Glad you posted this mes. I was actually thinking the REI was much longer and yet 7 days is actually the longest for tree fruits (apricots, pears I think). 14 days on grapes. 4 days on most stuff looks like.
Really, really glad you mentioned this…for some reason I was thinking it was way longer. Kids might actually get to use the yard this summer after all. Their REI will still be more like 21 days though.
I don;t know how long if you are concerned about residues, but I was speaking for that time it is still active enough to kill bugs- about 10 days.
I don’t use Imidan because it is easier and cheaper to use Asana- also probably safer when I’m spraying right next to homes, sometimes right against outside walls and windows.
Most of the public that has any perception of pesticides being dangerous, don’t really give a rat’s rump if you are spraying a pyrethroid, OP or neonic- if it’s synthetic it going to give you cancer. Very few in the general public understand different classes of of pesticides although bee lovers will sometimes be aware of neonics.
The thing is that when you are spraying Imidan, it’s pretty obvious from the smell that it is a synthetic poison and I have to even worry about joggers nearby orchards running along a road. In NY folks get sued for fairy tales all the time. The Imidan smell is enough to fire up one’s imagination.
Where I spray commercial type orchards I rely on Avaunt and Assail.
Appleseed, just tell them to stay out of the trees. If they are old enough to follow directions you can explain how it is contact with the trees that expose them to the chemicals- not running around on the turf nearby.
Was just going back and rereading some old dialogue.
Olpea, I get (sorta) what you are saying, but surely you know that the general public (here, and I’m pretty sure in KS too) has no idea of organophosphates or synthetic pyrethroids or anything like that. They would likely understand no spray or organic spray and after that, everything is just pesticides.
I’m reasonably certain that few if any of your customers buy your fruit because it’s sprayed with synthetics versus organophosphates…I’m pretty sure you agree…right?
So then there must be something else. I’m curious as to what you know, that I do not, that leads you in the direction you have chosen. I might (if armed with the knowledge) be interested in a similar path. For now, I’m just giddy with the effectiveness of Imidan, but since you’ve used it and have switched, I’m interested to know why? Efficacy I’m fairly certain is not an issue.
I’m not aware of any increased pesticide residue issues with organophosphates, nor have I read anything that leads me to believe there is significant reduction (if any) with synthetics in regards to the environment. I have read literally hundreds of pages of information concerning pesticides and have yet (probably missed it) came across anything. I do know that many growers were staunchly opposed to proposed epa limits and restrictions being placed on organophosphates when they were proposed years ago. Even then, they cited the non-existence of research suggesting any improvement of any kind with synthetics, and furthermore made a seemingly reasonable case that they could in fact, be worse.
The fact that so much time has passed, and those restrictions or prohibitions were never set forth, makes me think the growers were right…there was no such data. I’ve not came across rebuttal on the grower’s claims and that makes me think they were right, or at least mostly so.
If BMSB really makes a presence here, and I can’t control it without an organophosphate, I may be forced to use Malathion to control the pest.
Why would you need to be forced to use Malathion? I was under the impression that it was at least, perceived to be one of the safer pesticides hence it’s common OTC availability and extraordinarily long history as a BYO pesticide. Synthetics are out there too, I know, but nearly as much and even then, only somewhat recently.
I’m most definitely not questioning what you do or your reasoning for doing it, but rather interested in your rationale. Only because I know you are up on this stuff, and I’m interested.
Give me the scoop Olpea.
Apple,
You and Alan may be correct that most of the public really has no idea what organophosphates are.
My background to this subject comes from the history of organophosphates, some of which I have witnessed myself.
Back in 2010 there was a study which supposedly linked organophosphates to ADHD in children. It was published in the Journal of Pediatrics and caused a big hoopla in the press. It was picked up by over 400 national and regional media outlets including national morning news shows. Dr. Oz mentioned it on his show, recommending people purchase organic fruits and vegetables. The study was criticized for drawing spurious correlations. If I remember correctly, in fairness to the scientists who put the study together, they did admit the study was far from definitive, and more research was needed in order to draw any usable conclusions, but that part was not what the public focused on.
