I've seen some examples of this in my 110 lately, and I'm wondering if others see the same. I have jungle val along the back wall of my tank, and sometimes they like to send up runners in the middle of my bunches of stem plants. When they do, I see the bottoms of the stems start to die off. As soon as I move the jungle val shoots, The dieoff seems to stop. I'm wondering if the val's leech some sort of chemical into the soil, of if their rapid growth takes up all the nutrients in the tank. Has anyone else seen this?
Do Jungle val shoots poison other plants?
- Thread starter gt1009
- Start date
If its just the bottom leaves, the leaves are most likely not getting enough lights and the vals are blocking even.more light.
Yellowing bottom leaves is sometimes a Nitrogen deficiency. Your other stem plants could be showing this because the rapidly growing val out competes the stem plant for nutrients. It could also just be a light issue as mentioned.
my knee-jerk reaction was to suspect light personally. i have val spiralis and crypt wendtii (a combo notorious for not working together and sometimes rumored/suspected to show signs of allelochemicals) in the same tank with no signs of such activity afaik.
so, i checked around before just posting to see what i could find.
according to tropica (on their val page) the allelochemical reaction rumored between crypts and vals is a myth... but that says nothing about stem plants.
after that i hit google scholar... and found a good amount of papers/studies where allelopathic chemicals were mentioned/assumed due to observations. however, nothing suggesting the presence of the chemicals has shown conclusive evidence, thus far (obviously i didn't read everything already).
if i had to choose who to believe, i'd certainly have to go with an industry leader in the science of "aquatic" plants... tropica. however, there certainly seems to be plenty of reports/results to suggest it's possible.
no human ideal is set in stone.
if i were looking for a cure to your issue i would certainly look toward more light and/or nutrients.
so, i checked around before just posting to see what i could find.
according to tropica (on their val page) the allelochemical reaction rumored between crypts and vals is a myth... but that says nothing about stem plants.
after that i hit google scholar... and found a good amount of papers/studies where allelopathic chemicals were mentioned/assumed due to observations. however, nothing suggesting the presence of the chemicals has shown conclusive evidence, thus far (obviously i didn't read everything already).
if i had to choose who to believe, i'd certainly have to go with an industry leader in the science of "aquatic" plants... tropica. however, there certainly seems to be plenty of reports/results to suggest it's possible.
no human ideal is set in stone.
if i were looking for a cure to your issue i would certainly look toward more light and/or nutrients.
Allelopathy is baloney, even the research has many problems demonstrating it.
Aquarist will have far more issues even coming remotely close.
Someone gets some idea, and without any good research showing it occurs(it's tough to show even in terrestrial systems, let alone aquatic systems where the chemicals are immediately washed away) then like a myth fire......it spreads all over the web cause it "feels good".
Sonofagun.......myths are hard to kill. Much harder than plants.
One of the main problems is how to separate resource competition from allelopathy. To date, not one person other than perhaps myself has tried that in planted aquariums. I've suggested some controls etc.......so we can separate the two issues....but it supposes aquarist have the ability to prevent any confounding effects of resource competition (light, CO2 and nutrients) and can then solely look at allelopathy in and of itself.
Few aquarist seem to have that ability, all we can do is have examples that falsify the suspect hypothesis that Vals are alleopathic to other plants.
I've had them a lot over the years, and never noted any thing that could be considered allelopathy in any plant, nor has anyone else that had any suspected plant combo with some 300 or so species.
When plants grow, they start to consume more and more nutrients/light/CO2..........CO2 alone is difficult to measure and confirm. Unless these are non limiting in your test, they will confound any results.
Thus it becomes very hard to conclude anything.
Folks that have good examples where both plants are growing..falsify the hypothesis, so it must be rejected and you need to look for an alternative reason/hypothesis to test/falsify next. So back to nutrients/CO2/light more than likely, your test was likely confounded there.
About once every 3-6 months, some one brings up this claim/hypothesis.
Regards,
Tom Barr
Aquarist will have far more issues even coming remotely close.
Someone gets some idea, and without any good research showing it occurs(it's tough to show even in terrestrial systems, let alone aquatic systems where the chemicals are immediately washed away) then like a myth fire......it spreads all over the web cause it "feels good".
Sonofagun.......myths are hard to kill. Much harder than plants.
One of the main problems is how to separate resource competition from allelopathy. To date, not one person other than perhaps myself has tried that in planted aquariums. I've suggested some controls etc.......so we can separate the two issues....but it supposes aquarist have the ability to prevent any confounding effects of resource competition (light, CO2 and nutrients) and can then solely look at allelopathy in and of itself.
