COMPARISON OF WHITE ASPARAGUS CULTIVARS (ASPARAGUS OFFICINALIS) IN GERMANY

15 asparagus cultivars from France, Germany and the Netherlands were transplanted at the experimental station Geisenheim in 2000, at plant density of 13.889 plants/ha (1.80 m x 0.4 m). Spears were harvested two weeks in 2001, six weeks in 2002 and about eight weeks in the subsequent years. In 2001 all four replications of the trial were harvested without plastic covering; while in the following years three replications were covered with black/white plastic mulch, one replication was uncovered as control. This replication was selected as the replication with the smallest difference to the average of four replications. During the harvesting period spears were cut daily, trimmed to 22 cm, weighted and graded (diameter, discoloration, open heads, hollowness …). In autumn total stem number, height and diameter; thickness (diameter >10 mm above ground), young stem number; and disease tolerance were scored. On average the cultivars, covered with black/white plastic mulch, total yield varied between 5.4 and 11.4 t/ha in 2004. Higher variation was observed considering the yearly total averages. The ranking of the cultivars, based on marketable spear production of four years, starts with the Netherlands cultivar 'Gijnlim' followed by 'Ravel' from Germany and ends with the cultivar 'Grolim' from the Netherlands. The average spear weight for the whole season ranged from 35 gram ('Mondeo') to 72 gram ('Grolim').