Environ. Horticulture, Pears, Cherries, and Viticulture
University of California
Environ. Horticulture, Pears, Cherries, and Viticulture


Another Facet of Expertise: How do People Perceive an Expert? Lessons for Extension

I had an interesting conversation a number of weeks ago with my boss, Assistant Vice Provost Mark Lagrimini, concerning how we extensionists present information in a format that successfully changes the way people think about and approach a subject.

To Mark I shared my long running thesis that we as experts should address emotional reactions, as some topics within our milieu of work can induce, with not only empirically derived evidence, but also with emotional responses to be more effective in getting our point across.  

Take for example a discussion I participated in at a Board meeting of the California Strawberry Commission some time ago. Their public relations group was discussing how they are attempting to convince consumers that conventionally produced strawberries are free from pesticides and are safe to eat (of course they are, really!).  However, the tack presented was to deploy scientifically derived information, but I countered this by saying that what is driving people's concern of these berries is fear.  Fear is an emotion and using only logic and facts to assuage that I firmly stated will not be successful. 

Instead, fear needs to be countered by inspiring the gut instinct of trust, and trust in human beings comes from a lot more angles than just numbers and scientific facts.

This isn't exactly radical thinking.  Picture the following. You are on a flight over the ocean and suddenly the airplane enters some fairly powerful turbulence.  This shakes a lot of people up, so what will it take to calm people down?  Do you notice that usually at this point the pilot comes on the PA system in an easy tone and explains it's all going to be ok?  Might be a good time to buckle up, we'll be through this storm in a bit, or maybe they'll change course a tad and fly around it.  Does he or she launch into a lengthy explanation on the physics of flying and the engineering of the plane that is made to withstand this sort of disturbance? Of course not.  Knowing that a uniformed pilot, an expert with thousands upon thousands of hours of experience and training, is up there calmly at the helm does a lot to reassure us that all is well.

Ditto is goes with those of us, researchers, PCA's, and farm managers, who are engaged in working with growers.  I find it highly unusual that our audiences and clientele are convinced by a one off presentation by someone they barely know and sense hasn't worked with the subject for very long, no matter how solid the research and how polished the presentation. Confidence in the expert only builds over experience and time, which includes the creation of a good track record, construction of a good reputation and feeling of trust that follows.  


Posted on Thursday, August 8, 2019 at 2:42 PM

Exemplar Mucor Growth on Strawberry

I was holding some strawberry fruit a few weeks ago to check on a pathogen for a local grower (it's very likely anthracose, but more to come on that account), and of course this being late season had a lot of leak rot showing up.

Can't help myself here folks, but this one is a beauty!  The undisturbed conditions of the moist chamber let the fungus really blow up and spread out.  Again, as readers of this blog will know the sticky wet appearance of the sporangiophores tell us this is very likely to be Mucor rather than Rhizopus. 

The leak rots are difficult to manage in the field, and in fact the only thing strawberry growers have available are cultural controls. The UC IPM guidelines instruct us that to minimize leak issues, handle fruit with care at all times. Remove all ripe fruit from the field at harvest and avoid packing overripe fruit. Be sure when fruit is being picked that the entire fruit is removed from the stem, not leaving behind the fleshy receptacle of the fruit as it can serve as a site for invasion by fungus.

Mucor rot on strawberry.  Note the fluffy appearance and wet sticky aspect of the sporangiophores.   The paper towel used to be white, but has been completely stained with juice leaking out of the fruit.
Mucor rot on strawberry. Note the fluffy appearance and wet sticky aspect of the sporangiophores. The paper towel used to be white, but has been completely stained with juice leaking out of the fruit.

Posted on Thursday, August 8, 2019 at 12:20 PM
Tags: Mucor (3)

2019 Revision of Cost of Production for Organic Strawberries Now Available

My colleagues and I just finished our revision of the Organic Strawberry Cost of Production Study.  The previous study was from 2014 and really not up to date. This new one incorporates a lot of what is going on with labor as well as updates on fertility and pest managment practices.

As always, I am honored to work with colleagues Laura Tourte, Jeremy Murdock and Daniel Sumner on producing such a valuable document for our growers.



