review of 2013 vine crop diseases - cornell un 2014-05-15¢  surface irrigation water...

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  • Chris Smart Plant Pathology and Plant-

    Microbe Biology Cornell University

    Geneva, NY

    Review of 2013 Vine Crop Diseases

  • Growing vine crops has become difficult!

  • Common Diseases

    • Powdery mildew • Virus diseases • Downy mildew • Phytophthora blight

  • Powdery Mildew Podosphaera xanthii

    • VERY common – we see it every year

    • Some varieties have resistance

    • Kills leaves – Sun scald

    • Weakens handles in pumpkins

    • More susceptible to some other diseases

  • Powdery Mildew

    • Evidence that the pathogen can overcome some plant resistance – This is still the way to go!

    • That the pathogen can overcome some fungicides

    • Effective fungicides (conventional and organic) are available

  • Common Diseases

    • Powdery mildew • Virus diseases • Downy mildew • Phytophthora blight

  • Virus Diseases

    • Watermelon Mosaic – present every year, arrives later in the season

    • Cucumber Mosaic –not here every year or in every field, arrives early

    • Aphid transmitted • Post bloom – only foliar

    symptoms • Pre-bloom – fruit

    symptoms Photo: Marc Fuchs

  • Virus symptoms

    Cucumber Mosaic Watermelon Mosaic Photo: Marc Fuchs

  • Common Diseases

    • Powdery mildew • Virus diseases • Downy mildew • Phytophthora blight

  • Cucurbit Downy Mildew Pseudoperonospora cubensis

    Attacks all cucurbits – cucumbers most susceptible

  • Symptoms • First symptom is a

    yellowing spot on the upper surface of the leaf

    • Spots expand turning tan and papery, but are bordered by veins

    • Lower leaf surface has gray spores

  • Lesions

  • Bottom of Leaf

  • Mildews

    Powdery Mildew

    Downy Mildew

  • Downy Control • The pathogen blows in either from the south,

    or from greenhouse production around lakes Erie and Ontario, and generally does not arrive until late July or August – In Eastern NY, inoculum could come from either

    source, and usually arrives later in the season • No commercially available resistant cucurbits

    – but I am working with several breeders and we have high hopes!

    • Vegetable news letters provide information on where downy has been reported

    • Excellent website http://cdm.ipmpipe.org/ – Sign up for alerts

    http://cdm.ipmpipe.org/

  • Downy Control

    • The downy mildew pathogen is closely related to Phytophthora (both are water molds), many fungicides that are effective against downy are also labeled for Phytophthora blight – Many water-mold specific fungicides – Broad-spectrum protectant fungicides provide

    some control • Follow outbreaks and know when the

    pathogen is in the area

  • Common Diseases

    • Powdery mildew • Virus diseases • Downy mildew • Phytophthora blight

  • Phytophthora Blight Phytophthora capsici

  • Wide Host Range

  • Symptoms • Wilting and plant

    death – Crown and root rot

    • Fruit rot • Stem and leaf

    lesions

  • Phytophthora Blight

    • Over winters as thick- walled spores in the soil

    • Small white spores produced during the growing season, can’t survive over winter

    • Swimming spores also produced

  • What do spores look like?

    Oospores Sporangia Zoospores

  • How Does Phytophthora Move?

    • Culled fruit • Cultivation • Soil (tractor tires) • Rain

    water/splashing • Irrigation water • Flood water • Does not move in

    air/wind

  • Surface Irrigation Water • 60% of NY vegetables are irrigated with

    surface irrigation water

  • Irrigation Sources

    Irrigation Ponds

    Creeks

    Erie Canal

  • Surface Irrigation Water • 60% of NY vegetables are irrigated with

    surface irrigation water • Surveyed 20 sites across NY for

    Phytophthora capsici once a month for 2 years – pathogen can be present in water

    • Improving detection methods to identify pathogens quickly

    • Comparing methods for decontamination

  • What are we working on now?

    • Making great use of the ‘blight farm’

  • Blight Farm

    • Five faculty now have P. capsici projects • Testing different varieties for resistance • Testing integrated control strategies • Ways to improve soil health – cover crops • Pathogen detection • Four 2-acre blocks, one block is organic

  • Management Strategies

    • If you don’t have Phytophthora blight – KEEP IT OFF YOUR FARM!

    • If you have Phytophthora blight – Promote good drainage – Choose tolerant varieties – Rotate – Rogue if possible – Use effective fungicides (ROTATE

    CHEMISTRIES)

  • Management Strategies

    • Commonly used fungicides – Ranman – Presidio (18-month plant-back restriction) – Gavel – Forum – Revus – Tanos – Phosphorous acid fungicides – Ridomil (perhaps once/season in Western NY)

  • Thanks! • Smart lab members • Grower cooperators • Vegetable Extension

    Educators • NYS Ag Expt Station • NYS Dept of Ag and

    Mkts • USDA - NIFA

  • Questions?

    Slide Number 1 Growing vine crops has become difficult! Common Diseases Powdery Mildew�Podosphaera xanthii Powdery Mildew Common Diseases Virus Diseases Virus symptoms Common Diseases Cucurbit Downy Mildew�Pseudoperonospora cubensis Symptoms Slide Number 12 Lesions Bottom of Leaf Mildews Downy Control Downy Control Common Diseases Phytophthora Blight�Phytophthora capsici Wide Host Range Symptoms Phytophthora Blight What do spores look like? How Does Phytophthora Move? Surface Irrigation Water Irrigation Sources Surface Irrigation Water What are we working on now? Blight Farm Management Strategies Management Strategies Thanks! Questions?