Disease control in organic cherry production with new products and early plastic cover of the trees

摘要

The effect of 3 new natural fungicides to control Monilia (Monilia laxa) of sweet cherry as well as theudeffects of plastic cover during flowering period were tested in different trials on 4 organic farms inudSwitzerland during three years. Under low to medium disease pressure Serenade (Bacillus subtilis),udTrilogy (Azadirachtin-free Neemoil) and lime sulphur reduced Monilia incidence by 30 to 60 %udrelative to control. With high disease pressure, however, non of these products had a relevantudcontrolling effect.udCovering the trees during flowering period resulted in a >90 % reduction of the 3 diseases Moniliaudlaxa, Clasterosporium carpophilum and Blumeriella japii. Additionally, the proportion of burst fruitudand the loss by bloom frost was strongly reduced under plastic cover .udThe weak effect of all natural fungicides tested against Monilia laxa brings us to the conclusion thatudwe will focus research on indirect measures such as plastic cover during flowering period and moreudintensive variety testing under 100 % organic production conditions.