Berry Shrivel Blues, Part Two
Scientists, or at least science writers, love “eureka!” moments. Thanks to a realization he had in a dream, Otto Loewi figured out that nerve impulses are transmitted chemically. Nikola Tesla, out for a stroll one day, hit upon the idea for alternating current and, using his walking stick and a patch of dirt, drew a schematic right then and there. And Friedrich August Kekulé had a dream in which he saw the ring shape of the benzene molecule, thus solving a puzzle that had been teasing scientists for decades.
Most scientific problems don’t involve pretty, romantic stories about their solutions. Indeed, some problems can seem intractable. Take the grape-ripening disorder known as bunch-stem necrosis or BSN, for instance, a condition that brings foul words to the lips of otherwise stalwart, “seen it all” vineyard managers. BSN results in unripe and shriveled fruit that is useless to the grower.
“BSN has been known for over 100 years,” said Markus Keller, the WSU Chateau Ste. Michelle Distinguished Professor of Viticulture, “and there still is no solution.”
No bolting upright out of bed with a visionary solution? No, and not for berry shrivel (BS), either, another problem with which growers all over the world must contend. But, said Keller, if we can’t get to the answer in a flash, then we’ll do it the old-fashioned way: by testing one hypothesis after another.
Characterized by the sudden shriveling of berries while the stem remains green, BS can cost growers up to 40 percent of a crop, Keller said. “The berries start to ripen, then very suddenly decide they’ve had enough and start to shrivel,” he said. “The problem is it is very unpredictable — it only happens in some grape clusters, in some vines, in some blocks, in some years. It is a moving target.”
Keller and his colleague, grape physiologist and assistant professor of viticulture Baskar Bondada, have previously emphasized to growers that BS is different from BSN. Indeed, that is still the prevailing view in California and in Europe.
“Now, though, we think there is a transition from BS to BSN,” Keller said.
The change came about as a result of work done by Keller, Bondada and their graduate student, Geoff Hall. Hall is the lead author on a just-published paper in the Journal of Experimental Botany.
By employing several techniques to test the plumbing of grape clusters as the fruit ripened, Hall found that cells in the phloem of the rachis of affected plants were dead. The phloem is part of a plant’s essential circulatory system, moving water, sugar and other nutrients through the plant, mostly from the leaves to the fruit and the roots. The rachis is the bit of stem that connects the berries to the plant. When the phloem in the rachis dies, the hydro-nutritional system that supplies the berries collapses and the berry stops ripening and shrivels.
The weird thing about BS is that the rachis appears normal, unlike BSN where, as the name implies, the rachis is necrotic or, basically, dying. Hall, using the facilities at WSU’s Franceschi Microscopy and Imaging Center, was able to stain phloem cells with a special dye and then look at them under a microscope and see, in both BS and BSN affected plants, the dead cells in the rachis.
So even though Hall, Keller and Bondada didn’t get to run through the vineyards yelling “Eureka!” they did make progress with the ongoing berry shrivel problem. Showing that it is probably a continuum from BS to BSN is, Keller said, “important, because BSN is better understood by growers.”
European growers, said Keller, have been applying magnesium sprays to vineyards in an effort to control BSN. Even though no one understands why magnesium works, at least part of the time, the fact that is does is what matters to vineyard managers.
What is fairly clear about both BS and BSN is that it is not caused by a pathogen. Scientists in Europe and California have spent a lot of time looking for a pathogen or disease that might cause berry shrivel. “They have run a lot of tests, but so far, no one’s been able to identify a pathogen,” Keller said. “So if there’s a pathogen involved, it’s one we don’t yet know about.”
Keller said that when industry members first approached him about investigating berry shrivel, he was hesitant. “It’s a long-term problem,” he said, “that requires an ongoing commitment to research”
Keller and his team are certainly committed. Geoff Hall graduated last year and, after an internship in Italy, is now applying for jobs in the Pacific Northwest. His successor in the graduate program is Richard Hoff, who spent this past season watching as BS-affected clusters slowly began to show the symptoms of BSN.
