Courtesy University of California, RiversideUniversity of California, Riverside, plant pathologist Greg Douhan examines an avocado plant.Three new rootstocks may help avocado growers battle Phytophthora root rot, a multi-million-dollar problem in California.
The roostocks—Zentmyer, Steddom and Uzi—are the product of University of California, Riverside, plant pathologist Greg Douhan, and his team, according to a news release.
In addition to being Phythophthora tolerant, each rootstock has other desirable attributes.
Zentmyer, for example, is extremely vigorous but is not salt tolerant. It also often doesn't yield consistently under non-root-rot conditions.
Steddom has tolerance to both root rot and salinity.
Uzi is tolerant of root rot and yields well and consistently.
The rootstocks were selected for their root rot tolerance based on two years of greening screening.
Then they were tested in several field locations in California.
UC Riverside's Office of Technology Commercialization is seeking licensees for the rootstocks and will give preference to California avocado nurseries and growers.
Phytophthora cinnamomi was first confirmed as causing root rot in avocados in Puerto Rico in 1928.
In 1942 it was identified as the causal agent for a general decline of avocado trees in California.