Yazdy ji I don't know much about Tamarindus but Juglans allelopathic effects I know even before I was a student of botany. Hardly any plant grows beneath or in the vicinity of Walnut tree. Juglans (both species J. nigra the black walnut of America and J. regia, the English walnut) leaves, bark, stem, fruit pericarp and roots contain a colourless non-toxic chemical hydrojuglone. When exposed to air or soil chemicals it is oxidized into highly toxic allelochemic compound juglone. Rain washes juglone from leaves and other parts and carries it into soil. It is toxic to both herbaceous and woody species. Just for additional information, bark of Juglans fresh or dried is used for cleaning teeth in the same way as Acacia twigs in many parts of North India (Datun). On exposure to air and convertion to juglone the gums get orange-red colour, and is especially used by ladies to both clean teeth and colour gums.
But then there are always plants which are resistant to juglone, and these can grow/can be planted adjacent to Juglans trees. Among trees the resistant species are various species of maple, Ailanthus glandulosa, Quince, Red cedar, Sweetgum, pine, oak and Black locust (we often find this Robinia pseudoacacia growing alongside Juglans in Kashmir). Among shrubs and climbers Roses, Grape vine, Hazelnut and Thuja are resistant. Several herbaceous plants like species of Brassica, Cichorium, Convolvulus, etc. also manage to grow. Not having first hand information but the plants growing or grown under Tamarind may similarly be resistant to Tamarind allelopathy. -- Dr. Gurcharan Singh Retired Associate Professor SGTB Khalsa College, University of Delhi, Delhi-110007 Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018. Phone: 011-25518297 Mob: 9810359089 http://people.du.ac.in/~singhg45/ On Tue, Oct 5, 2010 at 5:57 PM, Yazdy Palia <yazdypa...@gmail.com> wrote: > Sangeetha Ji, > Thank you for the enlightenment. You will observe that I have > mentioned that these are the observation of a lay person. For your > reference, I will send you the picture of the growth under my tamarind > tree a few hours later. Thank you once again. I would love to receive > the study that has been conducted on the subject. > Regards > Yazdy. > > On Tue, Oct 5, 2010 at 11:43 PM, Sangeetha <sangeeth.mall...@gmail.com> > wrote: > > Palia ji, > > > > Tamrind root exudates have allelopathic competence and are evaluated > > for sustainable weed management programs. > > The bark and the seeds have differential (inhibitory and excitatory) > > allelopathic effects. They have some growth regulators which > > additively or synergestically involve in plant specific expression. > > > > Regards, > > Sangeeth mallika > > > > On Oct 5, 10:20 pm, Yazdy Palia <yazdypa...@gmail.com> wrote: > >> Dr. Gurcharan Singh Ji, > >> I do not know about walnut tree and allelopathy. I have seen that > >> nothing grows under a tree where the shade is so thick that no > >> sunlight penetrates. I have seen someone claim that tamarind tree has > >> also the allelopathy effect. I can not agree to that as I have a > >> couple of them and we have coffee growing very well underneath it. I > >> had a very healthy pepper vine on them and also thick growth of weeds > >> growing under its shade. > >> It is worth observing the rainfall in the area where such observations > >> are made. Another point to be observed is are the walnut trees so > >> close to each other that no sunlight penetrates under the thick > >> canopy. > >> We have a few jack fruit trees so close to each other and no weeds > >> would grow underneath it in spite of very nice mulch and nice loamy > >> soil. Once we regulated the shade, we found lush growth underneath it. > >> This though is the observation of a lay person. > >> Regards > >> Yazdy. > >> > >> > >> > >> On Tue, Oct 5, 2010 at 12:45 AM, Gurcharan Singh <singh...@gmail.com> > wrote: > >> > Yes walnut is the commonest example of allelopathy I would tell my > students. > >> > Hardly any plant grows beneath it. > >> > >> > -- > >> > Dr. Gurcharan Singh > >> > Retired Associate Professor > >> > SGTB Khalsa College, University of Delhi, Delhi-110007 > >> > Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018. > >> > > Phone:011-25518297begin_of_the_skype_highlighting 011-25518297 > end_of_the_skype_highlighting > Mob:9810359089begin_of_the_skype_highlighting 9810359089 > end_of_the_skype_highlighting > >> >http://people.du.ac.in/~singhg45/ > >> > >> > On Mon, Oct 4, 2010 at 11:08 AM, Sushmita Jha <sushmitas...@gmail.com > > > >> > wrote: > >> > >> >> Thank you, Mani ji. I did not know that walnut is an allelopathic > tree. > >> >> What are the other common trees that are allelopathic? Are neem and > banyan? > >> >> Regards, > >> >> Sushmita Jha > >> >> On Mon, Oct 4, 2010 at 11:29 PM, mani nair <mani.na...@gmail.com> > wrote: > >> > >> >>> Sushmita ji, nice photos. Last year during our visit to Kashmir we > go to > >> >>> see lots of Walnut trees with immature fruits. The tree is very > beautiful > >> >>> and is allelopathic - meaning it does not allow any other plants to > grow > >> >>> under or near it. > >> > >> >>> Thanks for sharing > >> > >> >>> Regards, > >> > >> >>> Mani. > >> > >> >>> On Mon, Oct 4, 2010 at 11:16 PM, Sushmita Jha < > sushmitas...@gmail.com> > >> >>> wrote: > >> > >> >>>> These images have been taken by my brother, Somnath Jha, who is > based in > >> >>>> Srinagar.- Hide quoted text - > >> > >> - Show quoted text - >
