Molybdenum (Mo) is the minor of the minor nutrients and usually doesn't show up in my strawberry and caneberry tissue samples at a concentration higher than 1 or 2 ppm. Molybdenum exists in the soil as molybdate ion (MoO4 -2 ) and in most soils one won't find more than an ounce per acre.
Low as the concentrations in the soil and plant tissue may be, molybdenum is more important than you might think.
Mo functions in nearly all nitrogen transformations in the plant which result in proteins. If you recall from your high school biology, one functional group of the amino acids is the amine, which of course contains nitrogen. In short, the plant takes up nitrogen as nitrate, which is then converted to ammonium, then to the amine containing amino acids followed by their combination to form proteins. Absent molybdenum, nitrate is simply taken up by the plant, not converted to protein and results in a visibly weaker plant.
Molybdenum become substantially more soluble (ie available) as the pH of soil rises, and as such the first approach of the grower or agricultural practitioner to addressing the admittedly rare event of Mo deficiency would be to raise the soil pH.
An additional problem concerning Mo can crop up from the use of sulfur containing fertilizers and soil amendments (for example, think ammonium sulfate [(NH4)2SO4] and gypsum [CaSO4-2]). Sulfate ion (SO4-2 ) and molybdate ion (MoO4 -2) are chemically very similar to one another and as such compete with one another for absorption by the plant roots. So lots of sulfate in a soil (as can be common in a soil which is acidic), equals more sulfate taken up by the plant and proportionally less molybdate.
The concluding statement I am going to make here is that while molybdenum deficiency it is rarely an issue (I've never seen it personally) in Central Coast grown strawberries and caneberries, I still feel knowledge of its purpose and causes of deficiency are important for growers and agricultural practitioners of this area.
Much of the information in this post comes from the article "Molybdenum in Vegetable Production" in the periodical "Vegetables West" August 2005 (pp 14-15) by Dr. Tom Ruehr from CalPoly.
This comes from my colleague Bernadine Strik up at OSU:
Oregon State University will be offering another Blueberry School on March 16-17, 2015 in Corvallis. Early registration for reduced rates ends on Feb. 5, 2015. http://osublueberryschool.org/
This two-day blueberry “school” is intended for both new and experienced blueberry growers, farm managers, crew leaders, advisors, packers/shippers, and consultants. Key issues addressed include blueberry markets, how you might be more successful in tight labor or volume markets; which cultivars are easiest to grow and are in most demand; how to establish new acreage using cutting-edge methods; how to best manage existing acreage to maximize returns of high-quality fruit; basic information on blueberry plant physiology; nutrient management programs; irrigation and fertigation practices; use of organic amendments and mulches; using weed mat as a mulch; machine harvest; pruning, maximizing pollination; and viruses, diseases, insects, weeds, and vertebrate pests. Information throughout the program will address the needs of conventional, transitional, and organic growers. For more information see our draft agenda posted on the web site.
Simultaneous interpretation for Spanish speakers is planned with sponsorship funds generated. If you'd like to sponsor this event, please contact Bernadine Strik (firstname.lastname@example.org)
Announcing the 2015 Annual Strawberry Production Research meeting on February 20.
Please note that it's a few weeks later than usual because of the North American Strawberry Grower's Association meeting from February 3 to February 6 (which by the way I strongly recommend - just looked at the schedule this morning and it is chock a block with good speakers and excellent content).
Additionally, the location will be back at the Elk's Lodge on 121 Martinelli Street in Watsonville.
See you there!
If you at all have any production relationship to caneberries, you should not miss this caneberry meeting. My colleague Mark Gaskell has brought in caneberry experts from around the country to put together probably the best caneberry meeting we have ever had!
Meeting will take place February 3 at the Veteran's Memorial Building on 780 Bello Street in Pismo Beach, California. Sign in starts at 8 am, meeting starts at 815 am.
Agenda posted below.
A summary of the last year's soil health symposium sponsored by the California Department of Pesticide Regulation was recently posted:
This symposium is a result of one of the recommendations made in the "Nonfumigant Strawberry Production Working Group Action" plan which was about developing alternative strategies as the industry transitions away from traditional pre-plant fumigation.
Key takeaway from the summary:
There is a sense of frustration expressed in the paper that our understanding of soil biology has not kept pace with fumigant research. The hope is that from here on out smart policy and well directed research funding that increases scientific knowledge of soil health can lead to the development of IPM solutions for soils and result of less fumigant use.
To wit, a total of 9 recommendations are given as research priorities, including the development of diagnostic tools to monitor soil health, establishment of economic thresholds for soil pests and pathogens, identification of components of crop plant root exudates which shape microbial communities and consequently develop strategies to enhance the growth of these beneficial microbes. Facilitation of dialog, perhaps through some sort of online format, between growers, researchers and regulatory agencies is also given as a priority.