I had several growers drop by my office early this morning regarding the management and regulatory regime for light brown apple moth (LBAM). I really enjoyed give and take of our little charla in the parking lot and thought this might be beneficial to the some of you, so I write a summary of our conversation below:
How is it that there is so much LBAM around right now, especially in the organic strawberries? Although we can't say for sure when exactly the last flight of moths and subsequent mating occurred, but it's usually been in March that we have one, another in June and then another in September. Figuring on egg laying in late March, and subsequent hatch and growth, doesn't make it surprising that we are seeing a lot of larvae now. Too, as the growers pointed out, it was difficult to get in and spray because of all the rain so a pretty sizable cohort of larvae came through safe and sound.
How is it that the USDA and CDFA people find the larvae so easily in my field when my field crews can't? The USDA and CDFA people are professionals, and are number of them are very good. I heard of one inspector, who upon arriving at a suspect field and casting a glance around at the surroundings, declared that he'd find something there and within minutes lo and behold, had found a larva. If you want to be a good angler, you need to fish where the fish are, and that's what the inspectors are doing. They check the edges of the field very close, especially when next to wooded areas, and when they find one larva, they slow down and look around there real close because there are sure to be others. Make sure your crews know WHAT they are looking for and HOW to look for them to best utilize their time.
How about the twist ties for pheromone based mating disruption? Twist ties for sure are the first leg of a sound LBAM control strategy. We all need to understand however that these take time to work, since they are disrupting mating and therefore reducing total volume of eggs laid sometime in the future. No moths, eggs, larvae or pupae are being killed here, and it's just that the numbers of those future generations will be reduced. So those people who did not put twist ties out in March let LBAM adults mate freely and are seeing the consequences currently. It's not too late though, since putting the twist ties out now will serve to disrupt the upcoming moth flight in late May or June. Raise them up a bit on flags, lines or sticks over the canopy, and make sure to spread them out EVENLY over the field – no “barriers”, big blobs of twist ties in the middle of the field or any other funny business. Configurations like every 10-15 feet every third bed should get you to the requisite 300 ties per acre.
What should I be spraying in organic to control this – in strawberries I only have 3 sprays of Entrust and don't want to use them all now. Managing LBAM is a lot more difficult in organic than conventional to be sure. Any formulation of Bt doesn't seem to work all that well, and the material that works well, Entrust is limited to three applications max. I agree, I would not panic and blow out all of my Entrust applications this early in the game because I may need one in a pinch later on, so would pursue a strategy of regular Bt sprays to keep down populations. It's understood that Bt's, while able to kill smaller larvae outright, tends to just make the bigger larvae sick, they stop feeding for a while, and when they start feeding again the Bt is worn out. Therefore on occasion it might be a good idea to closely space the applications, to have fresh material on the plant for our survivors to feed on. It's worth noting too, that spraying in the evenings is better than in the morning, since UV radiation can break down Bt.
Don't forget about your surfactants either, they are pretty important when it comes to enhancing the physical and in some cases chemical efficacy of a pesticide.
Always bear in mind to read the label of the pesticide you are using and hew closely to the instructions therein.
Really great having the guys come by this morning and hope I was able to help some. My time is your time, so please let me know if you need more information.
Growers need to be aware right now that our light brown apple moth (LBAM) issue on the Central Coast has been getting very serious. Initially receiving my first texted picture in late March (yes, you are the first!), the issue has now morphed into a number of fields having finds this past week, even with one larval find in fruit harvested out of a conventional strawberry field.
The uninitiated should know that LBAM, while not generally representing a pest problem, is nonetheless deadly serious business. The bottom line is that our trading partners in Canada, Mexico and the southeastern USA don't want it, and are depending on the regulatory machinery in California to keep it out. And the regulatory activity around an LBAM find is stressful, expensive and time consuming - just ask anybody who has gone through the process from a find to finally clearing the field.
There is a lot of material on the UC IPM guidelines and this blog on how to deal with the regulations and how to effectively manage this pest, but I want to re-iterate how important it is to regularly survey one's field, to which end I've provided a few pictures below from my collection to assist. LBAM is a leafroller and looks very similar to several others we have here at the larval stage, so concentrating on leafroller management in the berries is the name of the game.
On management, an identified population of LBAM should be pursued in three ways
1- The use of mating disruption obtained by the deployment of pheromone based twist ties. These are no longer available from the County Agricultural Commissioners, but you can get them from Troy Miller at 831 809 9211.
2- Judicious use of insecticides targeted to lepidoperous pests. Formulations of Bt can be added to any other tank mix, Coragen (for strawberries), Altacor (for caneberries), Delegate (for caneberries), Radiant (for strawberries) and Intrepid are all good, some act faster than others. Understand that before using any insecticide, one needs to check the label for use restrictions and recommendations.
3- Physical removal of the leaf rolls works. One should realize that the number of rolls in a field is generally not very high, but a single worm in this regulatory regime can be ruinous. GET THEM OUT. Also, understand that looking for LBAM larvae is unlike Easter egg hunting with eggs spread evenly across a physical space, but instead since the larvae emerge from egg clutches, tend to be bunched up around one another. Find one, and maybe you find a few more.
Finally, please understand that because of the massive cost a closure can bring to an operation, this is a very high priority issue for me. By all means let me know if you want me to pay a visit to your farm and discuss this LBAM problem further.
It's finally happened. Dale-Ila Riggs of New York, after three years of work and steadily reduced spotted wing drosophila in her blueberries has achieved total exclusion of this pest. This is a huge accomplishment!
Thanks to Fruit Grower News for sharing the video.
We've just completed the newest UC ANR sample cost and return study on conventional strawberry and attached it here.
Giant effort on the part of colleague Laura Tourte along with Jeremy Murdock and Daniel Sumner from the Agricultural Issues Center with UC ANR.
HUGE round of applause for the growers who worked with us to true our work - many hours spent poring over this document with so much great advice and input. Thanks all!!
Document is posted below, crack it open and learn what it takes these days to grow and harvest a crop of conventional strawberries on the Central Coast with all of the new challenges included and updated.
California Berry Cultivars, LLC (CBC) is hosting an open field day on Friday, May 5 from 10AM-12PM at their location at 181 Dairy Rd, Watsonville. Everyone is invited to attend. It's a good opportunity for the strawberry industry to see the work they've been doing in developing new varieties to meet the needs of our industry.
I have done a lot of research with CBC over the past few years, so I will be there as well to talk with growers and other agricultural professionals about our collaborative work - the effects of mustard seed meal, plastic color, nitrogen application rate and cold conditioning duration on the efficacy of the methyl bromide fumigant alternatives Dominus, chloropicrin, anaerobic soil disintestation and steam. Additionally, I can share information regarding a propriety fumigation alternative that I ran with CBC and another farm.
Also, this is a good venue for me to solicit from you ideas on future research needs, especially in the methyl bromide alternative arena.
Look forward to seeing you all there!
Link here with more info about the meeting: