- Author: Jeannette E. Warnert
The research aims to give vintners blending varieties that will make San Joaquin Valley wines with familiar names more interesting. Vintners may use up to a quarter of their grape volume to impart distinctive color, flavor and structure to a varietal wine without calling it a blend. Grapes being studied at Kearney may one day add a certain flavor note - such as cherry, tannin, black pepper or citrus - to fine San Joaquin Valley wine.
"High levels of color and tannin cannot compensate for a variety whose yield is far below the economic threshold," Wolpert said.
At another stop on the Grape Day tour, UC Cooperative Extension viticulture farm advisor Mark Battany demonstrated the "Paso Panel." Battany developed the tool - composed of an inexpensive, lightweight solar panel and digital meter mounted on an aluminum frame - to help farmers fine tune their irrigation scheduling.
The Paso Panel allows farmers and researchers to quickly and easily calculate the amount of canopy shade in a vineyard or a vineyard row. The data can be combined with climate data to calculate crop water needs.
Measuring soil moisture and using plant-based monitoring systems are other ways to determine plant water needs, but Battany said currently climate-based methods are underused.
"A lot of farmers guess when they need to irrigate," Battany said. "People tend to guess on the conservative side, and put on more water than necessary."
New York-based USDA-ARS plant breeder Peter Cousins was also at the field day to explain his grape root stock variety trials planted at the Kearney Agricultural Research and Extension Center. Cousins and his staff screen 3,000 to 4,000 seedlings a year. The best prospects are sent to California, where 140 experimental root stocks are growing.
"Here at Kearney, the vines grow so vigorously, we can get more than 100 cuttings per plant," said Cousins. "This is their last stop, where we determine whether you can grow them in a field and make wood that propagates vines."
- Posted By: Jeannette E. Warnert
- Written by: Matthew Fidelibus
Peter Cousins of the USDA-ARS in Geneva, N.Y., will be referring to these charts during his presentation at Kearney Grape Day. The title of Cousins' presentation is "The development of new grape rootstocks for the San Joaquin Valley."
- Author: Jeannette E. Warnert
USDA plant biologist Andrew McElrone is using high resolution computed tomography – a type of cat scan similar to the medical imaging diagnostic system – to cruise through plant veins and vessels to better understand grapevines’ water transport system.
The research is conducted on live and dry grapevines at the Lawrence Berkeley National Laboratory. Like in medicine, each cat scan produces numerous digital slices of grapevine, which are stacked on top of each other using special engineering software to reconstruct the system.
“We can then spin the images around into various orientations, moving through individual vessels,” McElrone said.
Grape Day registration begins at 7:30 a.m. Aug. 16 at the Kearney Agricultural Research and Extension Center, 9240 S. Riverbend Ave., Parlier, Calif. Field tours are conducted from 8 to 9:30 a.m. and classroom presentations will be from 10 a.m. to 12 noon.
Registration is $10 per person. Advance registration is offered online.
Field tour topics are:
- New wine grape varieties for the San Joaquin Valley by UC Cooperative Extension viticulture specialist James Wolpert, UC Davis
- The development of new grape rootstocks for the San Joaquin Valley by geneticist Peter Cousins, USDA-ARS, Geneva, N.Y.
- Using the ‘Paso Panel’ to aid in irrigation scheduling by viticulture farm advisor Mark Battany, UC Cooperative Extension, San Luis Obispo County
- Understanding water use of grapevines by plant biologist Andrew McElrone, USDA-ARS, Davis, Calif.
- Trapping and baiting for gopher control in vineyards by vertebrate IPM advisor Roger Baldwin, Kearney, Parlier, Calif.
- Critical weed free periods in vineyard development by vegetation management farm advisor Kurt Hembree, UC Cooperative Extension in Fresno County
- Fruitfulness of DOV raisin cultivars by UC Cooperative Extension viticulture specialist Matthew Fidelibus, UC Davis and Kearney.
For more information, contact event coordinator Matt Fidelibus, email@example.com, (559) 646-6500.