Ottawa 3 amélioré (O.3A) apple rootstock.
O3A is a new rootstock resulting from a mutation in an Ottawa 3 (O.3) stool bed discovered at the Agriculture and Agri-Food Canada (AAFC) Research Station, St-Jean-sur-Richelieu, Québec. It produces dwarf trees equal in size to O.3 but with better precocity (early fruiting), higher yield efficiency (based on yield/trunk cross sectional area), fewer suckers and wider branch angles. O3A is similar to O.3 in susceptibility to two races of Erwinia amylovora (Burrill) Winslow and four isolates of Phytophthora cactorum (Leb. and Cohn) Schroet).
- Date modified: