Ron Voss, University of California Extension vegetable specialist was on hand among the tagged piles of tubers to report particulars of the trials, measuring performance according to nitrogen rates and spacing.

Voss also discussed the U.S. Plant Variety Protection Act in view of interest by breeding companies in exclusive seed rights. The issue will be considered by the industry during the summer.

The Kern County trials, held at a ranch of D.M. Camp and Sons, had 64 entries in replicated trials from western and southwestern regional trials, plus 84 others for observation.

Voss said the season of 125 to 130 days, which began with planting of the replicated and observation trials at Arvin on Feb. 5 and ended with grading the week of June 18, was early. Vine growth and health were excellent, making the season a good one for growers.

Little learned

However, he added, from the standpoint of board-funded research projects to learn more about late blight and potato Virus Y, the season revealed little.

Despite inoculation from infected plants from Kern County fields, late blight did not appear in trials at Shafter, making the third season the trials have been blight-free. Although potato Y virus continues to be a major concern in development of new varieties, its incidence in this year’s trials was significantly less than in recent years.

In the second year of nitrogen-rate screening, 12 varieties were rated on response to rates of none, 80, 160, 240, and 320 pounds per acre. Applications were split: one-half at planting and one-half 45 days later.

"We have the full range of very deficient to sufficient levels of nitrogen rates," said Voss. "In the first year of the study, 2000, the different varieties did respond differently to nitrogen rates. Some reached maximum yields at lower rates than others. This study will be conducted for three years before conclusions will be made."

Complementing the nitrogen studies are in-row spacings of six, nine, and 12 inches. These tests are intended to determine specific cultural requirements for the new varieties. Of particular interest are management practices best suited for new clonally selections of Russet Norkotah, opposed to those used for the variety’s original strain.

Voss said the Plant Patent Act of 1930 excluded potatoes, and no one could claim exclusivity, own, or collect royalties on a potato variety.

But during the mid-1990s, potatoes came under the Plant Variety Protection Act of 1970, and the change included European varieties, which are privately developed and grown. Foreign potato breeders would not market in the U.S. without the program.

In the U.S., where Land Grant universities and USDA do virtually all potato breeding, varieties are named and protected as they are released.

Colorado russet lines, for example, Voss said, are protected, and growers pay an additional 50 cents per hundredweight of seed of those varieties.

In California, on the other hand, the CPRAB, through industry assessments, has funded more than $1 million since 1970 in development of new varieties.

UC, like other Land Grant institutions, has a policy for patents and other intellectual property, with licenses and royalties, including developments made in cooperation with other institutions.

The UC, California-Oregon Seed Co., and Zuckerman-Heritage, Inc. are interested in applying for protection of new potato varieties under the act, said Voss.

Must act quickly

Time is critical because of the act does not allow advertising or sale of a variety for more one year before an application is filed.

Following industry discussions, CPRAB has been asked for its recommendation on the issue at its September meeting.

Voss said although water shortages in the Tulelake/Klamath Basin reduced potato production this year, research continues at the Intermountain Research and Extension Center. Trials with fertilizer rates and planting spacing such as those in Kern County were confined to the russet varieties. After harvest in September, a field day will be held.

Observational trials for red, yellow, and white entries, excluded in the trials at water-short Tulelake, were done instead in the Delta near Stockton, also the setting for nitrogen rate trials on mostly red-skinned varieties in organic soils.

Voss said the Stockton area trials "give a important, and unique, production area in California some attention that it has not received in the past."

The California potato crop for 2000 was 14.7 million hundredweight, slightly more than the 13.8 million of the 1999 season.

The 18-grower CPRAB allocated $85,000 in 2000 for research on varietal development and the causes of Erwinia early dying, a disease responsible for yield losses in Kern County.