The following powerpoint was graciously shared with me by Max Edgley, a PhD candidate at the Tasmanian Institute of Agriculture. I think this is a very useful exposition of a common problem in blackberries and I am very grateful for him sharing it with all of us.
The information below is taken from Max's presentation. Max wrote in to stress that we please be aware that this information is from one season across and is as such very preliminary.
Red druplet disorder, or reversion, is the post-harvest reddening of blackberry fruit. While we understand that there is a loss of anthocyanin pigment in the affected druplets, it is still unclear as to what exactly is the cause of this disorder.
Physical damage to the druplets has been implicated, as have rapid changes in temperature – ie from the hot of the field to the sudden cold of the cooler which seems to swell and then shrink the cells walls of the fruit. Fruit which is harvested at temperatures with an internal temperature above 22 C (that's 72.5 F) before cooling tends to show symptoms the most.
In short, the work here investigates the above implications by testing staged cooling of freshly harvested fruit, physical damage, and the effects of different levels of fertilizer nitrogen in mitigating red druplet disorder.
Again, many thanks to Max for sharing this document with all of us.
Very nice presentation of management with pre-plant fungicidal dips of anthracnose given by Gerald Holmes of CalPoly of work he did together with Jim Adaskaveg, Doug Gubler, Stacy Haack, Helga Foerster and Kelly Ivors did earlier this year.
Look at the presentation, it's very well done. The upshot (copied directly from the concluding slide) is as follows:
1. Actinovate had NO efficacy on anthracnose in the conditions of this study.
2. Azoxystrobin (Abound) is highly effective in controlling Colletotrichum if the strain is sensitive, but not effective if the strain is resistant.
3. Switch is highly effective as a dip in controlling Colletotrichum in all the cases of this study. No phytotoxicity was detected in the conditions of this study (ie 4 minute dip with agitation, followed by 5 to 10 minutes drip drain).
4. Two new compounds, EXP-13 and Syngenta-2 (not registered yet) were found with high efficacy.
Most of you are probably familiar with the suppression of the study of genetics by Trofim Lysenko in the early years of the now defunct USSR. Geneticists who opposed Lysenko's own Lamarckist theory that plants could pass on traits acquired during their lifetime were, in classic Soviet form, jailed; very often for good.
This whole history has come to light again with the recent rehabilitation of Lysenko by nationalists in Putin's Russia, in addition to the recent release of the book "Lysenko's Ghost" by Loren Graham. What appears below is from a review of the book in the Wall Street Journal this past week (whole article in link below, no paywall).
There are important lessons to be learned from Lysenkoism about the challenges confronting science in the day to day affairs of humanity. These threats are continual, and something we should all be aware of in our own community as consumers and producers of scientific information.
Italics are mine for emphasis.
In particular the article states that "(t)he internal logic of science makes it quite resistant to external interference - Galileo's or Lysenko's critics can be silenced by force majeure but only for a time. Science is much more vulnerable to the blurring of objectivity that occurs when scientists become passionate advocates for some political cause in which their discipline gives them apparent expertise. The internal checks and balances of science are then cast aside, and the public yields to the expert, which may or may not be correct."
Politics and science never mix. Caveat emptor.
Nice clip here of a mechanical transplant operation underway in Santa Maria just a few days ago.
Great photography shot out of a drone.
The people running this machine clearly understand the dynamics of this system better than I do, but from a horticultural perspective I am looking closely at two things:
1. The machine is planting plugs (alleviating my concern about "J" rooting!).
2. How will the plug plants respond to a summer planting scenario, given (as far as I understand) that they have no cold conditioning.
Nice to see this sort of progress in the industry.
H/T colleague Surendra Dara who turned me on to this video.
On September 28, UC Cooperative Extension will be leading an anthracnose meeting in anticipation of the upcoming strawberry planting. Location will be the auditorium of the UCCE Building at 1430 Freedom Blvd, Suite E.
Yes, we will cater breakfast, and it will be good! Courtesy of Syngenta, we'll be having bacon, eggs, ham, fresh fruit, juice, coffee and the works.
Format of the meeting will be much the same as we did a few months ago with our lygus meeting. Information will be presented by real experts on anthracnose and its management, but participants are encouraged to comment, ask questions and explore the topic in its entirely.