Effect of biostimulator treatments on Prunus mahaleb stockplants and rooting rate of cuttings

The aims of our trial were testing the effect of biostimulators on Prunus mahaleb L. stockplants and their cuttings in rooting process. The treatments were applied on mahaleb stockplants 'Bogdány' and 'Magyar', which are the clonal rootstocks for sweet and sour cherries. The tested plant growth biostimulators are the following: Kelpak^® (0.2%), Wuxal^® Ascofol (0.2%) and Pentakeep^®-V (0.05%), applied on the stock plants in the above concentration once a week over four weeks. The first spraying was in the first week in May. One week after last spraying, in the first week of June, the shoots were severed and cuttings were prepared. The cuttings size was uniform (20 cm long with three leaves reduced in halves). Before preparation of cuttings the shoots total fresh weight, the number and fresh weight of appropriate shoots, starting weights of cutting were measured. After 8 weeks of rooting period, the number of rooted cuttings, the fresh and the dry weight of rooted cuttings were measured. The results showed that Kelpak^® pretreatment is the most effective in improving the productivity and shoot quality of Prunus mahaleb L. stock plants. Kelpak^® and Pentakeep^®-V pretreatments did not affect the rooting rate but increased the dry mass production of cuttings.