(cv. VSL 2) USPP#15,723
Sweet cherries planted on Krymsk® 5 are a more precocious rootstock than Mazzard or Colt, yet not as precocious as the Gisela® series. Additionally, Krymsk® 5 is very tolerant of stress conditions, such as high temperature and low soil moisture. The tree size is equivalent to Gisela® 6 and has good anchorage and tolerance of heavy soils. In heavy soils, significant suckers may occur. Krymsk® 5 is sensitive to the pollen borne ILAR viruses. Krymsk® 5 appears to be less sensitive to Bacterial Canker than Gisela® 6.
PARENTAGE: Prunus fruiticosa x Prunus serrulata var. lannesiana
ORIGIN: Krymsk Experimental Breeding Station, Krasnodar Region, Russia.
OLDEST TEST SITES IN THE US: Sweet cherries—2000 in California, Oregon, Washington and New York.
COMPATIBILITY: Sweet cherries and many sour cherries (Montmorency not tested). Significant graft union over-growth can sometimes occur.
VIGOR: 90% of Mazzard seedling.
GROWTH UNIFORMITY: Excellent.
PRECOCITY: Between Mazzard and Gisela® 6.
YIELD EFFICIENCY: Good with sweet cherry. Less flower density than Gisela® rootstocks. Crop load management needed, but less than with Gisela®. Yield efficiency with sour cherries is unknown.
FRUIT MATURITY: Fruit ripens with Mazzard. More testing is needed.
SUCKERING: Produces some trunk and root suckers. Can be excessive in heavy soils.
CHILLING REQUIREMENT: Appears to be higher than Mazzard seedling.
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: Less sensitive than Gisela® 6.
OAK ROOT FUNGUS TOLERANCE: Untested.
PHYTOPHTHORA SENSITIVITY: No problems have been encountered.
VERTICILLIUM RESISTANCE: Unknown.
DISEASE PROBLEMS—OTHER: Very sensitive to PNRS and PDV viruses.
ASPHIXIA TOLERANCE: More experience needed.
DROUGHT TOLERANCE: More tolerant to low soil moisture and high temperature stress than Gisela rootstocks.
CROWN GALL SUSCEPTIBILITY: Level of susceptibility is unknown, but not extreme.
HIGH PH TOLERANCE: Unknown.
CALCAREOUS SOIL TOLERANCE: Unknown.