UC – Riverside Rootstock Program Seeks California Growers to Test Rootstocks

The University of California Riverside Avocado Rootstock Program is seeking California avocado growers interested in participating and testing the soon-to-be released UCR avocado rootstocks selections beginning in Spring 2022. UCR Rootstocks selections have been chosen for their performance under Phytophthora root rot high incidence, alkalinity, heat, and salinity tolerance.

UCR is in search of California growers willing to establish two rootstock x scion field trials:

• 576 trees corresponding to Dusa, Toro Canyon, Stedoom, PP35, PP40, and PP80 UCR rootstocks grafted with Hass, Gem, Lamb Hass, and Reed (24 trees/rootstock x scion combination)
• 600 trees corresponding to Dusa, PP35, PP40, and PP80 UCR rootstocks grafted with Hass, Gem, and Lamb Hass (50 trees/ rootstock x scion combination). PP35, PP40, and PP80 are rootstocks with Phytophthora root rot resistance and exhibited good performance (tree health and yield) under high salinity and heat conditions. 

Selection Criteria

In order to test the rootstocks under the best conditions, UCR is seeking California avocado growers who meet the following criteria:

1. Growers must be willing to engage in a long-time commitment for the research trial (10 years) to ensure UCR can acquire data required for release. 

2. Sites will be selected based on the diverse challenges an orchard has: Phytophthora root rot, salinity and high alkalinity. Soil structure will also be considered, especially for soils with low drainage and high saturation.

3. Harvesting will be done in coordination with the UCR research team. The grower will need to provide assistance during the harvesting process. The research team also would prefer single stripping harvest.

4. It is a requirement that field sites for the new experimental trials be established in single growth areas and not between growers’ existing avocado trees (no inter-planting).

5. UCR will require open access to the gates of the field where the rootstocks will be evaluated during its quarterly visits.

Growers interested in participating in the UCR rootstock evaluation process should contact Patricia Manosalva at [email protected].