Auto toxicity of Avicennia Marina (FORSK.) Vierh in Pakistan

During field survey it was observed that despite the presence of full sunlight mangrove forests show gaps or small number of stunted seedlings. these observations leaded to consider evaluation of autotoxicity of a.marina,therefore a glasshouse experiment was conducted to observe the possible allelopathic effects of leaf and pneumatophore extracts of avicennia marina on its own seedling survival and growth. two different types of soil with a total of five treatments of leaves and pneumatophores were used including control amid five replicates. the results showed that the extracts from avicennia leaves and pneumatophores had inhibitory effects on it's own growth. the leaf extracts showed stronger allelopathic effects than pneumatophore extracts on root length and dry weight while pneumatophore extracts had greater allelopathic effects on shoot height. therefore,it may also be concluded that besides shade,allelopathy may be responsible for lack of avicennia seedlings under its own mother plant.