Smithco Turf Spraying Guide - Manual (Page 9)

charts are available at the end of this guide for some of the most popular tips used in the Turf industry.
Do not confuse the term volume with application rate, which will be covered later.
As pressure increases, the flow volume through a given nozzle also increases. For example, an
average size nozzle which discharges .52 GPM (1.4 LPM) at 30 PSI (2 BAR), will discharge .73 GPM
(2 LPM) at 60 PSI (4 BAR). In this example, an increase in pressure of 100% has caused an increase
in discharge of 40%
Some nozzles deliver a small volume (for example, 0.2 GPM [.75 LPM]). Some nozzles deliver a
relative large volume (for example, 1.5 GPM [5.7 LPM]), or 7 1/2 times as much as the smaller nozzle
in this example.
We will discuss more on the types of nozzles as we address the nozzle's other functions.
The amount of material (volume) to be applied is determined by the type of effect the chemical is to
have on the turf.
Just some brief general comments on turf management chemicals. They are made for four general
purposes:
1. Fungicides
Prevent or cure fungus on turfgrass.
They are made in 2 general types:
a. Systemic Chemicals enter the plant system and protect or cure it of
fungus.
b. Contact Kills fungus with which it comes into contact
2. Insecticides Eliminate damaging insects and worms (such as grubs, beetles, ants, etc.)
3. Herbicides Control and eliminate undesirable weeds and grass from turf areas and
non-turf areas such as bunkers, trails, fences, etc.
4. Nutrients & Fertilizer Promote growth, beauty and color in turfgrass
Some materials have to be applied so that they get into the soil below the plant leaves. (This is called
"soil application") In order to do this; they are best applied with a large volume of water. They are often
then watered in" using the irrigation system. This type of chemical material includes systemic
chemicals and chemicals designed to destroy pests, which live in the thatch and the soil.
Other materials must be applied to reach a problem that is present on the plant leaves. This is called
Foliar Application and requires a lower volume of water. Instead of irrigation water, dry air and
sunshine further activate these materials. They include contact fungicide and many herbicides.
Above all, the user of sprayers and chemicals must follow the directions provided with the spray
material. It is the only way to insure safe and effective results. It provides information on how much
chemical and how much water is to be applied to the area to be sprayed.
The second function of a nozzle on a sprayer is to form the liquid into droplets.
The size of the droplet is determined by two factors:
1. The design of the nozzle
2. The system operating pressure (PSI / BAR)
Some applications are done best by big droplets such as
systemic fungicides and insecticides and some herbicides
in order to reduce drift. Other applications
require small
droplets like contact fungicides and some herbicides.
This, again, often is determined by whether the chemical is foliar applied or soil applied. Large droplets
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