Results of variety trials in 2002 suggest new materials for improved returns for California's beleaguered bell pepper growers, according to Bob Mullen, San Joaquin County farm advisor.

“Now that there are a number of exciting new pepper cultivars available to producers, information on yield and fruit quality, as well as disease resistance/tolerance, is particularly desirable for the local industry,” he said.

The top yielding bell pepper in the replicated variety trials was Double Up with 30.5 tons per acre.

Mullen said the Sakata Seed variety was the highest in marketable yield for both green-colored and red-colored fruit on San Joaquin loam at a Biglieri Farms field near Dry Creek. The furrow-irrigated field was transplanted June 18 and hand harvested on Sept. 18. Baron was the field variety.

Encore from Novartis Seed came in second in yield with 28.43 tons and Golden Sun, a Hazera Seed variety with semi-long, yellow fruit, was third with 25.55 tons.

Mullen said the new varieties, predominately hybrids, represent a welcome advancement toward better production and quality.

Also of interest was how varieties stood up to pepper spot/black spot, or STIP, a disorder that shows up as gray or black spots when the fruit is about three inches in diameter. Later it develops into disfiguring green or yellow spots, making the fruit unmarketable.

The majority of the 12 varieties in the trials showed no, or very little, STIP, thought to be connected with a calcium nutritional imbalance. It occurs on the coast or, during cool, short-day periods in the Central Valley, particularly in older open-pollinated varieties.

Calcium and hybrids

In several years of studies, Mullen and Richard Smith, Monterey County farm advisor, were able to reduce STIP, at times significantly, with preplant and/or layby applications of calcium, but they could not completely eliminate it. Hybrids, many developed from European lineage during in the last five years or so, appear to have overcome the disorder.

Fortunately for the 2002 trials, virus pressure was relatively mild in Mullen's county, due to lack of high numbers of vectoring aphids, but he said sporadic but severe outbreaks of a complex of viruses, including cucumber mosaic, ring spot, tobacco mosaic virus and others, have taken a toll.

Faced with the added hazards of other diseases and disorders, plus low prices and high investment in drip irrigation and hybrid seed, many growers, in frustration, got out of peppers entirely.

Pepper acreage in San Joaquin County, where the crop is grown mostly from midsummer into late fall, plummeted from as much as 4,000 acres several years ago to about 2,000 acres in recent seasons.

Mullen said his trials also monitored fruit quality, including blocky shape, and good fruit-wall thickness. Harris Moran Seed's open-pollinated Gusto led with 6.6 millimeters. Others with 6.0 mm or greater were Hazera Seed's HA-535 and HA-959 and Seminis Seed's Mar Rojo.

Wall thickness

“Wall thickness is important to both growers and shippers because fruit having it ships better without cracking,” Mullen said.

He recalled an older variety, Flamingo, was a novelty because of its progression in color during ripening, from bright purple, to cream-colored, to orange, to carmine red. It's wall thickness, however, was only about 3 mm thick, making it too fragile in handling.

Mullen also took an early look at other varieties in an observation trial at the Biglieri Farms site using a dozen lines, with each line replicated only once. None of the entrants showed any signs of STIP.

Leaders in yields of marketable red-colored and green-colored fruit were Hazera Seed's El Charro with 33.4 tons, Hazera Seed's Alexandra with 31.51 tons, Hazera Seed's HA-2112 with 30.2 tons, Enza Zaden Seed's Tequila, a multi-colored specialty line with 29 tons, and Sakata Seed's XPP-1136 and Hazera Seed's Paso Real, both with 28.75 tons.

Fruit-quality standouts were Alexandra, Sakata Seed's XPP-0132, a yellow-fruited line, and Paso Real.

Alexandra and Sakata Seed's RPP-8532 both made a fruit wall thickness of 6.6 mm, while HA-2112, Sakata Seed's XPP-1135, Novartis Seed's RPP 8530, and Harris Moran Seed's HMX 0648 all measured 6 mm.

Crop value climbs

The pepper crop value for San Joaquin County was $16.6 million (on 1,900 acres) in 2002, up dramatically from the $9.4 million (on 2,180 acres) the year before.

Mullen, who anticipated continuing variety trials this year, said he suspects the improved returns will likely encourage an increase in acreage in his county this year.