Comparison of epidemics of Botrytis fruit rot and powdery mildew of strawberry in large plastic tunnel and field production systems

Epidemics of Botrytis fruit rot (Botrytis cinerea) and powdery mildew (Spha erotheca macularis f. sp. fragariae) in annual strawberry were compared in large plastic tunnel and field production systems during the 1998-99 and 19 99-2000 seasons. Treatments were factorial combinations of two main plots ( field and tunnel) and four subplots, including combinations of two cultivar s (Camarosa and Sweet Charlie) and two captan schedules arranged in a split -plot design with three replications. The mean incidence of Botrytis fruit rot was 88 to 94% lower in tunnels than in the field. The incidence of Botr ytis fruit rot for the untreated control in tunnels was less than 2%, which was 89% lower than that of the 7-day captan schedule in the field. This in dicates that Botrytis fruit rot can be controlled effectively without fungi cides in a tunnel cultural system. Powdery mildew was severe on susceptible cultivar Camarosa in tunnels. Early season yields of cultivar Sweet Charli e were significantly higher in tunnels than in the field. Shorter periods o f leaf wetness and higher temperatures in tunnels may have contributed to a lower incidence of Botrytis fruit rot and a higher incidence of powdery mi ldew on fruit in tunnels compared with open field plots.