This is simply a summary of one year of biological fungicide work in strawberries in 2012-2013 and should not be understood as a recommendation to use any of these products.  This investigation is will continue into 2013-2014 and will serve to confirm and adjust the work here.

Introduction: A number of biological fungicides registered for use in strawberries have not been thoroughly tested through empirical studies to give guidance to growers on their efficacy and use.

Materials and Methods:

Table 1 below is an outline of materials tested in 2012-2013.

The field involved in the study was organically farmed and had a tested infestation of Verticillium at the average level of 25 microsclerotia per treatment replicate.  Grower standard was managed as per grower practice, that is to say normal irrigation, fertility and pest management practices were applied.  This grower standard did not include any sort of biological fungicide either by dip or injection through the drip tape during the season.

Plot was replicated three times and each replicate consisted of at one bed of 180 feet in length. 

Application of the materials took place as indicated in the table below:

Table 1. List of treatments.

Plant dips were made by suspending the requested rate of fungicide in approximately twenty gallons of water and submerging and soaking about a half a box of strawberry transplants (about 500 plants) thoroughly and then distributing to planting crews for transplant.  Note that in the case of the two Actinovate treatments, plants were held for one night to prior to transplant, ostensibly to establish the organism on the plant roots.

Drip applications were made with a portable pump injecting each fungicide.  Each application normally was preceded by filling the drip tape with clear water, injecting the mix and then further pumping in clear water to make sure the fungicide had moved well out of the drip tape.

Application dates:

Preplant application – 11/3/2012

            Dazitol

            Terra Clean 5.0

            Terraclean 5.0 + Serenade Soil

            Tainio Spectrum + Pepzyme C

            Biotam

Root dip + one overnight hold – 11/7/2012 (planted November 8)

            Actinovate rate 1

            Actinovate rate 2

Root dip and immediate planting – 11/8/2012

            Double Nickel 55

            Soilguard

            Biogenesis + Pepzyme C

10 days post – plant – 11/20/2012

            Serenade 4 qt

            Serenade 2 qt

Monthly applications (12/11/2012, 1/16/2013, 2/26/2013, 3/27/2013, 4/30/2013,  and 6/13/2013)

Terra Clean 5.0

Terraclean 5.0 + Serenade Soil

Tainio Spectrum + Pepzyme C

Serenade 4 qt

Serendade 2 qt

Actinovate rate 1

Actinovate rate 2

Double Nickel 55

Biotam applied 2/26/2013; Serenade 4 qt per acre applied other dates in treatment

Soilguard

Several dying plants from different areas of the test plots were sampled in July to confirm that Verticillium was the cause of plant death.

As a gauge of plant vigor from each treatment, strawberry plant diameters were measured February 13, and April 13.  Measurements were in centimeters and from twenty plants in each plot.

With the beginning of fruit ripening, fruit harvest was done weekly in each treatment replicate.   On each pick date, fruit from each plot was weighed and counted.

Results:

Means followed by same letter do not significantly differ (P=.05, Student-Newman-Keuls)

Means followed by same letter do not significantly differ (P=.05, Student-Newman-Keuls)

Plant diameters measured on February 13, 2013, were significantly larger in the low rate of Actinovate than the other treatments with the exception of the high rate of Actinovate, Tainio and Double Nickel 55.

Both rates of Actinovate realized higher fruit yield than all other treatments except for the Dazitol, in cumulative fruit yield, which included six weekly harvests, up to May 14, 2013.  No further differences were realized between May and August.

As noted above, this field has a very high infestation of Verticillium and all plots began to experience pronounced plant dieback in June, with some 60-80% remaining alive or declining and by end of July, nearly all plants in all replicate plots had died.   There was a trend for plants which had produced larger amounts of fruit in April and May to experience lesser fruit production lesser vigor and earlier dieback as the season progressed.

Conclusion

The results of this trial are encouraging.  In the early part of the season up through the middle of May, several treatments had significantly higher amounts of fruits harvested than the grower standard.  Nonetheless, none of the treatments provided sufficient protection to the plants to prevent an almost complete die out of the plants by August, effectively ending the season.

It’s not easy for a farmer who is used to selling direct at farmers markets, a roadside stand, or to a processor to make the big step into selling boxed and labeled product to wholesale and other buyers. Yet these buyers really want to meet small farmers so they can serve the rapidly expanding market for locally grown food. The University of California Cooperative Extension offices in Santa Cruz and Santa Clara Counties, along with the Agricultural Sustainability Institute at UC Davis are planning to connect these farmers and buyers from the San Francisco Bay Area during a bus tour on Tuesday, November 5.

Farmers who want to join the bus tour need to pre-register by contacting UC Cooperative Extension Santa Cruz County at telephone (831) 763-8040; email cesantacruz@ucdavis.edu or by stopping by the office at 1432 Freedom Blvd in Watsonville.  There is a $20 registration fee, which is fully refundable upon boarding the bus.

The day long tour will leave UC Cooperative Extension in Watsonville at dawn, pick up more growers in San Martin on the way to San Francisco, then tour the San Francisco Produce Market and see different kinds of buyers in the area. The farmers will also visit an independent retailer who buys direct as well as a foodservice or restaurant buyer. The tour will be a “workshop on wheels” where participants will learn about food safety requirements and credit and loan opportunities. Farm Credit banks, which have provided support for the tours, will have a representative on board to discuss financing options.         

Link to further information and registration is provided here:

http://cesantacruz.ucanr.edu/files/174315.pdf                                          

The new edition of "Sample Costs to Establish and Produce Fresh Market Blackberries Study" is now available from UCCE. 

http://coststudies.ucdavis.edu/files//2013/09/30/blackberrycc2013.pdf

This is another great cost and return study in berries authored by Laura Tourte, Rich De Moura, Karen Klonsky, and yours truly.   

We certainly weren't in alone in writing this study, and this work could not have been accomplished without the substantial input and contributions from local blackberry growers - thank you all!

The UC Vegetable Research & Information Center (VRIC) will sponsor the UC Soil Fertility Short Courseon Wednesday, October 23, 2013 at the Buehler Alumni & Visitor Center, UC Davis. The short course will focus on the practical aspects of soil fertility management and topics will include  soil testing, interpretation of laboratory soil test results, comparing fertilizer sources, developing crop nutrient management plans, and fertilizer management and environmental protection. The content will be geared toward commercial scale production, and will assume a general knowledge of soil science; this course is not appropriate for home gardeners.

The program is intended for growers, certified crop advisers (CCA), pest control advisers, government agency personnel, and others involved in fertility management planning. Take advantage of the early-bird registration fee ($160.) The fee goes up on Oct. 4 to $190. The registration fee includes lunch, refreshments and study materials. UC Farm Advisors can attend at the special rate of $95. Enrollment limited to 70 attendees.

Cooperative Extension specialists Tim Hartz (vegetable crops) and Stu Pettygrove (soils) are the instructors.

The course is approved for California CCA continuing education credits. No DPR credit available for this course.

More information, visit the VRIC website (http://vric.ucdavis.edu).