permaculture

["Lawrence F. London, Jr." <lfl@intrex.net>]

-------- Original Message --------
Subject: [SANET-MG] passion fruit allelopathy, for weed control
Date: Thu, 15 Feb 2007 20:01:33 -0800
From: Hector Valenzuela <hector@HAWAII.EDU>
Reply-To: Sustainable Agriculture Network Discussion Group 
<SANET-MG@LISTS.IFAS.UFL.EDU>
To: SANET-MG@LISTS.IFAS.UFL.EDU

Hi all-

RE: passion fruit (lilikoi) allelopathy, for use on weed control

Has anyone observed or had experience with the use of passion fruit foliage/leaves for their allelopathic potential, 
i.e. to control weeds in other crops?

The research below, conducted in Vietnam, showed 40 and 70% reduction in weed pressure, when 1 or 2 tons/Ha (1-2,000 
lbs/Ac) of foliage, respectively, was applied on paddy rice fields. The added biomass might have also contributed 
nutrients to increase yields of the cash crop.

I wonder if this has potential for use on taro paddies or dryland conditions.

Aloha,

Hector Valenzuela
Univ. Hawaii at Manoa
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Citation:
KHANH TD, CHUNG IM, TAWATA S & XUAN TD (2006) Weed suppression by Passiflora edulis and its potential allelochemicals. 
Weed Research 46, 296–303.

Summary
Passion fruit (Passiflora edulis) is grown in the tropics for its edible fruits and for its many ethno-pharmacologic and 
pharmacological properties. Our study revealed that the plant contains a strong allelopathic potential. In a bioassay, 
aqueous extracts of P. edulis strongly suppressed germination and growth of lettuce, radish and two major paddy rice 
weeds, Echinochloa crusgalli and Monochoria vaginalis.

In glasshouse and field experiments, P. edulis also strongly inhibited the growth of paddy rice weeds. Application of 2 t 
ha)1 dry plant material of P. edulis reduced weed biomass by 70% and increased rice yield by 35% compared with the 
unweeded control. Ten newly identified substances in P. edulis extracts, including coumarin, long-chain fatty acids and 
lactones, may be responsible for the inhibitory activity of P. edulis. Coumarin and the lactones showed greater 
inhibition of germination and growth of E. crusgalli than the fatty acids. The authors suggest that P. edulis may be 
used as a natural herbicide to reduce the dependency on synthetic herbicides.

file: passion fr allelochem 06.pdf