Embryo Rescue: Making the Impossible Happen

Grapes like DOVine, Selma Pete, Sweet Scarlet and Scarlet Royal likely would not exist were it not for ARS scientists’ expertise with a laboratory technique known as “embryo rescue.” The technology “allows us to use two seedless grape plants as parents for new, seedless offspring,” says grape breeder David W. Ramming with USDA Agricultural Research Service (ARS) at Parlier, California.

“Seedless” grapes actually have a small seed inside, “but it’s so small that your tongue can’t detect it,” says Ramming. What’s the point of embryo rescue? To literally rescue the embryo within the minuscule seed so that it can be grown into an experimental vine for testing in the research vineyard.

DOVine, developed by the USDA ARS in 1995, as an early ripening raisin was the first variety released from the hybridization of two seedless grapes using embryo rescue techniques. DOVine resulted from a cross of 79-101 x Fresno Seedless made in 1983. 79-101 is a blue seedless grape of unknown parentage, probably bred by Elmer Snyder of USDA; Fresno Seedless is a sibling of Flame Seedless and resulted from the cross of (Cardinal x Thompson Seedless) x [(Red Malaga x Tifafihi Ahmer) x (Muscat of Alexandria x Thompson Seedless)].

As might be expected, when two seedless grapes are chosen as parents, the seeds inside the grapes of their offspring are also extremely small. Says Ramming, “In nature, those seeds would abort” instead of developing into hard little spheres, each with a healthy embryo inside.

To save otherwise-doomed embryos, Ramming and colleagues excise them with surgical precision from the developing berry (Fig.1). Then, the researchers nurture the embryos on a gel-like bed of nutrients until they form seedlings hardy enough to transplant.

Ramming pioneered the use of embryo rescue several decades ago to breed superb seedless grapes. Today, it still remains the survival secret of many of the team’s most innovative grapes and used by private breeding programs. 

Raisin and Wine Grape Mechanical Harvest Safety Training

The second annual Raisin and Wine Grape Mechanical Harvest Safety Training is set for July 18, 2012 at the C.P.D.E.S. Hall in Easton CA, located at 172 W. Jefferson Ave.

Training will be provided in both English and Spanish.

The free training for farm employees and supervisors will increase awareness and improve safety in the field during mechanical raisin and wine grape harvest. Trained participants are expected to pass the information on to the individuals they supervise.

“This is an excellent opportunity to prepare employees for a safe harvest season for Fresno County’s number one crop, grapes and raisins,” said Fresno County Farm Bureau Executive Director/CEO Ryan Jacobsen.

Participants will take part in breakout sessions, including: OSHA regulations; harvester safety; and tractor and equipment safety.

Registration will begin at 8 a.m.; the training will run from 8:30 to 10:30 a.m.

The training is sponsored by the Fresno County Farm Bureau, Nisei Farmers League, Raisin Bargaining Association, Sun-Maid and Allied Grape Growers.

For more information, or to RSVP, please contact the Fresno County Farm Bureau office at 559-237-0263 or info@fcfb.org, or visit www.fcfb.org to download and complete the registration form.

Please provide the name of each participant and which session, English or Spanish, they will participate in.

Raisin Harvester

Raisin Production Overhead Trellis Report

According to the USDA National Agricultural Statistics Service (NASS),California raisin type grapes using the overhead trellis management system totaled 19,543 acres (bearing and non-bearing) during 2011. This amounted to 9.8 percent of the total raisin type grape acreage. Varieties ‘Fiesta’ and ‘DOVine’ had the highest percentage of acreage using the overhead trellis system, at 52.2 percent and 41.2 percent, respectively. However, ‘DOVine’ at 609 acres is being grafted over to by growers other varieties including ‘Fiesta’. ‘Selma Pete’ has increased in acreage to 3,872 with approximately 33.1 percent of the plantings trained on an overhead trellis system. The remaining acreage is primarily trained to the open gable trellis system, which is less costly and allows growers to use most of their existing equipment. Approximately 31.5 percent of the total raisin type acreage planted since 2004 has been managed using the overhead trellis system according to the USDA NASS.

