Barley Production

Barley production in California consists primarily of fall-sown 6-row spring feed barley. Most of the acreage is concentrated in the Central (Sacramento and San Joaquin Valleys) Valley and surrounding foothills and in the south-central coastal valley foothills. Barley is grown as an irrigated rotation crop in the Central Valley and as a rainfed crop in the Central Valley foothills and south-central coastal foothills. A substantial acreage of spring-sown feed (6-row) or malting (2-row, primarily) barley also is grown under irrigation in the Tulelake basin in the northeastern portion of California and serves as a rotation crop for potato. Statewide, barley was grown on 280,000 acres in 1996, 8% more than in 1995. About 220,000 acres were harvested for grain; average yields were 1.44 tons per acre (compared to 1.68 tons per acre in 1995).

The 1996 season was characterized by higher than normal rainfall. Foliar diseases were severe in some areas. Barley stripe rust was present throughout the Central Valley. By mid-March, stripe rust was observed in the UC regional barley tests at UC Davis, Sutter, Butte, Merced, Kings, and Tulare as well as in commercial fields in Kings, Tulare and Fresno counties. Severities in the affected plots ranged to 40% when the growth stage of barley was late jointing to flag leaf emergence; the disease continued to increase in severity through early May as unusually cool, wet weather conditions continued to occur. Severities in nurseries as well as commercial fields were extremely high (greater than 50%) by early grain fill and yields were reduced by 10-75%. Some fields were cut for forage or simply plowed under because of the severity of the disease. Among commercial cultivars, UC 603 was least affected and appears to be a "slow-ruster". Some advanced breeding lines showed very high levels of resistance. One area where stripe rust was not observed was the major rainfed production region (the Paso Robles-Shandon area) of San Luis Obispo County. Four collections of barley leaf rust and 25 collections of barley stripe rust were submitted to the USDA Cereal Rust Laboratory for race identification. Estimated statewide yield losses were 25% for stripe rust and 1% for leaf rust.

Germplasm Development and Evaluation

The germplasm development program in California includes breeding and selection by public and private plant breeders and coordinated statewide testing of promising advanced lines from both types of programs. The main objective of the University of California barley breeding program is to develop feed barleys for the principal production regions of California. The project also is developing barley genotypes for smaller, specific niches. Two of the most recently developed University of California six-rowed feed barley cultivars (i.e. UC 337 and UC 828) are no longer useful to Central Valley cereal growers because of their susceptibility to new pathotypes of stripe rust (Puccinia striiformis) which produced an epidemic that was both widespread and severe during the 1996 growing season. The disease provided an excellent opportunity for selection of resistant plants among breeding materials at the Davis nursery. Fortunately, maladapted sources of resistance to stripe rust were not required for the breeding program because of a prior broadening of the germplasm base. In Central Valley yield trials UC 937, UC 933, and UC 932 exhibited both high grain yield and excellent to moderate resistance to stripe rust. In spring-sown northern intermountain regions, UC 958, which is also resistant to stripe rust, was the highest grain yielder on organic soils at Tulelake, CA and Klamath Falls, OR. Averaged over three locations, UC 960, also resistant to stripe rust, had the highest grain yield in northern yield trials besting Steptoe and Colter by about five percent under moderate to low levels of disease pressure. Previous observations in Bolivia had good predictive value in identifying the above five UC genotypes, all of which have semi-dwarf stature to reduce yield losses due to lodging. Curiously, we observed that UC 603 allows numerous "S" pustules of stripe rust but at a lower percentage than that observed for UC 337 or UC 828. The usefulness of the slow rusting of UC 603 remains to be determined.
 

