Grafting and Performance in the First Year of 'Marsol' Grafted onto Different Rootstocks

The seedlings of four (Castanea sativa x Castanea crenata) hybrids 'Marsol', 'Precoce Migoule', 'Maraval' and 'Bouche de Betizac', as well as three Slovene domestic Castanea sativa genotypes, i.e., 'Domaci', 'Martin' and 'Kozjak' were evaluated as rootstocks for 'Marsol'. At the beginning of September 2007, 50 two year-old seedlings per rootstock were grafted in an open field using the chip-budding method. Quantitative assessment of graft unions was then done in the following Spring. In the combination 'Marsol'/'Marsol', 100% of successful grafts were observed. The rootstock 'Kozjak' had only 65% of successful grafts, and in other cases, between 80 and 90% of the grafts were good. In October 2008, the grafted plants were qualitatively assessed. In all stock/scion combinations, strong central shoot of the 1st order together with syleptic lateral shoots of the 2nd order were developed. Central shoots of the grafted plants were the highest (between 220 and 228 cm), when 'Marsol' was grafted onto 'Bouche de Betizac', 'Marsol' and 'Precoce Migoule'. The last one also provoked vigorous growth of the central shoot's basal diameter. When 'Marsol' was grafted onto domestic genotypes, the central shoots of the grafts only measured between 175 and 191 cm in height. A statistically significant impact of the rootstock on the lateral branching was observed. 8,3 syleptic lateral shoots were sprouting on the central axis on the 'Marsol'/'Marsol' grafts, compared to 'Marsol'/'Kozjak', and 'Marsol'/'Domaci', where only 2,9 and 3 lateral shoots were developed, respectively. In addition, all the hybrids used, strongly influenced primary (in length), and secondary (in diameter) growth of the lateral shoots, as well as the number of leaves/shoot.