Clonal rootstocks have several advantages:

– can be selected for desired traits, such as disease resistance, nematode tolerance and vigor, giving farmers the opportunity to get the best results in wide range of soil types.

– all rootstocks are genetically identical (homozygous), which allows uniform walnut plantations and high yield.

Recent years several clonal walnut rootstocks were released, which are superior in resistance to various diseases and giving high yield, such as VLACH 2 (RX 1) and VLACH 3 (VX 211).

Walnut rootstock VLACH 2 (RX1)

VLACH 2 has the following combination of characteristics:

  • should be propagated by micropropagation in vitro;
  • has excellent survivability in the nursery and orchard;
  • has moderate resistance to Phytophthora citricola in greenhouse screens and in the field compared to other available walnut rootstocks;
  • has moderate resistance to nematodes.

Walnut rootstock VLACH 3 (VX211)

VLACH 3 has the following combination of characteristics:

  • should be propagated by micropropagation in vitro;
  • has excellent survivability and vigourin the nursery and orchard;
  • has moderate resistance to Phytophthora citricola in greenhouse screens and in the field compared to other available walnut rootstocks;
  • has the best resistance to nematodes compared to any other walnut rootstocks;
  • higher yield compared to other rootstocks and more uniform trees.

 Links:

  1. https://www.researchgate.net/publication/267276372_Clonal_Walnut_Rootstocks_in_Northern_California
  2. https://patents.google.com/patent/USPP21179
  3. http://www.duartenursery.com/walnuts/
  4. https://patents.google.com/patent/USPP20649P3/en
  5. https://www.westernfarmpress.com/super-paradox-walnut-rootstock-may-be-near
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3380502/
Walnut rootstocks VLACH-2, VLACH-3