|
[IBC] nematodes
Someone mentioned nematodes, so I thought I would talk about them. I
once had to spend a few days cutting the rear ends off nematodes and staring at them, and never once has nematode anal wrinkles come up at a cocktail party I've attended. I have to use this information *somehow*. Nematodes are roundworms, not related to earthworms. There are millions of them in each handfull of soil. Most are scavengers. A very few genera are plant pathogens. They are divided into 4 main categories: root knot nematodes, cyst nematodes, sting nematodes and foliar nematodes. Root knot nematodes make nodules on roots, and they disrupt water transport in the root system, as well as stunting roots. Cyst nematodes and sting nematodes feed on roots, causing stunting and "unthriftiness", but are often a problem by transmitting viruses, or, by creating wounds, allowing access to root rot fungi. Foliar nematodes are not well-studied, but they live in leaf tissue, and can injure plants if they are present in significant numbers. Nematodes are difficult to eradicate, and nematicides are usually very toxic. The best treatments are those that are safe, and which keep nematode populations low enough to avoid major damage. Potato growers plant marigolds, which exude compounds that nematodes don't like. Crop rotation works with nematodes that are crop-specific. In warm regions, like much of Israel, soil solarization can be used to kill nematodes. For bonsai, root knot nematodes are the biggest threat, since they have a broad host range and repotting the plant won't fix the problem (the female nematode is embedded in the gall). The best option is to prune roots to remove as many galls as possible, and then repot in clean media. There are parasitic fungi that kill nematodes, and use of such biocontrol agents will reduce the number of juvenile nematodes. -- Nina Shishkoff Riverhead, NY ************************************************** ****************************** ++++Sponsored, in part, by Evergreen Gardenworks++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
[IBC] nematodes
Thank you Nina for all that information. Ican't wait until the subject
of nematodes comes up at the many coctail parties I attend! ;-) I Hope I have had a few glasses of wines, so I can do justice to your description. :-[ Carl L. Rosner Nina Shishkoff wrote: Someone mentioned nematodes, so I thought I would talk about them. I once had to spend a few days cutting the rear ends off nematodes and staring at them, and never once has nematode anal wrinkles come up at a cocktail party I've attended. I have to use this information *somehow*. Nematodes are roundworms, not related to earthworms. There are millions of them in each handfull of soil. Most are scavengers. A very few genera are plant pathogens. They are divided into 4 main categories: root knot nematodes, cyst nematodes, sting nematodes and foliar nematodes. Root knot nematodes make nodules on roots, and they disrupt water transport in the root system, as well as stunting roots. Cyst nematodes and sting nematodes feed on roots, causing stunting and "unthriftiness", but are often a problem by transmitting viruses, or, by creating wounds, allowing access to root rot fungi. Foliar nematodes are not well-studied, but they live in leaf tissue, and can injure plants if they are present in significant numbers. Nematodes are difficult to eradicate, and nematicides are usually very toxic. The best treatments are those that are safe, and which keep nematode populations low enough to avoid major damage. Potato growers plant marigolds, which exude compounds that nematodes don't like. Crop rotation works with nematodes that are crop-specific. In warm regions, like much of Israel, soil solarization can be used to kill nematodes. For bonsai, root knot nematodes are the biggest threat, since they have a broad host range and repotting the plant won't fix the problem (the female nematode is embedded in the gall). The best option is to prune roots to remove as many galls as possible, and then repot in clean media. There are parasitic fungi that kill nematodes, and use of such biocontrol agents will reduce the number of juvenile nematodes. -- Nina Shishkoff Riverhead, NY ************************************************** ****************************** ++++Sponsored, in part, by Evergreen Gardenworks++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
[IBC] nematodes
Hi Nina: I believe Methyl Bromide was used for 50 years as a control tactic--a lethal control tactic. You said it! It's being phased out because of the danger, but none of the safer alternatives are as effective. Today, dried sesame plant(marketed as Nematrol)is used. I have found it to be effective in dealing with Root knot nematodes, which at one time threatened my specimen Elaeagnus. I've heard of it, but we haven't tested it at the lab. We've tried marigolds (they sure were pretty! But they didn't work too well) and mustards as green manures (not as effective as we would have liked). -- Nina Shishkoff Riverhead, NY ************************************************** ****************************** ++++Sponsored, in part, by Evergreen Gardenworks++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
[IBC] nematodes
In a message dated 3/7/2003 3:04:25 PM Eastern Standard Time, writes:
I've heard of it, but we haven't tested it at the lab. We've tried marigolds (they sure were pretty! But they didn't work too well) and mustards as green manures (not as effective as we would have liked). Nina: I also understand that adding egg shells promotes the introduction of organisms that eat the nematodes. To this day, I cannot believe that my Gumi survived the ordeal. Cordially, Michael Persiano members.aol.com/iasnob/index.html ************************************************** ****************************** ++++Sponsored, in part, by Evergreen Gardenworks++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
[IBC] nematodes
