Studies in the mangrove plantations and adjacent areas revealed little chance for the natural
development of a second rotation crop in the existing plantations. In some islands of Noakhali
Coastal Afforestation Division, gewa (Excoecaria agallocha) showed promising performance
towards development of a second rotation crop. Of the available saplings and poles, E. agallocha
alone constituted 35 and 70 percent respectively. Studies on the scope of natural regeneration of
this species for sustainable development of mangrove plantations may be undertaken.

Acacia mangium seeds were subjected to six one-day pre-sowing treatments and their effects
on germination and seed deterioration in germination medium were studied under laboratory
conditions. The pretreatments were imparted by soaking the seeds, with and without funicle,
(a) in tap water (25^C) for three hours, (b) in boiled water (immediately after removing from heat
source) for one hour, (c) in boiling water for 30 seconds, and (d) treating with 95% sulphuric acid
for two minutes. Hot and boiling water treatments produced maximum germination, and at the
same time maximum damage to seeds. Other treatments had little effect on germination. A dry- •
weight analysis ofseed parts recorded 21% funicle, 30% seed coat, 47% cotyledon and 2% embryo
of the total weight.

Acacia auriculiformis and A.mangium the two fast growing exotic species have been introduced to
Bangladesh for meeting the increasing demand offuelwood and poles. During last decade, thousands of
hectares of plantation have been raised with these two species. In a number of A. auriculiformis
plantations, several outstanding trees have been observed with good growth and vigour. These trees
possess many characteristics of both good growth and vigour. These trees possess many
characteristics ofboth A. auriculiformis andA. mangium. The hybrid trees coppice well and are somewhat
resistant to heartrot disease in addition to its higher growth rate. The per unit area productivity of this
hybrid would be higher than the existing output of either of the parent species. The use of vegetative
propagulesrather than seedlings as a commercialforestregeneration method present an opportunity in
genetic improvement.