The EPA has long targeted organophospates, as they have done with organochlorines (I believe most of the organochlorines are now gone, the most recent being endosulfan.) The organophosphate Guthion used to be labeled for all stone fruits, then only cherries and pomes, and was finally removed altogether (I believe 2014 was the last year it could be used.) I’m sure you are familiar with Imidan’s increased restrictions about 10 years ago.
The EPA has a special category of pesticides which aren’t considered ecologically or humanly safe enough to be “Reduced Risk”, but are considered safe enough to be classified as “Organophosphate Alternatives”. So I don’t think there is much question of the EPA’s stance.
In IPM programs, there has been a big push to reduce or minimize organophosphate use. There are no hard and fast rules of IPM. It’s a continuum, not a black and white set of rules, but I’ve seen many papers and some videos, where there is a big focus to try to use alternatives to organophosphates. I’ve seen one list of proposed guidelines to make IPM a hard and fast set of rules. As I recall, organophosphates were prohibited under those suggested guidelines.
Again, I’m not trying make the claim organophosphates are unsafe. You asked why I don’t currently use them. I’m just trying to explain some of my thought process as the issue relates to public perception.
Its my understanding that Imidan is often suggested as part of an IPM program because it is not as hard on some beneficial insects(especially perdator mites) as other synthetic chemicals, It is however extremely toxic to bees and the EPA is trying to get rid of it.
Blueberry,
Although I have seen Imidan recommended in some IPM programs, I think a goal of most IPM programs is the reduction/elimination of organophosphates. It seems most of the time Imidan is recommended as a concession material when a broad spectrum insecticide is needed. In that case Imidan is preferential to pyrethroids for protecting pedator mites. IPM is a continuum, so there is no definitive program for IPM.
“An IPM program in the fruit orchards of Washington reduced the organophosphate use in apples and pears by 75%.”
http://www.seattletilth.org/learn/resources-1/sustainable-landscapes/ipm
Here’s the kind of IPM example I’ve seen lots of (scroll down to page 25 and 26)
http://fskntraining.org/sites/default/files/ipm/use_of_pesticides.pdf
The EPA is working hard to get rid of all OP and the label for Imidan was changed to increase the entry time for the general public to 14 days, 7 days for workers, but 14 days for the public. Most chemicals do not make the distinction between farm workers and the public. Attached is an IPM progam fro commercial orchards in NC that mentions Imidan. http://entomology.ces.ncsu.edu/pest-management-overview/
I’m not a big fan or Imidan. I do not like the smell and unless you use the full rate of about 3 LB/acre it has not been very effective for me,
Olpea, please, please don’t think I’m in any way trying to put words in your mouth or suggest you are making any such claims. I just sincerely wanted to know from you, your rationale for going in the direction you did…that is all.
I know you are head and shoulders above all of us in this area and am genuinely interested in your reasoning.
So, the EPA isn’t keen on organophosphates…I knew that already, but my question is WHY? I remember (back on GW) before buying Imidan and being concerned over it’s health risks, both you and Alan both took the position of defending it’s safety. I even brought up (I think) the issue of ADHD…do you remember? You both made good cases and I was in many ways assured by that. Of course I double checked and studied and agreed with all of both of your positions. Correct me if I’m wrong on my recollection, I may very well be. I’m certain I was fearful of that since I have two very young children.
I don’t doubt for a second the EPA’s stance on their use, nor your’s…it’s all about the WHY that I’m interested in. Apparently the EPA isn’t very good at disseminating this information or perhaps I don’t google it correctly. Every widely used insecticide I know of is bad for bees, some better, some worse, but if applied correctly I have to think there is something more to it than just that.
What exactly makes synthetic pyrethroids a lower risk (and to whom?) than organophosphates?