Few aquarist seem to have that ability, all we can do is have examples that falsify the suspect hypothesis that Vals are alleopathic to other plants.
I've had them a lot over the years, and never noted any thing that could be considered allelopathy in any plant, nor has anyone else that had any suspected plant combo with some 300 or so species.
When plants grow, they start to consume more and more nutrients/light/CO2..........CO2 alone is difficult to measure and confirm. Unless these are non limiting in your test, they will confound any results.
Thus it becomes very hard to conclude anything.
Folks that have good examples where both plants are growing..falsify the hypothesis, so it must be rejected and you need to look for an alternative reason/hypothesis to test/falsify next. So back to nutrients/CO2/light more than likely, your test was likely confounded there.
About once every 3-6 months, some one brings up this claim/hypothesis.
Regards,
Tom Barr
Nearly what I was going to say...
Walstad's (excellent) book mentions allelopathy (brief chapter on the subject, mostly explaining the theory) but indicates that the research has been tenuous at best and that if it exists, it will more likely be demonstrated in some lily species than in anything we're keeping in our tanks (if memory serves).
There is good research indicating that terrestrial plants practice allelopathy as well as other chemical trickery to claim space and put problem herbivorous insects off.
And unfortunately, folks often seldom read that part where she states that it is speculative.
She's clear, but folks gloss that part over and run around suggesting this.
No, not just the OP, but about once every 3-6 months, someone on some forum makes a ta-do about it. Folks really should focus more on growing plants, light/CO2 mostly, and adding enough nutrients.
It's much less problematic then.
Regards,
Tom Barr
Thanks for the info everyone,
I suspected resource competition myself, as I am currently having trouble keeping my nitrates over 5 ppm. I need to start dosing liquid ferts, but I've had a lot of expenses this month and won't have any spare cash for about 3 weeks. The reason I pretty much ruled out light was that I have a huge clump of Lloydiella (2 bunches) and some red ludwigia around the back and sides of the Lloydiella. In that bunch everything was going fine until a val shoot popped up. I didn't notice the shoot until it was about 3 or 4 inches tall, but all the plants around that had started dying. After I removed the shoot and replanted the Lloydiella, there have been no further issues with the plants dying. I'm a sophomore at the University of North Carolina Wilmington, one of the best marine biology schools on the east coast. I'm debating doing a more in depth study on this now that I see this controversy. If I end up doing something in my phycology class next semester I will let everyone know the results.
I suspected resource competition myself, as I am currently having trouble keeping my nitrates over 5 ppm. I need to start dosing liquid ferts, but I've had a lot of expenses this month and won't have any spare cash for about 3 weeks. The reason I pretty much ruled out light was that I have a huge clump of Lloydiella (2 bunches) and some red ludwigia around the back and sides of the Lloydiella. In that bunch everything was going fine until a val shoot popped up. I didn't notice the shoot until it was about 3 or 4 inches tall, but all the plants around that had started dying. After I removed the shoot and replanted the Lloydiella, there have been no further issues with the plants dying. I'm a sophomore at the University of North Carolina Wilmington, one of the best marine biology schools on the east coast. I'm debating doing a more in depth study on this now that I see this controversy. If I end up doing something in my phycology class next semester I will let everyone know the results.
Anytime someone makes a statement like this I just have to poke at them a little.
http://www.sciencedirect.com/scienc...b73ac21ac70e7d5a16e1ef254965bb6e&searchtype=a
http://www.apms.org/japm/vol26/v26p50.pdf
http://www.apms.org/japm/vol27/v27p84.pdf
http://www.springerlink.com/content/942247201200243t/
http://www.springerlink.com/content/g60v361365uq4l15/
http://books.google.com/books?hl=en...e&q=allelopathy Vallisneria americana&f=false
But your are right that the research is a little bit illogical because they generally use terrestrial plants to show allelopathy in aquatic species. However there is some pretty cool data about how Vals produce algeacides.
I've seen some pretty cool examples of allelopathy in my experience with terrestrial plants. The one that sticks out was a cucumber plot trial that was followed immediately by a winter wheat rotation. The next spring you could see exactly where the cucumbers where (rows and alleys!!). The wheat there was 1/2 the size and had a drastically reduced yield. None of the other cucurbits showed any effects.
Anytime someone makes a statement like this I just have to poke at them a little.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T4F-3VR11PT-2&_user=10&_coverDate=01%2F01%2F1999&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1553578750&_rerunOrigin=scholar.google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b73ac21ac70e7d5a16e1ef254965bb6e&searchtype=a