Effect of Four Non-chemical Sanitation Treatments on Leaf Infection by Ventur/o inaequalis in Organic Apple Orchards

摘要

Effect of four non-chemical sanitation treatments was evaluated on spring and autumn leaf infection by Ven-turia inaequalis and on leaf litter degradation in two high-density organic apple orchards (Eperjeske and Debrecen-Jozsa, Hungary) on two moderately scab-susceptible apple cultivars ('Jonathan' and 'El-star') from 2001 to 2003. The sanitation treatments were: removal of fallen leaves, disc cultivation, shredding, and covering the orchard floor with plastic foils. At both locations and in both years, all treatments significantly (P<0.01) reduced leaf litter density. By mid-April, leaf litter density compared to non-sanitized plots was reduced by 82.8-88.6 %, 49.7-57.8 %, 42.2-49.6 %, and 99.5-100 %, in treatments of removal of fallen leaves, disc cultivation, shredding, and covering the orchard floor with plastic foils, respectively. These treatments, in the same order, reduced spur-leaf scab incidence in spring by 42.2-46.5 %, 7.1-25.7 %, 25.3-35.7 %, and 55.9-68.6 %, respectively, compared tonon-sanitized plots. Compared to non-sanitized plots, leaf scab incidence in autumn was significantly lower (P<0.05) only in the treatment of covering orchard floor with plastic foils in 2002 and 2003, in which percent reduction of scab was between 16.6% and 24.9 % and between 19.6 % and 27.3 %, respectively. Applicability of the sanitation treatments in organic apple production is discussed.