This is the time of the year you must complete shopping for nozzles because the spraying season is just
around the corner. Although nozzles are some of the least expensive components of a sprayer, they hold a
high value in their ability to influence sprayer performance. First, nozzles meter the desired amount of
liquid sprayed per acre.
Second, nozzles help spray the liquid uniformly over the width of the sprayer boom. Third, nozzles
influence droplet size, affecting both target coverage and spray drift risk. For these key reasons, you
need to make sure your sprayer is equipped with the right kind and size of nozzles, and they are still
performing within the acceptable range of performance they delivered when they were new.
Why are specific nozzles required by manufacturers of 2,4-D and Dicamba Herbicides?
Although manufacturers of these products claim that the new formulations containing 2,4-D or Dicamba are
more resistant to drift of these active materials due to high volatility characteristics of similar
products used decades ago, they are still extremely concerned about the physical drift of these products
in droplets. Therefore, since these products are systemic in nature, they should work even when
large-size droplets are used during spraying. With this in mind, the manufacturers of these products
have decided on recommending specific nozzles that produce droplets that are in the category of “Extra
Coarse,” or “Ultra Coarse.” Physical drift of such large droplets will likely reduce the risk for drift
to minimum. Although there are many nozzles that can provide these desired droplet size classes at
certain pressures, at this point you are advised to choose exactly the nozzles identified on their
labels.
Keep several types of nozzles on the boom
It is very likely that you will be using your sprayers to spray a variety of pesticides during the
growing season. Remember that one specific type of nozzle will not be best for all applications. For
this reason, it is best to have several types and sizes of nozzles on the boom so that you can switch to
the “best” nozzle choice for a given spraying job. There are various types of sprayer components and
setups you can buy to configure your boom so the new set up allows you to easily switch from one nozzle
to another instantly.
Some final thoughts
Nozzles are typically the least costly items on a sprayer, but they play a key role in the final outcome
from a spraying job: achieving maximum efficacy from the pesticide applied while reducing the off-target
(drift) movement of pesticides to minimum. Pesticides work well if the rates on labels are achieved
during application. This can be achieved only if the right nozzle type and the proper size of the
nozzles are on the sprayer, and the sprayer is operated properly.
A new Ohio State University Extension Publication, entitled “Selecting the Best Nozzle for the Job” gives
step-by-step guidelines for selecting the most appropriate spray nozzle for a given application
situation. The publication is available online: http://ohioline.osu.edu/factsheet/fabe-528.