I have an update on the strawberry field described in the January 6 post of this blog suffering extensive salt damage .

As you may recall, the determination on finding all of that salt damage was to immediately overhead irrigate to wash the accumulated salts away from the plant roots, and the grower did indeed do that already on the next day as shown in the first photo below.

As the reader can see from the second and third photos below, the recovery of this field is now near complete.  The plants are large, green with flower and fruit formation just beginning.  While the field seems to be have been set back some on the production cycle from the injury caused by salt, there is no doubt that the situation is a much happier one right now than in January, with nary a sign of salt burn anywhere and plants well into recovery.

Three soil samples taken from the field April 24, 2012 gave salinity at 1.3 dS/m, 1.5 dS/M and 2.3 dS/M, giving the impression that much of the salt from January had been now leached out.

The pictures below are of a farm call this morning concerning die back of laterals of maybe less than 1% of the total on blackberry.  The symptoms occurred fairly evenly across the farm without regard to inside or outside of tunnels, organic or conventional.

As one can see from the second picture below, the die back does not advance that far down into the lateral, and since the apical dominance has been pushed down from the tip, often a new branch can be found at the lower limit of the necrosis.  It certainly does not threaten the rest of the plant.

The key to understanding this situation was the presence of conidial masses on the outside of some of the dead tissue (Pictures 3 and 4 below), and also an observation by the attendant pest control adviser that plants are quite wet in the morning from guttation from the leaves.  Lots of surface moisture + cool weather + soft, nitrogen rich tissue at the tip of the lateral = Botrytis problems. 

Disease infection is very infrequent, the plant is rapidly maturing and the weather is warming so it is not expected that this disease will advance much further and no action is recommended.  Hat tip to the grower and his pest control adviser on picking up on this.

One of the points of curiosity of spotted wing drosophila is that while most everyone refers to the high fecundity of the female and her ability to lay so many eggs, have you given a lot of thought as to how such a small fly has the capacity to produce so many eggs?
Well thanks to the work of Katrina Hunter of UCSC and my research assistant Monise Sheehan, we have a better idea.  Simply put, and graphically illustrated below by cutaways, the abdominal cavities of these adult females are completely packed with eggs.  These pictures of Katrina's square very well with what Monise has observed under the microscope, in that she can squeeze up to 25 eggs out of one individual female at one time.   

It's pretty impressive and it just underlines why we as growers, pest managers and researchers have to stay on the ball with spotted wing drosophila.
 

Mark Bolda, Laura Tourte, Rich De Moura and Karen Klonsky
of University of California Cooperative Extension have authored "Sample Costs to Produce Second Year Strawberries" which is now posted at:

http://coststudies.ucdavis.edu/files/Strawberry2ndYrCC2011.pdf

Cultivation of second year strawberries (also known as "cut backs" or "renovations" by some) is a significant part of the strawberry industry on the Central Coast, currently covering some 15% of the total acreage.   This study, which took several months of research and a raft of interviews with local strawberry growers (thank you all!), is a thorough examination of this cultural method, its costs and returns.  For growers currently growing or considering embarking on the production of second year strawberries, "Sample Costs to Produce Second Year Strawberries" is going to be a really valuable piece of literature.