Propagation and Growth Parameters of Preselected Pomegranate (Punica granatum) Cuttings from the USDA–ARS National Clonal Germplasm Repository

The following pomegranate (Punica granatum) accessions from the USDA-ARS National Clonal Germplasm Repository, Davis, CA were accessed for propagation success and early plant growth: ‘Ki Zakuro,’ ‘Phoenecia,’ ‘Nochi Shibori,’ ‘Golden Globe,’ ‘Green Globe,’ ‘Loffani,’  ‘Wonderful,’ ‘Eversweet,’  ‘Haku Botan,’ ‘Parfianka,’ ‘Desertnyi,’ and ‘Ambrosia.’  Stem cuttings were harvested from basal suckers, cut to a length of 10.5 ± 1.0 cm long, and treated with 3 g·L^-1 of indolebutyric acid and planted in 1 Sunshine potting mix: 1 perlite in 2.5 cm x 2.5 cm potting containers, separated by block in plastic flats irrigated with DI water.  A randomized complete block design was used with 8 blocks and 4 pseudoreplicates per block, totaling 32 trees for each accession.  ‘Green Globe’ was found to root the poorest compared to the other cultivars, with ‘Ambrosia’ having the second poorest success rate.  All other accessions had rooting success rates above 80%.  ‘Parfianka’ had greater branching than ‘Eversweet,’ ‘Nochi Shibori,’ ‘Haku Botan,’ ‘Desertnyi,’ ‘Loffani,’ ‘Ki Zakuro,’ and ‘Golden Globe.’  Apical shoot length was also different between two groups, with ‘Golden Globe,’ ‘Phoenicia,’ and ‘Wonderful’ with greater apical shoot growth and ‘Ki Zakuro,’ and ‘Haku Botan’ growing slower.  ‘Golden Globe’ and ‘Phoenicia’ were taller than ‘Eversweet’ and ‘Haku Botan.’  Leaf chlorophyll was measured with a SPAD-502 chlorophyll meter, and ‘Haku Botan’ and ‘Loffani’ had greener leaves than ‘Eversweet,’ ‘Ambrosia’ and ‘Desertnyi.’  The results of this study indicate that pomegranate cultivars vary significantly in a range of pomegranate propagation parameters and that not all pomegranate cultivars are readily propagated by vegetative cuttings treated with exogenous rooting hormone.