Management of tomato diseases in high tunnels
Daniel S. Egel, extension plant pathologist
SW Purdue Ag Center, Vincennes
812-886-0198 [email protected]
Botrytis gray mold
Botrytis gray mold
Botrytis gray mold
white mold/timber rot
white mold/timber rot
S. Koike
June 3
white mold/timber rot
July 1
white mold/timber rot
white mold
leaf mold
leaf mold
Dithane F45
Badge X2
Use and Calibration of a Backpack Sprayer
Dan Egel
SW Purdue Ag Center
812-886-0198
[email protected]
Label information is well adapted to tractor pulled sprayers
Dithane M-45 tomato rate
3 lbs/A
20 acre field
20 acres X 3 lbs/A = 60 lbs Dithane M45
How much water?
20 gallons per acre
20 acre field
20 gallons/A X 20 acre field = 400 gallons of water
Add 60 lbs of Dithane M45 in 40 gallons of water
What about small acreages?
• What type of equipment to use?
• Calibration
Equipment
“Garden” sprayers-advantages:
• Cheap
• Easy to find
• Easy to use
Disadvantages
• Nozzle volume output is variable-spray or stream
• Spray volume varies with pressure/time
• Wand arrangement makes calibration difficult
.cdn.cnn.com
Backpack sprayer-$80
4-gallon tank
Gauge
3-nozzle boom-$25
Pump
Flat fan nozzle• Designed for pesticides
• Constant output
Pressure gauge
allows one to keep
pressure the
constant.
Calibration
100
5 rows
3 foot
foot
Example area calibration
5 rows x 100 ft. = 500 linear ft. x 3 feet wide = 1500 sq. ft.
1500 sq. ft./43560 sq. ft./acre = 0.03 acres treated.
How much product is needed
Dithane F45 is labeled for tomatoes-silent on greenhouses
2.4 quarts (32 fl. oz/qt.) per acre x 0.03 acres treated =
0.07 quarts or 2.24 fl. oz.
2.24 fl. oz. in how much water?
Estimate water needed
Total area to be treated =1500 sq. ft.
To estimate how much water we need, we measure• 50 ft (150 sq. ft.) = 1/10 area to be treated.
Measure the area to be calibrated.
Fill sprayer with known amount of water-128 fl. oz.
Good volume
Spray water on calibration area.
Spray both
sides
Pump regularly
Pressure
gauge
Constant pace
Measure water left over from calibration spray.
1-Measure area for calibration
3-Spray out water.
2-Add known amount
of water to sprayer
4-Determine how
much water sprayed
In our example, we had 96 fl. oz. left.
128 fl. oz. – 96 fl oz. = 32 fl. oz.
32 fl. oz. x 10 (to equal total area
to be treated= 320 fl. oz.
We mix 2.24 fl. oz. of Dithane F45
in 320 fl. oz. water
Application/calibration tips
1. The person doing the spraying does the calibration
2. If the person or equipment changes, new calibration
3. Foliage should be thoroughly wet, not dripping.
4. Keep speed constant
a. Metronome
b. Music
How to calculate rate for dry
flowable?
Penncozeb tomato rate
2 lbs/A X 0.03 acres treated = 0.06 lbs
How to measure 0.06 lbs?
1 lb = 16 oz
0.06 lb X 16 oz = 0.96 oz
1 liquid oz.
22 grams
Weight of dry oz.=28.3 grams
Use of liquid measurement for dry oz. underestimates Penncozeb by 20%
$14 kitchen scale
allows
measurements
of small weights
Getty images
Botrytis gray mold
Name these tomato problems!
Blossom end rot
Late blight
•Late blight
•Blossom end rot
•Anthracnose
Anthracnose
Proper diagnosis is critical.
Blossom end rot
Late blight
•Calcium deficiency •Doesn’t overwinter
in the Midwest
Anthracnose
•Survives on
crop residue
Botrytis gray mold