- Survey of plantations and development of a model for Acacia crassicarpa forest plantations for sandy sites in the North Central region.
Nguyen Thi Lieu
North central Vietnam forest scientific and production center
Summary
The results of a survey on planted forests showed that Acacia crassicarpa is the most promising species on sandy soils. This species is adapted to the hard conditions, grows well on flooded sandy sites, and tolerates wind due to its well-developed root system. In addition, the root nodule system, thick leafy canopy, and woody litter are advantageous to soil improvement and environmental improvement. A model of Acacia crassicarpa forest plantation was developed by different experimental formulas to identify suitable planting methods.
Keywords: Acacia crassicarpa, sandy soil, the North Central region.
- Report on a borer in Rhizophora apiculata forests, Can Gio district, Ho Chi Minh city and initial solutions to the control of this forest insect.
Pham Quang Thu
Forest Science Institute of Vietnam
Summary
Swamp mangrove ecology of Can Gio district, Ho Chi Minh City has great historical and environmental significance. Since 2004,dead trees have been observed in Rhizophora apiculata forest plantations. The cause of this situation has beenidentified. Road building and dams for aquaculture impedes water flow, causing drought in some areas and floods in others, causing a a decline in tree health. Borers appear in aged and high density forest plantations that areinfluenced by drought and flood. The borer was identified as Zeuzera conferta Walker species, Cossidae family, Lepidopteran order. Some initial solutions are proposed to control this forest insect, for the protection and and sustainable development of Can Gio Rhizophora apiculata forest.
Keywords: Rhizophora apiculata forest, Can Gio, Borer.
3. Results from Cutting Propagation of Rhodoleia championii Hook and Podocarpus imbricatus Blume for Genetic Conservation
Nguyen Hoang Nghia, Tran Van Tien
Forest Science Institute of Vietnam
Summary
Rhodoleia championii Hook is a valuable forest tree species, the only species of the genus and listed in Vietnam Red Book (MOSTE,1996). Branch cuttings taken from mature trees (more than 30 cm in diameter) gave quite high rooting percentage, about 50% while the control also gave 45% rooting percentage. The number of roots per cutting and length of roots showed high quality root system. Cuttings taken from shoot coppice gave 85 – 90% rooting percentage, while cuttings from top coppice gave 65 – 75% rooting and NAA gave highest rooting for both cutting types. Cuttings from shoot coppice gave 90% rooting in both rainy and dry seasons with high quality root system. Cuttings from shoot coppice of Rhodoleia championii Hook can be easily rooted with NAA in any season. Topophysis could not be observed when cuttings were obtained from horizontal branches of Rhodoleia championii Hook. Cuttings of Podocarpus imbricatus Blume taken from matured trees (diameter bigger than 30 cm) can be rooted with percentage of 45% while cuttings taken from young 2 — 3 years old seedlings gave highest percentage (90%) by using 1% IBA powder.
Key words: Cutting propagation, Rhodoleia championii Hook, Podocarpus imbricatus Blume.
4. Stinkbugs on Dendrocalamus membranaceus shoots in Thanh Hoa province and initial experiment to eliminate these by pesticides.
Le Van Binh, Dang Thanh Tan
Pham Quang Thu
Forest Science Institute of Vietnam
Summary
Dendrocalamus membranaceus is an important plant for food production and poverty reduction programs in Thanh Hoa and many other provinces. Recently, Dendrocalamus membranaceus shoots have been damaged by a stinkbug in large areas of Ngoc Lac and Lang Chanh districts. Dendrocalamus membranaceus shoots chewed by stink bug are less able to develop aerial stems, which influences the quantity and growing stock of Dendrocalamus membranaceus stands. Stinkbugs on Dendrocalamus membranaceus shoots have been identified as two species: Notobitus meleagris Fabricius and Notobitus sp., Coreidae family, Hemipteran order. Pesticide experiments to eliminate stink bug are proceeding.
Keywords: Dendrocalamus membranaceus shoot, Notobitus meleagris Fabricius and Notobitus sp., pesticide.
- Study to prevent exotic weed damaging forest by Colletotrichum truncatum (Schewein) Andrus & Moore fungi.
