Captan on Pears?

General Fruit Growing
#1

I bought a 6 1/4 bag of Captan 80WDG a few weeks ago and today I read up on the product label. Nowhere in the label does it mention application rates on pears. For that matter, it makes no mention of pears whatsoever. What’s up with that?
I am aware that certain varieties like Anjou and Comice can be injured by Captan apps, but many sprays have certain varieties that supposedly can be harmed yet app rates are still given for that fruit type in general. What about Bartlett and Potomac etc…is it safe to spray with Captan, and if so, would the apple rate be acceptable or appropriate?

Furthermore, the app rates are given in lbs. per acre. This has come up a lot before regarding Imidan and others. Olpea and Alan are always helpful in determining the correct mix rate per gallon. Could you guys tell me what 4 pouinds per acre translates to per gallon? I’m going with the “just over medium” application rate since sulfur @ 2 tbsp. per gal. will be combined with this spray for increased mildew efficacy as well as to combat resistance issues.

What has been the experience here with WDG vs. WP for ease of mixing. I ultimately chose the WDG due to less dust and also (mainly) because it offered the best bang for the buck. Both WDG and WP are now formulated with a sticker spreader already included.

I also purchased a new bag of sulfur and noticed the max. app. rates have been reduced to 3 1/2 tbsp. per gallon as opposed to 4 in the past. The highest app. rate for any fruit tree is 2 1/2 tbsp. per gallon.

So, that’s 3 different questions with a few FYI’s included. Any help will be greatly appreciated.

#2

I used to use a cup of Captan 50 for 25 gallons as I recall. Cornell says 1 pound per 100 for 50 and 5/8 pound for Captan 80 while recommending 2.5 pound per acre for 80.

Captan doesn’t do much for pears- pear scab requires Manzate as far as affordable possibilities. The Captan won’t hurt them in my estimation (not going to say experience, because I ALWAYS obey label laws even if I have only two pear trees in a mixed fruit orchard).

#3

Thanx h’man. I have saw recommendations for Captan on pears (actually a lot of them), so I’m kinda confused on that.
What has been your experience with WDG as opposed to WP. Did I do the right thing getting the WDG? I have read that it’s con is that it does not mix quite as readily as WP. It’s A LOT cheaper though…around 30%.

#4

Appleseed, I’ve used WDG without issues but my sprayer agitates aggressively. Once it’s mixed you are fine, just make sure its mixed. It’s not that hard to get it to dissolve.

Captan apparently has a degree if efficacy against pear scab and fab, just not enough.

#5

Apple,

Captan used to be universally labeled for pears. Now, as I understand it, only some homeowner formulations of Captan are labeled for pears. I’m guessing the reason is due to the potential of cosmetic fruit injury of some varieties. Since homeowners have fewer choices and there is no potential for income loss (because they aren’t selling the fruit) EPA and the manufacturers probably left the old registration in place for homeowners.

I recall something similar happened w/ Pristine. When Pristine first came out, it was universally labeled for blueberries. A few years ago apparently Pristine caused some blueberry crop injury in California (due to tank mixing Pristine with some other fungicide). The end result was that BASF voluntarily pulled their registration for blueberries from California. However, Pristine is still used on tens of thousands of acres of blueberries in Michigan and in the South.

Wettable Powders (WP) and Water Dispersible Granules (WDG) are basically the same thing. WDGs are basically “pelletized” or “granulized” wettable powders. Manufacturers do this for the reason you mention (less inhalation exposure for the applicator/mixer). Feed companies do the same thing to animal feed. There are a few other benefits to pelletizing/granulizing animal feed but a big one is it cuts down on dust.

WDGs take a few moments longer to break down the granules in the water vs. WPs but the difference is hardly noticeable. I wouldn’t let that be a factor at all in determining which to purchase. Both WDGs and WPs are suspension type formulations which means they will settle out of the suspension if allowed to sit for very long. The little micro particles don’t really dissolve in the water (like table salt would). Instead they just float around.

