Leaf spot and leaflet removal in day-neutral strawberry cultivars under different cultivation conditions, in organic management

Abstract

The objective of this work was to evaluate day-neutral strawberry cultivars regarding leaf emission, intensity of leaf spot [Mycosphaerella fragariae (Tul.) Lindau] and the impact of the removal of diseased leaflets on the number of leaflet remaining, under plastic-covered and open cultivation. The cultivars Aromas, Monterey, Portola and San Andreas were evaluated in open field and in beds covered with white or transparent polyethylene sheets. Plants grown under open field condition showed greater area under the disease progress curve (AUDPC) of incidence. The AUDPC of severity was greater in Monterey and San Andreas when compared to Aromas, but without difference in AUDPC of incidence. San Andreas emitted a lower quantity of leaflets than Aromas, and had lower number of leaflets remaining after the removal of diseased leaflets. Monterey and Portola showed intermediate scores. As conclusion, the incidence of leaf spot is eased by cultivation in open field. The cultivars San Andreas and Monterey, compared to Aromas, favor M. fragariae. The impact of diseased leaflet removal in the quantity of leaflets in Aromas is lower than in San Andreas.