En Español

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Tuesday - January 02, 2007

From: Leander, TX
Region: Southwest
Topic: Propagation
Title: Rhizobium inoculant for Leucaena and othr leguminous tree seedlings
Answered by: Nan Hampton and Joe Marcus

QUESTION:

What sort of Rhizobium inoculant would be appropriate for Leucaena and other leguminous tree seedlings?

ANSWER:

It is correct that legumes such as White Leadtree (Leucaena leucocephala) and, as another example, bluebonnets, require Rhizobium bacteria to enable them to fix atmospheric nitrogen for use by the plant. Furthermore, there are different strains of Rhizobium and the strains that are effective for bluebonnets are not necessarily effective for Leucaena. The Rhizobium strains are species specific. It is possible that the proper strain of Rhizobium is present in your soil already. You can check this by looking at the roots of your Leucaena. If there are nodules present, then it already has the correct Rhizobium species. If you have access to mature Leucaena plants, you can simply harvest some soil from around the roots of them and inoculate your seedlings' soil with some of it. It would only take a very small amount per pot. You could mix a handful or two of native soil into a pile of potting soil and that should do the trick—nothing fancy; the roots and the Rhizobium will find one another.

Research in Australia has cited two strains of Rhizobium that are effective with Luecaena. In acid soils Strain CB3060 (TAL1145) was most effective in N2 fixation. This is cited in Tolerance of Leucaena to Acid Soil Conditions by F.P.C.Blarney and E. M. Hutton, p.84. In the article "Establishment and Early Growth of Leucaena" C. M. Piggin et al., p. 87, report strain CB81 was found reliable and strain NGR8 less reliable. They also report (p. 88) CB3060 (TAL1145) is good in acidic soils as well as more neutral soils.

Unfortunately, there are few sources for obtaining Rhizobium cultures. I did find one source, Becker Underwood in Australia with worldwide production and marketing, for purchase of CB3060. The USDA has a Rhizobium Germplasm Collection that provides free cultures for research but they do not have a database of strains available. You can see a list of other bacterial culture collections worldwide.

For a good discussion of seed treatment and nitrogen fixation see Agroforestry for the Pacific Technologies from the U. S. Forest Service and also Nitrogen Fixing Tree Start-up Guide from Agroforestry.com.

You can also check with the Williamson County Extension Office of the Texas Agricultural Extension Service and see if they know of the availability of Rhizobium strains.

 

More Propagation Questions

Why is my Horstail falling over in Austin?
October 14, 2010 - I have a Horsetail plant. It was doing great but now, for the last few months, its not growing straight! Its falling over. Why?
view the full question and answer

Breaking dormancy of native seeds
November 22, 2006 - The science of seed preservation seems to be well advanced. However, Jill Nokes' book appears to be the only well-known information about breaking dormancy of native seeds. I'm grateful that she w...
view the full question and answer

Will sprouts under pecan trees become producing trees in Jefferson Co., AL?
May 30, 2009 - Do pecan trees that sprout up underneath existing pecans trees ever amount to anything such as producing and bearing pecans?
view the full question and answer

Propagation by seed of Texas Mountain Laurel
September 20, 2008 - I just harvested a grocery bag full of Texas Mountain Laurel seed pods. I want to cast them out in a field and wooded area near NW Austin. Is it best to leave the seeds in the pods or remove the pod...
view the full question and answer

Source of dollarweed for shady lawn in Hillsboro TX
December 19, 2011 - I live in Hillsboro,Tx - Where can I get Dollar Weed for my shady lawn?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center