The Almond Board of California’s annual conference is a chance to connect with others in the almond industry, listen to world class researchers talk about their work, and check out a huge almond-focused trade show all at one event. The 2012 meeting was last week (Dec 11-13). Here is a quick review of some of the things I picked up from researchers and informed industry members at that meeting…
Joel Siegel, USDA ARS entomology researcher, discussed results from his work into navel orangeworm (NOW) control in almonds. He again stressed the “numbers game” reality of controlling this pest. High levels of overwintering NOW mean the season starts with a higher population that can build rapidly once hull split begins and new crop nuts are targeted by female NOW laying eggs. Warm years are especially difficult for NOW control as more heat units drive the pest life cycle faster per calendar day. The earlier in the season the new crop reaches hull split, the sooner the NOW population shifts to new crop and grows faster. As a reminder of the importance of winter sanitation, Dr. Siegel reported that in mummy nuts surveyed in the winter 2011-12, there were up to 30% NOW infestation in almond and almost 100% NOW infestation in pistachio. On the plus side, Dr. Siegel’s research has found that softer pesticides that target NOW eggs and larvae without flaring mites are somewhat effective on adults as well. He found that spraying Altacor or Delegate directly on adult NOW resulted in 65% and 95% mortality, respectively, after 72 hours. Dr. Siegel reported that some operators tell him they have shifted to night application of hull split sprays so they are spraying when the adults are flying.
Brad Hanson, UC Cooperative Extension Specialist for Weed Science, reported that Rely will be largely, if not completely, unavailable in California tree crops for 2013 and, perhaps, 2014. What options does this leave growers and PCAs for control of the growing list of glyphosate resistant weeds? Dr. Hanson suggested pre-emergent herbicides and a handful of post-emergent materials like Treevix, Venue, and Gramoxone, among a very few others. He did caution that several of the post-emergent herbicides offered as Rely replacements are only effective on certain weeds, not a broad spectrum of grasses and broadleaves. To best match the treatment to the problem, Dr. Hanson stressed the importance of scouting orchards to know firsthand what weeds are present and tailoring your herbicide program to control those specific weeds. See Brad’s charts on herbicide registrations by crop (updated this month) at: http://www.plantsciences.ucdavis.edu/plantsciences_faculty/hanson/main/2012%20T&V%20registration%20chart%20with%20MOA%20info.pdf . Brad also has a very interesting blog on weed control in perennial crops at: http://ucanr.org/blogs/UCDWeedScience/index.cfm.
Jim Adaskaveg, UC Riverside Professor of Plant Pathology, reported that Manzate Pro-Stick fungicide received a supplemental label in almond last March. That’s good news. Since Manex was lost, it is nice to have, again, an effective fungicide class once again registered in almond. He also reviewed his research into scab and alternaria control, especially the dorment/delayed dormant use of oil + chlorothanil (Bravo, etc.) to suppress sporulation of over wintering scab lesions. He stressed that this isn’t a stand-alone program, but it compliments in-season spraying programs very well. Dr. Adaskaveg also talked about his work with chemical control of hull rot, and the possibility that the Monilinia component of the disease may infect hulls in the late spring, not immediately in front of harvest. This may change spray programs intended to control hull rot. More research is planned. For more details on almond disease management, see Fungicide Efficiacy and Timing in Deciduous Fruit Trees and Strawberries, updated annually, at: http://www.ipm.ucdavis.edu/PDF/PMG/fungicideefficacytiming.pdf. Dr. Adaskaveg is one of the authors.
Finally, in a trade-show floor conversation with an experienced nursery sales rep, I was interested to learn that growers in the Sacramento Valley, after two years (2010 and 2011) of late, wet harvests for Monterey and Fritz varieties are shifting at least some interest away from those pollinators towards early to middle pollinators such as Aldrich, Carmel, and Wood Colony.
The Almond Board of California’s annual meeting is my favorite almond meeting of the year. The 2012 program, shifted north to Sacramento this year, did not disappoint. Happy Holidays to all, and best wishes for a safe and prosperous 2013.