What are some of these “Organophosphate alternatives” you speak of? Are any of them, in your opinion, suitable for the home grower? That is to say, are they cheap enough, and with reasonable shelf life, and with good efficacy and broad spectrum control like Imidan? I really. really want a safer, reasonable alternative, but it has to work and work effectively.
The way Triazicide has been touted here and mentioned almost as though being an equivalent to Imidan is preposterous. Triazicide is in no way even in the same galaxy of effectiveness of Imidan…not even hand grenade close.
That’s my only real foray into synthetics and even when applied at exponentially greater rates than advised was woeful at best on PC. Imidan has delivered in a glorious way, but I have to think it’s effectiveness comes at a ecological price, but so far, I’ve not seen any data of any kind to suggest that. I really do think though that it has to be bad news, it must be, because it works so well.
Well join the club blueberry, I don’t like the smell either, but I’ve not found any insecticide yet that smells particularly pleasant I’m finding it extraordinarily hard to understand how it has not been effective for you, but I believe you. What was it that it was not effective for in your case? What were you using it on? Surely you have had good results against PC…right?
Blueberry, I’ve never heard of an application rate as heavy as 3lb. per acre, that is an incredible amount and unless I’m mistaken, that would be exactly 300% of the normal full concentrate spray. If you are telling me that you only get good efficacy at that rate then I honestly am at a loss for words.
I cannot get my head around how your experience could be so vastly different from my own. My goodness friend, what is it that you do spray?..I need to get some of it.
Blueberry, it’s not that the chemicals make a distinction between farm workers and the public…it’s (I think) about the exposure and whom is being exposed and their level of awareness. I suspect the EPA is thinking “pick your own” and the exposure types and levels are vastly different. I think (FWTW) that the EPA is right on this.
PYO will very, very often involve young children to which organophosphates and synthetics alike seem to have a much more profound effect upon. There are studies that suggest this and studies that prove this albeit, with other perhaps non-related chemicals. So, in short, this was, I’m thinking a wise and cautionary move on the part of the epa.
Appleseed70
You may want to re-check the proper rate for Imidan! I’m talking about Imidan 70 WSB The label from the product that I use shows the rate for Apples at 2-5 LB/acre. In the 2015 Orchard Management Guide for the Apples in the Southeast the rate is 3 LB/acre . Same for the 2014 NC Peach Pest Management Guide - 3 LB/acre. I dropped my rate to 1 LB per acre at petal fall on my 1 acre of peaches based on the fact that another grower indicated that he used 1 LB acre. My goal was to reduce the rate of chemical use and still maintain good insect control but I had a lot of problems with catfacing insects which damaged much fruit.
I’m guessing you are spraying less than an acre and you had to make a calculation to convert the labeled rate into something you can use. In my state Imidan is not a restricted use chemical so no license is required to purchase the product. I hate to anger a lot of good folks who are trying to solve their insect problems, but I’m not sure that its use in a home orchard is proper.
You are right blueberry, I was thinking 1 lb to 100 gal and 100 gal to an acre. I stand corrected. FWIW, I’m not sure it’s use in a home orchard is appropriate either, but really to say that I’d have to say growing fruit at home (for most people) is not appropriate either. I mean, you have to have something effective and if not Imidan…what then? I suspect reasonable alternatives are far less effective and perhaps more costly.
Synthetics are unsuitable for the average home grower for a whole host of different reasons with cost, shelf life and package quantities being the most notable.
Apple
This whole conversation demonstrates the complexity of converting a farm chemical to use in a home orchard environment. Although I have a restricted use pesticide license and lots of farm chemicals available for my use, I do not use any of them in my garden. I purchase consumer grade chemicals for use in the garden to avoid the complexity of trying to convert a chemical labeled in terms of pounds or ounces per acre into something I can use in my backpack sprayer. It’s a lot easier and safer when I can just look at the label on the consumer product and measure the proper amount of product for several gallons of spray. The problem for the back yard orchard seems to be that a lot of consumer grade chemicals are seriously diluted and over- priced.
