January 30, 2008
Did you ever stop to think as to why the hose going from the sprayer pump to the hand gun is 1⁄2" inch? Most sprayer manufacturers install 1⁄2" inch 600 psi hose as standard for the handgun. Some even put in 5/8" and 3/4" hoses and these can be up to 50 to 100 feet long.
It does not make much sense to have such a large caliber hose carrying all that water when the nozzle at the end of the spray gun is only about 1/16" in diameter. So the hose really should be as small as practical without causing friction losses or bottlenecks.
Generally, the size of hose that works best for hand guns and spray wands is 3/8", 600 or 800 psi, depending on how you spray. This hose is not only cheaper than the 1/2", but also has better working and burst pressure factors. It is flexible and lightweight and, because it is carrying less water, not only is easier to handle while spraying, but gets less wear and tear through abrasion when being dragged along the ground, because of its lower overall weight.
Another bonus is that your can get up to 30% more hose onto on a standard reel, and, if you only have a rack to coil it on, that is also easier and lighter work. So look at your hoses; and the next time you have to replace them, think of going with a smaller size and lightening you or your employee’s load.
January 28, 2008
One of the most overlooked items in the calibration process and especially in boom sprayers is how the nozzles are aimed.
Generally, we just point them directly downwards or at right angles to the plant (in the case of laterals) and expect the fog they produce to travel in and out of the canopy and cover all the foliage on both sides.
If we make a big enough fog, this will be very true, but constraints on the amount of fog we can make in the future (drift) are going to cut into the efficiency of our coverage, which we took for granted, until now.
Aiming the nozzles so that their pattern penetrates the canopy will greatly improve our coverage and reduce drift. However, we cannot follow a rule-of-thumb on this except to try to get the spray to drive into the plants as low as possible at an angle which will make it "bounce upwards" and travel to most of the areas of the canopy, without producing great amounts of drifting fog.
Each crop has to be looked at with that in mind: how to get the spray down into the canopy before it becomes a fog.
One approach is to use narrow angle nozzles. These would be spaced closer to each other on the boom to make up for the loss of pattern produced by the wider angle nozzles, and the narrow pattern will propel the spray deeper into the canopy, especially if it is aimed forward at an angle of 35 degrees or less to horizontal.
The narrower pattern will travel farther before it begins to "break-up’ and, if you regulate your boom height accordingly, you should notice practically no drift or fogging above the canopy.
Putting more nozzles on the boom because of closer spacing will require you to use smaller orifices to maintain the volume. This you can calculate and calibrate yourself.
In order for this to work, you must use Disc/Core type nozzles. Get away from the Teejet type fan nozzles, they are for herbicides and banding, not for under-leaf coverage. The disc/core nozzles will give you angles as small as 15 degrees. (you have been used to 80 to 90 degree angles until now.)
We are giving you the basic idea and what to look for. It’s up to you to decide how you want to aim your nozzles, but please give it some thought.
January 24, 2008
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?
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.
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.
January 22, 2008
I wish I could remember what I used to get rid of the blight on my watermelons two years ago……or how we controlled whitefly in our eggplant the year before. Whenever this happens I find myself going back through old storage boxes looking for the scraps of paper that I wrote the sprayer tank mixes down on.
Looking back now, how I wish I had kept more formal and detailed records of my sprays. Never seemed to have time or the inclination to really make a detailed history of what we did and why we did it.
Well, I have to, now. With FIFRA being modified by the 1992 Farm Bill and its revisions, now requiring us to keep formal spray records and make them available to our employees (Worker Protection Standard of 1992 and parts of the Right-to-Know Act).
Not only that, but we must keep files on the labels and “MSDS” (Material Safety Data Sheet – that fine-printed sheet that was always delivered with the chemical and we didn’t know what to do with it, nor had time to read it…. so we threw it away) of every labeled spray material we use.
Plus, since the vendors have to supply us with that documentation, we should now file it in binders and not have it knocking around on the floor of our truck.
Many of you have set up record keeping systems and are working with them. What I want to do is give you a check list to go over, and make sure that you are doing everything that is required. And for those of you that haven’t gotten around to it, this could be your guide to get yourselves in line with the Law.
Your friendly extension agent, chemical supplier or safety equipment vendor can also provide this information.
