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Post by txdirtdog on Jul 20, 2011 0:07:50 GMT -5
Well, I have been using BT as an exterior stem/leaf spray this spring and summer trying to control the SVB. Earlier in the spring it seemed to be helping, but as temps heated up combined with our drought, I don't seem to be getting as much benefit. I think the bacterium is dying before the SVB larva are emerging and drilling the stem. I will continue using the BT, as we head into fall and temps and moisture conditions should improve.
I see that I need to add a step (and more likely a hop, skip and a jump too) to try to break the life cycle of this critter. clearing out mulches may be on my agenda this fall as well as a couple of other things.
But I've spent some time reading about beneficial nematodes and am intrigued. Apparently there are several types of bene. 'todes. One study I read done in NC indicated the variety Steinernema riobrave TX strain had the best results. Of course I can't find that one sold commercially. Steinernema feltiae SN and Steinernema carpocapsae All strain were the next most effective and these seem to be fairly commercially available.
I understand that the ground needs to be moist to wet before application and then needs to be watered again to move the 'todes down into the soil to affect the cocooned larva. This may be a bigger job than it sounds. I'm thinking I'm going to have to wait until November or even December to meet temp/moisture requirements.
My primary questions are: Has anyone here used bene. 'todes to control SVBs? What was your experience?
Unfortunately trying to time planting here is not an option. The SVB moths appeared in March and haven't stopped yet. I thought on 2 occasions the season was done only to be proven wrong. We are pretty much at the end of the window for 100 day types to be planted to beat potential frost. I may try row covers at some point, but to watch a fully mature vine go down with fruit after the vine has been growing three months tells me that probably will not help either.
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peppereater
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Posts: 39
Joined: December 2010
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Post by peppereater on Jul 20, 2011 17:39:42 GMT -5
my experience with beneficials, nematodes in particular, is that once a population is there, they remain there in numbers sufficient to give benfit (perhaps greater benefit) in the next generation, and subsequent generations as well. I've seen this with BT used on cedar for bagworms...I've seen it with grashoppers treated late in the prescribed timeframe with nosema locustae, semaspore. I've seen it evident with nematodes in the case of flea girdling nematodes in treating a yard against fleas, the horrible infestation that was consuming the dog and infiltrating the house was reduced to near 100% elimination through 2 applications in one summer, never again saw fleas on dog or in house again, period, over roughly a decade. Sometimes a population of a given species simply doesn't exist until an innoculation/interventios is innitiated, and the predatory species is allowed to become established. with nematodes, and many other microbial beneficials, the greatest benefit is realized the second year, and the impact carries over more strongly in the 2nd generation, gradually tapering off in year 3, 4...or until the environment no longer provides for a strong response from said agent. I have seen numerous posts concerning svb, although I don't recall details. Pulling and destroying infected plants, if I recall, post season is a major factor. Sanitary practices in general are helpful, using reflective strips of aluminum foil near the plants/blossoms, I believe I have read, confuses insect and deters egglaying. Planting time and variety can be important. Other than that, nothing comes to mind at the moment, I think there is some mention of applying oil manually to blossoms or growing tips, but I honestly can't recall...hunting down eggs on leaves of parent crops and destroying them is a common, low impact (on the garden and beneficials) practice, but this is an area I've not explored, I have enough to process as it is with my first love (gardenwise,) tomatoes. The rest is one big, not-so-important fog of partially digested info, but I will say this, anything biotic promoted as good probably is, see amideutsch (sp) and others who highly tout biotic approaches and products, I don't think you can go wrong, although aggressive measures like spraying (take your pick, organic or synthetic, I'm strictly organic and accept the consequences) have their place as well. svb are a bit of a problem even if resorting to massive chem approach, as things that lay eggs may not be exposed to spray, ever, and offspring hatch can occur after damage is already done, and eggs can lay concealed without obvious signs of their presence...if you don't get response to this query, start googling, svb issues are discussed with fair frequency online, if not here than elsewhere. (geez how these proboards would benefit from better search funtions features)
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peppereater
Junior Member
Posts: 39
Joined: December 2010
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Post by peppereater on Jul 20, 2011 17:49:59 GMT -5
oh, btw, BT is not effective against svb, as the larva, pupa, whatever stage is damaging, are eating inside the vine, not on areas BT can reach. And it is only effective if consumed, which it won't be. Insects which lay eggs, i.e., svb and the like, on host plants, are only killed during the feeding, catterpillar stage, i may be repeating myself...and larva inside a stem or other plant part aren't exposed to it. Nor are most pesticides aside from systemics. I know, this information only serves to raise more questions than provide answers, but that's gardening...
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Deleted
Posts: 0
Joined: January 1970
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Post by Deleted on Jul 20, 2011 21:50:31 GMT -5
If you find those "bene'todes" online I would sure like it if you posted where you found them in this thread.
If you find any other ways to subjugate the SVB i'd love to hear about it.
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peppereater
Junior Member
Posts: 39
Joined: December 2010
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Post by peppereater on Jul 22, 2011 11:01:07 GMT -5
bonsai, do a google search for "hydrogardens," they're a large company out of colorado springs that carries some beneficials, more than other sources I know of...drawing blanks on other sources, I'll try to post if I think of them.
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Post by txdirtdog on Jul 22, 2011 12:22:53 GMT -5
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