Hi questor3-
This question has come up here before because others have had the very same question. In the end, we all found the calculations very difficult, if not impossible to do. Possibly Michael357 may have come up with something, but I'm not sure. For me, in the end, (and this is the only pesticide that I've done this with), I wound up going with Jellyman and Scott Smith's advice of 2 tbsp per gallon. But, the 2 tbsp per gallon was actually formulated with the less effective Kocide2000 and Scott (and possibly Jellyman?) are backing the dosage down to 1.5 or even 1 tbsp per gallon. I was going to back mine down to 1.5 tbsp/gallon this year, and then if all goes well, down to 1 tbsp/gal next year. Make sense?
-Glenn

I got mine and the website said 1-2 TBS. per gallon.

I plan to call the manufacturer to confirm.

Thanks to all. Some good stuff comming from everybody. Way to nail it down Michael357. I knew I would be in good hands here...:~)

Glen,
Yes, your plan to back off does make sense. Do so incrementally, so as to judge ongoing effectiveness. I feel that I should do a strong ended approach on the recommended rate scale this time around. I have never applied any Copper before, and may have a mix of issues to address. So can scale back from that.

Michael is going about it the same way I do when I convert rates per acre down to rates per gallon or very small areas, except I don't use metrics if I can avoid it (when I find I need to calculate in grams or fractions of an ounce, I take it to the post office and ask the postmistress to weigh the proper amount on her scale for me, then mark my measuring container.)

One important point here, though, is that if you are dealing with powders and the rates are given by weight, you really need to use a scale to get your measurements. If the amount you want to use works down to 1 oz, a tablespoon may be one liquid ounce, but will not be 1 ounce by weight. So, weigh out the proper weight of the chemical, then measure it and write that down so in the future you can use volume measures and know you are getting the correct weight. Each chemical will vary because it's density will vary.

Beeone: your P.O. story made me laugh! I live in a 200 pop. town with a P.O. but something tells me our postmistress would never let me use her scale for weighing out cides. Actually, I use my reloading scale that measures in grains which adds another conversion to the process. The gravimetric to volumetric idea is very good but since I only have Kocide to weigh and haven't found an acceptable spoon, I just weigh it.

Here's to your postmistress!

Great advice by all . I have a question about when to apply to a small orchard of apple and peach trees?? I just finished an dormant application on apple and peach trees. The buds have just swelled. When should I reapply and when should I discontinue??

I sprayed my trees about 10 days ago, but with all this rain (over 4 inches), i wonder if i shouldn't spray again... Still time. I think PLC will be horrible this year if not sprayed.

Joanie, it depends on how bad your diseases are, etc. If they are not bad you have done enough copper until leaf drop. With big problems more copper can be done later. I did my one peach/plum copper and thats all they get. I had bad fireblight last year on apples; they already had one copper at green tip and are going to get one more round before the blooms come out. Later copper sprays are at more dilute ratios and at some point its too late to spray any copper, mature leaves don't like it.

Frank, I don't have enough PLC experience to know the optimal timing for control sprays, hopefully someone else does or read up on it.

Scott

Great to have you back Glenn! Mrs. G

Thanks for the vote of confidence Glenn. Just the other day I was looking for a spreadsheet I thought I made up for doing those darned Kocide calcs., as they can get rather time consuming and found it! Man, pouring over the spreadsheet to make sure I use it correctly now is daunting after the brain tumor, surgery and radiation. the mind isn't as sharp as it was when I built that hairy spreadsheet. Damn, can't even find my bag of Kocide 2000, looked everywhere!

Sorry OP, can't help at this time.