As fall approaches, Fresno County, Calif., raisin grower Ken Shinkawa is casting one wary eye at his slow-to-mature Thompson seedless raisin crop and another at his calendar as the date edges ever closer to the Sept. 20 insurance deadline for machine picking grapes onto raisin trays for drying.

Also a concern is the ever-present field chatter about possible labor shortages.

Shinkawa’s 120 acres of vines north of Caruthers, Calif., are “a good two weeks later than I’d like to see,” he told GrapeLine. “Maturity is so late this year that growers will want to hold off harvesting as late as possible — which means a pretty small window to harvest grapes without weather damage.

“Those who normally work for me report that the supply of labor is short, not just in California, but also for apple growers in Washington. A lighter labor supply and a shorter harvest window will put quite a bit of pressure on grape growers and labor contractors to get the job done in a timely fashion.”

A smaller-than-expected California crop may help ease that pressure somewhat. The USDA’s National Agricultural Statistics Service predicts California growers will harvest 2.05 million tons of raisin grapes this year — down nearly 7 percent from the July forecast. This year’s bearing acreage is 210,000, the same as last year. The 2011 California Raisin Grape Objective Measurement Report describes the 2011 crop as shaping up to be of average size.

For Shinkawa, the maturity of his grapes is not only late, it’s also variable — even within clusters.

“Clusters have more berries of different sizes than usual,” he says. “Some berries are achieving sugar, while others on the same cluster haven’t softened yet.” He attributes this to erratic spring temperatures that prolonged the bloom.

You can read more about what Shinkawa and his fellow growers had to say about their 2011 grape crops by visiting back issues of GrapeLine at where you can also subscribe to future, exclusive in depth issues. Mailed twice monthly through September, the e-newsletter is sponsored by Chemtura AgroSolutions.