My wand sprayer doesn’t have any agitation. I stick the wand in the tank and pull the trigger to mix up chemicals. After that, the sloshing from driving around seems to keep things mixed up pretty good. I wish my wand sprayer had agitation, but when I bought it I couldn’t justify shelling out the money for a better sprayer.

I use Captan 80 early in the season to control scab. I use it on the 35 peach trees in my backyard with my wand sprayer. Most recommendations for commercial peach orchards state it takes 250 gallons/acre for a full dilute spray for a mature peach orchard. This is the basis I use to convert acre to gallon rates for use in hydraulic wand sprayers.

In your example, 4 lbs. of Captan/acre = 64oz. of Captan/acre. Since it takes 250 gal. of spray/acre for a full dilute spray that figures 0.256 ounces of Captan per gallon of spray solution (64 ounces divided by 250 gallons). If the tank holds 25 gallons, that would equal 6.4 ounces of Captan per 25 gallons. Of course this type of conversion depends on exactly how much you wet the tree, but for my sprayer tip and the way I spray, it works pretty well for me.

Alternatively, I’ve calculated the total square footage of the canopy of the trees I’m spraying and mixed the chemical based on converting acreage to square footage (i.e. 43560 sq.ft./acre. If spraying 10000 sq ft, that’s 22.9% of an acre. At the 4 lb/acre rate, that would be 0.92 lbs, or 14.7 ounces for the area spraying).

Both methods turn out pretty close for my wand sprayer, so I use the first method (gallonage conversion) because it’s easier.

#6

Pears are the only fruit that I never spray for anything, and I’ve never had any
disease or insect damage. Maybe it’s a geographical thing, but people in the
South don’t spray their pears. We don’t have to, but pruning is a different
story.

#7

In NY there are psyla, scab, fab leaf spot and coddling moth to deal with, but at some sites none of these are problems and I’ve seen perfect unblemished pears in unsprayed trees- even in an abandoned commercial Bosc orchard once. But once pests arrive they are usually a continuing problem.

Captan is not effective for me with pears and not worth using on them. I’m speaking from a good deal of experience on this one but I know nothing of its researched effectiveness.

#8

ok, so how would that translate to the gallon? I guess I’ll have to determine the weight per tbsp. or something and do the math. I wish I had a sensitive scale I could weigh it on.

#9

I think about one rounded teaspoon per gal.

#10

Apple,

As a general rule WDGs and WPs don’t follow the old rule, “Pint a pound the world around.” That rule works pretty well for most liquids which are close in density to water, but dry pesticides are much “fluffier” than liquids. As I recall, it takes about 1.5 times more Captan by volume to equal the same weight as water (I measured it once, but don’t hold me to that ratio. I’m going from memory here.)

For some commercial WDG and WP pesticides, they give you a free plastic measuring cup to measure their pesticide (It’s really not free when you consider how much the pesticide costs). I think this is becoming more common practice because it’s harder to measure with a scale than with a see through cup. I have some of the see through cups for dry pesticides but made my own see through cup for measuring liquids.

When I first starting spraying, I purchased a digital “mail” scale to weigh small amounts of pesticides. I think you can get them pretty cheap. I bought mine through some police confiscation website auction. They had tons of these little scales they’d confiscated from drug dealers presumably. They sold fairly cheap. I researched a bit and tried to get a good one. I think it was something like 80 bucks new and I think I bought it for something like $20. This was quite a few years ago, so I don’t know if the police auction still exists, but if it does it might be cheaper than Ebay, since they constantly had lots of these scales for sale.

The scale is also nice for weighing mail to know whether it needs an extra stamp. As a bonus, I’ll already have the equipment if I ever want to go into drug dealing (just kidding). :smiley:

#11

Olpea, you mention an early aspplication of Captan to control scab in your peaches. Would that be before petal fall or immediately after? I have young peaches in my orchard and I am always interested in staying ahead of any diseases.
I will be using Captan this year after petal fall to control sooty spotch and fly speck. By the way do you have a source for Oldmixon?

