My six-week Black Rot field trials have ended... lesions tabulated, votes for our mystery product counted. The verdict is in.
First, the trial's protocol:
I observed and photographed 34 plants throughout the vineyard, 17 in the Spray Group, 17 in the Control Group (those that received no spray)
We sprayed once a week for five weeks at a chosen concentration and application rate
Each subsequent week I counted the number of plants affected by Black Rot (BR) and the number of lesions on those plants
The weather was favorable for continued outbreaks of BR throughout most of the time period.
At the end of six weeks:
Number of plants affected with lesions: Spray group - 12, Control group - 16
Total number of lesions: Spray group - 57, Control group - 102
The Test Product did result in an overall diminished amount of Black Rot in the Spray group compared to the Control group.
The Control group had several plants with a large outbreak of lesions, while the Spray group had no major outbreaks, just scattered lesions, so it seems the product is effective in diminishing the severity of an outbreak.
The Spray Group appears generally healthier.
One of the most striking observations is the near complete lack of powdery mildew in the sprayed group. We have been using an assortment of sprays for powdery all summer and have seen very little until the last couple of weeks when the weather has been extremely conducive for it. The sprayed plants have essentially no powdery on them, a noticeable difference from some of their surrounding plants.
Our test product holds great promise, although the results are a bit disappointing. Many factors could account for disappointing results: inadequate coverage, ineffective concentration, rain events, spores already having infected the plant before coverage, etc.
My feeling is that with further controlled studies and more defined spraying concentrations and application procedures, this test product could very well be a reliable prevention of Black Rot outbreaks and definitely already is a very effective product for the control of Powdery.
Perhaps if it had been sprayed from the beginning of the season, it might have been able to keep BR from developing, thus controlling the disease by preventing continuing outbreaks of the pycnidia and conidia spores that perpetuate the disease.
So..... The verdict, you ask. All being told, at this point, unless more outside testing is done with this product or another product comes up that has a proven track record, I do not feel comfortable enough with the product's effectiveness to risk losing our crop next year to Black Rot.
I definitely would like to see the company pursue the development of this product for commercial use. I am currently trying to connect this company with another east coast organic company to see if they can combine efforts to create the product we organic viticulturists are hoping to find. I think it has a very high potential of becoming one of the major weapons in the arsenal of organic vineyards/farms across the country if they develop it commercially. I will stay in contact with them to encourage them to bring it to market.
So, how am I feeling about all of this? Of course, I am disappointed this is not the silver bullet I had hoped it would be. And now we most likely will have to spray with one chemical next year to prevent BR from devouring our crop. But I feel more committed than ever to find the product that will allow for organic viticulture in the east. I will not give up until the product is created. If we can put a man on the moon...we most certainly can find the organic solution to BR.
We will continue with our organic and biodynamic farming practices.
Next year would have been our third year of such practices, qualifying us to apply for organic certification. So now, that three year count will have to begin another year. At least in the meantime, I know I can feel comfortable with my grandbabies playing in the vineyard, our dogs rolling in the rows, our bees and birds flitting about.... except for those three times we will have to spray for the BR. The rest of the year we will remain free of chemicals and do what we can to continue to promote healthy microbial life in the vineyard.
The day will come when we have that organic solution. I am patient and committed. My journey continues with or without BR, and it is in that wonderful journey where all of life happens.
The autumnal equinox is here. The sun has moved back far enough to the south to illuminate our eastern valley with those glorious striations of rainbow colors of the pre-dawn light.
It's all good.