As you know, a farm chemical like Imidan requires you to break the water soluble bag and measure the proper amount of chemical for your application. Since the density of every chemical is different, you have to weigh the chemical on a scale rather than use a volume measurement like a tablespoon. The conversion to grams per gallon is a lot more accurate than trying to determine the amount of tablespoons per gallon and is recommended. The other complexity involves the fact that the farm chemical rates for apples and peaches are based on different amounts of water per acre, typically 400 GPA for Apples but only 100 GPA for Peaches. Although the rate per acre for Apples and Peaches is 3 pounds per acre, in order to convert these per acre rates into something that can be used on a small scale, a calculation for Peaches and a separate calculation for Apples must be made to determine the proper amount of chemical to use on each crop. Even if you are mathematically inclined, it’s not easy to convert a label rate for a farm chemical given in terms of pounds per acre with various full dilute spray rates per acre for various crops into something that the backyard orchard grower can measure and put into a small sprayer. Some people are willing and able to purchase a scale, read the label carefully, make the required calculations, confirm the calculations, measure the chemical and take the proper precautions. Although a lot of people seek the benefit of a chemical designed for farm use, not everyone can handle the complexity.
I don’t think scales and all that are really necessary blueberry, but I get your point and it’s a good one. Volume measurements work just fine, any difference in a wettable powder density is negligible imo, and the applications rates are fairly widespread anyway so it’s a huge target with fairly little room for error.
It seems it may behoove the feds to mandate small quantity mixing instructions on at least some products, but I suppose they may think that would encourage use of restricted chemicals by Harry homeowner.
I for one, will do whatever I have to do to get pristine fruit. I’d like to do that as safely and environmentally friendly as possible, but of course cost is also an issue…it always is.
Imidan has long been considered deficient in its control of catfacing insects (bugs, particularly tarnished plant bug here). It has held on here because of its strong protection against plum curculio.
If you want to be terrified by the use of organophosphates check out what wikipedia has to say on the subject, unfortunately they lump them all under the subject. I am astounded by how much of children’s exposure to it comes from conventionally grown food according to research they quote, which is hard to evaluate. The reason I always considered Imidan fairly safe was that I only used it a couple of times in spring, months before fruit is harvested. However, it always concerned me that dogs would walk on the wet grass of the orchard floor and return to the houses with it on their feet. The stuff doesn’t stick when it is wetted.
I too no longer use Imidan, although it is relatively cheap and effective against my most destructive pests. Asana does seem more disruptive because of its lethality to beneficials but has so far been as effective against key pests. It controls catfacing insects and pear psyla better than Imidan.
Apple,
Sorry, I’ve been so late in replying, it’s been pretty busy. Your question is a good one. I have always like to know the “why” behind things too.
I’m not sure I know the answer, but I’ll hazard a guess as to why the EPA has a less favorable view of organophosphates.
Generally speaking, organophosphates are more acutely toxic to mammals/humans than other classes of pesticides. As I recall, the oral LD50 for Guthion concentrate was about 50 mg/kg body weight. I looked up the LD50 for Imidan 70 and it’s 275 mg/kg. If you compare that to, say, Mustang Maxx at 310 mg/kg, it’s not a big difference.
However, that’s not the whole story. Mustang is applied at a max rate of 4 oz. per acre, whereas Imidan/phosmet is applied at a max rate of 5 lbs./acre (twenty times the amount of Mustang). So agricultural workers are probably exposed to more toxic material with Imidan than with Mustang. The same would be true with consumers eating the food. The maximum residue limit for phosmet on apples in the U.S. is 10ppm, whereas it’s only 2ppm for Zeta-cypermethrin (Mustang).
In short, even though the concentrates of Mustang and Imidan are about the same in acute toxicity, it takes much less Mustang to kill insects than it does Imidan, thereby exposing humans to much less of the compound. This is true with most pyrethroids. If you look at consumer Ready-To-Use (RTU) in home insecticides (for things like cockroaches, spiders, etc.) the active ingredient will probably be a pyrethroid and will have an amazingly small amount of the active ingredient (a very small fraction of a percentage).
