Four apple rootstocks (М9 - Т337, М26, ММ106 and Supporter 4 Pi 80) were studied in a commercial clonal stoolbed in 2005-2008. The rootstocks were planted in the spring of 2001 at a density of 1 562 (1.6 m x 0.4 m) plants per decare. It was found that the yield of the stool shoots of Supporter 4 Pi 80 was higher than М9 - Т337, but lower in comparison with the widespread М26 and ММ106. Supporter 4 Pi 80 is characterized by high and smooth shoots. This rootstock has the longest internodes and significantly less number of feathered stool shoots in comparison with М9 - Т337 and М26. In vegetative propagation rootstock Supporter 4 Pi 80 forms a greater number of roots compared to the more commonly used in practice M9 - T337 and M26. Over 59% of the yield of the Supporter 4 Pi 80 rooted shoots belong to the most desirable class for winter grafting - over 8 mm thickness. Unfortunately, the information about the resistance of Supporter 4 Pi 80 to the woolly aphid (Eriosoma lanigerum Hausm.) (Fischer 1997 a) cannot be confirmed.
First results of the study of the apple rootstock Supporter 4 Pi 80 in a stoolbed