The link below is to a paper written by Doug Walsh, Frank Zalom, Doug Shaw and my predecessor Norman Welch. It succinctly makes the point that a warm fall following transplanting decreases plant vigor, encourages precocious bloom and can predispose strawberry plants to infestation by twospotted spider mites. Rain can reduce overwintering mite populations, but still warm fall temperatures will decrease plant vigor.
With the understanding that this fall and winter has more than even odds of being an "El Niño" year (http://www.elnino.noaa.gov/), which could result in warmer temperatures and more precipitation, growers and agricultural people might want to be thinking about being a little bit longer than customary on cold conditioning of the day neutrals up here on the Central Coast.
UC Cooperative Extension Farm Advisors Shimat Joseph, Surendra Dara and Mark Bolda are holding a mite meeting in Spanish and English at the ALBA training facility at 1700 Old Stage Road in Salinas. All aspects of mite management will be covered, from proper identification of predatory, twospotted spider and Lewis mites, treatment thresholds, use of botanical and botanical controls, and aspects of chemical, cultural and biological control.
Meeting starts at 9 and will wrap up by 11 am. This promises to be a very good meeting.
Interesting case here of calyx browning caused by spider mites. Most strawberry industry people normally will correctly associate calyx browning with a lack of water or plant physiological issues, but this case of calyx browning is clearly being caused by spider mites.
As one can see from the series of pictures below, brown and spotted patches are all associated with mites and webbing.
The grower reports that the rest of the plant is fine and very few leaves are affected anywhere. It does beg the question why the mites would be specifically infesting the fruit calyces only, but control will be the same as for foliar infesting mites.