In article ,
says...
Sean Straw wrote:


Not all marigold varieties are effective against nematodes. French
Marigolds are more effective than Aftican Marigolds for instance.
You misstate the case. The books and gurus all _say_ that French dwarf
marigolds are repellent. Unfortunately they offer no demonstrations, much less
actual proof. I am aware of the conventional wisdom. I cut my teeth on Mother


https://startpage.com/eng/advanced-s...cat=web&query=

field: all the words

criteria: studies marigolds nematodes

Scroll down to "At this domain type"

select "edu"

click the search button.


I skimmed off the following articles.


http://horizon.documentation.ird.fr/...pleins_textes_
5/pt5/nemato/36417.pdf


http://www.norfolkbotanicalgarden.or...ticulture-news

Dutch researchers did cover crop studies looking at the effectiveness of
over 800 varieties of marigolds on nematode populations. The scientists
found that apparently nematodes are attracted to marigold roots but are
killed when they try to feed due to the release of ozone from the
damaged root. There are two caveats. One is that the effectiveness of
killing nematodes is only with living marigold roots, once the marigolds
have been tilled in, there is no further benefit. The second is that
these were not companion plantings because two crops were not
interplanted.

The conclusion of these Dutch studies is that when an entire area has
been covered with marigolds, cover crops reduced the numbers of the very
common root-lesion nematode (Pratylenchus penetrans) enough in one
growing season that other crops susceptible to that pest could be grown
for two or three years without suffering from nematode damage. The
French Marigold (Tagetes patula) was the most effective, with the
variety 'Single Gold' providing the greatest benefit with almost 99
percent control.

1/28/2010

http://www.ctahr.hawaii.edu/oc/freepubs/pdf/PD-35.pdf

http://www.ctahr.hawaii.edu/sustaina...g-marigold.pdf

http://www.aces.edu/pubs/docs/A/ANR-0856/