Mohd Hamami Sahri

Effect of the lateral growth rate on wood properties in fast-growing hardwood species

We investigated the feasibility of using several fast-growing tropical or subtropical hardwood species for timber production by measuring key wood qualities in relationship to the high rates of lateral growth. The trees tested were sampled from even-aged plantations of Acacia mangium, A. auriculiformis, hybrid Acacia (A. mangium × A. auriculiformis), Eucalyptus grandis, E. globulus, and Paraserianthes falcataria (Solomon and Java origin) that had already reached commercial harvesting age. The released strain of the surface growth stress (RS), xylem density (XD), microfibril angle (MFA), and fiber length (FL) were measured at the outermost part of the xylem at breast height in each tree. Results were then compared to the lateral growth rate (radius/age) at breast height, which provides a relative indicator of the amount of tree growth per year. Our findings indicated that RS was constant, regardless of lateral growth rate in each species. Similar results were observed for XD, MFA, and FL, with a few exceptions, suggesting that high growth rates do not intrinsically affect the wood properties of fast-growing tropical or subtropical species that have reached harvesting age. However, special attention must be paid to patterns of xylem maturation when developing plantations of such species.

Feeding Response of Subterranean Termites Coptotermes curvignathus and Coptotermes gestroi (Blattodea: Rhinotermitidae) to Baits Supplemented With Sugars, Amino Acids, and Cassava

ABSTRACT Feeding responses of subterranean termites Coptotermes curvignathus (Holmgren) and Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae) to bait matrices supplemented with various sugars, amino acids, and cassava were evaluated both in the laboratory and field. The results indicated that the two termite species consumed significantly different amount of filter papers that had been treated with various types and concentrations of sugars and amino acids. Based on consumption and survival data, filter papers with 3% glucose and 3% xylose were among the most consumed by C. curvignathus and C. gestroi, respectively. Both termite species consumed more of the filter papers treated with 3% casein than filter papers treated with L-alanine. Both species had a comparable survival rate compared with those in the controls. Results from laboratory and field trials on bait prototypes indicated that C. gestroi consumed more bait prototypes containing cellulose, 3% xylose, 3% casein, and cassava, whereas C. curvignathus consumed more bait prototype containing cellulose, 3% glucose, and cassava, than on pure crystalline cellulose baits. Thus, with an improved and cost-effective bait formulation, a much wider control of subterranean termite colonies could be achieved.

Effect of Initial Planting Density and Tree Features on Growth, Wood Density, and Anatomical Properties from a Hevea brasiliensis Trial Plantation

Abstract The effect of initial planting density (500, 1,000, 1,500, and 2,000 trees per ha) on tree growth, wood density, and wood anatomical properties was studied in a 9-year-old Heave brasiliens...