Posts Tagged: blueberries
Summer is upon us, and nothing quite says summer more than eating freshly picked blueberries or using them in delicious desserts. California blueberry growers can find an additional treat – the newly published UC IPM Pest Management Guidelines for blueberry on the UC IPM web site. California is quickly becoming a top producer of blueberries, and the new guidelines can help with management information on blueberry pests such as thrips, light brown apple moth, and spotted wing drosophila with additional information on pesticides and resistance.
In 1995 the University of California Small Farms Program and cooperating farmers started evaluating low-chill southern highbush varieties in San Luis Obispo and Ventura counties. They found that “low-chill” southern highbush varieties offered the most promise for extended season production on the central coast. By 1997, Kearney Agricultural Center trials found that southern highbush cultivars were also well adapted to the semiarid climate of the San Joaquin Valley. Further evaluations identified the best yielding and flavorful cultivars. Initial and ongoing UC Small Farms studies have escalated California blueberry production swiftly up the learning curve, providing California farmers of small to moderate operations a niche in a very competitive market.
Today, California blueberries are harvested from May through July in the San Joaquin Valley and January through May on the central coast. While consumer demands are on the rise and profits can be excellent, producing and harvesting blueberries in California is expensive. It can run over $10,000 per acre to prepare a field because successful cultivation in many areas necessitates soil and irrigation water acidification and adding tons of mulch per acre. Specialized equipment, labor-intensive pruning, and pests like light brown apple moth, thrips, and spotted wing drosophila can add substantially to cost. Therefore, getting the right information and planning is imperative. While the UC Small Farms Program continues to develop field and market research for blueberry production in California, growers can also turn to the newly published Pest Management Guidelines for blueberries.
It might be pouring rain today, but soon enough California will be dry again. As demand for water for a growing urban population and for environmental restoration increases, farmers throughout the state are working to grow crops using as little water as possible, and UC is working with them.
"Water supplies are being constrained. Farmers are facing reduced access to water," said Shermain Hardesty, a UC Cooperative Extension specialist in the Department of Agricultural and Resource Economics at UC Davis.
The research involves using some elaborate formulas for determining how much water is needed. UCCE advisor Richard Molinar, working with small farms in Fresno County, is irrigating small plots of strawberries with different amounts of water, some at 125 percent of the normal rate, some at 100 percent, and others at 75 percent and 50 percent of normal. In San Diego County, UCCE advisor Ramiro Lobo is doing similar research on strawberries and blueberries; UCCE advisor Manuel Jimenez is working with blackberries and blueberries in Tulare County; UCCE advisor Aziz Baameur is planting strawberries and blackberries in Santa Clara County, and UCCE advisor Mark Gaskell is studying blackberries in Santa Barbara County.
Once the berries are grown, they need to be tested - and testing means tasting in this project. The research team is holding tasting sessions to let the public judge which berries they prefer. If you've ever tasted a dry-farmed tomato, you might guess the answer. The first tasting session was held at the Davis Farmers' Market in June, with seven more coming soon at farmers' markets and grocery stores around the state.
Taste is a great quality to measure, but only one aspect of the study. Berries are already known for having a high nutrient content, but growing them with less water might give them even higher nutritional value. The team expects to find nutrition density to be highest at the lowest irrigation levels. To test this concept, UCCE specialists Elizabeth Mitcham and Marita Cantwell, experts in postharvest science affiliated with the Department of Plant Sciences at UC Davis, are doing nutritional quality analysis of the berries as they are picked.
Lawrence Schwankl, a UCCE specialist in the Department of Land, Air and Water Resources at UC Davis, says that many farmers are currently over-watering many crops.
"Over-irrigation is cheap insurance, especially for such high value crops," he said.
He explained that more water tends to grow bigger berries. Since the harvest is not mechanized for berry crops, it takes as much effort to pick a small berry as a large berry, making more efficient use of the pickers' time and filling the basket more quickly if the berries are bigger.