RIGHT TO KNOW:
First of all, remember that the basic application information must be made available to your employees and must be posted wherever you post other employee notices at least for the 30 days after the application. Remember, that according to WPS you must have a bulletin board in a central location for this and other notice purposes.
Many growers just tack a copy of the spray record sheet to the bulletin board, over the previous sheet. You can also put up a clipboard and just go adding the sheets to it as you go along, (remember to remove the old ones).
Your employees can certainly make the effort to leaf through the records if they actually want to look something up, and this way you don’t eat up valuable bulletin board space.
Don’t post these records inside the chemical storage room, they are not accessible to your workers, and will put you out in left field if you ever get inspected.
If you do want to post something in the chemical storage room, then put up copies of the WPS Poster, location and telephone of nearest first aid facility ( in metropolitan areas, 911 will do), personal protection equipment requirements and clean-up instructions. But remember that most of these posters must also be tacked onto the main bulletin board in the central location (next to the time clock or where the generally employees congregate.
There are several record keeping systems on the market both manual and computerized. I have found that due to the many things that we have to do and keep track of daily in this growing business, that best systems are the simple systems.
Generally, and this is not a knock, the systems being sold are complicated because those who have devised them, (generally not growers) want to give you as much as possible for your money. Sort of a justification to what they’re doing. (Most of the record keeping programs for computers that I have tried and looked at can do all sorts of things for you and, if you have the time, they could be great fun!).
But since this is not a question of fun, what I am going to do to-day is take you through the basic requirements and, if you want to get more sophisticated or try record keeping on the computer, go for it!
I have found that the best way to get this going is to draw up a form that will ask the questions required for complete recording (as far as the law is concerned) of the applications, so that when we fill it out we are putting everything down that has to be saved. (fig 1.) This form must be kept handy for at least two years and the most practical way is to keep it in a three ring binder in the office. A copy of this form can be used for employee posting.
The three ring binder should have all of your applicator’s names, license numbers and expiration dates posted on the inside of the front cover. I have also found that if you post a list of all the chemicals with their EPA Registration numbers also inside that cover, you will not have to repeat the EPA numbers every time you fill out the form.
This does not hold true for the Active Ingredient. You will have to write down the Active Ingredient every time on the form. (hopefully this will change in the future, and is one compelling reason to look at a computer program, as all that repetitious information is stored and printed out when you type the name of the chemical). And make sure that the EPA Registration Number is on the copy of the form that you post for your employees.
Remember to keep the listing of applicators and EPA numbers current. The latter is especially important if you have an emergency as medical first aid information is being indexed to EPA numbers as well as active ingredients. EPA numbers may change as products are reformulated and re-registered so be sure to read the labels on every new shipment as there may be important changes that you may have to record.
As you will see on the sample form the following are the records required.
- Date – Location – Area Treated (acres or sq. ft)
- Brand Names of Products Applied – EPA Registration Number**
- Active Ingredient of products applied
- Rate per 100 gallons of water
- Total gallons of mixed product used
- Applicator name – Method of application ( boom, broadcast, air, hand spray, etc.)
- REI (Restricted Entry Interval) REI expiration date and time
** EPA number is optional if it is already listed in the front of the binder. Do not confuse this with the EPA establishment number, also listed on the label. That is the factory number and not the Registration Number. The number you want is also shown as EPA Reg. No.
There are other items on the form that are purely informational.
As a rule of thumb, you should post all records of spray applications in the central location, for your employees to have access to the information. If you are spraying pesticides with REI (Restricted Entry Interval), the records should be posted before the application begins and kept on the board for 30 days after the REI. (if the REI is 48 hours, then the records cannot be removed for 32 days).
The minimum information required for this posting is: Area to be sprayed – Brand Name of Pesticide (s) – EPA Registration number – Date and time of application – REI (hours of restricted entry: 4, 12, 24, etc.) There is no filing requirement on these particular sheets.
Keep a file of all the labels you are using and have used. If a label changes, be sure to add it to your file and write the date you started to use the material across the label. Also write the same date on the old label indicating that is the time that you replaced it with the newer version. It is best to keep the labels also in a three ring binder for easy reference.
Again, I must insist the you keep your eyes open when receiving new shipments of chemicals to catch changes in the label contents. These can cover re-entry periods, signal words, PPE (Personal Protection Equipment), mixing and loading restrictions and application instructions. So consequently you and your applicators have to be advised of this. Remember to brief your applicators of all changes to label content.
