Break-even Points for Soybean Fungicide Applications Break-even Scenarios for Soybeans Soybean price Application cost ($/A) ($/bu) $ 10.00 $ 12.00 $ 14.00 $ 16.00 $ 18.00 $ 20.00 $ 22.00 $ 24.00 $ 8.75 1.1 1.4 1.6 1.8 2.1 2.3 2.5 2.7 $ 9.00 1.1 1.3 1.6 1.8 2.0 2.2 2.4 2.7 $ 9.25 1.1 1.3 1.5 1.7 1.9 2.2 2.4 2.6 $ 9.50 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 $ 9.75 1.0 1.2 1.4 1.6 1.8 2.1 2.3 2.5 $ 10.00 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 $ 10.25 1.0 1.2 1.4 1.6 1.8 2.0 2.1 2.3 $ 10.50 1.0 1.1 1.3 1.5 1.7 1.9 2.1 2.3 Cost for Various Treatments: Priaxor + Tilt = $16.25 - Generic Quadris + Generic Tilt = $13.32 Quadris Top SBX = $14.65 - Generic Quadris + Generic Tilt + Topsin = $18.94 Per acre application cost of $5.07 - Total Costs for all treatments = $18.39 - $24.01

Break-even Points for Soybean Fungicide Applications Here, a 3 bushel increase from the fungicide application is needed for a profitable return. Break-even Scenarios for Soybeans Soybean price Application cost ($/A) ($/bu) $ 10.00 $ 12.00 $ 14.00 $ 16.00 $ 18.00 $ 20.00 $ 22.00 $ 24.00 $ 8.75 1.1 1.4 1.6 1.8 2.1 2.3 2.5 2.7 $ 9.00 1.1 1.3 1.6 1.8 2.0 2.2 2.4 2.7 $ 9.25 1.1 1.3 1.5 1.7 1.9 2.2 2.4 2.6 $ 9.50 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 $ 9.75 1.0 1.2 1.4 1.6 1.8 2.1 2.3 2.5 $ 10.00 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 $ 10.25 1.0 1.2 1.4 1.6 1.8 2.0 2.1 2.3 $ 10.50 1.0 1.1 1.3 1.5 1.7 1.9 2.1 2.3 Cost for Various Treatments: Priaxor + Tilt = $16.25 - Generic Quadris + Generic Tilt = $13.32 Quadris Top SBX = $14.65 - Generic Quadris + Generic Tilt + Topsin = $18.94 Per acre application cost of $5.07 - Total Costs for all treatments = $18.39 - $24.01

Take Away from Economic Analysis Cost of application has a large impact on the net return from fungicide application. Know the fields environment and growing conditions to calculate the benefit of a fungicide application. Factors to consider: moisture, seed variety disease package, historical presence of disease, and signs of existing disease. You should consider all costs of fungicide application including: chemicals, equipment, labor, fuel, and time.