{'fraction_non_alphanumeric': 0.036613272311212815, 'fraction_numerical': 0.02517162471395881, 'mean_word_length': 5.169014084507042, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Breeding and Evaluating Apple Rootstocks for Northern Europe


The Research Institute of Pomology, Skiemiewice, Poland started its apple rootstock improvement program in the 1950s (9). As a result of that work, the “ P” series rootstocks have been released, of which P2 and P22 appear the most promising (4). The rootstock breeding program is continuing (10), and heritabilities of some horticulturally valuable traits are being studied.