#12

Tuff,

I don’t spray anything anymore on peaches before shucks off. Peach scab really starts after shucks off. The shuck pretty much protects the peach from insects and diseases. Some recommendations call for fungicide applications at pink or bloom, but this is for blossom blast, which I don’t see very often. There is a thought that a fungicide application at petal fall will minimize release of scab spores from infected twigs, but so far I’ve found it’s not necessary.

Vintage Virgina apples sells Oldmixon free. I think the Arboreum Company offers it for sale some years. I don’t grow Oldmixon free, I think are some on this forum who do. I bet if you gave a shout out, you could probably get some wood next year. Even if you don’t have any rootstocks, you can always graft your the scionwood to one of your existing peach trees until you get some rootstocks going.

That’s what I did this year. A friend sent me some pear wood I wanted to try, but I don’t have any pear rootstocks. I grafted the scionwood to a couple different mature pear trees as a repository for the wood so I can graft the wood to some pear rootstocks I hope to grow from seed.

#13

Just out of pure curiousity…what was the pear variety?

#14

Yes, sniff, you weren’t interested in any of my pear varieties last year (smiley face).

#15

Apple,

It was Harvest Queen. It was a blight resistant pear put out by the Harrow breeding station in Ontario.

:smile: Alan, I don’t know if you’ve tried that one or not. I’ve always wanted to try it ever since (years ago) the Fluffy Bunny said it was the best tree ripened Euro pear he’s tried on the Nafex forum (I don’t even know if that forum exists anymore.) Some other Nafexers also said Harvest Queen didn’t get the credit it deserved. I recall someone (can’t remember who) said everyone always wants to plant another Ontario pear (Harrow Delight) but they claimed Harvest Queen was better. That always stuck in my mind because I had Harrow Delight but not Harvest Queen.

I’ve got a couple Bartlett pears which lost a lot of wood last year to fireblight, so I need to replace them with something. I put the scions on top of the Bartletts for safe keeping, until I can get some rootstocks growing. In reality, it’s probably not the safest place to store pear scionwood. If the Bartletts succumb to fireblight this season, I will have lost my scionwood, but I’m hoping both won’t die the same season.

I occasionally slip over to the GW forum just to see if there is anything interesting going on over there. Not much happening over there but I did notice last week the Fluffy Bunny was posting some over there. That was a surprise. I also noticed Bill Fleming from Montana State Univ. had a few posts over there. Wish they were posting over here.

1 Like
ReplytoOlpea-topic Harrow Program Pears
#16

Olpea,I’ve never tried it and when Fluff raved about it I thought he was talking about Atlantic Queen and probably made a comment about how over rated “it” is. Its description sounds like a great sub for Bartlett. I almost posted a duplicate comment but decided to look it up first after all the endorsements you listed sunk in.

I should invite my former enemy now good on-line friend over to this forum. I sent him some wood this year and he sent me a $20 gift certificate to Walmart in appreciation. I don’t know if there was some joke in that because he probably realizes that we East Coast liberals shop at Cosco for our bargains. They pay their help much better.

#17

I realize this is an A - B conversation but as a C listener I find this humorous and I don’t even know who the person in question is. :grinning:

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#18

Appleseed, I just invited him to our forum. If he joins he will be noticed.

#19

Olpea, I started a new topic/thread in regard to Harvest Queen among other Harrow Pears.

the fluffy one

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#20

Alan,

I really,really pondered long and hard about that gift card. Originally I thought some type of food,but had no idea as to your taste.then I thought gas station but I had no idea what chains were in your area.So I figured Walmart was everywhere. Actually before that I thought about getting you autographed pictures of the Koch brothers but…

fluffy