Mark Bolda's Berry Blog
Paper: Evaluating the Utility of an Electrostatic Sprayer and a Tractor Mounted Vacuum for Lygus Management in Strawberry
Former UCCE Entomology Advisor Shimat Joseph and I just had the linked paper below published in Crop Protection.
Excellent overview of the lygus problem in California strawberries and evaluation of a combination of bug-vac use and the insecticide sulfoxaflor (not registered yet, but useful for this study since it actually works) for management of this pest.
A few points out of the paper to take back to the farm:
1- The use of the bug-vac alone was not sufficient to reduce lygus populations to below that of the untreated check.
2- Treatments using the insecticide sulfoxaflor alone and in combination with the bug-vac reduced the numbers of lygus and the number of cat faced fruit.
3- Neither the bug-vac or sulfoxaflor had any effect on predaceous heteropterans and spiders compared to the untreated check.
The implication out of this work and paper is that the use of an effective insecticide will continue to be the best tactic for control of lygus and mitigation of its damage in strawberries.
Link is here, it will be active until the beginning of October:
Interesting farm call this morning. A strawberry grower near Watsonville reported a large group of worms (caterpillars) migrating north out of the mixed cover crop including barley and mustard.
These worms were identified by our new UCCE entomologist Alejandro del Pozo as being a species of armyworm, for which this sort of behavior is not unusual. One distinct characteristic to ID these worms is the ‘Y' shaped suture on their forehead. For instance, the beet armyworm,Spodoptera exigua, could be a problem in strawberries when high infestations are left unmanaged. You could read more about the beet armyworm as pest of strawberries on the UCIPM guidelines at http://ipm.ucanr.edu/PMG/r734300611.html
Knowing that these creatures do feed on strawberries, the advice to the grower is to mow and disk the cover crop to destroy the majority of these worms. Yes, the grower is forfeiting some of the benefit of the cover crop he expected to keep going until the end of August, but the risk to his strawberry crop of this large population of armyworms is greater.
UC Cooperative Extension is hosting a Perishable Commodities Act meeting at its office on 1430 Freedom Blvd, Ste E in Watsonville on August 2.
See flyer posted below for details.
PACA Meeting poster
I don't write too much about it in this space because it tends more in the area of "shop talk" for us in extension, but a great interest of mine is how one successfully executes a program of extension.
One of the temptations for the new extensionist is to jump in with both feet first, hit the ground running and get some change underway immediately. In our world of berries, there are so many things that need to be done, from getting away from chemical fumigation, reducing pesticide use, improving labor efficiency, managing invasive pests and the implementation of technology.
The problem is, as many eager people find out to their chagrin, that there are many, many interested parties involved in all of these things, and might not take so kindly to pushes for abrupt change.
To get my point across, I'll refer to the economic reformation of China that become the dictum under Premiere Deng Xiaopeng in the late seventies. Called "Crossing the River While Feeling the Rocks" it is change brought about in a piecemeal manner. Rather than forcing giant leaps forward, it rather worked towards change in a cautious way, first testing policies on a small scale, ramping up the successes and discarding the rest.
This piecemeal approach reduces risk and disarms opponents. Initial successes encourage others to back the changes, and one change leads to the next in an evolutionary manner. In such a way, rather than an approach using giant steps, the damage of such a small step orientation to the social fabric of the community to which one has been assigned is minimized.
A cautionary tale of perhaps how not to start out is from our own industry of an organization that was setting up its own research and extension program a number of years ago. Casting aside any hint of a piecemeal approach, and certainly not feeling their way as they went along, they pressed the pedal to floor and moved hot and fast. It was clear these were people with a real agenda, with the smarts, vigor and access to deep pools of money to make it all happen.
Unfortunately, attempting to make giant steps forward without getting too many bearings of the surroundings didn't work out so great. An aggressive and well funded program emerging in the midst of a number of established campaigns is bound to make waves and this one did not disappoint. With that alone there was lots of turmoil, but what really roiled the water was the decision, either through hubris, lack of experience or something else, to trash everyone else working in the community of berry research. Which of course blew a pretty decent sized hole in the social fabric, to say the least.
Perhaps unsurprisingly, rather than disarming opposition, this program solidified it. None of the big changes intended to be brought about were supported by anyone else, collaboration evaporated and they found themselves outside of the industry research and extension mainstream. Needless to say the whole operation collapsed and is now only a shadow of what it once hoped to be.
Good to start steady and slow, and feel out the rocks.
We found them. Referring back to the previous post, as our readers know we've been looking for spotted wing drosophila pupae under fruit in raspberries, and now on the second read have confirmed that they are indeed pupating within a centimeter of the fallen fruit. In the meantime, the pupae collected on the first read have eclosed and the adults are SWD.
Pictures below. Really nice work on the part of Staff Research Associate Monise Sheehan on figuring this out.
Looking to do a bigger run of the same late this summer and then get a nice paper written about it.