You should also have a record of the training that your personnel has received in Worker Protection Standard. The applicators should have been trained in the Mixing and Loading protocol known as Handler Training.
You should have sheets on file showing their names, Social Security Numbers, type of training, date, place, trainer Id., and EPA card number, if such was issued by the trainer.
Your workers should have been given the WPS Worker Training and you should have sheets on file showing their names, social security numbers, type of training, date, place, trainer Id and EPA Card number, if such was issued by the trainer.
If you do not have those records, contact the person that trained your personnel to issue them. You must have them on file at your place of business.
If you have not trained your employees in WPS, you must do so immediately to avoid sanctions and fines. Remember, EPA training must be repeated every five years. If you trained your people back in 1993, you will have to train them again this year.
Although not directly related to Record Keeping, I want to just go over a couple of points which will help you comply with the storage rules.
1. Keep everything off the floor in the storage room.
What you have on the floor can be put up on pallets and, as long as it is not indirect contact with the floors, will be acceptable. Another way is to get some concrete blocks and use them as bases for planks that will make shelves holding the materials.
2. Do not store fertilizers and other nutrients in the chemical storage room together with pesticides.
Remove all fertilizers and nutritionals to another ventilated and protected storage area. Also be sure to keep them off the floor.
3. Make sure all bags and containers are closed when mixing and loading is not taking place.
You can get clamps for the paper bags and make sure you keep the stoppers and caps on the bottles.
4. The chemical room must be well ventilated and yet lockable.
5. Keep the room clean and free of spills.
If you have broken or leaking containers, transfer contents into good containers. Make sure you label them properly and clearly.
6. Check all the labeling on the packages and containers in the chemical room.
Make sure they are all legible. If any need replacing, relabel them clearly and with an indelible pen.
Hopefully I have been able to refresh you on some points of record keeping. I know it is not the most attractive task in the world, but it is very necessary and, who knows, in a couple of years you’ll be able to instantly look up what you did to get rid of the aphids before they gave your citrus trees the “Tristeza”.
January 21, 2008
As the season for whiteflies approaches (and may be in full swing in certain areas), we should take a practical look at some of the decisions and plans of action we should take. This is above and beyond selecting which pesticide and how to zap them and control try to achieve control as we have been doing for the past few years.
Much has been written and said about how best to control whiteflies and a lot of it is very good advice. But do we end up following that advice, or just go ballistic when they really do appear.
Immediately, we try to control them with large quantities of whatever our chemical salesmen, crop advisors and colleagues say will knock them out? Generally, more of the latter, than the former.
I am not going to get into what chemical(s) works best or better or not at all. I’m going to leave that up to the experts and formulators.
My approach to this whole thing is to PLAN AHEAD, and we can do so by covering the following points:
Know your adversary: Be familiar with the life-cycle of the whitefly and the various stages it goes through and how those stages affect your crops.
This is very important and you must keep this in mind at all times.
The larval stage is the most damaging to the plant because it is when the insect actually eats and damages the foliage. Larva feed mainly on the undersides of leaves so it makes no real sense to spray over the top, now does it? And larva can be controlled but with only a very small portion of the “arsenal” labeled for whitefly.
Of course the easiest to control are the adults. Most insecticides available are indicated for knocking down the adults. Adults will lay their eggs mainly on the undersides of the leaves and in protected areas. If you want to control them, you should think of a product that will have residual effect and apply it on the undersides and not over the top.
The residual effect (the active ingredient staying potent on the surface for several days after application) will deter future visits to that area by adults that are looking for a good place to lay their eggs. You can also achieve this effect with certain spray oils and soaps, but application is the key to your success with whatever product you use.
Over the top spraying will help, but not give you good control.
And now the eggs. The adults will lay scores of eggs, mainly in the venal recesses of the underleaf epidermis. These eggs are not really affected by most insecticides.
Ovicides and a few bio rationals mainly derived from Beauvaria Bassiana will have a destructive effect on them, but again, application is the key.
Since these are all contact materials, they must touch the target to do any damage. And you must make sure you achieve that coverage, otherwise you’re throwing money and effort down the drain.
Resistance is also a very important factor in your planning. We have noticed that the adults mainly, develop resistance to certain ingredients, especially when those are being widely used and continually used in the same area.
