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Chukrasia tabularisA. Juss produces a valuable timber but plantations are susceptible to attack by the shoot-tip borer Hypsipyla robustaMoore. An integrated pest management (IPM) approach is desirable to limit the extent of damage. Therefore, this study was undertaken to evaluate the deployment of IPM measures in plantations in Vietnam. Data on tree damage and the biology of H. robustawere gathered in 4 provinces over one year and used to build an investigation schedule. Two preliminary IPM trials were then established in which Bacillus thuringiensisand Metarhizium anisopliaewere applied to the foliage when the damage incidence (P%) was in the range 5–10%; and insecticides (Carbaryl, Carbosulfan) were applied when the P% exceeded 10%. In addition, larvae and pupae were removed manually over time. In the first trial, the combination of manual and biological control methods reduced the damage index (DI) of trees from 4 tolerant families by 82% compared to the untreated control plots. In the second trial using standard planting stock, application of insecticides was required to reduce the DI by 83%. Six extended IPM trials were undertaken using the same IPM protocols and these reduced the DI to the same extent as in the preliminary trials. Over an 18-month period, the deployment of IPM increased height growth by 19–22% and diameter growth by 38–41% compared to the controls. These findings highlight the value of planting improved seed and the benefit of adopting an IPM approach to manage the shoot-tip borer.

ABSTRACT This paper presents results from experimental and numerical studies on the structural behavior of double-lap joints of steel splice plates bolted/bonded to pultruded hybrid CFRP/GFRP laminates. A total of [...]

ABSTRACT This paper presents the structural behavior of an innovative hybrid Fiber Reinforced Polymers (FRP) beam consisting of carbon/glass fibers and vinyl--ester resin. The advanced feature of this hybridization is [...]