1. „Dwarfing Sweet Cherry By Rootstock, Compact Or Spur Scion And Growth Regulators“ Student: Adis Lizalo Prof. Dr. Husnu Demirsoy Prof. Dr. Leyla Demirsoy S. Sansavini Universitiy of Bologna Italy

2. Why dwarf or “growth controlled” trees?  Safer- little to no ladder work  pruning/training  harvesting  spraying  Begin flowering earlier  Bear earlier  More productive  Less pruning How do we control the size of fruit trees?  Very hard pruning  Dwarfing rootstocks

3. different methods used to dwarf or reduce growth in cherry trees there are many rootstocks which can serve this purpose; however, those with a true dwarfing effect also display undesirable side-effects From the collected data, it appears that the use of an interstock consisting of a weak clone of sour cherry (e.g. "North Star" is a feasible alternative for all 5 varieties assessed over 7 years; some of them reduced the tree canopy size by about 50%.

4. Four direction have thus far been undertaken dwarfing tree:  The search for and propagation of dwarfing and semi – dwarfing rootstock  The use of weak dwarfing iterstock  The creation of compact or spur varieties  The combined use of chemical and agronomic method (growth retardants, summer prunning, etc.).

5. Rootstock several factors must be taken into account when selecting rootstocks for a new orchard (soil fertility, scion cultivar choice and desired training system..) When compared to ‘Mazzard’, ‘Colt’ and even ‘Mahaleb’, size- controlling rootstocks have allowed sweet cherry growers an opportunity to plant high- density, pedestrian orchards that afford high early yields, easier management and a safer and more productive working environment. Sweet cherry trees on dwarf and standard rootstocks.

6. Table 1. Planting parameters for various commercially available cherry rootstocks

8. Interstock with sour cherry In the U.S.A as in Europe the use of an interstock is quite common in the sweet cherr production. Vigorous cultivare and rootstocks, a weak interstem, sour cherry can be helpful. Interstock usually require an extra year in the nursery so that cost of plant is higher. Risk – possible appearance of symptoms of grafting incompatibility and lifespan will also be shortened.

9. Is there another way to keep sweet cherry trees small—but still productive and yielding high quality fruit—without using dwarfing rootstocks? With summer pruning

10. Summer pruning Small, dwarf, or size controlled fruit trees provide easier pruning, thinning, spraying, and harvesting and could lead to production of high-grade fruit at lower production cost. Summer pruning has long been used as a management method for fruit trees - it was shown to be a valuable method of controlling tree growth, increasing flowering, increasing fruit color, increasing soluble solids concentration, increasing flower bud formation, and decreasing titratable acid content. Disadvantage of summer pruning include reduced cold hardiness of flower buds, delayed defoliation, carbohydrate levels in the tree, fruit size, and trunk enlargement.

11. Thank You!