The 6~8-year-old trees were grafted and grown on M. sieversii rootstocks, and were trained along a central leader system at a spacing of 2 × 4 m. The plants of all six varieties
were cultured in an orchard at the Horticultural Experimental Station of Northwest A&F University, Yangling (34°20 N, 108°24 E), China, where they received standard horticultural treatment, including pest and disease control.