Allelopathic potential of the newly emerging weed Solanum mauritianum Scop. (Solanaceae) in the wet tropics of north-east Queensland

S.K. FlorentineA,B and M.E. WestbrookeB

A School for Field Studies, Centre for Rainforest Studies, Yungaburra, Queensland 4872, Australia.

B School of Science and Engineering, University of Ballarat, PO Box 663, Victoria 3350, Australia.


Summary

Solanum mauritianum (Scop.), commonly known as wild tobacco tree, has become a weed of major concern in pastoral areas and tropical rainforest restoration sites of the Atherton Tablelands, north-eastern Queensland. We examined the effects of aqueous leachates of Solanum mauritianum leaves on the germination of Lactuca sativa seeds and on the growth of four native tropical rainforest species (Neolitsea dealbata (Lauraceae), Syzygium australe (Myrtaceae), Diploglottis diphyllostegia (Sapindaceae),and Elaeagnus triflora (Elaeagnaceae).

Both the germination and radicle development of L. sativa was inhibited with increasing concentrations of leachate from S. mauritianum. Most tropical rainforest species experienced a significant (P <0.05) reduction in shoot and root biomass after 36 days of treatment.

Solanum mauritianum contains water-soluble phyto-inhibitors in its leaves which can have severe impacts on the growth of seedlings of native tropical rainforest species under controlled environment conditions. Whether these effects are found in the field is yet to be determined.

 

Plant Protection Quarterly (2003) 18 (1) 23-25.