Heritability of Powdery Mildew and Scab Resistance within Apple Progenies

The occurrence of both diseases was evaluated for four years in a selected orchard where 22 different apple progenies, totalling 699 seedlings were planted. During this period, no chemical protection against the diseases was applied in the orchard, and the incidence of the diseases was rated using a 9-point scale (from 9 = not infected to 1 = very highly infected). For the finalisation of the results, each seedling was characterised by the highest rate of infection from all four years of the evaluation. The lowest mean level of mildew infection equal to 7.47 was observed in the progeny of Resista x McIntosh Wijcik. Concerning the scab, the best was the progeny of Resista x Karmina having a rating equal to 8.27. The highest level of segregation of seedlings having joint resistance to both diseases was found out in the progenies obtained by crossings of HL665 x HL782 and Resista x HL447.