Finished pruning now to spray

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Sage

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Finished pruning yesterday, snowing today...

I need to get in a late fall spray. mostly fighting powdery mildew in the summer. What is the best preventive chemical? Looks like good spray weather in about a week and I want to get equipment out of storage and ready.
 
As a side note I have noticed a lot of powdery mildew on weeds outside the vineyard fence. Anything to be gained by spraying a swath around the fence? Maybe normal upwind direction?
 
Lime Sulfur...it is a joy to work with. But I would wait till later this winter before applying...
 
Wonder if “Dormant spray” would be good, I use it on my Peach trees. Basically mineral oil in solution. Suffocates any eggs payed on the bare branches. Good if you have pets.
 
Based off what I read I would say yes. The fungi and mold go dormant with your vines but if or when you get a winter warm spell they could potentially wake up before your vines and do some real damage.

Additionally logic would dictate that you may be able to more damage than normal to these microorganism since they and their defenses would be asleep which is especially important if you have surrounding vegetation. In my opinion.
 
Lime sulfur info from Mike White at Iowa State

Dormant Liquid Lime Sulfur Treatment

Liquid Lime Sulfur (calcium polysulfide) is used in vineyards primarily as a dormant application to disinfect the cordons and canes just prior to bud break to get early season Anthracnose control. Whether-or-not an early season lime sulfur application is needed should be based on past experience and the susceptibility of the grape cultivars being grown.

The potential of Anthracnose infections is much greater during wet springs. Experience here in Iowa has shown that many of the Elmer Swenson cultivars like Brianna, Edelweiss, Esprit and others seem highly susceptible. You can review the Relative Anthracnose lesions on the fruit, Disease Susceptibility chart on pages 100 & 101 of shoot and leaf of Esprit grape. mlw the 2017 Midwest Fruit Pest Management Guide. You will see that Cayuga White, Fredonia, Frontenac, Marquette, Marquis, Reliance, Steuben, Vidal Blanc and Vignoles are listed as highly susceptible. You may also find out that you may be growing cultivars that are fairly tolerant to grape Anthracnose and do not need a special spray for Anthracnose control.

Application during the first week of April in Iowa would be a good time-frame to get this done. Liquid lime sulfur is also toxic to the overwintering inoculum of Phomopsis and Powdery Mildew that reside in the bark crevices, canes and buds of the grape plant. Applying liquid lime sulfur just prior to bud break provides excellent control of Anthracnose, good control of early season Phomopsis and some control of Powdery Mildew. Reducing the amount of overwintering inoculum can dramatically reduce and delay the infection rate of these diseases as the new shoots and leaves emerge from the buds. Rain splash and runoff down the cordon and canes are the primary methods of infection of the new shoots.

Most liquid lime sulfur labels (27-29% calcium polysulfide) are very vague as to the exact product rate and water carrier rate to use for dormant applications to grape cordons and canes. They often recommend mixing anywhere from 4-20 gallons of liquid lime sulfur in 100 -200 gallons of water when using an airblast sprayer. Many vineyard operators will mix 1 gallon of liquid lime sulfur to 10 gallons of water and spray their recently pruned cordons and spurs or canes with a sprayer handgun. They make sure to completely cover the cordons and canes. They typically will end up using only 2.5-3 gallons of liquid lime sulfur per acre when applying it in this fashion. Others are using only 1 to 2 nozzles of their air blast sprayer directed at the cordon. This normally requires higher amounts of liquid lime sulfur per acre because of the overspray that misses the cordon. Liquid lime sulfur in 5 gallon jugs normally runs around $16 per gallon. Many forms of liquid lime sulfur are approved for organic grape production.

NovaSource Sulforix (27.5% calcium polysulfide) is a liquid lime sulfur product that contains proprietary wetting agents intended to have better spreading and retention than the common liquid lime sulfur products. Many commercial vineyards have been using this product instead of the typical liquid lime sulfur product. The Sulforix label recommends a rate 1 – 2 gallons of Sulforix per acre applied as a dormant application. Many growers are mixing around 1 gallon of Sulforix per 25 gallons of water and spraying through a handgun spray nozzle. Sulforix costs approximately $25 per gallon in 2.5 gallon containers. Sulforix is NOT approved for certified organic production.
These dormant applications can be applied to both sulfur tolerant and intolerant grape varieties prior to bud break

Note: Liquid lime sulfur is very corrosive. Suggest spraying the sprayer vehicle with a light coating of PAM, diesel fuel, kerosene or mineral oil to protect the paint and metal surfaces.

“I don’t want to apply Liquid Lime Sulfur, what else can I do?” This is a common question. Many do not like to spray a messy and corrosive sulfur mixture. I understand. My second suggestion would be to use a preventative fungicide or fungicide mix that is effective on anthracnose as soon as the shoots begin to emerge. Manzate / Penncozeb would come to my mind first due to their low cost and additional effectiveness on Black Rot and Phomopsis. Other fungicides that are also listed as highly effective on Anthracnose can be found on pages 95 & 96 of the 2017 Midwest Fruit Pest Management Guide.

Experience has shown that cordon pruned vines tend to have a higher amount of Anthracnose and Phomopsis disease pressure than cane pruned vines.
Cane pruned vines have much less old wood that can harbor these early season diseases.
 
Sprayed last week with sulphur lime mix. I will spray again when buds swell and look about ready to pop.

I put on a very thorough spray, soaking vines and loose bark as much as possible.

Still considering spraying the ground in the immediate areas around the vineyard. Insects must also be carriers.
 
I spray wettable sulphur ( Microthiol Disperss Fungicide , organic ) right before bud break in the Spring , and then every two weeks after that . When the grapes are getting ready to flower I will stop for a week or so , and then when the grapes are done flowering and are forming small berries/fruit I will start my 'every two weeks ' spraying again, but will delay spraying if the temperatures get too high ( 85 F or higher ) I stop spraying sulphur when I am about 5 weeks to harvest time. After harvest I will usually spray one more time before winter arrives.

I have adopted this spray practice for several years. I have a small Gentleman's Vineyard comprised of Riesling , Sangiovese , and Nebbiolo.

If I do not spray sulphur like this , then I will have powdery mildew ( Pacific Northwest is damp ) . Powdery mildew will not only mess with the foilage, it will also retard the development of the grape berries and stop them from becoming nice,juicy grapes. It WILL ruin your crop.

As much as I did not want to have to put spray on my grapes , I found out the hard way that if I didn't , I would lose most of my crop to powdery mildew. Amazingly enough , the powdery mildew is not an issue for some food-type grapes growing right next to the vinifera!
 
I am in the north west also and yes, spray or loose it. I might alternate another spray but I think it's going to be mostly sulfur.
 
I'd recommend Quintec around flowering...its very effective and fairly cheap as well. Only use once a year.
 

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