- Author: Mark Bolda
Excellent article posted on the Salinas Valley blog by colleagues Richard Smith and Tim Hartz on zinc nutrition of crops and soils in the Salinas Valley.
Key takeaways:
1- Historically zinc deficiency was common in California, but now because of widespread use of zinc fertilizers, zinc deficiency is pretty rare. I concur, and as a matter of fact have yet to find a single plant sample which was deficient for zinc.
2- Bioavailability of zinc is limited by increasing soil pH, high clay content, high phosphorous and low soil temperature.
3- Tissue zinc sufficiency is between 15- 30 ppm (anecdotal note- blackberries tend to be in the range of 40 ppm)
4- Most common soil zinc test is DTPA extraction, which gives a good estimate of what is plant available. Generally, soil DTPA extracts from 0.5 ppm - 1.5 ppm means crop plants in that soil would probably respond to the addition of a zinc fertilizer, while a test above 1.5 ppm means there likely will be no plant response to zinc addition.
You really should read the whole article, it's quite good and definitely worth the while:
http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=13163
- Author: Mark Bolda
This is announcing the fifth meeting in our UCCE series on strawberry management on the Central Coast. On April 24 at the Spence Road USDA Research Station, 1572 Spence Road in Salinas, courtesy of Steve Fennimore, UCCE Specialist, we will discuss weed management in strawberries, first working on properly identifying weeds and then discussing their control, including through the use of herbicides.
The entire meeting will be conducted in Spanish, with translation to English. Agenda is below.
- Author: Mark Bolda
The lygus meeting planned for tomorrow, March 27 at the end of Jensen Road in Moss Landing will now be held at the UC Cooperative Extension office at 1432 Freedom Blvd in Watsonville.
See you there!
- Author: Mark Bolda
For grower and PCA reference, this sample came into Steve's lab on Monday. No disease found, and checking with the grower it showed up in the warmest part of the field one day after application of 32 fl oz per acre of Diazinon 2E. Interestingly, it showed up on the fruit only, not on the leaves or flowers. Problem is starting to clear, with new incoming fruit looking fine.
- Author: Mark Bolda
If you read the story through the link, there is a great example of confirmation bias and narrative creation concerning a very well-known political consultant's observations that a huge bloom of yard signs in Florida supporting a presidential candidate in Florida before the 2012 election indicated a sure win in the national elections. In fact all the yard signs didn't mean anything at all, because, as everybody knows, the candidate ended up losing by a significant margin.
http://www.bloombergview.com/articles/2014-03-19/the-alibaba-story-telling-failure
So what was the problem in believing that all those yard signs meant certain victory? As the author of the article writes; “What was the method for measuring those signs? How widespread was this nationally, and more importantly, in swing states? What is the past correlation between numerical signage advantages and election outcomes?”
The political consultant so badly wanted to believe that what she was seeing really meant something that she ignored any sort of empirical approach to the situation which would have provided her information to the contrary.
How can this possibly relate to our business of producing berries? A lot, as a matter of fact. Think about how one approaches diagnostics in the field. Evaluate your own attitude when approaching the problem - is there some given outcome that you are carrying around and will blind you to a truly empirical approach to the problem? Is one's sampling method correct for the issue being evaluated? What can we make of the problem from the samples we have taken? Is there a correlation between the samples we take and the problem as a whole?
Beware the narratives!