2019 Cost of Production Study for Organic Strawberries Now Available
2019 Cost of Production Study for Organic Strawberries Now Available

Posted on Wednesday, August 7, 2019 at 11:34 AM

New UC Strawberry Varieties: News Release

One of the tasks of the UCCE Farm Advisor is to assist his or her colleagues from the UC with their outreach to growers, at the same time they help growers interpret information coming to them from these sources.

Such is the case with the article announcing the release of a five new strawberry varieties from UC Davis published in the Santa Cruz Sentinel which I've included below.  Since it is from the UC Davis News Services, I'm assuming this went to other press organizations as well.

As I will elucidate in the following paragraphs, growers should not look to the popular press for information on making planting decisions for their operations.  

Take a walk with me: 

Two of the new varieties ostensibly outyield what is on offer now, which I assume are varieties such as Cabrillo and Monterey.  I've seen these new varieties and yes the yield is impressive, but this throws a good deal of doubt to the statement that these varieties would use less water, fertilizer and pesticides. 

We all know from experience that large men drink and eat more to sustain themselves than small men.  This axiom is also very much the case in the world of plants.

Take as an example the work that I did a number of years ago with Dr. Tim Hartz of UC Davis modifying the nutritional requirements for strawberry which we developed for the variety ‘Albion' that in good hands yields on average 8000 boxes per acre to the newer ‘Monterey', that yields on average 12,000 boxes per acre.  Our update for the 50% higher yield on 'Monterey' found that sure enough the nutritional requirements, especially that of the key nitrogen, were also 50% higher.   With these newly released varieties producing up to 16,000 boxes per acre (in research plots anyway), the nitrogen use will be proportionally higher. To feed them less in spite of their tremendous yield potential would be a mistake.

The paragraph on runnering has given me some pause also.  According to our 2016 Cost of Production Study for Conventional Strawberries, runner cutting (in addition to hand weed removal) costs growers on average $1600 dollars per acre, which yes is a huge expense, but a far cry from $5000.  So I am really wondering where this high a cost is coming from.  I realize we've had a jump in labor costs over the past three years, but more than double?  Or is someone overchilling their plants, pushing vegetative growth and then having to cut all the resulting runners, along with taking it in the chops on yield?  To generalize this situation for the industry as a whole is just wrong.

Furthermore, as the source of the subsequent transplant crop for the whole California strawberry industry, runners are not just “handy” for plant propagation. Nor are they “vine like fingers” of the plant, they are actually botanically stems growing along with the ground producing the nodes from which aerial and soil roots arise.

Lastly, making a few calls around reveals growers may want to note that these varieties are yet to be available at any appreciable scale from our nurseries.

Here is the article, see for yourself what I am ranting about:

By Diane J Nelson

UC Davis News Service

The Public Strawberry Breeding Program at UC Davis has released five new varieties that will help farmers manage diseases, control costs and produce plenty of large, robust berries using less water, fertilizer and pesticides. Two of the new varieties could increase yields by almost 30 percent.

The strawberries were test grown in Salinas and Watsonville among other places.

“These new varieties are intrinsically different from the ones they replace,” said Steve Knapp, professor and director of the UCD Strawberry Breeding Program. “After more than three years of field tests, we're seeing higher yields, greater disease resistance and better quality after harvest.”

The new pedigrees should benefit consumers, as well. “The price and quality of strawberries improve when farmers have access to varieties that help them grow better berries more cost efficiently,” said Dave Murray, a farmer and partner in Andrew & Williamson Fresh Produce.

Since its inception in the 1930s, the Public Strawberry Breeding Programhas developed more than 60 patented varieties, turned strawberries into a yearround crop and increased strawberry yield from about 6 tons per acre in the 1950s

to more than 30 tons per acre today. The U.S. is the world's largest producer of strawberries, and almost 90% of them are grown in California's cool, coastal climates. About 60% of the state's strawberry fields are planted with varieties developed at UCD.

Each of the new varieties will have its own farming niche — thriving better in certain environments under specific growing conditions. Three of the new varieties — Moxie, Royal Royce and Valiant — will perform well throughout the long, warm days of summer. Two varieties — Victor and Warrior — are bred for cooler climates from Santa Maria south along California's coast.

