Sprayers

You should decide which sprayer to use after you think carefully about how much weight you're willing to lift and carry around.

Handheld sprayers work perfectly well.  They're a bit of a pain when it comes to reducing spray material portions to suit their small capacity, but you may decide it's worth it for their light weight.  Besides, you can mix the total amount you'll need in a larger container and refill the sprayer as it empties.

I know a woman who uses identical soft plastic spray holders to moisten her clothes for ironing and to spray her roses (she never interchanges the two).  She bought both sprayers for under $2.00.

Tank sprayers range in capacity from two to five gallons.  The same handle you use to pump the sprayer doubles as a carrying handle, or as a shoulder strap if you want to transfer weight to your back.  The spray nozzle is at the end of a metal wand, connected to the tank by a rubber hose.  Tank sprayers are more expensive than handheld models, but they're still cheap.  If you take care of them and rinse container tanks after each use, they will outlive most of your bushes.

Backpack sprayers hold from three to seven gallons of spray material.  If your pelvis can take the weight, they're advantageous since both hands are free.  Spray material is compressed with air pumping the tank with a metal handle that can be attached on either side--if you do a lot of spraying, it's nice to be able to switch hands for pumping.  The nozzle and tank attachment are the same as for pump sprayers.

Larger containers require engines and container tanks with built-in agitators.  We use a fifty-gallon commercial model pulled by a tractor for spraying the field at Garden Valley Ranch, and we're just about to outgrow it.

Sprayers with electric motors are worth considering.  You won't wear yourself out pumping, and some models are designed to produce particularly fine mists of spray that cover foliage completely.

No matter which size sprayer you get, make sure the part holds spray materials is made of one of the modern plastics.  Except for stainless steel, metal tanks corrode and flake off into liquid spray material.  The size of your sprayer doesn't matter if your technique is right.  The woman I mentioned who uses the handheld sprayer does a better job spraying her bushes, because of her technique, than do many rosarians I know who use expensive motorized sprayers.