Yield response, pest damage and fruit quality parameters of scab-resistant and scab-susceptible apple cultivars in integrated and organic production systems

Abstract

In a 4-year Hungarian study, 10 apple cultivars (5 scab-resistant and 5 scab-susceptible) were evaluated for yield, scab incidence, codling moth injury, soluble solid concentration, and calcium content of fruit in high-density integrated and organic apple orchards. Yield was significantly higher in the integrated plots compared to the organic ones in all years (mean values were 18 and 13kgtree−1, respectively). Yield was significantly lower on the younger trees (5–6years old) compared to the older ones (13–14years old) in both production systems (mean values were 14 and 17kgtree−1, respectively). Mean final scab and codling moth incidences were considerably higher in the organic than in the integrated production system, except for the resistant cultivars which had no fruit scab symptoms. Fruit of all cultivars was protected in the integrated production system (mean fruit scab and codling moth incidences were below 2.5 and 4%, respectively). Only the scab-susceptible cultivars were moderately or highly infected by harvest in the organic production system (mean fruit scab incidence was above 5%), while all cultivars (including scab-resistant ones) were highly damaged by codling moth by harvest in the organic production system (mean incidence was above 20%). Mean soluble solid concentrations and calcium contents were significantly higher in the organic production system only in one year compared to the integrated one (mean values were 17 and 16%, and 204 and 191mgkg−1, respectively), and cultivars of scab-susceptibile vs scab-resistant had significant effect on soluble solid concentrations and calcium contents also in one year (mean values were 16 vs 17kgtree−1, and 202 vs 175kgtree−1, respectively). Our results indicated that a multiscale selection approach is required for choosing cultivars for integrated, and especially for organic growing methods in order to facilitate successful apple growing in environmentally benign production systems.