Calibration is critical How many gallons of mix per acre? Constant walking speed, spray pressure, nozzle type Different people walk different speeds Careful calculation of pesticide per gallon of water depends upon calibration
Calibration is critical Proper pesticide rate per acre = Enough product to control the pest Too much product can damage trees and waste money Too much product is illegal Not enough product wastes money, doesn’t kill the pest, can cause weed escapes
Pesticide use: IPM Correctly identify the pest Is the pest population above a level of damage concern? Can an early treatment stop the population & reduce the need for repeated applications? Is the pest life cycle at the succeptable time to treat?
Don’t spray by the calendar! Are you a licensed applicator? - necessary for purchase & application of Restricted Use Pesticides
Choosing a Christmas tree pesticide Always read and follow all label directions There must be specific recommendations for the site: Christmas trees Conifer plantations? Not forestry (Oust XP) Not non-crop
Modes of Action questions Why does one pesticide control some species but not others? You can tank mix some pesticides Two or more herbicides in a tank Mix an insecticide + a fungicide
Herbicide activity types Foliar spray: what stage of plant growth is best for control? Early leaf, bud stage, full extension, late summer? Soil active spray: prevent weed seed germination
Soil Active Herbicides: Conifers & Plant selectivity Physical selectivity: Soil active – solubility, soil adsorption breakdown half life Herbicide location in soil vs. plant roots Growth stage selectivity: Weeds actively growing? Seedling weeds? Conifers dormant?
What does this all mean to the grower on the ground? Mix herbicides with different modes of action can broaden the weed control spectrum: Westar: Oust + Velpar pre-mix Mix your own: glyphosate + Atrazine Understand the seasons of control by herbicide
Herbicides and conifer safety Conifer safety depends upon the herbicide Dormant conifers are less likely to be damaged Directed sprays reduce tree exposure and damage
Prevent herbicide resistant weeds! Rotate your herbicide use Use different mode of action herbicides Tank mix with different modes of action herbicides
Insecticide & miticide use Scout often to watch for insects & mites When do they hatch? What is the population trend? What is the best growth stage for good control? Weather forecast: hot weather can cause a mite population explosion
Miticide modes of action What life stage does the pesticide kill the insect or mite? Egg, larva, adult? Does the miticide kill the adults or adults and the eggs? Does the pesticide kill beneficial insects too?
Fungicide use Scout your fields for needle discoloration, fungal fruiting bodies from last year When will the trees be harvested? Most fungicide treatments are 2-3 years before harvest. Especially the harvest year!