Spray or Not to Spray: Scout- Based Fungicide Decisions in Wheat. Andrew Friskop NDSU Cereal Extension Plant Pathologist

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1 Spray or Not to Spray: Scout- Based Fungicide Decisions in Wheat Andrew Friskop NDSU Cereal Extension Plant Pathologist

2 Wheat Disease Plan for Know your variety 2. Common diseases 3. Cropping system 4. Pay attention to weather 5. Use forecasting models 6. Scout!! *Fungicide response will vary depending on variety susceptibility, weather and cropping systems

3 Wheat Disease Plan for Know your variety

5 Wheat Disease Plan for Common diseases 3. Cropping system

6 Resident Fungal Diseases Tan spot Septoria Fusarium Head Blight (Scab) s/ /logov2.png

7 Non-Resident Fungal Diseases Leaf rust Stripe rust

8 Wheat Disease Plan for Pay attention to weather

9 Weather

10 Wheat Disease Plan for Use forecasting models

13 Wheat Disease Plan for Scout!!

15 Fungicide Response

16 Foliar Fungicide Timing Trials replicated trials in Fargo Varying levels of disease 1. Low Disease (few lesions on oldest leaves) 2. Moderate Disease (Flag-1 Leaf) 3. High Disease (Flag Leaf)

17 Foliar Fungicide Timing Trials replicated trials in Fargo Varying levels of disease 1. Low Disease (few lesions on oldest leaves) 2. Moderate Disease (Flag-1 Leaf) 3. High Disease (Flag Leaf)

18 Low Disease Very few lesions in lower canopy Planted into broadleaf Cool weather Low amounts of moisture and dew No disease development prior to flag leaf Only a few lesions at soft dough

19 Foliar Fungicide Timing Trials replicated trials in Fargo Varying levels of disease 1. Low Disease (few lesions on oldest leaves) 2. Moderate Disease (Flag-1 Leaf) 3. High Disease (Flag Leaf)

Moderate Disease on Flag-1 10-20% of leaf covered with lesions Planted cultivated wheat ground Cool weather Sporadic events

20 Moderate Disease on Flag % of leaf covered with lesions Planted cultivated wheat ground Cool weather Sporadic events of moisture and dew Few lesions in lowest part of canopy at flag leaf Disease progressed onto flag-1, very few lesions on flag

21 Foliar Fungicide Timing Trials replicated trials in Fargo Varying levels of disease 1. Low Disease (few lesions on oldest leaves) 2. Moderate Disease (Flag-1 Leaf) 3. High Disease (Flag Leaf)

22 High Level of Disease on Flag Leaf Planted into minimal till wheat Cool weather Frequent events of moisture and dew Rust and tan spot detected on all leaves around flag leaf High level of severity on flag leaf at soft dough

23 Foliar Fungicide Timing Trials Low Disease - 13 Trials Moderate Disease - 26 Trials High Disease - 20 Trials Triazoles and Strobilurins 4-6 leaf stage and flag leaf

24 Fungicide Timing Yield Response Percent (%) Difference from check % 1% Low Disease 4-6 leaf Flag 3% 4% Moderate Disease on Flag-1 Leaf 4% 9% High Disease on Flag Leaf Disease Pressure

25 Fungicide Timing Disease Risk Mean Yield Response % Anticipated Wheat Yield 50 bu 60 bu 70 bu 80 bu 4-6 Leaf Low 0.01% 0.05 bu 0.06 bu 0.07 bu 0.08 bu 4-6 Leaf Moderate 3% 1.5 bu 1.8 bu 2.1 bu 2.4 bu 4-6 Leaf High 4% 2.0 bu 2.4 bu 2.8 bu 3.2 bu Flag Leaf Low 1% 0.5 bu 0.6 bu 0.7 bu 0.8 bu Flag Leaf Moderate 4% 2.0 bu 2.4 bu 2.8 bu 3.2 bu Flag Leaf High 9% 4.5 bu 5.4 bu 6.3 bu 7.2 bu *Based on mean values over 59 replicated trials at Fargo, ND *Yield response may be higher or lower depending on year, environment, disease

26 Fungicide Economic Decision Tool Montana State University and North Dakota State University Online tool Uses several variables to predict economic return on fungicide application

27 Fungicide Timing Disease Risk Leaf Yield Response % 50 bu 60 bu 70 bu 80 bu 4-6 Leaf High Flag 4% 2.0 bu 2.4 bu 2.8 bu 3.2 bu

28 Fungicide Timing Disease Risk Leaf Yield Response % 50 bu 60 bu 70 bu 80 bu Flag Leaf High Flag 9% 4.5 bu 5.4 bu 6.3 bu 7.2 bu

30 Fungicide Application for Scab Triazoles only (efficacy differences) -Prosaro, Caramba, Folicur Scout fields for growth stage -Heading, flowering etc. Weather conditions prior and at heading -Forecasting models, gut-instinct

32 USWBSI Scab Timing Trials

FHB - Variety by Fungicide Timing 7 Non-treated 6 6.

33 FHB - Variety by Fungicide Timing 7 Non-treated Flowering Flowering days DON Level (ppm) % % % 77% Susceptible Moderately Resistant Variety Reaction to Scab 2014 & 2015 Fargo and LREC

34 Summary Stay ahead of foliar diseases -Use all management tools -Scout Scab application -Consider risks -Window of application has widened

DISEASE AND FUNGICIDE MANAGEMENT FOR CORN & WHEAT Heather M. Kelly Field Crops Plant Pathology West Tennessee Research and Education Center

DISEASE AND FUNGICIDE MANAGEMENT FOR CORN & WHEAT Heather M. Kelly Field Crops Plant Pathology West Tennessee Research and Education Center University of Tennessee Disease Pyramid 1. Plant susceptible