Sprayer Technology for Applying Organic Products

Dr. Jason S.T. DeveauApplication Technology Specialist

SimcoeFebruary, 2014

According to Ontario Publications 360 and 838, there are 23

sprayable organic and biopesticide products registered for use in Ontario on vegetables,

and 28 on fruit (c.2014)

And that doesn’t include all the other things you might spray, like teas, fertility amendments, etc.

No matter what you spray, a successful application must account for six influencing

factors

Far too much for a 30 minute talk…

Horizontal Boom

Handboom & Mistblower

Handgun & Trolley

Airblast

There are all sorts of organic sprayers

All sprayers have the same basic parts

All sprayers have the same basic parts

PumpStrainer

Tank

Boom and Nozzle(s)

All sprayers have the same basic parts

PumpStrainer

PressureGauge

Tank

Bypass

Boom and Nozzle(s)

Agitator

Tip Strainers

If the goal of spraying is to achieve a safe, efficient and effective result, we have to talk about a few key sprayer components and how they impact your results

Pressure affects

everything:

•droplet size•output rate

•spray angle •droplet count

Consistent Pressure = Consistent Output

Install a gauge Save your arm…

Use CO2

Pressure + Nozzle Selection = Output

Pressure + Nozzle + Density = Output

THINER WATER THICKER

Tabulations in a nozzle catalogare based on spraying water.

If your spray mix is thin, or viscous, it could change the output by as much as

Calibrate your sprayer

Here’s what it can mean…Here’s what it can mean…

You can’t just eyeball the boom because you can’t detect even a 50%

difference in output from nozzle to nozzle

Perform a timed output test!Perform a timed output test!

The Importance of Becoming Agitated

If you don’t use hydraulic or mechanical

agitation, many products (e.g. copper, kaolin clay, etc.) will fall out of suspension. Or perhaps

they’ll separate. You’ll get uneven mixing, and very spotty coverage

SEPARATES EMUSLIFIES

No agitation?No problem.

Adopt the ‘wiggle’

method and sway as you

spray!

Here’s a situation where agitation impacted an organic

application

The Case of the Missing NematodesAn organic product mis-applied

A classic three-point hitch boomA classic three-point hitch boom

The tools of the tradeThe tools of the trade

Notice!

Monitoring pressure

Collecting in a graduated

vessel

Timing for one minute

(not pictured)

Counts per millilitre over time– where were our nematodes?

Samples taken over 2 hour time span

Cou

nt p

er m

l

Downward trend in live nematodes sampled

Ideal nematodeconcentration

The only form of agitation used…The only form of agitation used…

Were they mashed by the roller pump?Were they mashed by the roller pump?

Were they snagged by the bypass?Were they snagged by the bypass?

Were they caught in the filters?Were they caught in the filters?

By the way, I certainly hope you have three levels of filtration, compost tea people – tank, pump and nozzle!

By the way, I certainly hope you have three levels of filtration, compost tea people – tank, pump and nozzle!

Research has shown (and our work confirmed) that nematodes survive the roller

The bypass was barely operating because the pump was maxed out

Our theory? They are clinging to the inside walls of the poly tank, like soap scum in a bathtub, and desiccating there

Possible solution: Tank Rinse Nozzle

We tried it the next season.

Found ‘em!

There are three places spray can go once it leaves your nozzles

On the target crop

On the ground: miss or runoff

Into the air: drift

To achieve sufficient coverage, you have to know

your target

The nature of the pest, its location, and the product’s

mode of action should impact how

you spray

Soil pest

Disease under leaf

Weed

Insect on fruit

There’s a quick and easy way to know if your spray hit your target, and what kind of coverage you achieved

Looking for wetness or residue on leaves, noting a cloud behind the sprayer or waiting to see if your crop gets eaten are not viable methods

I always rememberto buy a few

packages

Try Water Sensitive Paper!

Courtesy of T. Wolf (AAFC)

125 L/ha 85 L/ha 45 L/ha

Fine

Medium

Coarse

VeryCoarse

ExtremelyCoarse

Placed in the target crop, it will show you where your spray is

going… or not going

It also tells you how to correct for any problems

<150 µm 150-300 µm >300 µm >300 µm (AI)

Fine dropletscover more

surfaces, butdrift

Medium dropletsprovide good coverage withmoderate drift

Coarse dropletsmay run off, bounce

or miss small targets,but have low drift

Similar to coarsebut may also shatter and

improve coverage

Droplet size and coverage

Imagine this golf ball and this ping pong ball are spray dropletsThe golf ball is a coarse droplet and the ping pong ball is a fine droplet

Imagine throwing them – how will they fly?

Droplet size & behaviour

Now, imagine throwing them twice as hard (i.e. increasing the

pressure) what will happen?

The clear winner!

Droplet Size & Behaviour

Only the golf ball goes further

This is why increasing pressure does not improve canopy penetration for small droplets. Ironically, higher pressure makes droplets even smaller!

Droplet Size & Behaviour

• Monitor pressure• Use agitation• Calibrate your equipment• Match droplet size and volume to

spray conditions• Account for target location and

product mode-of-action• Use water-sensitive paper to

monitor coverage and adjust your spray program accordingly

Take Homes

Sprayer Technology for Applying Organic Products

Dr. Jason S.T. DeveauApplication Technology Specialist

SimcoeFebruary, 2014

Tom Wolf@nozzle_guy

Jason Deveau@spray_guy

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