Krymsk® 7
(cv. Elta) USPP#16,353
Krymsk® 7 is a unique rootstock for sweet cherry, showing similar precocity and vigor to Mahaleb. Cherry trees on Krymsk® 7 tolerate high temperatures. Compared with Mahaleb, Krymsk® 7 is more tolerant of soil moisture extremes. Krymsk® 7 is well suited to varieties needing improved precocity over Colt and Mazzard. Fruit maturity may be advanced by 1 to 3 days relative to Mazzard. Krymsk® 7 is not sensitive to the pollen spread ILAR viruses . It is cold hardy and stress tolerant. Krymsk® 7 is adapted to a wide range of soil and growing conditions.
PARENTAGE: P. lannesiana (P. serrulata - Japanese Cherry).
ORIGIN: Krymsk Experimental Breeding Station, Krasnodar Region, Russia.
OLDEST TEST SITES IN THE US: Sweet cherries--2005 in California.
COMPATIBILITY: Sweet cherries. Sour cherry compatibility unknown.
VIGOR: 90% of Mazzard seedling. Equivelent to Mahaleb.
GROWTH UNIFORMITY: Excellent.
ANCHORAGE: Good
PRECOCITY: More precocious than Mazzard and Colt. Slightly more precocious than Mahaleb.
YIELD EFFICIENCY: Good with sweet cherry. Similar or better fruit size than Mahaleb.
FRUIT MATURITY: Fruit may ripen 1-3 days ahead of Mazzard, similar to Mahaleb.
SUCKERING: Produces very few trunk and root suckers.
CHILLING REQUIREMENT: High, similar to Mazzard.
COLD HARDINESS: Excellent for all but the coldest growing sites in the US.
NEMATODE RESISTANCE: Unknown. No problems have been encountered.
EFFECT OF ROOTSTOCK ON BACTERIAL CANKER SUSCEPTIBILITY: Unknown.
OAK ROOT FUNGUS TOLERANCE: Untested.
PHYTOPHTHORA SENSITIVITY: No problems reported.
VERTICILLIUM RESISTANCE: Unknown.
DISEASE PROBLEMS--OTHER: Not sensitive to ILAR virus.
ASPHIXIA TOLERANCE: Good – much better than Mahaleb.
DROUGHT TOLERANCE: More tolerant than Gisela® rootstocks, to low soil moisture and high temperature stress.
CROWN GALL SUSCEPTIBILITY: Level of susceptibility is unknown, but not extreme.
HIGH pH TOLERANCE: Unknown.
CALCAREOUS SOIL TOLERANCE: Unknown.