CELEBRATING 133 YEARS AS CANADA’S PREMIER HORTICULTURAL PUBLICATION
APRIL 2013
VOLUME 63 NUMBER 04
CLIMATE CHANGE
Weather-proofing the farm KAREN DAVIDSON Mark Twain once wrote: “Everyone talks about the weather, but no one does anything about it.” Grape grower Trevor Falk is throwing those century-old words to the wind, literally. This spring, he’s installing 34 wind machines in his Niagara-on-the-Lake vineyards. In fact, the upgraded replacements have satellite monitoring devices that when connected to a smartphone, will allow him to start or stop the machines on a dime. At an operational cost of up to $50 per hour in fuel, he’s determined to be as precise as the weather is unpredictable. “Clearly, the weather seems to be more erratic,” observes Falk, noting extremes in recent years of hot and dry, hot and humid, cold and wet, and winter injury from temperatures north of minus 20 Celsius. “I’m doing everything possible to negate the negative effects of climate change.” These new machines have larger blades that will provide frost protection for up to 15 acres, rather than 10, explains Joe Pillitteri, owner of Lakeview Vineyard Equipment. Powered by diesel, they look much like older models. However, the difference is the computer link that allows real-time monitoring of wind speeds, temperatures and engine variables such as fuel levels. “If you have a block that gets colder earlier than others, you can
INSIDE Alien invasive species worry growers Page 6 Potato roundup
Page 15
Irrigation
B section
www.thegrower.org P.M. 40012319
This is one of 34 wind machines that Trevor Falk is installing this spring to protect against unseasonable frosts. With 500 acres of high-risk, high-value grapes at Niagara-on-the-Lake, Ontario, he’s backing up crop insurance with hardware and software that allow remote monitoring of wind, temperatures and diesel engine variables. Photo by Denis Cahill.
activate a specific machine based on data,” says Pillitteri. Grapes are a high-risk, high-value crop that warrants the capital investment. It’s not enough to depend on crop insurance, increasingly viewed as a fall-back position. Last year’s unprecedented spring frost has forced other Ontario farmers to the same conclusion. Apple growers, who usually tally a $65 million crop, lost 90 per cent in 2012 and then learned that insurance premiums would be prohibitive this year. That’s why seminars at the Ontario Fruit and Vegetable Convention were so popular about how new technologies can protect against frost. Apple grower Dan DeVries shared the family farm’s challenges using frost fans at Fenwick, Ontario. His records show a cost of $5,000 to run one machine. That’s an unexpectedly high cost, he cautions, due to the extreme conditions last year. He calculated $32 per hour for 158
hours to protect 12 acres. He ran his frost fans 15 to 20 times, on average from four to six hours, but as many as eight hours.
“
We saved 50 to 75 per cent of the crop depending on apple variety.” ~ Dan DeVries
Frost fans are not perfect but they are better than no coverage at all. DeVries suggests investing in a solar panel so the battery on the machine stays charged. He also observed that frost fans will not warm up an area in five minutes. Fans must be activated for 30 to 45 minutes. He’s learned to start his fans at 1.5 degrees above zero Celsius.
“We saved 50 to 75 per cent of the crop depending on variety,” he says. “We hope that the weather situation last spring was abnormal.” Hope is not a management strategy. That’s why DeVries is investing in better temperature and wind speed data for each orchard location. He’s convinced weather patterns are changing and for that reason, he’s got six frost fans in operation and two more on order. For berry growers, the weather challenges are equally daunting. Mark Longstroth, an extension berry specialist with Michigan State University, summarized his in-depth knowledge. With blueberries, for instance, growers must know the critical temperatures depending on each stage of development: tight clusters tolerate -6 to -5 C; bud swell tolerates -9 to -7 C, and blooms tolerate -2 C. Longstroth is especially wary of a radiation freeze. That’s when the winds are calm with a clear
sky and a cool air mass. Under these conditions, overhead sprinklers work well for blueberries and strawberries. The goal is to capture the energy from the change of state of water. “It takes energy to melt ice or boil water into steam or vapour,” explains Longstroth. “Freezing water to ice or condensing water is a warming process. Once you make ice and keep it wet, everything is right at the freezing point and no damage occurs. If you use water for frost protection, understand what’s going on. Improper use of water can increase cooling causing greater damage than if you had done nothing at all.” In blueberries, Longstroth advises not to protect bud burst, only when there’s white blooms. Apply water fast enough to keep ice wet all the time. Uniformity is needed for effective frost protection. Don’t shut water off until water is melting, that is when bubbles form under the ice. CONTINUED ON PAGE 3