Effect of Arbuscular Mycorrhizal Colonization on Early Growth and Nutrient Content of Two Peat­ Swamp Forest Tree Species Seedlings, Calophyllum Hosei and Ploiarium Alternifolium

Tropical peat-swamp forests are one of the largest near-surface reserves of terrestrial organic carbon, but rnany peat-swamp forest tree species decreased due over-exploitation, forest fire and conversion of natural forests into agricultural lands. Among those species are slow-growing Calophyllum hoseiand Ploiarium alternifolium, two species are good for construction of boats, furniture, house building and considerable attention from pharmacological viewpoint for human healthly. This study was aimed at understanding the effects of arbuscular mycorrhizal (AM) fungi on early growth of C. hosei and P.alternifoliumunder greenhouse condition. Seedlings of C. hosei and P.alternifoliumwere inoculated with AM fungi: Glomus clarum and Glomus aggregatum ,or uninoculated under greenhouse condition during 6 months. AM colonization, plant growth, survival rate and nutrient content (P, Zn and B) were measured. The percentage of C. hoseiand P.alternifolium ranged from 27-32% and 18-19%, respectively. Both inoculated seedling species had greater plant height, diameter, leaf number, shoot and root dry weight than control seedlings. Nutrient content of inoculated plants were increased with AM colonization- Survival rates of inoculated plants were higher (100%) than those of control plants (67%). The results suggested that inoculation of AM fungi could improve the early growth of C. hoseiand P.alternifolium grown in tropical peat-swamp forest therefore this finding has greater potential impact if this innovative technology applied in field scales which are socially acceptable, commercially profitable and environmentally friendly

Wood Density Variations of Tropical Wood Species: Implications to the Physical Properties of Sawdust as Substrate for Mushroom Cultivation

The physical properties of sawdust including particle size distribution, particle density, porosity and water retention of tropical wood species were examined taking sixteen different wood densities users into consideration. Sawdust of each wood species was prepared using a milling machine (type CE TUV, made in Germany) with thickness of band saw size of 2 mm. Particle size of sawdust was classified into 3 classes; Over Size (OS) < 24 mesh (<710 µm); Coarse Particle Size (CPS = 350µm~710 µm) and Fine Particle Size (FPS = 177 µm~250 µm). In relation to the physical properties analysis, OS particle was excluded due to high variation in the particle size distribution but significant lowest in the proportion comparing to the FPS and CPS. Although statistical analysis showed that different wood density revealed relatively weak relationship with particle size distribution however wood density had positively correlated with the particle density. High of wood density tended to make higher particle density of sawdust. In addition, comparison between CPS and FPS for each wood species generally showed that CPS was significantly higher in porosity but lower in particle density and water retention than that FPS. Further, a comparison between different wood species in porosity and water retention showed different pattern, increasing wood density was negatively correlated with the porosity in CPS and also FPS; however the different wood density not showed significant relationship with the water retention