Upload
matthew-fidelibus
View
1.697
Download
0
Embed Size (px)
DESCRIPTION
An overview of traditional and mechanized raisin production in California, including typical varieties and trellis systems.
Citation preview
Grapevine varie*es, trellis systems, and mechaniza*on of the California
raisin industry
Ma:hew Fidelibus
Vi*culture and Enology UC Davis
Outline
• Overview of CA raisin industry • Tradi*onal produc*on methods
• Mechaniza*on op*ons for tradi*onal vineyards
• Newer dry-‐on-‐vine (DOV) systems
• Future goals
California Raisin Industry
• 140 year history • Located ~ 60 mile radius around Fresno in SJV
• 90% natural sun-‐dried
• ~170,000 acres
• ~340,000 tons dried raisins/yr
California Raisin Industry
• Small family farms; ~40 ac mean size
• Historical 10-‐15% ROI + land apprecia*on
Varie*es
THOMPSON SEEDLESS
Problems with Tradi*onal Raisin Produc*on
• Labor intensive • Fruit laid on ground • Produc*vity limits
Op*ons for growers with tradi*onal Thompson vineyards
• Dry-‐on-‐vine (DOV) • Con*nuous tray
Con*nuous-‐Tray
• Harvest pruning (HP) facilitates abscission; minimizes ‘juicing’
• Harvester removes green fruit
• A layer of green berries are spread on paper ‘tray’ that runs the length of the row middle
• Berries dry as in tradi*onal trays • Raisins collected with a pick-‐up machine
Fresno N
umbe
r of
occ
urre
nces
August September October
½ Aug. = 2
½ Aug. = 2
½ Aug. = 0
½ Aug. = 0
Sept. total = 12
Sept. total = 12
Sept. total = 0
Sept. total = 0
0.24”
.01”
0.74”
.25”
.75”
½ Oct. = 5
½ Oct. = 3
½ Oct. = 0
½ Oct. = 8 Sum, all
Dry on the Vine (DOV)
Dried on the Vine (DOV) Raisin Produc*on
• Eliminates the need to hand harvest and lay fruit on paper trays
• Requires that fruit bearing canes be severed at harvest
Thompson Seedless DOV Systems
• Tradi*onal trellis • South-‐side
South Side Systems
+ Exis*ng Thompson Seedless acreage Equipment availability
– Yield limita*ons Trellis modifica7on
Can Thompson Seedless be dried on the vine in CA?
• Yes, and harvest costs can be reduced, but late maturity makes adequate drying difficult and yield poten*al is limited
• Varie*es that ripen earlier than Thompson, on more expansive training and trellising systems, are required for op*mal DOV produc*on efficiency
Fiesta DOVine Thompson Seedless Selma Pete
All canes severed 8/14/01, pictured 9/10/01
DOV Raisin Varie*es
BLACK CORINTH (ZANTE CURRANT)
FIESTA
DOVine
SELMA PETE
SUMMER MUSCAT
DIAMOND MUSCAT
Open Gable
• Large Y-‐shaped trellis supports larger canopy • Increased yield poten*al– about twice as produc*ve as standard trellising on a per acre basis
• Decrease harvest cost, but increased pruning costs and significant investment for trellis installa*on required
OVERHEAD ARBOR
• 2.5 to 3 *mes as produc*ve as conven*onal trellis systems
• Not well suited for Thompson Seedless or other mid-‐season cul*vars
• Significant investment required
Changes in raisin produc*on methods
Area planted to raisin grapes declining, and becoming increasingly
mechanized
California Raisin Industry
• DOV produc*on
• New cul*vars & trellis systems
• Corporate farms
• Fewer acres
Future?
Acknowledgements
• L. Peter Christensen, Stephen Vasquez (UC) • David Ramming (USDA-‐ARS)
• Earl and Randy Rocca (Rocca Ranches) • California Raisin Marke*ng Board