Last year my cukes succumbed to cucurbit bacterial wilt, although thankfully not before producing a lot of fruit. This year I planted cukes in another garden and have been dutifully going out 1-2x per day to knock cuke beetles off my plants (which I understand carry the bacteria that causes wilt). Unfortunately, the wilt started earlier this year and despite my efforts I may not get any cukes. :(
My question is, how do you deal with bacterial wilt? Rotation? Killing beetles? Do you know of any resistant strains? I grow organic so synthetic pesticides are out, but if there is something organic that kills beetles I'd be willing to try! :)
Thanks
pam
How do you deal with cucurbit wilt???? (X posted)
I've never seen a variety resistant to wilt. I'd sure snap it up if I did!
The problem with killing the beetles is saving the bees at the same time. No bees, no cukes.
Yeah, that's why I go out with my little cup of soapy water and knock beetles into it. Save the bees! :)
What I do is pull off the spent flowers in the evening, after the bees have gone to bed. The beetles seem particularly attracted to the flowers, especially the big squash flowers. There are usually some beetles in them, and I dump them into a bag and spray them.
Of all the vegetable crops I raise, it is the cucurbits [cucumbers, squash, cantaloupe, and watermelons ] that give the fits against disease!!!....wilts.
I used beneficial nematodes this year for the first time. I was impressed with the way they controlled spotted cucumber beetles(which by the way like more than cucurbits and damage roots of corn and other crops). I have rows and rows of squash, cukes and melons with very few spotted beetles and no wilt.
I had the best luck with BNs by wetting the entire garden, spraying the BNs then washing them off the plants and into the soil. The ones applied early, just at planting time or when the seedlings were first up gave the best control. They were great for cutworms too.
The stripers in my garden gnaw the corn silks down to the nub - leaving me with empty cobs. If nematodes will gnaw on them, I'll be very happy! They are by far my worst pest.
I haven't seen the striped cucumber beetles, but if they spend part of their life underground, the nematodes will kill them.
Around here it seems like those corn root worm beetles can swarm in from perhaps the fields by the hundreds. For corn silks...If you are not against spraying a whiff of sevin liquid on the new silks before they are eaten, it will work well against those critters eating the silks. Last year I didn't have any problem with silks through 6 plantings of sweet corn and wasn't watching closely on the last two plantings. Yep, the beetles pretty well ruined the silks on the 7th and were eating the leaves up on the 3 foot high 8th planting...their favorite stage when of leaf eating. Later the leaves are too mature.
When the silks are eaten too badly, many grains do not fill out and the ones that do tend to be over-sized and starchy and you just cannot get the silks off the ear either.
I have sprayed Surround [kaolin clay] on my squash and pumpkins. I have not had zucchini last this long for several years.!!!
This is one reason I keep trying for the earliest possible corn, because of the beetles getting the late corn.
It seems that nature is determined to a share in the garden bounty!
I've read that several drops of mineral oil applied to the silks repels everything that normally attacks the corn ears. Never tried it myself.
I ONLY plant parthenocarpic cukes...those self-fertilizing ones... so I can cover them when I plant them with a light weight synthetic row cover. The row cover protects them from beetles all summer and I have great cuke production. The cuke variety I like best under the row covers is Diva.
I think that the mineral oil is helpful to stop earworms.......after pollination. I doubt a few drops would stop beetles from eating the silks when they first appear.
Some of the wilt problems [including the dreaded mature vine decline] likely come from soil fungi. Bugs? They can be dealt with perhaps, but soil disease is something else. Rotation?....if you have 10 acres of wonderful soil.
Therealapplefan, I have Diva but haven't planted it yet. Now I can't wait to try it.
Indy, I guess for soil fungi one could do soil sterilization with plastic if there is time. Some of the farmers in our co-op use corn oil for corn ear worms and Indy is right, you have to wait till fertilization occurs to apply it.
I have a question about corn worms. When the plantings were about 2-3 ft tall, small grey or black caterpillars were eating the leaves. Where those corn root weevils? Bt stopped them. I had to spray twice.
catalily,
I never have heard of corn root [worm?] weevils. I think that they are only beetles. The corn root worm beetles emerge from the soil just like cucumber beetles and are simular is size and habits. The crwbs are darker in color on top than cuke beetles. Spotted cucumber beetles are southern early in the season and drift northward on the wind.
As far as solarization goes, it ruins a season up north and only sterilizes a few inches deep.....plus you have all that plastic to buy and dispose of........it breaks down quickly in the heat if highly transparent and doesn't cook hot enough if thicker and more durable in my opinion.
I think the oil treatment is meant to control the corn =earworm= another silk-chewing pest.
Here is a WONDERFUL site that tracks the appearance and level of several pests of sweet corn.
http://www.pestwatch.psu.edu/sweetcorn/tool/tool.html