The tree fruit meeting included talks by these researchers:

Carlos Crisosto, a postharvest physiologist with Cooperative Extension, provided participants with a computer flash drive they can use to access the 20 years of Central Valley Postharvest Newsletter.  Others can access the same material at

Crisosto said he was frustrated that work on keeping temperatures steady during shipping has been curtailed. “For decades, we have not been doing this right,” he said. “Now, we’re not working on this; we’re not finishing this.”

Jim Adaskaveg, a plant pathologist with UC Riverside, said he was sorry to hear CTFA “had to close out; we’re losing a piece of the puzzle; the picture is not complete.”

Adaskaveg described his work at Kearney in a building where research was conducted on fungicides. “In the past 10 years, at least 15 new fungicides have been introduced,” he said.

Adaskaveg said the center has been able to do work to get material registered through the IR4 process for specialty crops like tree fruit. “We’ve been able to get dollars allocated to help the industry solve its problems,” he said. Otherwise, it would likely not have the resources to get materials registered, considering tree fruit’s smaller acreage when compared to crops such as corn and wheat.

“It costs $150,000 to do the residue work” on a pesticide, he said.

UC researchers have worked extensively with chemical companies, Adaskaveg said. “You’re not bearing the burden alone.”

Adaskaveg said Kearney is “going through a transformation; the university is not supporting agriculture in the way it used to.”

Problems addressed by the industry and UC over the years include sour rot, which became more of an issue, Adaskaveg said, as the industry moved to more tree ripened and pre-conditioned fruit.

Mike McKenry, nematology specialist in Cooperative Extension, talked of replanting experiments for “buffer zones” around houses and schools where use of fumigants is banned or tightly controlled.

He said one technique involves the “starve and switch,” using systemic herbicides to kill root systems after a final harvest and then waiting a full year prior to replanting with a rootstock of a different parentage from the previous rootstock.

Some of the replacements are in the HBOK (Harrow Blood and Okinawa) series, which has shown some protection against root knot and root lesion and tolerance to rejection.

“A key in buffer zones is to not rush the replant,” McKenry said. “Treat with Roundup and wait a year.”

McKenry is also growing Butternut, a walnut, to study its use as “a trap crop” that brings nematodes to it and kills them.

Scott Johnson, Cooperative Extension pomologist, talked of his work with 30 other states, Canada and Mexico to test 15 different rootstocks in 17 peach growing areas throughout the U.S.

He is now on sabbatical leave, gathering information on rootstocks from Europe, Russia and elsewhere that may be more suitable for dwarfing, doing well in challenging soils and thwarting nematodes and disease.

Johnson said he will share information from his research in early December at the Kearney center.