California’s wheat harvest is underway.

Although there are widespread reports of high levels of stripe rust in several varieties and blank heads due to frost, the 2011 crop is expected to be a good one.

There are 750,000 acres of wheat in the state this year with a little more than 100,000 acres of durum/pasta wheat grown mostly in the Imperial Valley, which started its harvest in mid-May.

Growers are currently harvesting central San Joaquin Valley wheat fields for silage, and Steve Wright, farm advisor, University of California Cooperative Extension, Tulare and Kings counties, says growers are reporting “good yields.”

He expects the same information for fields harvested for grain when combines start rolling in the near future.

To justify his prediction, Wright repeated the ageless axiom that bad weather for cotton planting means good conditions for heavy grain yields. It has been a cool, wet spring, far from ideal for cotton planting, but near perfect for finishing fall-planted cereal grains.

“Varieties not impacted by stripe rust are looking real well,” he said, adding, however, that frost at the boot state in some fields is showing up as blank heads.

He predicts about 50 percent of the wheat acreage in his area will be harvested for silage and the other half for grain. It once was two-thirds silage and a third for grain. The switch is based on the return for silage from dairies and the return of grain, which has been high the past couple of seasons.

“On the West Side of the San Joaquin Valley where there are fewer dairies, more of the wheat will be harvested for grain,” he said.

Grain yields have slowly been increasing with improved varieties. Yields of 4 to 4.5 tons are above the average, but not unusual today. In the days of widely planted Yecora Rojo, 3 to 3.5 tons were considered exceptional yields.

One of the more popular, newer wheat varieties has been Joaquin. It was a very close second to PR 1404, the most widely planted red or white wheat. Both were separated by a fraction at basically 21 percent apiece.

“Joaquin has been very popular because it makes good yields and good protein,” said Wright. “It has done its job, but for the past two years the amount of stripe rust found in Joaquin fields is increasing, many after fungicides were applied.”

Stripe rust has been around awhile, but it reared its ugly head in California in 2003 in epidemic proportions. It virtually eliminated Yecora Rojo from the California wheat picture. At one time 80 percent of the state was planted to that variety. This year it is less than 3 percent.

“It hit us in the face that year, and yields were down 50 percent or more that year from stripe rust. It hit some of the best varieties we thought were resistant.” By 2005, another bad year for stripe rust, California wheat growers lost another very popular variety, Blanca Grande, because of its susceptibility to stripe rust.

“There is so much stripe rust inoculum moving around with storms; it covered the state” he said. Wright said Lee Jackson, retired UC Davis wheat expert, has identified at least 19 different races of stripe rust, as he evaluates wheat trials around the state for stripe rust.