In order to get the most out of a herbicide program, the herbicide must be applied accurately and uniformly. This is particularly difficult when applying granular herbicides.!
# 1 Landscape Weed Control Challenge: Proper Application!!!!
Herbicides are applied on a Per Area Basis! NOT oz per gal!
YES:- oz per 1000 sq. ft.
- oz per gallon applied to 1000 sq. ft.
NO:
- oz per gallon
- % (exception - Roundup)
- oz per backpack
Granules: uniform spread Pre-measure amount for area; See table 1 for pre-measure amounts for circular landscape beds Spread herbicide over the area in different directions at least 3 times
Sprays: Calibrate sprayer. Output per area basis! .
Maintain constant - pressure, walking speed, nozzle height. Today pretend you are a tractor!
Broadcast vs. directed; Broadcast is preferred; yet directed applications in tall trees & shrubs are practical.
Rarely do we use % by volume. Exceptions - spot applications of glyphosate, glufosinate and spray adjuvants
% = percent = # per 100
So, 2 % = 2 ounces in 100 ounces = 2.5 ounces per gallon (1 gallon = 128 ounces)
0.25% Surfactant in 1 gallon --- 0.25% is 0.25 per 100
128 ounces x 0.0025 = 0.32 ounces
NOT 32 ounces!! That would be 25%Grams of granular herbicides needed for circular landscape beds of various diameters
| Grams of Product, by Recommended Rate (lb Prod/A) | ||||||
|
Diameter |
Area |
80 |
100 |
125 |
150 |
200 |
|
(ft) |
(ft2) |
----------(grams of herbicide product)---------- | ||||
|
4 |
12.6 |
11 |
13 |
16 |
20 |
26 |
|
6 |
28.3 |
24 |
29 |
37 |
55 |
59 |
|
8 |
50.3 |
42 |
52 |
65 |
78 |
105 |
|
10 |
78.6 |
65 |
82 |
102 |
123 |
164 |
Study Questions
Complete these problems and bring your work to the next class.
- You have a landscape bed that is approximately 0.2 acres in size. You wish to apply Surflan 4L at a rate of 4 Quarts Per Acre.
- How much Surflan 4L (the product) will you need to treat this bed?
- Your sprayer delivers 30 gallons per acre. How many gallons of spray will you need to treat this landscape bed?
- You are using a 4-Gallon sprayer. How much Surflan 4L will you put in the sprayer?
- You wish to add 2% (by volume) Roundup-Pro to this spray application. How much Roundup-Pro do you put in the 4-gallon sprayer?
- You wish to apply Pendulum 2G as a granular preemergence herbicide for crabgrass and goosegrass control to a landscape bed. The recommended rate of application for 150 lb product per acre.
- How much Pendulum 2G would be needed to treat a landscape bed that is 5000 sq. ft.?
- You need to calibrate your rotary spreader to achieve this rate. You measure the width of the pattern to be 10 ft, and there is a 50 ft piece of plastic. There are 454 g/lb. Determine how many grams of product should be collected on this sheet of plastic to properly calibrate the spreader.
