There have been many, many questions over the past few weeks about why so many strawberry flowers are aborting in addition to a noticeable uptick in crooked, mis-shapen fruit.  So, while I cannot present any empirical evidence as to why more strawberry flowers than usual are failing, in the interest of offering information that could be helpful I can share some of my own hypotheses.

There are several reasons for the failed flowers, better known by growers and crop managers as aborted fruit or duds.  These aborted flowers are flowers with blackened centers (see the photos attached below) which are the dead floral reproductive parts and subsequently will no longer make as a fruit.  Most commonly this is the result of extended period of very high temperatures (roughly above 90^o F) or, for certain varieties, the higher ultraviolet radiation (UV) of the longest days of the year at the end of June.

This past year has been different since we have not had very hot days so far and it has been often quite cloudy or foggy all the while that there has been a remarkable amount of fruit loss attributable to aborted flowers and mis-shaping.  This indicates a different reason than the excessive heat or UV radiation described above, and from the situations of failed flowers that have been shared with me I am thinking there is a weakening of the plant from a lack of nitrogen nutrition at cause here.  In addition to plants which appear less green, tissue samples that I have seen associated with failing flowers have had leaf blade nitrogen under the recommended 2.5%, and soil nitrates under the 10 ppm (sometimes even at 1 or 2 ppm) which is often seen as a minimum for good strawberry plant performance.

I am certain that these low levels of nitrogen in the soil and the plant clearly have a direct relation to the leaching effects of the heavy rains and flooding of this past winter.  What's more, this would account for the description many growers and industry personnel share with me of “tired” or “worn out” plants with light green leaves, a lack of vigor and little of the bright green leaf luster that we all associate with a strong and healthy plant.

In turn, the call for additional nitrogen to correct these deficiencies would not be a bad one, and could very well minimize the amount of flower abortion as well.

With a large event concerning biological solutions for agriculture taking place this week in Salinas, I feel it is a good time to make a comment regarding the research taking place here.  I started working with these materials in 2012, and have off and on tested them since, for the most part in strawberries.

To open, I will state that while these technologies in theory offer a lot of promise, we don't want to get over our skis with this because that promise has not yet been realized.

Most of my work with biological solutions has been with biological fungicides, so I will make the following points:

1. The biological fungicides should not be seen as replacements for preplant treatments such as soil fumigation. I have yet to see any one product come even close in efficacy to soil fumigation and would be quite comfortable betting very serious amounts of money with anyone who feels otherwise.   They could be an interesting element of an Integrated Pest Management program, but not as a stand-alone replacement for soil treatments such as fumigation.  
2. People need to be realistic about how long it's going to take to really learn how to use these biological materials.  I am working on a farm in Santa Cruz County with USDA microbiologist Nick LeBlanc and UCCE Plant Pathologist Yu-Chen Wang studying two promising biological materials to understand not only what these materials do, but also how they do it (in other words what are they doing to the plant and the surrounding soil) and for our team of three to run more than the one trial a year we are currently doing would be a real strain for us; remember that it's not just the regular injections of material and data collection, but also preparation for each task and getting to and from the test site.  All of us are very busy with other things.  If there is a big push from the state or a major agency to work more on biologicals, maybe that would change; it's certainly interesting work and we three would get good publications out of it, but I doubt that the deliverables to the farmer would be very large.
3. Time and time again, my colleagues and I have seen, with certain products and not others, a boost in plant performance (like fruit size and yield), especially early, but never anything like a defense against a disease.  It's remarkable that products that are completely different, as in a bacterium or a fungus, have the same outcome on the plant.  This common thread in effect on the plant is something we are thinking about and looking at closer; at this point we aren't really interested in enhancement in disease resistance because that has not actually shown itself in the field.

What I have written above is a summary of where we stand currently our research with them on the Central Coast.  The principle that these biological solutions should work is very compelling and we are not going to give up anytime soon, but it will take time and effort to really understand them and how they will fit into our farming here.

A fact of extension work is that you do a lot of presentations in front of audiences, and for people who take it seriously it is a challenging yet very rewarding aspect of the work.  

I think that what (starts at minute 9:26, I've set it to start there for you) James Hetfield of the rock band Metallica is saying here puts very much into words what I feel myself when doing a presentation.  Not to say the audiences to which I present are anything close to what he and his band play to, including probably the largest crowd of people ever assembled in history, some 1.6 million people at a show in Moscow in 1991, I still find his " sense of purpose, sense of being, sense of communication" to really capture the feeling of what it is like to be performing in front of a group of people.  Too, the distinction a bit later on of how one acts in front of a large crowd as compared to being with smaller, more intimate group is spot on, although not that many people in the presentation business really pay attention to that. 

Also, look at the light in James' eyes when he talks about playing and performing, he truly loves his work.