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Recently a request came in from a San Luis Obispo Master Gardener asking about some unusual mottling on orange leaves.  They didn’t follow a typical nutritional deficiency or fungal disease.  They actually looked like huanglongbing symptoms, but there was no history of Asian Citrus Psyllid. …

Or rather Verticillium Collapse or Wilt.  An avocado that goes down fast.It's that time of year to see some drama in avocado orchards. Once healthy-looking trees can suddenly turn brown in a weekend and all the surrounding trees still look fine. And it can be quite common in some years along the coast…

Citrus InformationDr. Robert McNeil, emeritus professor of the Fruit Science Department at Cal Poly San Luis Obispo, taught citriculture and avoculture there for many years.  He has made his citrus notes available on our website - https://ucanr.edu/sites/default/files/2025-07/mc%20neil%20citrus%20guide…

Federal and state agriculture officials recently expanded the areas quarantined for citrus greening disease in California. They expanded the quarantined area in the Coto de Caza area of Orange County by 11 square miles, the Rancho Santa Margarita area of Orange County by 93 square miles, the Perris area of…

Brown Marmorated Stink Bug showed up in Santa Barbara and Ventura Counties about 12 years ago. It had been roaming around LA and Orange Counties before that.  There was a small outbreak on avocados at the time, but it was mainly seen on a lot of other plant species, like tomatoes.  We have not seen…