If there ever was a time when sprayer set up was easy, that time is long gone. It disappeared as quickly as increasing weed resistance made it apparent that you could no longer rely on glyphosate as your primary weapon in every situation.

Bryan Young, a Purdue University weed scientist, researches nozzles and sprayer settings to obtain control and avoid drift with many types of herbicides. He discussed his findings with Indiana Prairie Farmer. Here are some basic thoughts he offers before you head out to spray.

IPF: The conventional, extended-range flat fan nozzle was a traditional nozzle for years. Is it still what most people use today?

Young: No. The older, flat fan nozzles from the 1980s tend to produce spray droplets which are finer than what you need to achieve with many products today. There is a wide range of newer style of nozzles which do a better job of delivering the correct droplet size for many of the products that farmers apply today.

IPF: Two common nozzle angles are 80 and 110 degrees. Traditionally many people used 80-degree nozzles. Is that still true today?

Young: No. The trend is toward 110-degree nozzles. The wider angle of spray tends to give better coverage and more spray overlap with the herbicides used today.

IPF: If you are going to apply Liberty for the first time, what should you know?

Young: It is a different product than glyphosate, and it must be applied differently. Glyphosate is a systemic herbicide, which is translocated within the plant. Liberty is a contact herbicide. Coverage is extremely important with contact herbicides, which aren’t absorbed and moved up and down inside the plant.

IPF: How can you obtain good coverage spraying Liberty?

Young: Increased carrier volume is a must. If you were only applying 10 gallons of total spray volume per acre with glyphosate, you need to apply at least 15 gallons per acre if you’re spraying Liberty. Applying 20 gallons per acre is better. It’s all about obtaining adequate coverage within the canopy so the contact herbicide can kill weeds.

IPF: If carrying extra spray volume is an issue but you’re committed to spraying Liberty, is there any way to reduce the amount of volume?

Young: Some get good results at 15 gallons per acre. Many who do so reduce their spray droplet size from what they’ve typically used with glyphosate to create more droplets to provide better spray coverage. However, we’re still not talking fines. We’re talking coarse droplets that are somewhere between fine droplets that drift and extremely coarse or ultra-coarse droplets recommended for dicamba. Even then, you won’t get good results if you drop under 15 gallons per acre.

IPF: For dicamba in a dicamba system, what size drops do you need?

Young: First, check the appropriate website for approved nozzles and spray pressure for each herbicide label. These combinations will essentially produce extremely coarse to ultra-coarse droplets. If you see fines fogging up from around the boom, stop! Applications using smaller droplets are illegal and could run into drift issues.