Performance of North American Strawberry Cultivars under Conditions Mimicking California Production Systems

Abstract

<jats:p>Runner plants from 16 strawberry (<jats:italic>Fragaria</jats:italic> ×<jats:italic>ananassa</jats:italic> Duch.) cultivars were grown using annual Mediterranean production systems to test for differences in productivity, performance traits, and vegetative growth attributes. Genotypes were included from germplasm adapted to four geographic regions: California and northwestern, northeastern, and mid-Atlantic or southeastern United States. The California genotypes were divided further into day-neutral and June-bearing categories. With these treatments, California cultivars had significantly larger plants and grew more rapidly during the fall and winter, had larger fruit, and produced at least twice the quantity of fruit of cultivars from the other regions. Variance components due to region explained 64% and 26% of the phenotypic variance for early and total yield, respectively, whereas differences among cultivars within regions explained 12% and 7% of the variance for these traits. Cultivars from all regions had significantly larger plants and were more productive when treated with 3 weeks of artificial vernalization. However, region × vernalization effects were nonsignificant for all traits, a result suggesting that selection in Mediterranean environments has not adapted germplasm specifically for low vernalization conditions.</jats:p>

Relative Performance of Strawberry Cultivars from California and other North American Sources in Fumigated and Nonfumigated Soils

“…Differences among sources were also apparent for average fruit weight and fruit appearance scores (Table 2). These results are consistent with those obtained previously for tests conducted in fumigated soils alone (Rariden and Shaw, 1994).…”

“…Runner plants from nine California strawberry cultivars and nine widely used cultivars from other North American sources were harvested from a the UC Davis Pomology Dept. 's Wolfskill Experimental Orchard near Winters, Calif., on 4 Nov. 1994, stored at 2 °C, and planted in experimental plots on 14 Nov. (Rariden and Shaw, 1994). The nine California cultivars ('Camarosa', 'Carlsbad', 'Chandler', 'Cuesta', 'Irvine', 'Laguna', 'Seascape', 'Selva', and 'Sunset') were representative of those released from the UC strawberry improvement program during the last 15 years.…”

“…Trials were established and treated according to recommendations for commercial winter plantings (Welch, 1989), with modi-fications previously described for plantations established using low-elevation nursery sources (Rariden and Shaw, 1994;Voth and Bringhurst, 1990). Experimental plots were established on tworow diagonal beds with 1.5-m centers, 33 cm between plants along rows, and 30 cm between rows.…”

“…1995. The commercial appearance score was assigned to the fruit harvested from each plot as an integer value of 1 to 5, with larger values indicating more desirable appearance (Rariden and Shaw, 1994). Total yield was evaluated for each plot on a per-plant basis.…”

Relative Performance of Strawberry Genotypes on Fumigated and Nonfumigated Soils

“…However, although germplasm outside California have been selected for specific pathogen tolerance. growth and yield reductions in our trials were not due to any identifiable pathogen, Furthermore, when evaluated in California, the best materials obtained from outside of our program produced at most 50% of the annual yield of modem California cultivars (Rariden and Shaw, 1994), and the barriers to utilization of this germplasm in California are not expected to be trivial. There is apparently no simple solution for developing cultivars specifically adapted to sublethal effects of nonfumigated soils.…”