Use of the plant growth regulator Ribav-extra for rooting of woody cuttings of pear and quince clonal understocks

This article presents the study results on the application of the plant growth regulator Ribav-extra that helped rooting of woody cuttings of pear and quince clonal understocks. The study materials were pear clonal rootstocks – PG 12 (k), PG 2, PG 17-16, PG 333, Kavkazskaya (Caucasian), K-1, K-2, 4-26, 4-39, OHF 333, Piro II and quince forms – VA 29 (k), Severnaya, Provanskaya, Penzenskaya, № 25, № 40, № 21, № 31, № 13. Then, the study concerned the following parameters as rootstock height, cm, rooting degree, score, conditional root neck diameter, cm, root length, cm, number of roots, pcs.