Foliar Disease Management in Pulses What are the tools and how to use them

Sabine Banniza, Crop Development Centre Steps for disease management decisions

1. Disease identification 2. Assessment of severity of infection 3. Assessment of risk for further spread 4. Identification of short-term management tools 5. Long-term management strategies

Step 1 DISEASE IDENTIFICATION

Organisms that cause plant diseases Fungi (: 5 – Viruses 50 μm) (17-1000 nm)

Bacteria Mollicutes (0.6 – 3.5 μm) (0.3 – 1.0 μm) Nematodes (250μm – 12mm) SYMPTOMS CAUSED BY PLANT PATHOGENS

CHLOROSIS

SCABS & CANCERS NECROSIS

WILTS

S. Chatterton GALLS & TUMORS Chickpea ascochyta blight Lentil ascochyta blight Pea ascochyta blight Faba bean ascochyta blight

Lentil anthracnose Lentil stemphylium blight Sclerotinia (L) and (R) on lentil Chocolate spot of faba bean

Soybean pictures (bottom row in the presentation) from University of Minnesota Extension (copyright protected) (https://www.extension.umn.edu/agriculture/crop-diseases/soybean) BUT….

….some of these symptoms can be mixed up with • Herbicide damage • Nutrient deficiencies • Physiological abnormalities • Environmental damage

Faba bean

Chocolate spot Herbicide or surfactant burn Soybean Many (but not all) major diseases in W-Canada are caused by fungi

PEA LENTIL CHICKPEA FABA BEAN SOYBEAN Ascochyta blight (each crop with its own species) Septoria brown spot Anthracnose (Anthracnose) Bacterial blight Botrytis grey mould (Botrytis cinerea) Chocolate spot Frog eye (Botrytis fabae) spot (Cercospora) Sclerotinia white mould Stemphylium blight Anthracnose Aphanomyces root rot Phytophthora stem rot Pythium & root rots Fusarium root rots Disease identification

• Disease guides: → DFCC – APS compendia (http://my.apsnet.org/APSStore/C ategory?Category=Compendium) • Diagnostic Labs • APPs (?) Step 2 ASSESSMENT OF SEVERITY OF INFECTION

When to scout

• Root rots: – Seedling stage as root rot is most damaging • Foliar diseases of chickpea: – throughout the lifecycle for ascochyta blight • Foliar diseases of other pulses: – Whenever it has rained and/or your canopy has been wet – Definitely before canopy closure – After canopy closure, particularly for late season diseases

How to scout

• IN the field • Starting at spots with highest risk – adjacent to a field with infested crop residue – Spots with high fertility or high moisture levels Step 3 ASSESSMENT OF RISK FOR FURTHER SPREAD

SPREAD OF PATHOGENS

BY

Spores (fungi) Sclerotia (asexual melanized fungal cells) Infected plant debris, seed, plants….(all pathogens to varying degrees)

THROUGH

Wind Rain Vectors (insects, animals, YOU, YOUR TRACTOR) THE DISEASE TRIANGLE

Pathogen: Environment: Abundance RAIN Amount virulence humidity of disease temperature

Host: susceptibility Infection process

Symptoms Appressorium Germ tube Penetration peg

Germination & Penetration Incubation period Cell invasion, symptom development, new spores Lentil Fungicide Decision Support Systems Fungicide Decision Support Systems For chickpea: http://www.agriculture.gov.sk.ca/Default.aspx?DN=8 319f54f-769e-4db5-ba9f-807ad9c60204 (or http://www.agriculture.gov.sk.ca/crops Then click on chickpea production diseases ascochyta blight of chickpea) Step 4 IDENTIFICATION OF SHORT- TERM MANAGEMENT TOOLS

Short-term management tools

• Fungicide application – Rotate active ingredients

Fungicides: The more colourful the better CHEMICAL GROUP 3 7 11 44 M3 M5 FUNGICIDE NAME \RESISTANCE RISK med med high low low low Acapela Bravo 500, Echo 720 Delaro Dithane, Kingpin, Manzate, Pencozeb Elatus Headline EC Lance Lance AG Priaxor Proline Propel, Tilt Propulse Quadris Quash Quilt Serenade Vertisan

Short-term management tools

• Fungicide application – Rotate active ingredients – Timely application before or within about 24 h after rain – No fungicide is transported throughout the plant → new growth is unprotected – Actives will eventually degrade (see pre-harvest interval) – Efficacy of applications decreases as canopies become denser (late season diseases, aka sclerotinia)

Short-term management tools

• Manage crop canopy – Dense canopy = wet canopy = higher disease risk – Weed management • Keep your plants stress-free & happy (….whatever it takes) – Adequate fertilization Picture removed because of copyright protection Step 5 LONG-TERM MANAGEMENT STRATEGIES

#1 Tool: CROP ROTATION

• Aphanomyces infested land: – No pea or lentil for 6 to 8 years • Land free of Aphanomyces: – 4-year rotation, but see host range of pathogens Picture removed because of copyright protection Many major diseases in W-Canada are caused by fungi

PEA LENTIL CHICKPEA FABA BEAN SOYBEAN Ascochyta blight (each crop with its own species) Septoria brown spot Anthracnose Anthracnose Bacterial blight (?) Botrytis grey mould (Botrytis cinerea) Chocolate spot Frog eye leaf (Botrytis fabae) spot (Cercospora) Sclerotinia white mould Stemphylium blight Anthracnose Aphanomyces root rot Phytophthora stem rot Pythium & Rhizoctonia root rots Fusarium root rots # 2-6 Tools

• Cultivars with resistance • Disease free seed • Seed treatment • Correct plant density, adequate nutrient supply • Good weed control

GENERAL INFORMATION ON DISEASES

SK Ministry of Agriculture http://www.agriculture.gov.sk.ca/crops Then click on [Your Crop] production diseases Ag Knowledge Centre Tel.: 1-866-457-2377, Got a question? E-mail: [email protected] http://www.agriculture.gov.sk.ca/AKC SPG: http://saskpulse.com/growing/

Thank you !

Picture removed because of copyright protection