We now hear that there may be a resistance problem with the “Silver Bullet” Imidacloprid, and this is mainly due to its extensive and continuous use as most growers found it to be a very effective preventive material.
Consequently, you should be on your toes and do some preliminary testing on the first colonies you get to assure yourself that the materials you will be using will be effective. Don’t wait until you have an infestation and then hit them with something that you will later realize (when it is too late) that they are resistant to.
If Imidacloprid works for you, remember that it has a relatively short effective period (21 to 28 days in vegetables) and therefore you will want to schedule it when it will be most effective in your particular plant’s growing cycle.
If you are growing a 3 month ornamental and don’t at the time of potting have whitefly pressure, you should wait and apply it (in whatever way recommended) when the colonies are threatening, which could even be in the latter stages of the plant’s production cycle.
Scouting is your best defense against whitefly damage. I’m not saying you won’t get them in your crop, but advanced notice of their presence will be a great help to your control program.
Also of great help will be to have your program in place so that you don’t have to be running around like mad trying to get the materials of setting up the sprayers and other equipment.
As far as thresholds are concerned, don’t wait to have three or more adults per plant. Swing into action with your prevention program when you first spot them. Remember, if you can stay ahead of them, you will be the winner.
Monitor fields around you, especially to “windward”.
Whitefly blow in with the wind, and if you are unfortunate enough to have a field of eggplant to windward of you, you are going to get a lot of visitors. Talk to your colleagues that are located around you and share all the information with them.
You alone will not be able to control this, but if all your neighbors get together and act on it, the insect pressure will be considerable lower and it will work out to everyone’s benefit.
Remember that the pressure of whiteflies will increase when you come out of the rainy season and go into a dry spell. Adults that normally would live in other vegetation surrounding you will move out of it when it dries up and seek green, tender, irrigated leaves. This should also be a warning to you.
Remember: Plan Ahead, Scout, Know Your Enemy, Apply Effectively, Work with your Neighbors and……cross your fingers and hope for the best!
January 19, 2008
Yes, as far-fetched as it sounds, a California company, Cal Crop, U.S.A. introduced a line of Spray Adjuvants containing garlic extract, as an insect repellent.
Cal Crop U.S.A. has been producing bio-rational products for the organic and commercial grower markets for six years and now they have launched three additives to enhance spray deposition and performance.
An organic acidulant and buffering agent for lowering pH and is based on citric acid with calcium and garlic extract technology. It is really a “breath of fresh air” since it does not use corrosive mineral acids that can damage spray equipment.
All natural and “mix-friendly” by using citric acid, it gets away from those so-called “Yuppie” buffers and acidifiers that claim to change colors and do all sorts of other things while they are supposedly treating your spray water.
A non-ionic surfactant, is a unique blend of low foaming, slow drying and biodegradable surfactants formulated with garlic extracts for increased systemic performance. It can be used with herbicides, defoliants, desiccants, insecticides, fungicides, acaracides, plant growth regulators and nutritionals.
This makes it an all-purpose adjuvant, safe to use and with the added feature that it might even repel some insects!
A blend of slow drying, penetrating methylated seed oil and organosilicone surfactants formulated with garlic extracts for increased systemic performance. Havoc’s chemistry allows for enhanced wetting and systemic absorption of those products which labels recommend adding an adjuvant to improve performance.
Adding Havoc to the tank will result in a more uniform spray deposition as it physically modifies the wetting and spreading characteristics of the spray solution.
This is a targeted-use surfactant specifically designed for low application rates (2 to 20 gpa) where superior coverage, slow drying and good penetration is desired in low humidity and high temperature conditions. Recommended for both ground and aerial applications.
The addition of garlic extract to the surfactants is a good idea because it not only acts as an insect repellent, and you all know how much we need any help we can get in that area.
The HAVOC product looks especially attractive for use in hot weather because it is slow drying. One of the problems that we have with the regular organosilicone surfactants is that they tend to dry quickly in high temperatures and thus can contribute to poor absorption, reduced contact residual action and, the most feared of all, elevated phytotoxicity and burn.
This generally is not the case with surfactants based on fatty acids (Amway APSA 80) and mineral oils (Stylet, Sunspray, etc), as they tend to resist quick evaporation. However, extreme care must be exercised in hot weather because the oils will act as anti-transpirants and cause epidermial burn or other problems of the stomate and/or hydathodes.
