So that growers, PCA's and other agricultural people might have a bit more access to UC and UCCE scientists, entomology Advisor Shimat Joseph is sponsoring a breakfast meeting at my auditorium at 1432 Freedom Blvd in Watsonville on March 10. We have both Plant Pathology Farm Advisor Steven Koike speaking about diseases, followed by our special guest entomologist and IPM Advisor Pete Goodell out of the Kearney research station in the Central Valley (he has a enormous amount of experience with lygus).
Point is to have a good discussion between people involved in strawberry production and UC scientists, along with having a great breakfast of course. Come by if you have the time - starts at 630 am and will be wrapped up by 8.
Got a rather lengthy text from a colleague this afternoon concerning J rooting of strawberry plants - question was: does it really make a difference whether or not a strawberry transplant is J rooted?
Let's go to the Green Sheets, which have been a real treasure trove of information.
The one included in the link below was a summary of field work done by the late Warren Bendixen, who served as the Farm Advisor in Santa Maria for many, many years:
This work was done by Warren in response to a shift going at that time in Santa Maria from 40" inch beds with 5- 6" deep planting slots with very little J rooting to the 64" beds so familiar today, but with planting slots which would result in a lot of J- rooted plants.
Key takeaway from the paper, it's in bold because it's so important.
Plants with J roots reduced fresh fruit yields by 18.5%.
If this doesn't get your attention as to why we shouldn't be J rooting, I don't know what will.
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.
Nice introductory video from Dr. Chieri Kubota with the Arizona Controlled Environment Center at the University of Arizona.
Lots of advantages in Arizona for hydroponics - no pesticides, winter production, less water use and SAME DAY delivery from the greenhouse to the store. At five bucks a pint not that cheap though.
Interesting history of strawberry production in Arizona, including the cultivation of an everbearing variety all the way back in 1893.
A recent article referred to one of the reasons that growers need access to new strawberry varieties is that there is an inherent loss in vigor through the propagation process. That growers need access to new varieties to remain competitive is absolutely true, but that they need access to new varieties because the existing ones decline in vigor is not.
Plants do not invariably “lose their pep after years of cloning”. Indeed, reputable nurseries avoid a loss of vigor in a variety by periodically going back to meristem culture in order to keep their plant stock strong and productive. It does happen (especially in some formerly popular caneberry varieties - compare Ollalieberry in the field today to what was around in the early nineties) that older varieties of less demand don't have the meristem work done as frequently and subsequently become less vital over time.
What is meristem culture? Meristem culture is the excision of a cluster of actively dividing cells from the meristem (tip) of a newly formed strawberry runner, followed by surface sterilization, placement on a special medium, subsequent rooting, gradual acclimation of the new plant and transfer to a secure greenhouse. While some cases of genetic instability from repeatedly doing meristem culture have been noted in the literature, this cannot be described as a drift towards a loss in vigor of a variety. At any rate, programs for production of true to type (identical) plant stock using meristem culture have been used for a long time at any of the strawberry nurseries in business today.
A good example of how well and long a popular variety can be maintained through meristem culture would be the strawberry variety ‘Chandler'. Chandler continues to be widely planted by direct marketers because consumers just love its flavor and quality. Consider though that this variety was patented in 1984 by the University of California, and has had no apparent loss in vigor in all this time because the nurseries continue to go back to meristem culture to maintain it.
Growers have rumored that the variety ‘Albion' has been losing its vigor, but work at the Pomology Field Station in Watsonville over several years shows that this was not at all true. The Albion grown at this field station has experienced NO loss in yield since it was first released. Rather the rumored "loss in vigor" of the very widely planted Albion is almost certainly because of the industry wide steady drift away from methyl bromide fumigation to less effective alternatives like 1,3-D and chloropicrin.