The performance of different rootstocks in varying soil conditions

In 2011, an orchard trial of apple (Malus × domestica Borkh.) rootstocks was established using ’Golden Delicious’ as the scion cultivar. Five rootstock genotypes were planted in previously used rows under different soil conditions: replanted (R), fumigated (F) and free orchard (FOS) soils. The conventional M9 T337 was compared to rootstocks selected by Cornell-Geneva (G.41, G.16 and G.202) and Consorzio Italiano Vivaisti (P21). After five years, tree size was significantly bigger on P21 followed by G.202, G.16 and G.41. M9 T337 had similar vigor as G41. The dwarfed genotypes G.41, G.16 and M9 T337 showed higher yield efficiency over five years than G.202 and P21. Tree size was the highest in FOS followed by trees in F and R soils. Trees on M9 T337 showed a significant growth in FOS compared with trees in F soil. Total shoot growth was higher in FOS and in F soil in the first year only, compared with those in R soil. Trees on P21 showed more shoot growth in two years in F and FOS. G41 increased shoot growth in F only in the first year. Trees in F soil had higher yield only in the second and fourth year than trees in R soil and FOS. Fumigation and FOS did not affect the cumulative yield. Trees on M9 T337 and P21 had lower CY in F soil and FOS respectively.