But in the case of HAVOC, they have combined the two elements: an all-natural seed oil with organosilicones to give us a combination that is claimed to be relatively safe in high temperatures. (Florida, Texas, Caribbean and Central American vegetable growers, take note.)
January 18, 2008
First of all, what are fill pads? Also known as rinse pads and fill stations, yes, they have been required by various federal and state laws for the past ten or so years.
The purpose of the fill pad is to contain any overflow or splashing that occurs during the sprayer tank mixing and loading operations so as to prevent the material from leaching into the soil.
This is a tricky subject because it brings all sorts of different areas of government into play, the least not being D.E.R.M. (Department of Environmental Regulations Management), and of course, E.P.A. and the State Departments of Agriculture, Natural Resources, Water Management, and so-on. (read: everybody and his brother)
Environmental groups, extension people and universities have been harping on fill pads for several years, but the problem is that growers are usually very mobile and can’t really afford to build pads all over their fields, especially when these are leased and may not be in production the next season.
Static growers, such as nurseries and tree farms (fruit growers, too) have fixed installations and should consider installing their fill pads where they service the sprayers.
I don’t recommend putting this decision off, because it is only a matter of time, and then maybe a short time, before enforcement begins on this issue.
Especially in areas where there is local sensitivity to water quality and soil contamination or clean-up projects, you should keep your ear to the ground on this subject.
The parameters for locating the fill pads are very simple: keep them away from wells, at least 100 feet. Some states demand 250 feet. That’s a long way to run a pipe!!
Meanwhile, you can circumvent the issue by using a portable containment basin, such as those sold by Chemical Containers, Inc.. These containment basins are very much like inflatable kiddie pools, but really do the job, especially if you are moving around.
Another thing to remember: never mix and load in the same place twice. Move around. If you get caught on a spot that has hundreds of pesticide spills in it because it is the “fill station” (the north end of row 57) you are going to be looking at “mucho dinero” for a clean-up, and I mean “much, mucho, mucho, dinero!”
You also might want to run discs or blades over old fill areas to loosen and aireate the soil that may be loaded with residues. This will help clean it up.
Remember to train your mixer./loaders to mind the hose while filling the tank and not walk off for a smoke and then come back when the thing has been overflowing for a couple of minutes. This is contamination and also hard on your pocket because of the water wasted.
Yes, this is something that we don’t have in the forefront of our mind, but you should keep it in mind and do something about it in the near future.
January 16, 2008
Watching an operator recently taking off his spray gloves – I could not believe my eyes! He removed them just as most of us would. He pulled the left one off with his gloved right hand and then pulled the right one off with his bare left hand, getting all the chemical onto his hand. This kind of defeats the reason for wearing gloves to protect you from spray materials?
Well, that wasn’t anything compared to the sprayman that removed one glove and then removed the other one by pulling with his teeth because he did not want to get the chemicals on his bare hand!
The simple and correct method to do this is:
- Wash your gloved hands first to remove chemical residue from the gloves.
- Remove the gloves without getting the material on our hands.
- Finally, wash our hands again.
Washing the gloves also preserves them as it removes the chemical residue that otherwise would dry on the surface and possibly crack and deteriorate the glove material.
Try This Simple Test
Have your operator remove their gloves as if they were finished spraying.
Did they follow the steps above?
If not! Remind your personnel to follow these simple steps. Consider taking pictures and post them for easy viewing. They tend to forget what they have been taught and need periodic reminders on all safety practices. That’s all part of WPS – Worker Protection Standards and safe spraying.
Disposable Gloves at eBay
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January 15, 2008
Various sprayer manufacturers have different ideas as to how to handle the return lines from the spray pump. Depending on the type of pump, there is a need to return the spray material that does not go to the nozzles back into the tank.
All well designed sprayers have a pressure relief valve in the line coming out of the pump (pressure side). The pump produces a certain volume of liquid: pressure builds up when the outlet of that volume is restricted (the nozzle).
Pressure will continue to build up because there is less going out the nozzle than is being produced by the pump. In order to balance this, a relief valve will divert the extra volume so as to keep the pressure constant.
When the pressure in our sprayer drops, we usually blame the pump, but the first thing we have to look at is the wear in the pressure relief valve. The abrasives in our spray materials wear the seat and plunger in the valve and, when these do not seal properly, they will allow liquid to escape back into the return line.
