Good pest management is key to any growing facility. Insects and diseases can cause huge economic losses when they prevent sale or cause damage that reduces yield. The tools used in this fight are key. While you need the right pesticides to control your problems, the right equipment ensures that these products hit their target. If your equipment is hobbled by maintenance issues, your problems can worsen, even though you are using expensive chemicals and labor to solve them. Proper sprayer maintenance can help ensure your applications are effective and make the most of your pesticide applications.
Low Hanging Fruit – Spray Nozzles
One of the simplest things any grower can do to keep their sprays effective is to replace nozzles. Spray equipment is meant to perform in a specific way. For a hydraulic sprayer, solution is pressurized and pumped to the gun. When the trigger is pulled, the solution reflects off internal components in the gun and exits through the nozzle. The flow rate and pressures combine with the geometry in the gun and the nozzle to create spray droplets. A new nozzle will provide the desired spray droplets. In general, finer droplets will cover more surface area and reduce run-off. (you can learn more about spray droplets in our white paper: Selecting the Right Sprayer)
However, over time, these nozzles will wear with pressure and abrasive solutions. As they wear, the flow increases, as does the droplet size. Often, growers won’t be aware of these changes, but it is not atypical for worn nozzles to increase their output by 25%. If a grower is expecting 1 gallon per minute with their sprayer, but are, instead, getting 1.25 gpm, they are most likely using more water and more pesticide per square foot than intended. They are creating larger droplets, providing poorer coverage, and they are losing more spray solution to run-off. In short, they are using more product for a worse result.
Considering that spray nozzles cost far less than one container of any pesticide, regular replacement should be common and is an inexpensive sprayer maintenance must. With seasonal greenhouses, we recommend annual replacement. In year round facilities, replace your nozzles every 6 months to ensure that they are calibrated properly, allowing your equipment and spray team to be more effective.
Filters
Almost all sprayers have some type of filter to protect the nozzles from clogging and to reduce pump wear. These filters are normally visible and easy to reach. However, sometimes they are under the tank or below the pump. Often, they do not have an isolation valve that allows you to shut off the flow so you can open the filter cartridge and clean the screen. This requires you to plan ahead. This also makes prevention more important. If you fill the tank to spray and find the filter is blind, you need to drain to get at the filter. If the filter is clean beforehand, there is less of a concern.
Both sediment in the water and chemicals can clog filters. Make sure that these are regularly cleaned to prevent a loss of flow to the pump. Clogged filters can reduce pressure and flow.
Sometimes filters need to be removed for specific chemistries, such as some biorational pesticides. In these cases, make sure to obsessively flush the pump and plumbing to prevent issues later.
When cleaning your filters, inspect them for wear. Areas that become plugged with deposits or, worse, holes in the screen, means it is time to replace the cartridge.
Finally, if your sprayer or fogger uses air, there are often air filters that may need attention. The Dramm Autofog or the TurboULV both employ air filters to protect the compressor or blower. If these clog, this will reduce the air to the nozzles and impact the compressor or blower over time as they heat up from working harder to take in air. Some air filters can be cleaned, others need replacement over time.
Pumps
The pump is the heart of any sprayer. Over time, they will need some attention. Seals are meant to create pressure from a piston or diaphragm. As seals wear, pressure declines. Additionally, if your pump is oil-lubricated, you may see water in the oil sight. This is a sure sign that the seals need replacement. Another sign is when your sprayer is difficult to prime or does not build appropriate pressure. Your sprayer manufacturer should offer a seal kit with instructions on how to replace these parts. The Dramm Hydra and Dramm MSO Sprayer both have kits for this service.
O-Rings
Sometimes there are o-rings and gasket seals that need replacement. Look for leaks at threaded fittings and replace these to ensure proper spray and pressure. This can also help you from getting inadvertently sprayed during an application.
Systems using air often have o-rings in the air system. The Autofog has o-rings at the nozzle that should be replaced annually as part of our Annual Maintenance Kit. While these o-rings failing won’t get you wet, they will reduce the ability of the fogger to do its job properly.
Clamps, fittings & hoses
When undertaking seasonal maintenance on your equipment, it is a good time to check that fittings are threaded tightly and hose clamps are snug. Inspect these for cross-threading or wear. Check all hose fittings to ensure that use has not weakened any connections that might come loose under pressure. Make sure to check connections at the pump, hose reel and other places where the pressure is high.
Anytime you are taking stock of the connections, check your hoses for wear. These are often dragged over rough surfaces and around jagged metal corners with pressurized spray solution inside. Hoses take a lot of abuse. Inspect the jacket for cuts and nicks that could become holes. Look at the ends near the fittings for weakening that could split.
If you see damage, replace the hose before it becomes an issue during an application.
Thorough Cleaning
Periodic sprayer maintenance is a great time to wash away the seasons-worth of chemical deposits, peat-dust and residue that has layered on your spray equipment. A light detergent or dish-soap will often be all that is necessary to help remove old spray material that has collected.
Cleaning the tank with dish-soap or Tank Cleaner can help remove pesticide residue from inside the tank.
Finally, a good system flush, running plenty of plain water through the pump, bypass, regulator, reel, spray hose and gun will ensure your sprayer is ready to go for the next crop.
The Dramm Team is ready to help with parts, tips and service if needed. Reach out to your Dramm representative or to our service team with questions on how to best maintain your Dramm sprayers.
