Mancozeb instruction

[berrycrush]

I am reading this Mancozeb instruction for grapes which says " do not make more than 3 applications per season". Does that sound right?

 

[grapeman]

The labels vary from state to state and that may vary quite a bit. Did you buy the product in your state so the label is for you? Usually it will give a total amount not to exceed for the season. Also some spray classes will limit the number of appliocations to reduce the chance of rsistance buildup.

 

[blueflint]

That is what the Bonide (37%) label states...Do Not Make More than 3 Applications Per year. Ok, now Bonide is marketed to gardeners and hobbyist and this is the easiest to understand instruction they can print.

That said, the agricultural applications are based on volume per acre per year. Another competing Mancozeb label, a 75% concentrate, states it differently and typical for agricultural products:

"Do not apply more than 24 lbs (18 lbs active) per acre per season, Do not apply within 66 days of harvest." On this, the 18 lbs of active product can be spread out over different application amounts depending on the circumstances.

The amount of mix/spray per acre on 1 year old vines vs. 5 year old established vines will be dramatically different. An acre on 1 or 2 year old vines will use less (1/2) of the volume per application per acre.

Confused? Sorry. Hope this helps.

Tony

 

[grapeman]

Thanks Tony for helping. I just don't have much time to type right now> I use one of those 75% products namely Mandzate 75DF and yes that product can be applied up to 66 days before harvest. So far this year I have put on 10 pounds per acre of the product and will need to stop after one or two more applications.

 

[berrycrush]

I bought it from Amazon. So given the small number of vines I would never reach that total limit per acre. Speaking of "66 days", how do you estimate the harvest date, by the size of the cluster?

 

[grapeman]

You need to estimate it by the normal date it will ripen in your area for that variety. Check with other local growers.

 

[berrycrush]

I have used about 4 applications of Mancozeb now I am thinking about switching to Captan. The Captan instruction says mixing 4 lbs in 20-200 gallons of water. That is a big variance. What kind of concentration do you guys use?

 

[grapeman]

It all depends on your application equipment to obtain thorough coverage. A controlled droplet spay nozzle will require less than you normal home sprayer. Take a tank of straight water out and spray a measured area and determine how much you use for total coverage, get out the calculator and determine what part of an acre you have and you can figure out how much water it takes for an acre. If say you spray one hundredth of an acre and it takes a gallon you will be applying 100 gallons per acre. Then mix up the appropriate amount of spray and go for it. Do the math until you are sure of it.

 

[berrycrush]

It all depends on your application equipment to obtain thorough coverage. A controlled droplet spay nozzle will require less than you normal home sprayer. Take a tank of straight water out and spray a measured area and determine how much you use for total coverage, get out the calculator and determine what part of an acre you have and you can figure out how much water it takes for an acre. If say you spray one hundredth of an acre and it takes a gallon you will be applying 100 gallons per acre. Then mix up the appropriate amount of spray and go for it. Do the math until you are sure of it.

Does it depend on the vine foliage density? My single row of vines doesn't have a lot of foliage now. When I spay Mancozeb, it only takes one gallon to go over all of my vines ( I stop when it starts dripping from the leaves ). If I take a middle number between 20 to 200 which is 100 gal and then size it down to my area which 1/13 of an acre that gives 7 gallons. That is enough to make 7 passes and most of the chemical will just run off to the ground. Is this what I am supposed to do?

 

[saddlebronze]

Just to put my two cents in. I use mancozeb on a 1/4 acre vineyard with about 100 vines. At bud break it might take a gallon or two but when the vines are fully leafed out it takes the entire 15 gallons of my ATV sprayer to get it done. The key is to wet both sides of the leaves and that depends on spray pressure, trellis pattern, etc. Bottom line is to mix up the label concentration and keep filling the spray tank until all leaf surfaces upper and lower have been wetted. Whatever gallons you use, thats the number. For that week.

 

[grapeman]

Good way to sum it up Saddlebronze. That is why I suggest a test spray of water to see how many gallons it takes. It definitely varies with age of the vines and time of year relative to budbreak. A bit of common sense goes a long ways.

 

[berrycrush]

Japanese beetles are back. Now I have to spray Sevin every week until end of July. (Or maybe not? does their eating of the leaves works the same way as trimming the vines? I don't know) What I worried about is if it is OK to spray Sevin and fungicide on the same day, would it be cross diluted?

 

[grapeman]

Sevin will mix with most fungicides in the same spray. I only spray for JB if they get to be really devastating. Many experts feel they aid in summer pruning and leaf thinning. I generally only need to spray young vines here occasionally.