COMPARISON OF SELF-ROOTED AND TIP-GRAFTED SEEDLINGS OF (PRUNUS CERASUS X P.FRUTICOSA) HYBRIDS AND AMELANCHIER ALNIFOLIA
This study was initiated to reduce acreage and time for tree fruit breeding at the University of Saskatchewan. Seedlings of sour cherry hybrids and saskatoons were chip-budded onto the tips of branches of mature, bearing trees. After two growing seasons, seedlings on their own roots were compared to the same genotypes that had been tip grafted. For both crops in the study, vegetative growth of tip grafted seedlings was similar to that of the trees onto which they were grafted and significantly different from self-rooted seedlings. Sour cherries that were tip grafted had decreased leaf number (by 64%), shoot length (by 84%), and shoot diameter (by 76%); subsequently they also had decreased flowering (by 69.7%). Tip grafting promoted cold acclimatization and hardiness of cherries. By August 12, terminal growth of tip grafted branches had ceased but seedlings were still actively growing. By the end of October, leaf retention was higher in seedlings. Only 0.3% of the tip grafted branches showed winter damage, versus 69.2% of the self-rooted seedlings, which had winter dieback. After two growing seasons, tip-grafted saskatoons had 93% more leaves, shoots were 257% longer and shoot diameter was increased by 42%. This increased vegetative growth resulted in higher flowering rate and flower number. Due to the cold hardy character of saskatoons, tip grafting in this species had little effect on cold acclimation and cold hardiness.
Lu, Q.J. and Bors, R.H. (2004). COMPARISON OF SELF-ROOTED AND TIP-GRAFTED SEEDLINGS OF (PRUNUS CERASUS X P.FRUTICOSA) HYBRIDS AND AMELANCHIER ALNIFOLIA. Acta Hortic. 636, 105-110
juvenile period, vegetative growth, terminal bud cessation, leaf retention, cold hardiness