Comparative Study of Two Bench Grafting Methods at Apple (Malus domestica, Borkh.) and Pear (Pyrus communis, L.)

Abstract

The study of technological and histological aspects during early stages of graft union formation between apple varieties and apple rootstock respectively newly bred pear varieties and quince rootstock in order to assess the best bench mechanical grafting technique and to study the compatibility/incompatibility related growth characteristics in early stages of development is a critical step in the fruit nursery material production activity. Two bench grafting methods were adopted for apple and pear propagation at SCDP Bistrita, graft combinations were studied in greenhouse and open field conditions in the nursery. Scions of ‘Golden delicious`, ‘Florina` were bench grafted on M26 apple rootstock using omega “ Ω “  and “V” top grafting techniques , as well as ‘Argessis`, ‘Monica`, ‘Carpica`  pear cultivars grafted on BN70 quince rootstock. Successful graft unions were observed in all combinations and samples, however sapling development was differentiated according the two methods. It was found that the overall percentage of graft survival was 80% at omega grafting and 85 % at V grafting at apple respectively 65 % of graft survival in omega grafting and 80 % of graft survival  at V top grafting at pear combinations. Results showed that sapling development was reduced at combination with omega grafting technique, plants were weak developed, without lateral shoots, while  in V grafted saplings the development was more intense with numerous lateral shoots. Samples of graft union sections were examined under microscope and microphotographs were taken, results confirmed that after 10 month of sapling development no signs of incompatibility was observable, conductive tissue formation being  adequate.