“It was a perfect year for that,” Keller said. “Bad for the growers, because the cool weather meant the grapes had to hang on the vine longer than usual. But it was good for us in terms of seeing the progression of this syndrome.”
Keller counsels patience and the painstaking process of experimental science. It may not lead to immediate gratification but, as in the words of Louis Pasteur, himself no stranger to the toils of trial and error, “Chance favors the well prepared mind.”
–Brian Clark,WSU Marketing, News, and Educational Communications
Read the first part of the berry shrivel blues story at http://bit.ly/f7FDoJ.
Learn more about berry shrivel research at WSU by visiting http://bit.ly/haVLFl.
This article is based upon the scientific paper “Loss of rachis cell viability is associated with ripening disorders in grapes,” which is available, courtesy of the Journal of Experimental Botany, online at http://bit.ly/haDgGw.
A Zeal for New Zealand
Master winemakers may disagree on lots of things but one thing they have in common is a deep respect for a well-trained palate. An important part of that training is tasting wines from as many of the world’s great winemaking regions as possible.
In keeping with that idea, Theresa Beaver, coordinator of WSU’s online professional certificate programs in viticulture and enology, organized a trip to New Zealand. Like the wine industries of Washington, California, South Africa, and Australia, New Zealand’s is a “second wave” industry that emerged in the 1970s with newly sophisticated consumers’ demand for European-style premium wines.
As Beaver said, “The parallels and differences between Washington and New Zealand made it an ideal place for a wine-tasting trip with a strong educational focus.”
26 people were on the two-week trip, Beaver said, including many Washington winemakers along with viticulturists, winemakers and writers from across the country.
“We visited 18 wineries,” Beaver said. “They were all fabulously hospitable, serving us to great meals and offering wonderful tastings. We met with New Zealand winemakers and learned about their processes. There were many discussions between winemakers and lots of note taking. As an added benefit, I saw lots of connections occurring between the participants on the trip.”
The professional certificate programs Beaver manages are in very high demand. The two-year programs were recently expanded to accommodate more students, Beaver said, although the waiting list is still long. For those in a hurry, the course materials are available separately as self-directed modules – students don’t get the contact with faculty but the information is the same as in the full-meal-deal programs.
–Brian Clark and Theresa Beaver
Learn more about WSU’s self-directed courses in viticulture and enology by visiting http://bit.ly/hqXAOg.
Learn more about WSU’s professional certificate programs in viticulture and enology at http://bit.ly/di2wYd.
It’s all about the connections. Check out this short video focusing on the connections made by students in WSU’s professional certificate programs: http://bit.ly/9pBj2S.
10th Anniversary of Celebrate Washington Wine Is this Saturday
A few tickets are still available for the Celebrate Washington Wine gala dinner and auction this Saturday to benefit the WSU Viticulture and Enology Program. The popular event features a reception, gourmet dinner, and both silent and live auctions. Both auctions feature an array of interesting and unusual items, ranging from an African safari to golfing getaways to a football helmet autographed by the Seahawk’s Marcus Trufant, and of course an amazing selection of fine Washington wines.
This year’s festivities include two fun new features, a jewelry raffle and a bottle pull.
One hundred keys will be available for $25 each, and one of those keys will unlock a box containing a beautiful pair of one-half carat A+ quality diamond earrings valued at $1,200.
In the wine pull, a $25 donation enables the purchaser to pull an anonymous bottle of wine from a special collection. All wines in the collection will be excellent but a few will be exceptional and valued at well over the donation price.
The celebration gets underway at 6 pm this Saturday, Jan. 22, at the Chateau Ste. Michelle Winery in Woodinville. We’d love for you to join us. To see the complete auction catalog and reserve tickets, visit http://www.wineauction.wsu.edu.