Consequently, pressure cannot be built up because the relief valve is not restricting the flow because it is leaking. By checking out the relief valve first, we can usually save ourselves a costly and unnecessary pump repair as well as shorten down time, as relief valves are usually very simple to rebuild.
The relief valve is basically a plunger that sits in a seat and is held against that seat by a spring. The pressure in the line presses against that plunger and, when the pressure exceeds the pressure of the spring holding the plunger against the seat, the plunger is pushed away from the seat, allowing liquid to pass through.
The passing liquid then goes out through a line that takes it back to the sprayer tank. When the pressure drops, the spring pushes the plunger back against the seat. This system adjusts continually to maintain a steady pressure as set by the pressure on the spring, which is controlled generally by a screw/handle on the top of the pressure regulator.
A practical example is the pump that is producing 6 gpm for a spray gun using 2gpm, then the extra 4gpms are diverted through the seat of the relief valve, back into the tank. And this could be at any pressure, as long as the spring is strong enough to control it.
That is why we have pressure relief valves rated for 0-100psi, 100-300psi, 100-700psi, etc. Each one of these models has a stronger or weaker spring which generally can be adjusted within those pressure ratings.
Speaking of springs, this could be another cause for losing pressure. Some of these springs are corroded by the materials being by-passed in the relief valve and can weaken or even break and then yes, there will be no pressure at the nozzle.
So when troubleshooting loss of pressure in your rig, first look at the relief valve, (also known as control valve or unit). If the spring tensioning screw or adjustment is all the way down, chances are your failure is in this unit and not the pump.
Another item to look for is a hydraulic agitator (eductor) connected to the relief valve discharge line: This is not recommended for the following two reasons:
- The volume coming out of the relief port may not be constant, as it would change with variations in pump speed and number of outlet nozzles open. This could make the the operation of the agitator erratic, as there could be times when nothing is coming out of the relief discharge, therefore no agitation in the tank.
- The effect of the agitator (eductor) is similar to a nozzle, producing back pressure in the relief line. Some pumps, especially diaphragm pumps are affected by this back pressure, which could cause premature pump failure. Consequently, make sure that the relief circuit from the valve to the tank is not restricted in any way.
Certain centrifugal pumps, Hypro, for example, do not require pressure relief valves in the discharge circuits. These pumps are designed to allow certain slippage inside the volute (impeller housing) and pressure as well as volume can be safely controlled with a "throttling valve", usually a ball valve in the discharge line that either restricts the output flow or diverts part of that flow back to the tank. A hydraulic agitator (eductor) can safely be used in this system.
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January 14, 2008
Injection Systems offer new safe ways to avoid mixing, loading mishaps and messes when spraying applying fertilizers and chemicals.
Did anyone tell you that in the very near future, regulations are going to control the way we mix pesticides and load sprayers in ways we haven’t imagined! And we are not going to be able to carry mixed loads down the road to the field or between the fields we are spraying!!
The result of all this eventually, will be that we are going have to inject the pesticide into the pressurized spray line somewhere between the pump and the nozzles.
GREAT! No More Agitation Headaches!
The up-side of all this is that the injectors will carry the materials right out of their original containers into the flow and out onto the crop. Mixed liquid will not recirculate into the tank and therefore the tanks will be clean. Relief valves in the main pump will carry only water back into the tanks, the excess that is by-passed by the pressure control units.
“Mixing and loading” will be limited to water treatment, such as adding surfactants, pH buffers and stickers. (on second thought, some of these are messy, and so some residue will stay in the tanks, but none of it is really toxic.)
The spray equipment will have to be modified to include areas where the containers of concentrated chemicals can be placed to feed the injectors. Sprayers will have to have banks of two or more injectors to allow the injection of two or more chemicals that are normally used in combination with each other in current tank mixes.
Applying soup mixes (combinations of insecticides, fungicides, nutritionals) will become impractical and too costly. (This, in my opinion, is a blessing, because many of those soup mixes combined chemicals that actually “cancel” each other out; but who is going to convince the grower of this, when he maintains that it has worked for him for years).
The chemical suppliers will be reformulating and packaging their materials in user-friendly containers and there will be a proliferation of injection systems on the market, as well as the usual complement of “gimmicks” designed to make the operation more effective, safer and economical. Wettable powder and soluble granule formulations will have to be converted to flowable combinations that can be handled by the injectors.