I've heard of it, but we haven't tested it at the lab. We've tried marigolds (they sure were pretty! But they didn't work too well) and mustards as green manures (not as effective as we would have liked). From everything that I have been able to determine -- from reading and a little bit of trial and error down here in bug/nematode/and fungus heaven -- few, if any, of those companion-plant-as-pesticide-repellant stories are more than old wives' tales. Just because marigolds smell odd . . . Jim Lewis - - Tallahassee, FL - "People, when Columbus discovered this country, it was plum full of nuts and berries. And I'm right here to tell you the berries are just about all gone." -- Uncle Dave Macon, old-time musician ************************************************** ****************************** ++++Sponsored, in part, by Evergreen Gardenworks++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
[IBC] nematodes
From everything that I have been able to determine -- from reading and a little bit of trial and error down here in bug/nematode/and fungus heaven -- few, if any, of those companion-plant-as-pesticide-repellant stories are more than old wives' tales. Just because marigolds smell odd . . . It's funny- if you examine a nematode on a microscope slide, it dies within seconds. But in its natural habitat, the air/water/soil microcosm, it is very tough. Anyway, as I'm always telling you guys, first thing you do when you get a new plant, you check the roots so you know what healthy roots look like (assuming you bought a healthy plant, of course). Then you'll know when something changes- a root rot, a nematode infection, etc. If you see galls, be aware that some plants have nitrogen-fixing nodules (famously, legumes). Also, galls can be caused by root aphids (especially on crabapple!), or the crown-gall bacterium. If you see galls, you should take the plant to your Cooperative Extension Office for diagnosis. -- Nina Shishkoff Riverhead, NY ************************************************** ****************************** ++++Sponsored, in part, by Evergreen Gardenworks++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
[IBC] nematodes
Nina really caught my attention with this one. I've been seeing root
aphids and galls on a few crab apple seedlings. Others nearby are unaffected. The same infected ones seem to develop swellings on twigs and even trunks in places. Later in the season, these swellings get concentrations of woolly aphids. Are these aphids returning to attack a favoured spot on the trunks/twigs or emerging from the swellings? Could they overwinter inside the young unbroken bark or twig? Kev Bailey It's funny- if you examine a nematode on a microscope slide, it dies within seconds. But in its natural habitat, the air/water/soil microcosm, it is very tough. Anyway, as I'm always telling you guys, first thing you do when you get a new plant, you check the roots so you know what healthy roots look like (assuming you bought a healthy plant, of course). Then you'll know when something changes- a root rot, a nematode infection, etc. If you see galls, be aware that some plants have nitrogen-fixing nodules (famously, legumes). Also, galls can be caused by root aphids (especially on crabapple!), or the crown-gall bacterium. If you see galls, you should take the plant to your Cooperative Extension Office for diagnosis. -- Nina Shishkoff Riverhead, NY --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.459 / Virus Database: 258 - Release Date: 25/02/2003 ************************************************** ****************************** ++++Sponsored, in part, by Evergreen Gardenworks++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
[IBC] nematodes
Michael Persiano wrote:
I also understand that adding egg shells promotes the introduction of organisms that eat the nematodes. Specifically, organisms that "eat" the chitin in the nematode's egg shells. Looking around for evidence, tho, it seems more appropriate to compost crab or shrimp shells, which contain larger amounts of chitin, rather than hen's eggs which are almost entirely calcium carbonate. Those of us who use homemade compost in our bonsai soils might take note... Basically, sounds to me like an excuse to have a crab-boil every week! :) Anita Northern Harford County, Maryland, USDA zone 6 ************************************************** ****************************** ++++Sponsored, in part, by Evergreen Gardenworks++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
[IBC] nematodes
Nina Shishkoff wrote:
...I once had to spend a few days cutting the rear ends off nematodes and staring at them, and never once has nematode anal wrinkles come up at a cocktail party I've attended. Dearest Dr. Nina - you just need to try harder! Perhaps if you start the conversation out in the direction of Botox injections for facial wrinkles, a "hot" topic lately. Then with great subtlety and finesse, mention the extreme difficulty of injecting tiny wrinkles such as might be found, say, on the anus of a nematode. Then you're off and running! Out the door, perhaps ;) from Anita, who's not planning on hosting anything more formal than a barbeque in the pasture when Nina moves to Maryland! Y'all are invited.... ************************************************** ****************************** ++++Sponsored, in part, by Evergreen Gardenworks++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
[IBC] nematodes
Nina Shishkoff wrote:
If you see galls, be aware that some plants have nitrogen-fixing nodules (famously, legumes). And since Michael brought up the subject of Elaeagnus (Russian-olive, autumn-olive and related species), keep in mind that it is one of the plants with those nodules... i.e. if you repot your Elaeagnus (darn! it never looks right, no matter how I spell it...) DON"T PANIC at the sight of nodules on the roots. They are *normal* for the genus. If your E. looks unhealthy, consider nematodes as a distant possibility, but look to other causes first. And nematrol (sesame plant) at least will do no harm, to either you or the plant, Not something you can say of methyl bromide. Anita ************************************************** ****************************** ++++Sponsored, in part, by Evergreen Gardenworks++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
| All times are GMT +1. The time now is 11:21 AM. |
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
GardenBanter