Nguyen Thi Thuy Nga, Pham Quang Thu
Forest Science Institute of Vietnam
Summary
Colletotrichum truncatum (Schewein) Andrus & Moore fungus has been isolated from infected grass. Purified and cultured on PDA medium, the hyphae produces asexual spores after 18 — 22 days. Asexual spore solution with a concentration of 1 x 106 cell/ml was applied to branches and leaves of the weeds Eupatorium odoratum and Mimosa pigra. After 48 hours, 100% of Eupatorium odoratum and Mimosa pigra were infected. The level of disease progressed during the experiment , and reached an index of 2.4 for Eupatorium odoratum and 3.6 for Mimosa pigra. This result is significant for managing exotic weeds invading the forests in the future.
Keywords: Colletotrichum truncatum, Eupatorium odoratum, Mimosa pigra.
- Development of a model for forest plantings of indigenous trees on degraded forest soil in Tu Ne commune, Tan Lac district, Hoa Binh province.
Nguyen Ba Van, Nguyen Quang Khai
Forest Science Institute of Vietnam
Summary
Forest planting of large leafed indigenous trees in the Northern mountainous provinces, and in the whole country is part of the Government’s guidelines. The project: “Recovery of Degraded forests by silvicultural techniques and agro-forestry in the Northern mountainous provinces of Vietnam” is part of a program of cooperation between Korea and ASEAN. As a result of the project, 13 hectares of large leafed indigenous trees and an agro-forestry model have been developed, including 8 hectares of planted forest by cutting belts and digging holes, 4 hectares of new mixed forest plantation with trees for green shade and soil improvement (Tephrosia candida and Acacia), and 1 hectare of agro-forestry. Models were developed in Tu Ne commune, Tan Lac district, Hoa Binh province between 2002 and 2005. Initial results showed a high rate of live and growing trees. Those models should bring socio-economic and environmental benefits for local people.
7. Acacia hybrid growth characteristics and yield at rotation age in plantations in Southeast Vietnam
Nguyen Huy Son, Nguyen Van ThÞnh, Bui Thanh Hang
Nguyen Thanh Minh, Phan Minh Sang
Forest Science Institute of Vietnam
Summary
Hybrid acacia in southeastern grow quite rapidly,, on average, an increment in diameter of 2.38 — 2.52cm/year and in height of 3.56 — 3.64 m/year. The standing tree volume at harvest is 136 -180m3/ha and increment is 27.2 — 36.0m3/ha/year. The increase in diameter was described by the Schumacher function with the equation:
Keywords: growth characteristic, rotation age, hybrid acacia plantation
- The influence of planting density on the growth of 3-year-old Hybrid acacia forest.
Pham The Dung
South Vietnam forest science sub-institute
Summary
Hybrid acacia is a fast growing tree and it has a short economic rotation. It can be used as material for paper making and medium size wood for processing. In order to make full use of Hybrid acacia trees, defining initial planted density is important to reduce costs and ensure forest productivity. The results of a 3-year-old Hybrid acacia forest planted with differentdensities in Tan Lap showed that for production of paper material, it is necessary to follow up on the experiment but the possible density is 1428 trees per hectare. To plant forests for both paper material and medium size wood, the suggested density is 1111 trees per hectare.
Keywords: Hybrid acacia, density, growth.
- Study of methods for treating Eucalyptus camaldulensis Dehnh sawn timber before kiln drying to prevent surface end splits.
Nguyen Xuan Hien
Forest Science Institute of Vietnam
Summary
The practice of kiln drying timber and laminated board has shown that the most serious defects of timber from the kiln drying process are cracking and splitting. To identify the causes of splits, test timber samples (50*30*50mm) were treated for different times and different kiln drying environments (T0, φ%) and , the level of cracking and deformity of the samples with time progress was defined. Methods of treatment of timber before drying are suggested to reduce the level of cracking, and improve the effectiveness of timber used.
Keyword: treatment before drying, Eucalyptus camaldulensis Dehnh timber
10. Results of research into the chemical composition of cashew nut peel oil as active elements to make forest products preservatives
Bui Van Ai
Forest Science Institute of Vietnam
Summary
In Viet Nam, Cashew nut peel oil is a natural raw material. The main component of the oil consists of natural phenolic compounds which can prevent attack by harmful insects. In research to use cashew nut peel oil to make forest products preservative, the cashew nut peel oil was treated with chlorine gas to increase its anti-insesticidal properties. Some new compounds inCashew nut peel oil and their change after treatment with chlorine gaswere determined by appropriate analytical methods.
Keywords: Cashew nut peel oil, forest products preservative chemical products
Latest news
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