June 18, 2017 01:49PM
One of the products touted by Marrone Bio Innovations is Grandevo, which I've have mentioned previously as a promising option for moths. Yet I never had reason to trial this organism product (being the microbial response of Chromobacterium subtsugae to fermentation) since pure neem oil already keeps codling moth and company in good stead, by which I mean low pressure, here in my northern New Hampshire orchard.

New information has been added to the product literature. Listed among targeted insects are San Jose Scale, Apple Maggot Fly, and Spotted Wind Drosophila. Indeed. This would be the material to rotate with spinosad to protect berries when SWD comes through at the height of summer. There's also a study showing activity on flea beetle (for ornamentals) which suggests to my mind other possible small beetle prospects. Mix things up and who knows?

The spray I just did was directed principally at Oyster Shell Scale (a species guess on my part) which has become relevant in the interior of my older trees. Now is purported to be good timing for scale as these insects come out of barnacle-mode and into the crawler stage in order to mate around this time. I included 1/2# of Grandevo (low rate), 2 ounces of Entrust, and 10# of Surround as part of the spray mix, being a half tank's worth, knowing curculio is still on the prowl. I used this on the plums and throughout the interior of the bigger apple trees. Additionally, I covered a hedgerow of highbush cranberry where the Viburnum Leaf Beetle is back for a second season of total destruction. Fingers crossed on that last one.

Let's weigh in how Grandevo actually does, folks. I'll definitely expect reports on its use for SWD. Keep in mind that as promising as all this seems, I've never heard anyone speak to its use as yet.

Lost Nation Orchard
Zone 4b in New Hampshire
Re: Grandevo
June 18, 2017 09:10PM
Ordering now, will report. Rookie question: the application rate is 1-3 lbs per acre. But it's saying that assumes 100 gallons of liquid? 100 gallons of liquid per acre on berries seems very excessive. How am I understanding this wrong. If if scale down the 1-3 lbs per 100 gallons of water to volume that gets the canes in an acre just to the point of runoff, I will be putting less Grandevo on the crop than 1-3 lbs.

Second question: should I be concerned with pest immunity build-up? If so, what to do about it?

Roan Highlands Farm 6b, Roan Mountain, TN elevation: 3200 ft.
Re: Grandevo
June 19, 2017 07:21AM
The amount of water needed to fully wet a crop-acre can be 50 gallons, 100 gallons . . . or it can be the 300 gallons long assumed necessary for standard-size trees. You know what you need for what crop, thus the given rate is provided in terms of so many pounds per acre. I approach this from having a 100-gallon spray tank, and often, but not always, that's sufficient to wet the "average tree acre" here in my orchard. Grandevo offers a significant range when it states 1# to 3# per acre. I chose the low end to start in part because I had another active ingredient in this tank mix in spinosad. We absolutely need to rotate materials to lessen the odds of building up pest resistance. The limitations on the Entrust label make that very clear. That's done by Mixing Things Up which could easily be a thread in its own right. Let's keep this one for Grandevo and field results thereof.

Lost Nation Orchard
Zone 4b in New Hampshire
Re: Grandevo
June 22, 2017 02:17AM
I don't have personal experience with Grandevo, but I was just last week speaking with another local organic apple grower and he said he had recently used it. I thought he said he was trying to control aphids with it because we are having a bad aphid year, but we were also talking about leaf rollers so it might have been for that. He was unimpressed with it.

I have never heard of it for SWD. We sprayed our blueberries for the first time ever today (in five years) after finding the first larvae. We use the Naturalyte GF 120 which is the spinosad bait. It has no pre-harvest interval and just needs to be applied at a spritz per plant as an attractant rather than full coverage. However we need to keep doing it twice a week. The threat is so bad that I would be very reluctant to switch to Grandevo without a strong firsthand recommendation from someone who used it. Luckily we only have two weeks of harvest left out of six week cropping.

Fruitilicious Farm
Zone 9b in California
Re: Grandevo
September 10, 2017 08:06PM
Reporting back on the early summer berry harvest. The way I sprayed, I saw no noticeable reduction in SWD population. However, I did wait until pressure was high before spraying. I should have done two initial sprays two days apart to knock down the numbers initially. Take away: Grandevo isn't a miracle worker. Because of it's relatively low cost, next year I will probably spray every 6 days starting a week before harvest. Spray costs are really hurting my berry profitability. I'm tempted to plant it out in apples just to not have to deal with SWD.

Edited 1 time(s). Last edit at 09/10/2017 08:10PM by Ethan Gouge.
Re: Grandevo
September 17, 2017 01:16PM
I spray spinosad (Entrust) and SWD seemingly goes away overnight. That was 12 days ago, and now as numbers start to swell anew in these warm days, I played the Grandevo card two days ago. There's impact but more on the order of 70%. I'm especially judging this by the compost pile where pomace from pressing cider draws SWD. Yes, I address the compost vector too, spraying not so much the entire pile (subsequently covered with chicken bedding) but rather the edges and the containing logs where the fruit flies seem to like to hang out. There were still flies in the fall raspberry patch when picking this morning but not overwhelming hoards. The good news is there's a biological to rotate with spinosad even if it's not as effective. And it may be that Grandevo works more slowly, over several days time as more flies come into contact with treated surfaces.

Earlier use of Grandevo for scale doesn't appear to have worked, however, but then I need to learn the timing of this (new to me) pest in older trees. I'm amazed to see individual scales actually embedded on the skin of MacIntosh apples as I thought this to be entirely a bark-oriented issue.

Lost Nation Orchard
Zone 4b in New Hampshire

Edited 1 time(s). Last edit at 09/18/2017 09:47AM by Michael Phillips.
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