Copper is toxic but more in the long term if too much builds up in the soil. It is a very good preventative for many kinds of diseases. It damages many leaves however so cannot be sprayed throughout the season except on grapes. I spray copper right before the leaves come out and use a heavy duty sticker to attach the copper firmly. I will still see some copper several weeks later after inches of rain. All the time the copper is helping since in each rain a little washes into the water and prevents diseases (which also need the water) from flourishing. The main advantage of Captan is it can be sprayed on leaves, so it is useful when there is no possibility to use copper. I personally don't use Captan then, I use sulphur, serenade or Saf-T-Side oil, all of which are not very toxic to bees but are not as powerful as Captan.

Scott

I don't believe Captan to be either toxic to bees or beneficials and certainly is no problem after petal fall when I use it. Mancozeb is the fungicide that seems to be harmful to bennies.

I use Captan but don't spray it until after petal fall on my peaches, plums and apples. It is a great fungicide for eliminating peach scap on my peaches and sooty blotch on my apples. Those are the two biggest issues I have down here in central Alabama.

Hope this helps,

Ken Barber
Millbrook AL

Most orchard fungicides used at labeled rates are not toxic to bees.

There is some newer research I've read that indicates some fungicides will deter bees from pollinating flowers. Interestingly Bumper (propiconazole) was on the list as a bee discourager, which is a compound I use.

In terms of which fungicide is best, it depends on what fungus you are trying to control. For instance, you would never try to use Captan to control cedar apple rust.

Captan does provide good protective control of scab, and I've found it has good staying power.

Scott,

I wonder if copper has significantly more staying power than other pesticides. I've found Captan clings to peaches so determinedly that it's difficult to wash the residue off if sprayed close to harvest. For this reason I've decided to discontinue it's use as a late season protectant, even though it has a zero PHI.

I'm suspecting the reason copper has a reputation for maintaining residue is due more to it's high colorant than anything else. Most other chemicals have poor visibility, even immediately after application.

Thanks very much I am learning some thing new every day.

Abe

Captan both sticks and washes off. The two reasons Cornell recommends using Captan with Rally (myclobutanyl, AKA Immunox) are to delay scab resistance to Rally and because the Rally stays where it is while Captan washes to new growth in light rain.

Interesting how Captan is considered safe to eat but unsafe to be around for, is it 48 hours?... after rain.

Hman,

I've read some of the same things regarding wash off of various pesticides, and like you recall research indicating Captan has good redistribution properties during rain, but can also wash off completely with heavy rains.

However, I have a lot of difficulty getting the residue to wash off. The residue is unsightly and I spent a good bit of time last summer cleaning peaches of it. It may be the researchers are speaking more from the perspective of leaf wash-off (apple scab) whereas my focus is on the fruit, which in the case of peaches, seems to hold the residue firmly.

"Interesting how Captan is considered safe to eat but unsafe to be around for, is it 48 hours?... after rain."

The formulation of Captan 80 I use has an REI of 24 hrs. I understand some formulations of Captan 50 have a REI of 72 hrs. or more, depending on the crop, but yeah at first glance the label seems a dichotomy on this point.

But, as you well know, the EPA assumes a worst case scenario w/ regard to exposure to applicators (8 hrs/day of constant exposure) and so are much more restrictive for REI vs. PHI where person's exposure from eating 5 fruits/day is minimal.

No, I completely understand you not wanting it on your peaches when you sell them. That's also a huge issue with Surround.

Hman - does Cornell mean alternating Captan and Immunox, or mixing them up in the sprayer?

Olpea, I think chemicals sticking to peaches is a special case -- that fuzz holds on to things very tightly. I have not used Captan so I don't have much data on how well it sticks, however. For the copper when I spray at delayed dormant I can put a huge amount of Nufilm in and so it stays on a very long time.

Scott

Same tank-mix.