Covering the orchard is the only sure way to have a cherry crop in Chile’s wet growing region.
Iuar Iraira (foreground), manager of the Fundo Agua Buena orchard (in the center picture), discusses the Voen louvered rain cover with international visitors. The area, south of Temuco, receives more than 70 inches of rainfall annually.
Producing some of the latest maturing cherries in Chile is Leonardo Salas's competitive advantageand perhaps his only one.
His orchard is at Gorbea, south of Temuco, on the southern limit of Chile's cherry-producing region. The climate is relatively cool and wet, with more than 1,800 mm (72 inches) of rain annually.
The Salas family has about 500 hectares (1,250 acres) of forest and farmland that used to be cultivated mainly to wheat and canola. Recently, they have been planting cherries, hazelnuts, and blueberries. Finding enough experienced labor is a problem because cherry is a new crop in the area, Salas said. People don't know how to pick cherries.
His ten hectares (25 acres) of cherriesLapins, Sweetheart, Kordia, and Reginawere planted in 2002, mostly on Colt rootstocks, and are all under rain covers. "Otherwise, harvest is not possible because of rain cracking," Salas said. "You need to put on the rain cover. If not, it's like going to the casino every day. You have to pay the money, otherwise you never pick the fruit that you need to."
Lapins harvest begins around January 1. The orchard is not covered until just before harvest to avoid a build-up of humidity leading to fungal diseases. Brown rot and botrytis must be carefully managed because the fruit can look good at harvest but develop rot during shipping. Incidence of bacterial canker is three times higher than in Chile's northern cherry-growing districts, and more intense disease management results in higher production costs, he said.
Salas is testing two Hungarian varieties, Katalin and Alex, which are resistant to fungal diseases and cracking.
The only positive aspect of growing cherries in such a cool and rainy area is that prices can be higher at the end of the season, when the market is empty, Salas said, and higher returns can offset higher production costs.
Salas finds hazelnut production to be far less problematic but also less lucrative. However, he has no plans to plant more cherries.
Iuar Iraira, manager of the Fundo Agua Buena orchard at Collipulli located between Los Angeles and Temuco, faces similar challenges with the weather.
He established the orchard in 1999, planting lots of varieties on different rootstocks in order to find out which worked best. He has Lapins, Kordia, and Regina on Colt and Santa Lucia 64 rootstocks and has found Colt to be much less productive with the same variety. He also has Kordia on Gisela 5, which is not a good combination because production is low, even though the trees bloom well, he said.
Rainfall at Collipulli averages 1,600 mm (64 inches) a year. Because it rains almost every week, the fruit is selectively picked, based on cracking. Harvest normally begins before Christmasaround December 20and ends by January 15. His later varieties tend to be less susceptible to rain cracking than the earlier varieties because January is comparatively dry.
Pickers are encouraged to put good fruit in a tote and poor-quality fruit in a special container on the side of the tote. Culls go on the ground. Iraira pays pickers 8,000 pesos ($16) a day, and one worker can pick between 60 and 70 kilos (130 to 150 pounds) per day.
Rain cover trial
Salas is testing a rain cover from Germany called the Voen, which is made up of overlapping pieces of stitched plastic that allow the wind to pass through the flaps. Ferdinand Siler, technical manager for Voen, said the air movement prevents the build-up of temperature and air pressure beneath the cover.
"When you have big storms, you have no big pressure," Siler explained. "The flaps open, and the wind goes through. If you have a closed system, you can have a lot of wind damage."
Preventing heat build-up under a cover is also important, he said, because high temperatures can result in faster development of the fruit, and lower acidity and firmness.
The louvered cover is installed on poles 4.5 to 5 meters (15 to 16 feet) tall with 70 centimeters (2.5 feet) in the ground. The top of the cover is secured every three meters (nine feet) to a cable running down the row. Cross cables run over the top of the cover. The bottom of the cover is clipped to the cover in the next row.
Voen has installed 500 hectares (1,235 acres) of covers in Europe and Australia since it developed the concept in 2002. They are used mainly for cherries, but also for other fruits, such as apricots, plums, raspberries, and blueberries.
In Europe, the cover costs 3.5 to 4.5 euros per square meter (46 to 60 U.S. cents per square foot). It takes 150 hours per hectare (60 hours per acre) to build the cover and support system and 80 to 100 hours per hectare (32 to 40 hours per acre) to put the cover away for the season. However, some growers roll it up to the top wire and cover it in black plastic rather than remove it each year. Then, in the spring, it can easily be closed for frost protection. Unless they need the cover for frost protection, most growers don't close the cover until after bloom, Siler said. Covering the orchard early can delay maturity by several days, though in some regions that's a benefit.
Paul James, with Primary Industries in South Australia, said experience in his country shows that placing bright plastic markers in a covered orchard during bloom helps the bees find their way back to their hives. In an uncovered orchard, they use the sun for orientation.