Pyrethoids are not a reduced risk pesticide or classified as an “organophosphate alternative” by the EPA. Those alternatives have even higher LD50 values (some above 5000 mg/kg) making them much less toxic than organophosphates or pyrethroids.
I also suspect the long term effects of cholinesterase inhibition from too much organophosphate exposure are more problematic, but I’ve not put any effort in researching this.
All that said, I’m not trying to make a case in order to frighten people about organophosphate use. Although they are generally more toxic, Alan has frequently made a good point that past studies show applicators live longer lives (on average) than the rest of the population. These studies were conducted when organophosphate usage was in it’s heyday. That millions and millions of pounds of organophosphates were applied by thousands of applicators, and yet the applicators lived longer lives is a testament to their overall safety, when applied and used as directed.
Now that’s the kind of answer I was looking for and expecting Olpea. That pretty much puts that subject to bed for me.
One thing though, are the LD50 numbers calculated by using the product weight or volume (the chemical), or the final mixed spray solution? My instinct would say it’s based on a final mix spray solution since data otherwise would be much less valuable, or so it seems to me.
I was just reading about tick control using insecticides and of course the usual cast of characters were highlighted. The carbamate Sevin by efficacy (although not the best) was just about as effective as anything, yet because of the small quantities of pyrethroid required it was later mentioned that they (pyrethroids) were as much as 64 times more effective. This was noted in regards to the significantly smaller quantities involved in solution. To the casual reader this is hugely misleading. If that were in any way true, no carbamate or organophosphate could even merit listing on the efficacy chart comparisons, yet they do, and some are quite effective. Dursban (Lorsban - Chlorpyrifos) was actually the organophosphate used in example and it is extremely effective, yet when mix quantities are mentioned the author gets confused and extrapolates that to mean the pyrethroid is magnitudes times more effective.
I wonder if cattle etc are now being sprayed with pyrethroids in place of Chlorpyrifos?
Lastly, whether LD50 is calculated at weight / volume or in finished solution, I think it may be important to note that organophosphates have a high percentage of active ingredient per weight / volume whereas the pyrethroids have much less. Mustang Max is over 90% inert, where Imidan is only 30%.
Maybe none of this even matters, and whether it does or not, you’ve convinced me organophosphates are probably more dangerous to humans. Enviromentally I’m not sure one way or the other, my instinct would say Imidan is probably worse due to the quantities involved.
Well, I guess I’ll use my Imidan until it’s gone, maybe by then there will be some inexpensive and stable material available in reasonable quantities. I’ll probably save back a pinch or two for PC control because nobody could ever convince me anything works as well as Phosmet.
As a further followup for those who might be following I’ve went and done another search for insecticides that may offer some replacement value for Imidan and that is reasonably priced, stable and available in smaller ish quantities.
I was only ably to locate two, and only have limited experience with just one of them.
Brigade (Bifenthrin) Kills PC and it’s mode of operation is a total paralytic both by contact and ingestion. It also kills BMSB and some other target pests including pear pscylla, but lacks Imidan’s broad spectrum control of all target pests. It is available for around $70 shipped in a WDG form and goes a long way.
Macho 2.0 (Imidicloprid) Has very good control of PC , JB, Borers etc and limited control of a few others. It does not provide broad spectrum control as some target pests are evidently unaffected. It is available for about $25 shipped for 1 pint, it too goes pretty far.
My problem with this chemical as a replacement for Imidan is that it’s non-selective and has been implicated in severe issues with bees. This to me, makes it a tough sell for the early spraying required for PC control.
Anybody else have any ideas?
Below is an interesting publication describing a program to control pests in apples from NC State. IPM is a big part of the program and the list includes many of the newer chemicals, but Imidan is also on the list. http://entomology.ces.ncsu.edu/pest-management-overview/