Incidence of Infection of Asparagus Spears Marketed in Connecticut by Fusarium spp.

Sixty-seven samples of asymptomatic asparagus spears (avg. 26.5 spears per sample) were obtained during 1995 and 1996 from 22 retail markets in New Haven County, CT, from three commercial growers in Connecticut, and from experimental field plots in Connecticut and North Carolina. Surface-disinfested basal and apical segments were placed on media selective for Fusarium spp. Eight species of Fusarium were identified among 418 isolates from 1,776 spears. Of these, 30 and 62% were F. oxysporum and F. proliferatum, respectively. The incidence of Fusarium colonization was greater from the basal segments (15.5%) than from apical segments (8.1%). Spears shipped from Mexico, Peru, and North Carolina had higher incidence of colonization by F. proliferatum than spears shipped from California, Washington, or the northeastern United States. In both years, spears purchased during June had the highest incidence of F. proliferatum compared with other months. Since F. oxysporum and F. proliferatum are pathogens and infect asparagus crowns and roots, it is probable that infection originated in the field. The less frequent species were found slightly more often on apical segments than on basal segments.