Cooperative Extension Teams with Strawberry Industry to Identify New Disease Developments

The Issue

In California, strawberry is a dominant coastal commodity. It is a very high value industry in the state, and it is popular with consumers throughout the country. However, new plant problems (such as patches of plants exhibiting severe yellowing of foliage, calices turning brown and withered, and changes in preplant soil fumigation) have caused loss of fruit quality and decline or death among plants. Strawberry collapse, as well as yellowed plants and calyx tissue damage, are all problems that cannot be diagnosed and understood without focused investigations and laboratory testing. Growers have lacked the time and facilities needed for discovering the causes behind these dilemmas.

What Has ANR Done?

With support from the California Strawberry Commission and local growers, CE coastal farm advisors Steven Koike and Mark Bolda teamed up to tackle these recent developments. Field visits and investigations were supplemented with testing conducted at the Cooperative Extension diagnostic lab in Salinas. This system successfully discovered the following: 1) Leaf yellowing issues are not due to a pathogen but instead to high levels of sodium. 2) Fruit calyx damage is caused by two factors, with some cultivars having a physiological defect that expresses itself as calyx browning. Furthermore, the leaf blotch pathogen, previously known to only affect leaves, is also infecting fruit calices. 3) Strawberry collapse is the greatest disease concern for this industry, and the CE lab has been instrumental in identifying the precise cause (one of three fungal pathogens) of collapse cases found throughout the coast. Following these field investigations and lab confirmations, Bolda and Koike rapidly informed the strawberry industry of findings via blog entries, online newsletters, e-mail reporting and the traditional farm calls and phone contacts. The growers have thus been kept apprised of these new developments and in a timely manner.

The Payoff

The California strawberry industry is continuously educated about problems as they arise through a unique CE diagnostic program that efficiently discovers, investigates and solves industry problems

CE farm advisors and the strawberry industry have partnered to support growers with a diagnostic service program. It has become the first place growers and agricultural professionals go to when faced with tough, unsolved issues. Field problems and diseases are efficiently investigated with this combined field and laboratory approach.

Contact

Supporting Unit:

Santa Cruz County Monterey and Santa Cruz Counties: Steven T. Koike, stkoike@ucdavis.edu; and Mark Bolda, mpbolda@ucdavis.edu