Such a trade-off for the farmers! The public may decide that they prefer smaller berries with more taste, and the scientists may decide that smaller berries are more nutritious, but will it be profitable to grow better berries? It may depend on how much smaller, and on how much less water for how much better nutrition and taste. It may depend on the water rates, says Hardesty. She will be taking all of these variables into account to determine the potential impact on profitability of lower irrigation rates on berries.
The team, which also includes UCCE advisors Michael Cahn in Monterey County and David Shaw in San Diego, will report the results of their study to California farmers in the final year of the project. This project is funded by a California Department of Food and Agriculture Specialty Crop Block Grant.
The annual Blueberry Open House at the UC Kearney Agricultural Research and Extension Center last month warranted lengthy coverage by Western Farm Press.
Freelance writer Dennis Pollock reported that Manuel Jimenez, UC Cooperative Extension advisor in Tulare County, a small-scale farming expert, walked among the mature blueberry plants at Kearney, describing their good points and bad points.
"The perfect blueberry would be one that is big, firm, sweet, easy to harvest and grows in high pH (soil conditions)," he said.
At the event, Richard Molinar, UCCE advisor in Fresno County, small-scale farming, conducted a blueberry tasting, allowing those who attended to vote for their favorite three varieties. He said that variety isn't the only factor impacting flavor.
"Flavor is also affected by weather, soil factors, plant nutrition and irrigation frequency," Molinar said.
Jimenez introduced growers to two new research projects in blueberries:
- Jimenez and Larry Schwankl, Kearney-based UCCE irrigation specialist in the UC Davis Department of Land, Air and Water Resources, have teamed to study the effects of varying irrigation levels on blueberries.
- Jimenez has grafted popular blueberry varieties onto the roots of farkleberry (Viccinium abroreum), which has greater tolerance of alkaline soils like those found in the San Joaquin Valley. By reducing or eliminating soil and water acidification, using the alternate rootstock may provide a significant cut in production costs.
Manuel Jimenez leads a tour of the 15-year-old blueberry research plot.
Manuel Jimenez of Tulare County, who has been studying blueberry production and varieties at the UC Kearney Agricultural Research and Extension Center since 1998.
California’s abundant sunshine enables growers to produce high-quality, very sweet Southern Highbush variety blueberries. But, blueberry plants are difficult and expensive to establish and maintain, in part because of California's soil chemistry.
“Blueberries are adapted to grow in forests, in acidic soils,” Jimenez said. “We’re growing them in a desert in alkaline soil. That requires that we acidify the soil when we establish the crop and continuously acidify the irrigation water – which is very costly.”
For example, a 2009 Blueberry Cost Study produced by UC Davis calculated that equipment needs for acidification - including a storage tank, pump and monitoring kit - amounts to $5,500. In addition, the growers must purchase large quantities of sulfuric acid to add to the soil and irrigation water.
Reducing acidification cost is the goal of a new blueberry trial at Kearney, in which Jimenez has grafted the most common commercial blueberry varieties on the roots of farkleberry plants (Vaccinium arboreum). Farkelberry is a small, stiff-branched evergreen bush that is more tolerant of alkaline soils than blueberries.
So far, the two-month-old plants seem to be growing well in their naturally alkaline soil. The coming years will reveal whether using this technique will improve the economic viability of California blueberry farms and provide California consumers with local, healthful and delicious blueberries at a reasonable cost.
The project is being conducted in collaboration with Oregon State University and Florida State University.
Learn more about the blueberry trial by viewing the video below:
As blueberries have become more a popular plant for home gardening, variety choices have blossomed, wrote Laura Christman in the Redding Record Searchlight.
When it comes to flavor it's hard to go wrong with any variety of homegrown blueberry, said Manuel Jimenez, a University of California Cooperative Extension farm advisor specializing in blueberries.
"All the varieties that ripen on the plant are good," said Jimenez, who is based in Tulare County.
Among the varieties Jimenez recommends are Misty, Reveille, Sharpblue, Star, Legacy, Emerald and Jewel.
The best time to plant blueberries is in the fall, when the ground is warm and plants can establish roots, Jimenez said. However, most nurseries don't feature them in fall. The biggest selection of blueberry plants is available now.
Manual Jimenez talks blueberries at the UC Kearney Agricultural Research and Extension Center last fall.