When drenching nursery crops, workers must be kept at least 100 feet away from the treated area.

True or False?
Answer: False

During drenching operations and until the expiration of the REI, workers and other persons must stay out of the treated area. (Only the treated area.)

The 100 foot restriction is for pesticides being applied:

• Aerially, or in an upward direction
• Using spray pressures greater than 150 psi
• Applying fumigants, smoke, mist, fog or aerosol

There is also a 25 foot restriction when pesticides are being applied:

• Downward, from a height of more than 12 inches above the medium
• Using a fine spray
• At pressures greater than 40 psi and less than 150 psi
• Or other circumstances not listed in both sections above and yet the label of the product requires use of a respirator.

NOTE: The Special Greenhouse Restrictions apply to fumigants, fogs, etc and other situations where the labeling requires use of a respirator and generally encompass the entire enclosed area.

Yellow Latex gloves are approved for spraying carbamates and organophosphates.

True or False?
Answer: False

Yellow Latex gloves are water resistant, not chemical resistant. The correct gloves for spraying carbamates and organophosphates are the green nitrile chemical resistant gloves.

Disposable Gloves

We tend to take the blowers for granted. The propeller blades just keep turning and blowing the air, but what we don't realize is that they need to be checked periodically and cleaned, to remove the residue that cakes up on the surfaces and makes them less efficient.

There can also be nicks and cracks caused by picked-up debris and fatigue, which can throw the propeller out of balance and produce vibrations. These vibrations usually affect the chassis and the tank to the extent that I have seen steel tanks crack and break or pumps break loose because of those vibrations.

So, when you're cleaning out filters, inspecting hoses and checking nozzles, take a good look at the blower: clean the blades (you may have to scrape them), tighten the bearings, lubricate the moving parts and check for loose bolts and broken brackets.

When our sprayer pressure does not come up, or takes a while to reach the setting, we blame the pump, when in many cases the problem is in the line leading to the pump.

A sprayer designed and built with some degree of engineering has a filtering system between the tank and the pump, and that system is sized in line with the suction capabilities of the pump. (I have seen sprayers built with no inlet line strainer - I have seen sprayers with undersized inlet lines and strainers)

The pump is the heart of the sprayer and needs to be protected. An undersized strainer and/or inlet line will cause high suction vacuum and put a strain on the inlet side of the pump very much like what Arteriosclerosis and clogged arteries will do to our own hearts. And so will a clogged strainer.

The rule of thumb for inlet lines and strainers is that they be of a diameter equal or greater than the suction end of the pump. Also look at the bulkhead fitting in the bottom of the tank where the suction line attaches and the shut-off valve right after it, these must also be that same size..(there should be a shut-off installed between the tank and strainer so that you can do maintenance work even with a full tank).

Any bottleneck in this system will overtax the pump. If your sprayer has any of the design flaws mentioned above, correct them immediately.

Periodic, and I mean periodic maintenance of inlet strainers is critical to your pump.

Surfactant Problem

When you clean out the mesh in the strainer, look for clumps of spray material. This will tell you that you are not agitating correctly or that your materials are not mixing well with the water - a surfactant problem.

Correct those problems right away and you will have less strainer clogging.

Poor Filtering

Also, look at the screen and make sure it is not deformed as this would cause poor filtering. The holes in the screen should be slightly smaller than the smallest nozzle in your spray system. If your mesh is too tight - very small holes - replace it with a lower mesh number (the lower the number, the larger the holes_ 50 and 20 mesh screens are the most popular, but if you have very small nozzles :D-1 or 8001's - you might need an 80 or 100 mesh filter). Selecting the correct screen will prevent nozzles clogs.

Poor Agitation

Poor agitation will also cause sedimentation of unmixed materials on the bottom of the tank. When the pump starts up these are drawn out all together and overload the strainer. Make sure you flush out the tank and spray lines after use and do not leave any sediment in the bottom or in the strainer.

When you reassemble the strainer, make sure the gasket is properly installed and in good condition. Many times I am called out to troubleshoot a pump and find the strainer is sucking air because the gasket is either not there, broken or crimped.

The pump would much rather pull air than water, because its easier and, when you have air in the system, you don't have pressure or your pressure is erratic.

Odd Objects

Another thing to look for is a clog in your suction line. I have found labels, old rags, socks, poly bags, paper and all sorts of other things clogging the inlet lines usually between the tank and the strainer. One way to check this out is to remove the strainer bowl, open the valve and watch the flow. If it does not come out with force and volume, check for an obstruction.

When initially you have normal pressure and it drops off some 30 seconds to one minute after opening the nozzles, you have an inlet obstruction. Correct it immediately. High suction vacuum may not show itself the same way, but can go undetected until the pump breaks down.

Pump failure will be evident in piston pumps generally in the inlet valve area. The valve discs will break outwards (sucked out). Diaphragm pumps can also have inlet valve failure, but their most common breakage is in the diaphragms. These are literally pulled away from the piston head because of the vacuum. Roller and centrifugal pumps will show cavitation wear in the housings, and seal breakdown.

Look at the pipes, valves and fittings on your spray booms. Make sure you have no bottlenecks on the way to the end of the booms. Remember, if you have a 1/2" pipe boom and the spray must go through a 3/8" valve to reach it, you have a bottleneck.

This can cause lower pressures out at the end of the boom and then your nozzles will not be putting out the same patterns and volumes as those close in.

Be logical and think in terms of an efficient irrigation system: always from larger to smaller until the end. Spend some time on it, look carefully, you may find an elbow, tee, fitting, close coupling, hose nipple, hose, filter, valve, anything that could cause that bottleneck. And it could be anywhere between the pump and the last nozzle.