And high pressure sprayers will have to add a booster pump to elevate the pressure to working levels after the injection stage, because the cost of a high pressure injection system would be prohibitive and impractical.
One of the basic concepts in injecting chemicals into a stream (in this case the spray hose), is to keep the proportion of the injected material as close to the specification as possible. Consequently, because the flow of spray will not be constant due to nozzle controls, pressure variations and other operator changes during the spraying process, the injector should be a proportioner that will adjust to the variations in the flow.
There are different types of injectors on the market, but only those that are driven by the actual flow in the line will proportion as well as inject and react to changes in the flow rates.
In other words, electric and vacuum (venturi) injectors will not assure the accuracy of the mix of spray chemicals if the flow rates and pressures in the spray lines are not constant.
Flow-driven injectors such as the Dosatron and Dosmatic are ideal for this type of installation because they are non- electric (powered by the actual flow of the line they are injecting into), simple, accurate, chemical resistant and easy to maintain and service.
However, these proportioners were designed for low pressure systems as they basically were meant to be used in irrigation systems, which rarely operate over the 100psi pressure level, and more likely run at about 60 to 70 psi.
The Dosatrons and Dosmatics are very accurate and easy to calibrate, generally from 0.2% up to 2.5% and in volumes from practically ounces per minute up to 100 gpm, and, being non-electric (water driven) they are virtually trouble- free.
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As a matter of fact, these units can be set up in tandem to proportion 4 or 5 chemicals into the same flow and mix them in the order that the manufacturers recommend, for a well-balanced final spray solution.
This system will work very well with the large boom sprayers and herbicide applicators that operate at pressures under 100 psi and can be just “plugged” into the spray lines beyond the pumps and relief systems. A back-flow prevention device will have to be placed in the line between the pump and the injectors so that the mixed solution does not have a chance of being flushed back into the tank and fill systems.
When the sprayer operates above 100 psi, a booster pump will have to be added after the injection station to take the pressure up to the required level for the nozzles. This would be on boom sprayers operating above 100 psi, air-blast sprayers and mist sprayers that require high pressures to generate fogs or other small droplet patterns.
These pumps would be the current pumps on the machines, such as piston, plunger or diaphragm units and would have to be re-plumbed to kick-in after the injection process.
There will be a host of other injection systems and proportioner pumps being made available either for retro- fitting or as original equipment on new sprayers. Some of these pumps generate high pressures and thus can be installed after the main pressure pump on high pressure units.
However, even though they are very accurate in the flow that they deliver and can be calibrated to exacting specifications, the proportion of the material that they are injecting into the spray line can change with the normal changes in pressure and flow caused by variations of the pumps, pressure relief valves and shutoffs, especially in on-off cycling applications such as Smart Sprayers, Tree-Sense, Tree-See and other specialty applicators controlled either by computer or operator.
A possible solution to this type of situation is to have the injectors feeding into a holding tank from where the mixed solution is then pressure pumped to the nozzles. This tank would act as a compensation chamber and the proportion of mix solution in it would be always constant to what has been set by the operator.
The Relief Loop
Another consideration in the use of pressure pumps after the injection point is that their relief system will have to loop back into the pumps own inlet valves, very much the same way that pressure washers are plumbed, because the excess coming out of the relief valve is a mixed solution and cannot go back into the fresh water tank. This may also require another backflow preventer to protect the injector pumps and keep the pressure down in the holding tank.
It may take some time for legislation to mandate these changes to the way we are running our spray machines. If you operate at pressures below 100 psi, you will not be facing major changes. If, however, your machines are high pressure units, you will be looking at some important modifications and alterations to your present equipment.
You might want to look at the use of drift control nozzles and lower pressures and do some testing of your own to see if you can get the coverage and results on your crop that until now, you thought you could only achieve with high pressure fogging or atomization.
Meanwhile, the first indication of these sweeping changes will be the wider use of pre-packaged chemicals: soluble packs and pre-measured containers. The market will see manufacturers offering “quick-fill” systems and special collar systems that practically eliminate spillage and even contact with the materials. And you will be urged to mix what is necessary to treat the specific field and not transport it out on the roads to other locations.
But, unless something earth-shattering happens to our system of government, the implementation of the rules is still a ways down the road, if WPS is any example.