A consulting company working with the USDA will be at my office at 1430 Freedom Blvd, Suite E in Watsonville on August 31 in the interest of gathering information to put together an "actual production history" (APH) Crop Insurance Program for raspberries. Grower input will be very valuable in making this insurance program relevant your production model.
As I think many of you have been doing, I've been cracking the pages of the latest CalAg edition dedicated to berries.
The following article, written by Tom Gordon of UC Davis and his former graduate student Margaret Lloyd – now serving as a Farm Advisor in Yolo, Solano and Sacramento Counties – concerns an aspect of berry culture as we move into an environment of less effective soil fumigation.
1- The increase of soil pathogens we are experiencing in strawberries has been concomitant with decreased soil fumigant availability not just here, but also in Spain, Israel and South Korea. In other words, buckle up because the best is yet to come.
2- A higher level of genetic resistance to soil disease in strawberry will not be the cure all, but rather it must be used together with a means of reducing soil pathogen inoculum load in the soil. This combination was understood for a long time by the UC strawberry breeding program, and should not be forgotten.
3- The only route to pathogen inoculum reduction in soil is not necessarily soil fumigation. Rotation with non-host crops is one (indeed, the authors state that in general inoculum loads can be decreased by 50% per year in the absence of host plants) is given as one.
4- Not introducing pathogens into the field in the first place is important and one should be paying attention to movement of soil, on people, tools and machinery in and out of fields. An important note, and I'll write it in bold so you don't miss it, is that a pathogen population must increase to a certain threshold before it causes disease, in other words the absence of visible signs of disease does not mean a field is clean.
5. The final page is the most interesting, in that it discusses the idea of a regional plan for maintaining uninfested, pathogen free soil as a fundament of a thriving agricultural industry in the reduction or even absence of effective soil fumigation.
To begin, the system of rotating berries and vegetables as we have done for decades on the Central Coast may no longer tenable in the absence of an effective fumigant. For those not familiar with the system of cropping in the Pajaro and Salinas Valleys, a very generalized picture has been the fumigation of soil, followed by a crop of strawberries, and then rotated to lettuce or cool season vegetables which oh yes very much benefited from the fumigation for the berries a year or more prior. Following the vegetable crop, fume again to set the pathogen population back to zero, plant berries followed again by vegetables. And repeat.
What to do now as the effectiveness of our fumigation slips is the question very much on the front of the minds of farmers, researchers and businesspeople.
We all understand that private land is private land, and to suggest regulation over it from an outside agency is anathema in the United States, as it should be. Then again, that much of the privately owned farming land in the Pajaro and Salinas Valleys is leased and used by multiple growers, who produce food for millions and employ thousands, means that the preservation of the quality of land and the usability and productivity of its soil, is of more than individual interest and enters into the realm of a public good.
The article briefly explores how the maintenance of productive, pathogen free soils could be incentivized. The development and deployment of tools to identify sick soils that could bring risk to a grower's bottom line is one route. Much in the same way Carfax informs the used car buyer what is up with his or her intended purchase, a contaminated soil will be known by both lessor and potential lessee to be so, and as such would be negotiated at a lower rate than a soil which is clean and presents less risk of loss.
The other more intriguing, and far more difficult in my mind, is the development of local cooperative governing mechanism for soil management. This is a huge topic, but would be something that growers and landowners create and agree to amongst themselves. Something along the lines of the agreement in the 1960's of Salinas lettuce growers to adopt a “lettuce free” period to manage lettuce mosaic disease is given as an example. As far as I know, this wasn't imposed on people by the State or some sort of enforcement agency threatening fines or punishment, rather growers agreed to it since it clearly benefits everyone and as such still stands today.
Lots to think about here, good article by Tom Gordon and Margaret Lloyd.
The newest issue of "California Agriculture" just came out and it's all dedicated to research on strawberries.
The main idea of this issue is what the well written intro editorial by Cal Ag Executive Editor Jim Downing describes: what is this industry really going to look like going forward post methyl bromide?
Very high quality line up of peer reviewed writing, including an insightful article written by Laura Tourte and yours truly concerning the evolution of the berry industry on the Central Coast.
Set aside some space to read this, it's going to be time well spent.
Very nice set of guidelines for Botrytis fruit rot in strawberry that Steve Koike and I wrote up as an expansion of a blog post we wrote a few years ago. Thanks to Joy Jacobs of the California Strawberry Commission, we now have them available for you in a beautiful full color format.
Download, print, use as you wish, this is the latest word in Botrytis management for berry growers.
The following powerpoint was graciously shared with me by Max Edgley, a PhD candidate at the Tasmanian Institute of Agriculture. I think this is a very useful exposition of a common problem in blackberries and I am very grateful for him sharing it with all of us.
The information below is taken from Max's presentation. Max wrote in to stress that we please be aware that this information is from one season across and is as such very preliminary.
Red druplet disorder, or reversion, is the post-harvest reddening of blackberry fruit. While we understand that there is a loss of anthocyanin pigment in the affected druplets, it is still unclear as to what exactly is the cause of this disorder.
Physical damage to the druplets has been implicated, as have rapid changes in temperature – ie from the hot of the field to the sudden cold of the cooler which seems to swell and then shrink the cells walls of the fruit. Fruit which is harvested at temperatures with an internal temperature above 22 C (that's 72.5 F) before cooling tends to show symptoms the most.
In short, the work here investigates the above implications by testing staged cooling of freshly harvested fruit, physical damage, and the effects of different levels of fertilizer nitrogen in mitigating red druplet disorder.
Again, many thanks to Max for sharing this document with all of us.