Presentation on theme: "Scouting and Fungicides Jeff Miller. Scouting for Disease Can be used to determine when to apply fungicides – When needed instead of “just because” Very."— Presentation transcript:
Scouting and Fungicides Jeff Miller
Scouting for Disease Can be used to determine when to apply fungicides – When needed instead of “just because” Very useful for late blight Not applicable for some diseases – Rhizoctonia – Pink rot – White mold – Early blight
Principles of Scouting Pages 142-144 1.Examine every field 2.Take a directed sample (altered from book) 3.Sample across the entire field 4.“Take” enough samples 5.Keep good records
What is a Fungicide? Any substance or mixtures of substances intended for preventing, destroying, repelling, or mitigating fungal pests. Definition adapted from the Environmental Protection Agency www.epa.gov/pesticides/
Think of Fungicides as Crop Medicines
Fungicides for Use in Potato Soil fumigant Seed treatments Soil-applied products Foliar-applied products Post-harvest applications
Soil Fumigation – Shank Injection
Soil Fumigation – Chemigation Chemical injected through water. Sensitive to drift by wind. Large buffer zones necessary.
Potato Seed Treatment Dust, liquid, or both Dust – Alder, fir bark – 6% MZ – Worker hazard Liquid ST – Low volumes (e.g. 4 fl oz/cwt)
Soil-Applied Fungicides Incorporated during row-markout – Broadcast – incorporated – Banded in the row In-furrow at planting – Low volume (~5 gpa) – Banded over the seed piece
Foliar Applications 1.Aerial – Airplane – Helicopter 2.Chemigation – Injection in water 3.Ground
Foliar Application Comparisons ChemigationAerial Cost/acre$1.50-2.50$7.00-9.00 Spray Volume~ 4500 gallons (0.10-0.15”)5-10 gallons Labor (grower)HighVery low Residue in canopyLow*High* Estimated usage40-45%45-50% Canopy residue is lower with chemigation, but distribution is more uniform.
Post-Harvest Fungicides After harvest, prior to placement in storage Few fungicides labeled – Thiabendazole – Phosphorous acid – “Disinfectants” During storage Applied as a volatilized product through plenums – “Disinfectants” – Phosphorous acid
Disinfect vs. Disinfest
Miller Research LLC
Pesticide Labels When used according to the label, pesticides will not cause unreasonable harm to the environment. The label is the law as to how a product can be used.