During the years I have been teaching sessions on Spray Application Technology, I have many times opened up the session with a big poster that says: MORE IS NOT BETTER.

I have used that phrase to illustrate the need to reduce spray volumes and try to keep the spray material on the foliage and not let it dribble down onto the ground. And that is fine when you are spraying pesticides and nutrients on crops that you want to develop and grow.

But what about when you want to kill weeds. For years now, we have seemed to favor pouring everything but the kitchen sink at the weeds, hoping to eradicate them forever, and in our zeal we have used a lot of herbicide and a lot of water, thinking that, in this case, More IS Better!

Well - More may be better in some cases, but stop to think for a moment as to what we really want to accomplish when we spray herbicides: Kill the Weeds? Yes, but are we going to get results giving them a bath or will we get a better kill by making sure that the expensive materials we are applying stay where they are supposed to: ie:: on the plant?

L.T.R.

Enter Low Rate Technology a phrase coined by Monsanto to promote the more effective application of their new formula Roundup Ultra.

Low Rate Technology is nothing more and nothing less than just reducing the amount of water you mix with the herbicide and apply less volume on the crop, while maintaining the per acre rate of the chemical.

Because Roundup Ultra is an enhanced version of the old Roundup into which they have added surfactants, stickers and stabilizers and thus made it more user friendly, rainfast and improved the way it distributes on the foliage and gets absorbed by the stoma, it is ideal to apply with this new Low Rate Technology.

And you can adjust this Low Rate Technology to suit yourself as long as you keep the "per acre" dosage of the herbicide relatively constant. In other words, if you are presently using Roundup mixed at 0.5% and putting 2 quarts into 100 gallons in your tank and applying 100 gallons to the acre, you are effectively applying 2 quarts to the acre. You can re-calibrate your sprayer and reduce your application to 25 gpa or even down as far as 10 gpa, but always keeping the 2 quarts to the acre dosage.

What you accomplish with this is:

• Better effectiveness of herbicide because it stays on the plant and does not run off.
• Time and Labor savings due to fewer refills. Your sprayer can cover up to four times the acreage in one day as you reduce the number of time consuming fill-ups, and we know how the clock keeps running during these "pit stops".
• You radically reduce the amount of herbicide leaching into the ground.

Does that benefit us all? Yes!

What you can't accomplish with LRT is:

• Apply pre-emergents. Most pre-emergents need water, so this would be one case where LRT is not applicable. However, even though they are listed on the labels, these pre-emergents should not be used in conjunction with foliar herbicides in LRT because the absence of water will not allow them to run off onto the soil.
• Soil incorporation. Plenty of water is a benefit in this case as it helps carry the material into the treated areas and retards evaporation, especially in warm soils.

A word of caution: When mixing different herbicides together, make sure that you know how they work and that they will be working in conjunction. i.e.: use the foliar formulations together and the soil application formulations together. Don't mix foliar with soil unless specifically recommended by your crop advisor or extension agent.

Generally, when you mix a soil and a foliar, depending on your method of application, only one will work and you'll be throwing away your money on the other.

Calibrating for LRT:

These are the basic rules for Low Rate Technology application:

Calibrate your sprayer to apply between 10 to 25 GPA as this is the volume range that has given the best results. Make sure that your sprayer can maintain the volume you have calibrated it to. Nozzle type and size, spacing, pump pressure and field speed are all factors in determining this spray volume.

• Use flat fan or low volume flood nozzles. Lowering volumes by merely increasing field speed will may decrease control effectiveness. It is very important to use small orifice nozzles.

  Flat fan "Extended Range" (XR 11015 to 11003) and low volume flood (TK-SS.75 to TK-SS1.5) are recommended. They produce small, highly concentrated droplets which are uniformly distributed and adhere tightly to the leaves.

  This results in better coverage and improved control of target weeds. Also recommended, especially when drift control is a factor, is the use of Turbo-Drop drift control nozzles which will enhance the effectiveness of the coverage while dramatically reducing spray drift.

• In-line filtration is very important to LRT success. Since the system uses small orifice nozzles to reduce the application volume, 100 mesh in-line filters must be used to assure proper nozzle operation.
• Always use clean water. Using water drawn from ditches, ponds, etc. will clog the filters and reduce the effectiveness of the application.
• Prior to spraying, set the height of the boom so that there is a 30% to 40% spray pattern overlap before the spray hits the top of the leaves.
• Apply at speeds no higher than 5 mph. The speed of the sprayer should be slow enough to ensure proper coverage. High speeds can stir up dust, make the boom bounce and cause an irregular rate of application, as well as distract the driver from properly monitoring the situation.
• Maintain spray pressure of 20 to 30 psi (depending on the type of nozzle). Too low pressure will not propel the spray into the foliage. Too high pressure will pulverize the material, causing it to drift or evaporate.

Other Pointers:

Use sticker-spreaders generously with your contact herbicides. Of course read the labels first and check the formulation to see if the material already has surfactant materials added to it (such as the case of Roundup Ultra).

Sticker -spreaders will improve the coverage and give you a certain "staying power" on the leaves. You don't worry about phytotoxicity in these cases because, after all, your want the weeds to die and never come back! (Sort of reminds me of the
Electric Chair being labeled as "cruel and inhuman punishment").

Check into ways to "fine tune" your materials. Consult with your suppliers on water treatment such as pH levels to increase potency of the product.

Don't add acid to Roundup Ultra. Follow the label and add ammonium sulfate to your tank mix. Acid won't do anything to improve its effectiveness, but ammonium sulfate will.

Give this Low Rate Technology system a try. It should give you good results and at a fraction of the cost of your present program. And, once you get a "handle" on the LRT program, you can experiment with reducing chemical rates and save even more.

Low Rate Technology really comes into play when you are applying herbicides with other types of equipment such as CDA (Controlled Droplet Applicators - Herbi), wiper and sponge applicators, etc. Here the proportions of herbicide mix to water are usually between 30% and 75% and, in some cases, 100%.

When coverage, either as a Ultra Low Volume spray from the CDA or as a direct contact and "wipe" by the panel type equipment, is good, the results are impressive. However, many times it is necessary, due to a host of reasons, to go over the targets a second time to assure that the chemicals have gotten on the foliage.

Consequently, we recommend first that all wiping and CDA applications be done at lower speeds and with care and patience to assure coverage. Unless you are using a tracer dye, you generally won't be able to tell for sure if your coverage is good, so take your time and get it done right the first time.

Which brings me to the subject of Chemical Mowing

For those of you not familiar with the term, it is in essence, applying a herbicide as a dilute to work as a growth regulator and generally reducing by one third, the times you have to run the Bush Hog. Chemical Mowing is being used quite successfully in citrus groves in Florida, Texas and California, as well as in Brazil and is basically done with panel wipers, rather than sprayers.

The panel wipers, generally mounted on the front of tractors, are run through the rows between the trees at higher speeds and transfer through contact a small amount of herbicide to the growth that reaches their height. This keeps the weeds controlled and replaces the need for mechanical mowing, at least temporarily.