UC Riverside nematology professor Ole Becker showed how nematodes can infect carrot roots at his presentation of "Everything You Always Wanted to Know About Turfgrass Nematodes and Their Control" at the Annual Turfgrass and Landscape Research Field Day held Sept. 11.
Photo: Courtesy of Larry Shield

On Sept. 11 UC Riverside held its Annual Turfgrass and Landscape Research Field Day at its Department of Botany and Plants Sciences. The event gave landscape professionals a place to gather, share ideas and learn about research activities on the campus in Southern California. Attendees saw several new state-of-the-art research areas designed to study water and salinity management issues on turf and landscapes.

The seminar, "Everything You Always Wanted to Know About Turfgrass Nematodes and Their Control" was led by UC Riverside nematology professor Ole Becker.

The Pacific shoot-gall nematode Anguina pacificae is a serious pathogen on annual bluegrass (Poa annua) on golf course along the Northern California coast. The disease symptoms manifest as conspicuous galls at the grass
shoot base.

The galls may contain all development stages of the nematode such as eggs, juveniles and adults. Infected plants may die or branch into several shoots that often become infected and stunted. Putting greens become patchy and bumpy under several disease pressure.

"Nematodes use roots as a feeding site and cause the roots to swell," said Becker. "Every years it does $1.5 billion of crop damage in California. However, it's not always a problem, once the soil temperature goes below 65 degrees, the nematodes stop feeding."

The trial was performed on a nursery putting green at the Pebble Beach Golf Links on the Monterey peninsula. In addition to Anguina pacificae, the green was fairly uniformly infested with spiral nematodes and right nematodes. The trial was installed mid-April and continued until mid-September.

"We did a study along the Northern California coast, from Carmel to Eureka," said Becker. "We took some samples of each replication at Pebble Beach along with visual reading plots. Galls on nematodes were counted and there was no difference in the plant materials."

Preliminary results indicated that none of the plant parasitic nematode populations differed significantly between the non-treated control and Neemix 4.5 treatment during the four-month monitoring period. Likewise plant health, indicated by monthly visual turf ratings, fresh weight determination of turf cores and number of shoot galls after four months were not significantly affected by the treatment.

You can read or print full research reports in their entirety from the Field Day website, ucanr.org/sites/turfgrassfieldday.