BTk - for cole crops

[JRinPA]

BTk for caterpillars and such. I looked around last year while out shopping and never found anything. Looking on the internet, I have no idea what is good or bad or diluted or whatever.

If anyone has used some and thought it was the good stuff and a good deal, please post or PM some links. I have a lot of garden to try to protect so a little bottle might not go far. I could rig a 1 gallon sprayer up for it if needed. I have tried to stay very far from pesticides or herbicides, so I don't have a big vocabulary for this stuff.


Another thing I have problems with is harlequin bugs in the fall. The orange and black things, get on radishes, broccoli. But I don't think BTk will touch them? I have used DE in the spring, good against flea beetles and cucumber beetles, but never tried it in the fall.

[Setec Astronomy]

Last bottle I bought was Safer Brand (they call it Caterpillar Killer), they have it at Amazon, and Home Depot has Monterey, another brand. A little cheaper at Amazon, the 16oz bottle will make 32 gallons of spray.

BT is really safe and works really well and fast. The Harlequin Bugs look a little tougher; since I like to stay with organic pesticides, Arbico Organics is a good resource, you can search by pest there, they show a few things for Harlequin Bugs, neem oil (I personally don't like the smell of this), insecticidal soap, and kaolin clay, also pyrethrins, which although OMRI-listed are a little nastier...I don't remember using a pyrethrin spray, maybe in the old days.

[bower]

My Dad used the Safers brand as well, back in the day. They are reputable afaik.
BTk will only work on caterpillars. Doesn't affect flies or bugs or beetles or anything else. Just your moths and butterflies.

Re Harlequin Bug - your preying mantis should eat those if you attract them to the area.
Minute Pirate Bugs also are said to eat the Harlequin Bug's eggs, which is a nice way to clean them up.

My grains last year attracted some bugs that eat them, but they also attracted a ton of Nabis type bugs, which eat them.
So far the score is 99 for the damsel bugs, 1 for some little grain worm.
Damsel bugs habitat is grasses of any kind I guess, the grains were fantastic habitat for them and they multiplied like mad.
So I think the right patch of stuff can attract the good guys.

[JRinPA]

That Safer Brand does not specifically mention diamond back moth, but I expect it will kill them too. I get those worms, striped and with thread, along with the two cabbage worms. Sounds like a good fit, I'm gonna order some. Will try it for the SVB too.

EDIT
Also, on application, does everyone just use water? Or do you add molasses or anything for stickiness? Can you add this to VCT or AVCT? Been a while, but I used to do vermicompost tea with an aerator, still could, just seems like most of my stuff grows pretty well now without it.

[Setec Astronomy]

I don't think a sticker is required for BT.

[GoDawgs]

I use Bonide's Thuricide. BTk listed as active ingredient.. Under Additional Product Information it does list diamondback moth. I've used it a long time as my feed and seed carries it. An 8oz bottle of concentrate lasts a looooong time.It has worked well for me as have other products where bTk is the active ingredient.

https://bonide.com/product/thuricide-liquid-conc/

[worth1]

I Googled BTK and it sent me to the serial killer.

[JRinPA]

Yeah how bout it worth. I was expecting it, though I forgot he was caught. I was thinking BTK was one of the killers that was presumed dead. They always want to make the evil ones famous. I had to add "Safer Brand" BTk to filter past that trash, it was deep.

I always think BT as BTi, mosquito dunks, so that is why I specified BTk.

So with the Safer Brand BTk, now that I had a baseline product to look at, I saw a half dozen or so that all have 98.35% active ingredient. Some of them said to mix with...I think small amount of oil, small amount of soap per gallon. One of them said to use the mixed product within 24 hrs. And then there are some other BTk products that are at 15% with garden hose hook up on the top of the can. And everything I found that has an origin listed says China.

Of course I went with cheapest 98.35% pint (1 TBSP per gallon/ makes 32 gallons) with I think was Garden Way. The label said satisfaction guaranteed, proof of purchase /receipt and complaint gets you a refund. I always appreciate seeing that right on the package. Not "return the product for a full refund". Tractor Supply carries this as well, but it was not in stock around here.

Reading about the expected results, I'm rather mad at myself for not getting some of this 5 years ago. It sounds like I should be able to go brussels sprouts to fruition for once.

After ordering I fell into a rabbit hole reading about slug bait/ slug killer, seems to be 3 types there but the old effective stuff is bad for dogs, and the next two types might be also...I had to give up. I'll follow up on that another time.

[JRinPA]

Has anyone tried BTk for onions/garlic to try to prevent Allium Leaf Miner?

I don't see it mentioned, and I have read some pages on ALM that say nothing works except tunnels. But there is also some info out that says ALM don't affect garlic, just onions, which I know to be absolutely false. Unfortunately.

[Whwoz]

It would definitely be worth a try @JRinPA. Not sure if BTk is the right strain to use or not, may need to chase up one of the other named BT strains.

[Tormahto]

BTk for caterpillars and such. I looked around last year while out shopping and never found anything. Looking on the internet, I have no idea what is good or bad or diluted or whatever.

