I was brought out to the situation in strawberry pictured below.  Yellowing leaves and very little flowering or fruiting.   For whatever reason, the street’s call on this was that it is iron, but to me the youngest leaves being as green as they are (Photo 2 below), is a dead giveaway that it’s not iron, because the youngest leaves in iron deficient plants are the first to yellow, not the last.

No sense standing around arguing about the problem, we just have to roll up our sleeves, get dirty and figure it out! 

The charts below are threefold replicates of sampled leaves and soil of affected plants in the field.

Table 1 : Tissue analysis

Table 2: Soil analysis

So, it looks like the main culprit here is indeed a lack of nitrogen, seeing that at an average of 1.4% it is well under the 2.4% tissue concentration threshold given in the UCCE nutrient guidelines.  Just to be sure though, we should check to see if any of the other nutrients are low, but they are not and everything else is within normal ranges.  I would have some concern about the high levels of sodium (197 ppm) and chloride (7930 ppm), but beyond some marginal burning of the leaves, these plants don’t seem to be exhibiting symptoms consistent with real salt poisoning.

Looking to the soil, sure enough we get confirmation of what we are seeing at the tissue level, and see that nitrates are pretty low here, running at a lean 4 ppm.  I would probably want to bump that up a bit.

This is an announcement for the beginning of a series of meetings to run through the upcoming strawberry season concerning the principles of successful strawberry cultivation on the Central Coast of California.  The first of these meetings will be a review of strawberry transplanting and will take place at the ALBA Rural Development Center on 1700 Old Stage Road on October 8. Agenda is here:

http://cesantacruz.ucanr.edu/files/170337.pdf

Further meetings are to follow and should take place more or less every month at various locations around the Central Coast and will concern topics of a timely nature in strawberries.  So for example there will be a meeting on lygus bugs in April or May, fertility management in February, irrigation in March, pathogens in March and spider mites in June.  If we get a new bug coming our way, why we'll have a meeting about that too.  We have the good fortune to count with a first class group of academics and agricultural professionals from UC Cooperative Extension, the University of California and other industry associated organizations and thus have the privilege to extend some of the best information around in a language everybody can understand.

Depending on who is presenting, some of the meetings and presentations will be held in Spanish with translation to English, while others will be in English with translation to Spanish.  The emphasis is that these meetings are open and accessible to all of you involved in the industry of producing strawberries on the Central Coast.

So just be aware that over the next ten months this series of meetings will be taking place and to stay apprised of when they are coming about. 

I am really looking forward to putting on these meetings with all of you!

Mark

Field bindweed, Convolvulus arvensis, also known locally as morning glory, is a persistent weed pest in blackberries grown on the Central Coast of the California.  Much of this stems from the long period of time between plant establishment and final removal of the crop some five to six years later.

While cultivation of the aisles between the hedgerows is successful in keeping the field clear of most weeds, field bindweed is another matter.  Not only does field bindweed establish very deep root systems which frustrate control by cultivation, but the lengthy vines of this plant grow into the hedgerow and even up onto the plants themselves (Photo 1).  Spray applications of translocated herbicides like Roundup are risky due to sensitivity of blackberry to spray drift.  For this reason we have selected ropewick application methods to reduce the possibility of spray drift and crop injury.

The study described here is an experiment of two methods of wick applications of glyphosate (Roundup).  One method, pictured below, is of a ropewick applicator (Photo 5) which applies a 33% volume per volume (v/v) dilution of formulated product through the ropewick applicator directly to the bindweed leaves by briefly passing over the area in a purposeful back and forth swinging motion.  The second method, used occasionally on woody vines which die slowly, was to clip approximately 1”x1” sponges soaked with a 33% v/v dilution of formulated product with colorful refrigerator magnet clips to individual bindweed leaves (Photo 3).  In both cases, great care was taken to avoid contact with blackberry plant parts, especially canes hanging down close to the ground. Please note – blackberry is very sensitive to Roundup (Photo 7) and contact with foliage must be absolutely avoided.

As can be seen from the pictures below (Photo, 3, 4 and 5), after two weeks both methods are quite effective in controlling field bindweed in blackberries.  It should be noted that the clip method, while quite effective in controlling field bindweed, is far more time consuming than the ropewick applicator and not recommended.

It is lastly important to note that regular retreatment of the field bindweed especially in the fall will be more successful with the ropewick method described here.  One should treat regularly but not too frequently and every month to six weeks should work.  Let the bindweed regrow some, since it is going into the fall and it is storing starch reserves for its roots.  As the bindweed makes sugars in its leaves it is sending that sugar downward into its roots deep in the ground, and this is the time to send some glyphosate into those roots.  These roots are the bindweed wheelhouse and this is where to hit it where it hurts.

The use of glyphosate (Roundup) is extensively written about in this article.  Before using any of these products, check with your local Agricultural Commissioner's Office and consult product labels for current status of product registration, restrictions, and use information.

There will be an organic strawberry meeting sponsored by Lisa Bunin with the Center for Food Safety taking place at the UCCE auditorium 1432 Freedom Blvd in Watsonville this coming Monday, September 18.

Featured will be developments in organic plant stock, anaerobic soil disinfestation, steam disinfestation and development of organic plug plants.

Agenda is featured below.  Please let Lisa Bunin <lbunin@centerforfoodsafety.org> know if you are planning on going so as to be able to adequately prepare for the meeting.