In general, all the new berries are large, flavorful, firm and disease- resistant. Victor and Valiant perform well in organic systems. Moxie and Royal Royce are showing yield increases of as much as 29% over previous UC varieties.


Two new varieties — Moxie and Royal Royce — could save farmers up to $5,000 an acre in labor costs because they sprout fewer runners, the vine-like fingers that strawberries send out that produce roots and develop into duplicate plants. Runners are handy when propagating strawberries, but farmers have to continually cut them back during the growing season to help plants conserve energy for producing bigger berries.

“Runners are a huge expense,” explained Greg France, a longtime California Strawberry Commissioner and family farmer from Santa Maria. “We have to hire labor throughout the season just to cut back the runners. These new varieties will be a big deal for us.”

Disease-resistant berries will also reduce production costs and improve environmental sustainability, farmers say.

Strawberries are especially vulnerable to soilborne pathogens, which can destroy an entire crop. Since the 1960s, many strawberry growers have depended on fumigants like methyl bromide to fight disease, but methyl bromide and other fumigants are being phased out by the Environmental Protection Agency.

Since Knapp took over the strawberry breeding program in 2015, he and his team have been working to develop varieties with genetic resistance to disease to reduce the need for fumigants. All five of the new varieties will be less susceptible to a range of diseases, including Fusarium wilt, Verticillium wilt and Macrophomina.

To create a beneficial variety, plant breeders cross plants with desired traits and select the best offspring over multiple generations. UCD strawberry breeders are continuing that work on test sites and farms along California's “strawberry belt,” from Ventura to Watsonville, each with its own particular climate and crop management strategies.

“Every farmer has his or her own recipe for growing the berries, which is good,” said Glenn Cole, breeder and field manager with the strawberry breeding program. “It helps us see how the crop performs in different environments.”

The team anticipates releasing one or two additional varieties in early 2020 that can be planted in the summer and harvested in time for the winter holidays.

In the meantime, farmers can buy the newest UCD varieties at nurseries starting this fall. Also, detailed data on how each variety performed throughout the breeding trials is available to everyone at the California Strawberry Commission website.

“The great thing about UC Davis strawberry cultivars is they are available to all growers,” said strawberry farmer Dave Murray. “The world-class research on which these varieties are based benefits us all.”


Just released UC variety 'Warrior'.
Just released UC variety 'Warrior'.

Just released UC variety 'Valor'.
Just released UC variety 'Valor'.

Just released UC variety 'Moxie'.
Just released UC variety 'Moxie'.

Posted on Thursday, July 11, 2019 at 9:22 AM

UC Agriculture and Natural Resources - Dig Deep for Santa Cruz County 4H

June 5, 2019 has been designated by my organization UC Agriculture and Natural Resources "Big Dig Day", which basically means dig in the soil, dig in your heart and dig in your wallet for the programs you care about.

Sure we have people doing a lot of good things statewide, but since state and Federal funds are not adequate to meet the challenges coming at us in the future, from population growth, to technology deployment to management of scarcer resources, private contributions on this day are being requested to help us enhance our work. 

I'm pretty fortunate though since I am able to count on support from individual growers (this is huge), grants from Federal and state agencies, private interests and the California Strawberry Commission.   In other words, for the time being, I'm good.

Then again, as County Director for UC Cooperative Extension Santa Cruz county office, I oversee a lot more than just strawberries and caneberries!  One of the programs I particular take pride in is the 4H program we have here; in case you haven't heard it's about more than cows and cooking these days and they are doing work on keeping our youth engaged in science and technology.  For sure, getting kids ready for our future through a tried and true program like Santa Cruz County 4H (110 years and counting) is a big job that your donation is going to help enhance.

On this Big Dig Day, personally I'm doing more than talk about it and putting up some of my own money to this great program and all the wonderful things it is doing and will do for the kids in our community.  I'm asking you to think about doing the same.

On June 5, tomorrow, not earlier and not later, you'll find 4H Santa Cruz County donation button two or three clicks away.  Me, the volunteers and kids in this wonderful program thank you.






Posted on Monday, June 3, 2019 at 6:55 PM

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