If anyone has used some and thought it was the good stuff and a good deal, please post or PM some links. I have a lot of garden to try to protect so a little bottle might not go far. I could rig a 1 gallon sprayer up for it if needed. I have tried to stay very far from pesticides or herbicides, so I don't have a big vocabulary for this stuff.


Another thing I have problems with is harlequin bugs in the fall. The orange and black things, get on radishes, broccoli. But I don't think BTk will touch them? I have used DE in the spring, good against flea beetles and cucumber beetles, but never tried it in the fall.

Would the 1 gallon sprayer be hooked up to a hose?

[JRinPA]

No, I meant a pump up sprayer.
There are some hose ready products that replace the hose nozzle. It looks like they contain about a 15% concentration, but I they are only a quart or so container, not a gallon.

[bower]

Is Allium leaf miner a moth or a fly? BTi would be the one for a fly.
But leaf miners are tricky. Once the larvae are inside the leaf your spray wouldn't reach them, afaik.
In order for the BT products to work, they have to contact the larvae I think.
I am not 100% sure about that, but I remember with the fungus gnats, it was said to be especially effective on one larval stage, so the key was to get it on those. I could not follow their timing instructions (too complicated!) but drenching the soil before they showed up really worked.
Maybe applying it early would help, if it doesn't wash off in the rain....

[Setec Astronomy]

BT works against the larval stage, so in the case of the leafminer, the larva would have to eat a sprayed surface. Arbico only shows a broad leafminer category and nothing specific for the Allium leaf miner, but they don't seem to show BT as a treatment.

As far as the fungus gnats, I presume that the larva eat something in the soil, so if it's got the BT on it, it should get them. I haven't had any fungus gnat problems since I started sprinkling Mosquito Bits on the tops of my planters periodically.

Oh, and I found this: https://extension.psu.edu/preventing-al ... d%20onions.

[bower]

One thing to remember is, the BT is a living product. It's an inoculum just like your mycos etc. The Bacillus thuringensis I believe is a soil dweller anyway, so it is able to live in the soil if conditions suit, once applied it should be able to dwell there for awhile thus retaining effects on emerging gnats.

Yep just googled, described as
"widespread endospore-forming bacteria with a complex life cycle, which has been commonly found in soil, water, plants, stored cereals and dead insects. " "....some studies have demonstrated that, as long as the Bt metabolic requirements are met, this bacterium grows vegetatively in a variety of environments, such as soil, leaf surfaces and other internal plant tissues, although this growth occurs in much lower levels when compared with that inside insect cadavers "...."under specific conditions, Bt spores can germinate and grow well, such as in humid, nutrient-rich soils, with pH near neutrality, even in the presence of other microbial populations."
"..there are some evidences indicating Bt as a poor leaves colonizer, being found mostly as spores in these habitats. Even with nutritionally rich leaf surface that leads to spore germination, vegetative Bt cells sporulates again after a few rounds of division, which confers a survival ability for long periods, even under stressing conditions, such as desiccation [42]. Despite serving as nutrient sources, leaf exudates can also affect Bt survival negatively; for instance, organic acids that decrease surface pH can increase mortality rates of Bt in this environment [18,46]. Because Bt demonstrates a better survival and persistence in soil than in leaves, these have been suggested to work as a secondary reservoire that aid in the recycling process of the bacterium by returning cells and spores to the soil through rain, falling leaves, feces from phytophagous and dead insects bodies.."
Prolly worth reading if you're going to use the stuff:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592628/

On a first glance, I would hazard that your vermicompost is probably close to ideal as a medium for dispersing/sticking Btk onto brassica leaves. They like it rich, but pH neutral. Even better if you throw some dead insects in the brew. Or wait until you see caterpillars then spray em gently so they just lay dead upon brassica leaf, as a host for the Bt to protect from the next wave.
But apparently you could just as well apply it to your seedlings and let them be colonized by Bt as an endophyte. Wow!
"the efficient Bt colonization of cabbage seedlings roots suggests this might be in fact the main route of its penetration in the plant. After this event, vegetative cells, spores and crystals were found in several parts of the seedlings, which characterized a complete Bt colonization.."

[JRinPA]

15.JPG

...I thought thuricide sounded familiar. Been seeing that name for years, everytime I go in the comm garden shed.

I suppose that stuff is dead, since it has been outside for years and has a cracked corner from freeze/thaw.

[Whwoz]

Maybe not completely @JRinPA, you may still find it effective if you mix at double strength. Cannot tell what strain of BT is used, but a lot rely on a parasporal crystal for there toxicity, these do not degrade very fast and neither do the spores under the storage conditions in the bottle. Freezing is how we microbiologists keep bacteria alive for extended periods. Definitely worth a trial.

15.JPG
...I thought thuricide sounded familiar. Been seeing that name for years, everytime I go in the comm garden shed.

I suppose that stuff is dead, since it has been outside for years and has a cracked corner from freeze/thaw.