Krymsk® 1
(cv. WA 1) USPP 15995
Krymsk®1 rootstock is an interesting treefruit rootstock for providing vigor control and improved fruit size. Additionally, Krymsk®1 appears suited to areas requiring cold hardiness.
Krymsk®1 is competitive with traditional rootstocks such as Lovell as a rootstock for either European Plums or Japanese Plums. Early information has demonstrated good yield efficiencies and some enhanced fruit size. While not appropriate for high bacterial canker sites, Krymsk®1 performs relatively well under Rootknot and Lesion nematode pressure.
Some trials with peaches and nectarines have reported 50 to 60 % the vigor of peach seedling with enhanced fruit size. Other trials have reported numerous incompatibilities.
Krymsk®1 rootstock also appears interesting for trialing with Apricot. Yield efficiencies and fruit size are similar to standard rootstocks for Apricot. Tree vigor is 50 to 70% of standard rootstocks.
Compatibilities with all fruit should be checked, especially with Peaches and Nectarines.
Tree spacing should account for the vigor of this rootstock in the grower’s local conditions.
PARENTAGE: Prunus tomentosa x Prunus cerasifera (Chinese Bush Cherry x Myrobalan Plum)
ORIGIN: Krymsk Experimental Breeding Station, Krasnodar Region, Russia.
OLDEST TEST SITES IN THE US: 2001 & 2002 NC-140 Peach trial, 2002 in New York Plum trial, 2004 in California Apricot trial.
COMPATIBILITY: Plum (European and Japanese), some Peaches and some Apricots. Apricot Cultivars tested are Apache, Robada and Orangered for 6 years. Numerous Peach and Plum cultivars tested for 3 to 6 years. Numerous Peach cultivars tested in Russia for 15 years.
VIGOR: 50 to 70% of Nemaguard or Lovell with both Plums and Apricots. About 50 to 60% of Lovell or Nemaguard with Peach.
GROWTH UNIFORMITY: Good with Apricot and Plum, variable with Peach depending on compatibility.
ROOTSTOCK INDUCED TREE FORM: Similar to Lovell.
ANCHORAGE: Similar to Lovell.
YIELD EFFICIENCY: Excellent with European and Japanese Plums. Good with Peaches and Apricots. Has shown some enhanced fruit size with European and Japanese Plums and some Peaches in Washington state.
SUCKERING: Produces some trunk and root suckers. Can be excessive.
CHILLING REQUIREMENT: Appears to be similar to Lovell and higher than Citation.
COLD HARDINESS: Has shown hardiness better than Lovell in upper New York.
NEMATODE RESISTANCE: Moderate resistance to Rootknot and good resistance to Lesion nematodes.
EFFECT OF ROOTSTOCK ON BACTERIAL CANKER SUSCEPTIBILITY: More susceptible than Lovell.
OAK ROOT FUNGUS TOLERANCE: Untested.
PHYTOPHTHORA SENSITIVITY: Untested.
VERTICILLIUM RESISTANCE: None.
DISEASE PROBLEMS–OTHER: Unknown.
ASPHIXIA TOLERANCE: Spain has seen moderate tolerance.
DROUGHT TOLERANCE: Unknown
CROWN GALL SUSCEPTIBILITY: Susceptible. Level of susceptibility is quite high, but needs more evaluation to determine the impact in orchards.
HIGH pH TOLERANCE: Sensitive to pH above 8.
CALCAREOUS SOIL TOLERANCE: Moderate.
REJECTION COMPONENT OF REPLANT DISORDER SUSCEPTIBILITY: Unknown.