The full USDA NASS 2011 California Raisin Grape Overhead Trellis Report can be found here.

ATTENTION RAISIN GROWERS!

2012 will mark 31 years since the first San Joaquin Valley Grape Symposium. The inaugural symposium was held at the old Hacienda Inn at Clinton Ave. and 99 Hwy in Fresno, CA. The meeting had presentations by farm advisors and specialist covering soils, irrigation, grapevine nutrition and mechanical pruning in addition to other topics. This years meeting will be similar but will focus on raisin production and marketing activities.

The 2012 SJV Grape Symposium is being held at the C.P.D.E.S. Hall in Easton, CA and will include a catered lunch highlighting dishes made with raisins. The California Raisin Marketing Board is co-sponsoring the meeting and will be sharing raisin marketing activities that took place throughout the nation.

Meeting information and registration:

SAN JOAQUIN VALLEY GRAPE SYMPOSIUM

Date: January 4, 2012

Time: 7:00 AM - 1:30 PM

Location: Easton CA

COST: $10 preregistration (LATE registration & at the door $20)
Registration must be received by Wednesday, December 28, 2011.

Online Registration: (pay with a credit card) http://ucanr.org/sjvgrapesymposium

 

Presented by:

University of California Cooperative Extension
California Raisin Marketing Board

HANDLING RAINED-ON and HIGH -MOISTURE RAISINS

Rain is predicted for this Tuesday and Wednesday, October 4-5, 2011. Should rain occur, follow these practices to minimize damage and infestation to raisins:

Tray-dried raisins
• Slip trays to prevent their sticking to the soil. Move them just enough, 1 to 2 inches, to break the seal between the paper and the soil. This interrupts the wicking of moisture from the soil into the tray.

• Turn the trays as soon as possible to expose bottom fruit.

• Do not save fruit stuck to the bottom of trays or mix it with other fruit. Use new trays as needed, or reverse old trays at turning by putting the soil side next to the raisins (but only if soil is not sticking to the underside of the tray) and leaving stuck fruit on the outside.

• Pick moldy or rotten fruit off the tray before rolling. This is the best opportunity to reduce moldy fruit by hand.

• Get rolled fruit out of the field as soon as possible. Do not fill bins with raisins above 18 percent moisture. Use half-filled bins at 18 to 20 percent moisture. Sweat boxes are suitable for raisins up to 20 percent moisture; half-fill them with raisins between 20 and 22 percent moisture. Begin on-farm or commercial drying as dictated by moisture. Immediate drying is needed when raisin moisture exceeds 22 percent.

DOV raisins
• Raisins that are dry enough to be harvested should be removed from the vineyard. DOV raisins that do get rained on will pick up moisture. However, depending on the weather after the rain event, they will dry down to their previous moisture but may need 1 to 2 additional weeks to meet delivery standards. Late season rain events will greatly reduce the chances of naturally drying the fruit. Growers should make arrangements with a packer or dehydrator to finish drying the fruit. NOTE: DOV fruit is sensitive to excessive handling and should be delivered to a packer as soon as possible.

Boxing and Delivery
• Watch for spoilage in boxed raisins. Dump fruit over and spread into more containers at first signs of spoilage.

• Run fruit across a shaker, if possible, to reduce insect infestation and to provide another chance to pick out mold. Do not run fruit with too many uncured berries over a shaker.

• Cover tightly with polyethylene during rainy, foggy, or humid weather. Otherwise, raisins will absorb moisture directly from the air. Use paper covering, such as tar-impregnated paper, underneath the plastic to prevent water condensation.

• Deliver the raisins as soon as possible to the packer so that they can be fumigated.

Commercial washing and drying (wet reconditioning) may be necessary to further remove mold and embedded sand. The service is offered by many packers and most commercial dehydrators. The need can be determined by a USDA inspection.

Puddles

Aftermath of extensive rain w/ puddles between rows.

Turned raisin tray

Wet raisins placed on a new tray and turned.

Biscuit-mold

Biscuit roll with mold.

DOV-mold

DOV raisins displaying mold.

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