Asparagus cultivar evaluation trials in the Sacramento-San Joaquin delta region of California

For the past three seasons, data on asparagus marketable yield, spear number and average spear weight have been collected from two furrow-irrigated cultivar trials in California's Sacramento-San Joaquin Delta Region. In addition, the first full-harvest-season data was taken on a new, drip irrigated asparagus cultivar trial. Asparagus establishment was accomplished with the use of one-year-old crowns and 10-week-old seedlings. International Asparagus Cultivar Evaluation Trial II, established in 1995 on Roberts Island near Stockton, California, contains 18 replicated cultivars and 17 single replication observation cultivars. Highest replicated trial marketable yield was attained by UC 157F(1) one-year-old crowns at 5,154 kg/ha (kilograms per hectare), followed by 10-week-old, seedling-planted cultivars UC 157F1 (4,462 kg/ha), UCR 8 (3,907 kg/ha) and UCR. 7 (3,899 kg/ha). All of these cultivars exhibited excellent spear quality (tight tips at 23 cm or greater spear length, spear straightness, uniform color). Spear weight at 23 cm trimmed length ranged from 22.3 g to 32.4 g. Best observation cultivar marketable yield came from Golia (4,621 kg/ha), followed by 89P72 (4,453 kg/ha), Eros (4, 263 kg/ha), Tainan #2 (4,031 kg/ha) and DA 911 (4,004 kg/ha). UCR 115, DA 911, 89P72 and Golia provided the best spear quality. Spear weight varied from 21.2 g to 32.7 g. Another asparagus cultivar evaluation trial on Victoria Island, in a field using subsurface drip irrigation, was harvested for the first complete season in 2000. Twelve replicated and eleven observation cultivars make up the trial that was established with one-year-old asparagus crowns. Greatest replicated trial marketable yield occurred with Atlas (9,176 kg/ha), followed by UC 157F1 (6,943 kg/ha), Grande (6,553 kg/ha) and UCR 115 (6,451 kg/ha). These same cultivars produced excellent spear quality; spear weight ranged from 27.9 g to 42.5 g. Best marketable yield in the observation cultivars came from Cipres (9,718 kg/ha), UCR 69 (9,187 kg/ha), UCR 122 (6,905 kg/ha) and PLA-2232 (6,662 kg/ha). UCR 69, UCR 122, UCR 96 and UCR 64 provided the best spear quality; spear weight varied from 22.3 g to 43.8 g. A final asparagus cultivar evaluation trial, established on King Island with one-year-old asparagus crowns in 1997, contains 7 replicated and 6 observation cultivars. Plagued by disease (Fusarium) and insect (garden symphylan) problems, this trial has never produced well. Best replicated production came from UCR 5 (2,987 kg/ha), UCR 4 (2,854 kg/ha) and UCR 10 (2,394) kg/ha. UC 157F1, UCR 5, UCR 7 and UCR 4 gave the best spear quality, while spear weight ranged from 17.8 g to 24.6 g. The best observation cultivar in yield and quality was F145 x A1 (3,149 kg/ha).