For the statewide testing program in 1996, evaluations were conducted in the intermountain valleys of northeastern California, the Sacramento and San Joaquin Valleys, and in the south central coastal region. Entries in the tests included standard cultivars, new and soon-to-be released cultivars, and advanced breeding lines from both public and private (Resource Seeds, Inc., Western Plant Breeders, Arizona Plant Breeders, Sunderman Breeding Co., World-Wide Seed) barley breeding programs. Intermountain winter barley was evaluated at 2 locations (Montague and Butte Valley, Siskiyou County); fall-sown spring barley, at 8 locations (Sacramento and San Joaquin Valleys and the south central coastal region); and intermountain spring barley, at 3 locations (Tulelake and Scott Valley in Siskiyou County and near Pittville in Shasta County). The Western Regional spring barley test (32 entries) was evaluated at the UC Intermountain Research and Extension Center at Tulelake. The intermountain winter barley test contained 13 entries, all 6-row feed barleys. Two of the entries, Steptoe and Colter, were spring barleys. Stripe rust was very severe on several entries at the Montague site, including Colter, Steptoe, Showin, Sunstar 204B-1 and Sunstar Double. Average yields ranged from 5890 lb/acre (4150 - 7050 lb/acre) at the Butte Valley site to 6170 lb/acre (5050 - 6870 lb/acre) at the Montague site. Eight-twelve was the highest yielding at the Montague site. Sunstar 204B-1 was the highest yielding at the Butte Valley site. In tests conducted from 1994 through 1996, Westbred Sprinter, Scio, Hesk, Eight-Twelve, Boyer, and Kold have been the highest yielding.

The fall-sown spring barley test contained 25 entries for irrigated sites and 27 entries for rainfed sites. All entries were 6-row spring feed barleys. The tests at Yolo (rainfed), Kings, and San Luis Obispo (rainfed) sites were destroyed by grower-cooperators when complying with the Karnal bunt destruction of adjacent wheat tests at those sites. Disease pressure from barley stripe rust was extremely high and contributed to the low yield performance and low test weights of the more susceptible entries at Butte, Sutter, UC Davis, and Merced. Among released cultivars, UC 603 had the lowest stripe rust rating (most resistant). Advanced breeding lines UCD 92-10615 (UC 937) and UCD 92-10588 (UC 932) also showed very good resistance. Cultivars such as UC 337, Sunbar 458, Fiesta, Max, Nebula, Tipton, and UC 828, as well as many advanced breeding lines, were very susceptible. Although low to moderate levels of scald (Sutter, UC Davis, Merced), leaf rust (Butte, Sutter, UC Davis, Merced), and net blotch (UC Davis, Merced) also occurred at some sites, the damage from stripe rust was overwhelming. Lodging was very severe at UC Davis and Merced; at the UC Davis site, only UC 603 showed adequate lodging resistance. Average yields ranged 1200 lb/acre (90 - 2720 lb/acre) at the Butte site to 3360 lb/acre (940 - 5480 lb/acre) at the Merced site. Stripe rust resistant entries UCD 92-10585 (UC 933), UCD 92-10615, and UCD 92-10588 were highest yielding in the Sacramento and San Joaquin Valleys, while UCD 92-10511 and Solum were highest yielding at the rainfed Tulare site. In the three-year period 1994-96, entries RSI 32306 and RSI 219 were the highest yielding in the Sacramento Valley; RSI 32306, RSI 219, and Tipton, in the San Joaquin Valley; and RSI 32306, Tipton, and Arivat, in rainfed areas.

The intermountain spring barley test contained 20 entries, including 2-row and 6-row feed and malting barley. Stripe rust was late occurring and moderately severe at the Tulelake site, where entries Colter and Maranna were most severely damaged. Five advanced breeding lines from the University of California (UCD 92-10615, UCD 92-10591, UCD 92-10493, UC/NK 2867, and UC 961) showed very good resistance to stripe rust. Severe early season moisture stress and high levels of BYD occurred at the Scott Valley site. Many entries lodged severely at the Tulelake site; entries Walker, UCD 92-10591, UC/NK 2867, Foster, and Sunstar Prince showed excellent lodging resistance. Average yields ranged from 3200 lb/acre (1710 - 4210 lb/acre) at the Scott Valley site to 5530 lb/acre (4170 - 6850 lb/acre) at the Tulelake site. Baronesse was the highest yielding at the Scott Valley site, Rollo was the highest yielding at the Shasta site, and UCD 92-10591 was the highest yielding at the Tulelake site. Over the three locations, UC/NK 2867 and Rollo were highest yielding in 1996. In the period 1993-96, entries Colter, Gustoe, Steptoe, and Maranna were highest yielding at Tulelake; and Steptoe, Colter, and Rollo, over-all. Yields for entries in the Western Regional spring barley test ranged from 3600 - 7670 lb/acre. Test weights were low due to the late appearance of stripe rust. The highest yielding entries, UT 2468 and DA 592-47, both were very susceptible to stripe rust; the disease, however, occurred too late in the season to reduce grain yields.