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101.
Nguyen Thi Thu Cuc Nguyen Thanh Son Tran Minh Trung Nguyen văn Trang Lâm Minh Đang Marc Pilon 《Crop Protection》2010
Polianthes tuberosa is a commercially valuable flower crop in the Mekong Delta of Vietnam that is propagated by the harvesting and planting of bulbs. Cultivation of P. tuberosa is infected by an endemic Aphelenchoides besseyi nematode that damages a high proportion of plants and persists within the bulbs. Here we report on the comparison of hot water and pesticide treatments as control methods to protect P. tuberosa from A. besseyi damage, and conclude that a hot water treatment consisting of soaking bulbs in water for 30 min at 57 °C is the most efficacious method to produce healthy flowers in a cost effective manner. 相似文献
102.
In a study of the population dynamics of Magnaporthe oryzae in the Mekong Delta in Vietnam, 226 isolates were collected from various sites in December 2001, September and December 2004.
The pathogenic races of isolates were determined using international differential rice varieties. Isolates with the same race
number were not found, not even in the same field or on the same seedling, suggesting that the fungus in the Mekong Delta
was dynamically changing. But focusing on the known major resistance genes in the Japanese differential varieties, some isolates
in the area were found to be the same race. Phylogenetic analyses based on the transposable elements Pot2 and MGR586 in the genomes supported that the pathogenic races were critically variable in comparison with the genomic diversity.
Isolates with MAT1-1 predominated in the Mekong Delta, but in some provinces those with MAT1-2 coexisted at low frequency
with MAT1-1. However, no isolates produced perithecia and ascospores. Isolates in the Mekong Delta probably had hot spots
in their genomes that are easily altered and associated with some avirulence genes. 相似文献
103.
An evaluation of fish health‐management practices and occupational health hazards associated with Pangasius catfish (Pangasianodon hypophthalmus) aquaculture in the Mekong Delta,Vietnam 下载免费PDF全文
Tran Minh Phu Nguyen Thanh Phuong Tu Thanh Dung Dao Minh Hai Vo Nam Son Andreu Rico Jesper Hedegaard Clausen Henry Madsen Francis Murray Anders Dalsgaard 《Aquaculture Research》2016,47(9):2778-2794
This study aimed to evaluate the current status on the use of probiotics, disinfectants and antimicrobials in hatcheries, nurseries and grow‐out farms producing Pangasius catfish (Pangasianodon hypophthalmus) in the Mekong Delta, Vietnam. Semi‐structured interviews were conducted with 83 aquaculture enterprises (15 hatcheries, 32 nurseries and 36 grow‐out farms). Farmers reported use of a total of 24 different antimicrobials, e.g. for treatment of bacillary necrosis and motile aeromonad septicaemia, and a variety of disinfectants, probiotics and nutritional supplements. In contrast to small‐scale farmers, all large‐scale grow‐out farmers studied were certified and therefore had higher levels of formal education and specialized aquaculture training to diagnose and treat diseases. All farmers prepared their own medicated feed with a high risk of treatment failure, negative environmental impact from released antimicrobials and resistance development. Small‐scale farmers were at particular occupational health risks when handling antimicrobials and other chemicals, e.g. mixing medicated feed with bare hands. There is an urgent need to improve knowledge and use innovative approaches, e.g. private‐public partnerships, to assure a prudent use of chemicals, to improve capacity and access to disease diagnosis, particularly for small‐scale grow‐out farmers and nurseries. Efforts to control use of antimicrobials in aquaculture should be coordinated with the livestock and human health sectors taking an One‐Health approach. 相似文献
104.
The aim of this experiment was to determine the effects of dietary supplementation with mannan oligosaccharide (MOS; BioMos, Alltech, USA) on the gut microbiota and histology of marron, Cherax tenuimanus. Marron were fed six different diets supplemented with 0%, 0.05%, 0.1%, 0.2%, 0.4%, and 0.8% of MOS for a duration of 112 days. Total bacteria in the gut were highest when marron were fed diets which included 0.1% to 0.4% BioMos, whereas total bacteria/Vibrio spp. ratio was highest in the marron fed 0.4% BioMos diet only. The marron fed 0.2% and 0.4% BioMos diets showed normal morphology and higher densities of microvilli, and thicker layer of gut epithelium than other inclusion rates. The results suggest that application of 0.2% to 0.4% of MOS in the diet improves digestive system health in marron. 相似文献
105.
This study was conducted to evaluate dietary protein and carbohydrate requirement of juvenile Hawaiian limpets Cellana sandwincensis. A total of 64 juvenile limpets (3.12 ± 0.86 g) were fed five different dietary protein levels ranging from 270 to 470 g kg?1 for 90 days. Carbohydrate and lipid levels were held constant at 180 and 49.7 g kg?1, respectively. Weight gain and growth rates of the animals did not differ significantly (P > 0.05) among the protein levels ranging from 270 g kg?1 (0.30 % day?1) to 470 g kg?1 (0.23 % day?1). Next, opihi were fed four diets with protein levels from 210 to 500 g kg?1 with a constant carbohydrate level at 120 g kg?1. Weight gain and specific growth rates of opihi increased with increasing dietary protein from 210 to 350 g kg?1, and significantly (P < 0.05) decreased at the 500 g kg?1 diet. Highest weight gain, growth rates, and protein efficiency ratio were achieved at 350 g kg?1. Elevated carbohydrate levels (180–370 g kg?1) produced a significant difference (P < 0.05) in growth. The fastest growth rates of animals were obtained with 270 g kg?1 (0.27 % day?1) and 320 g kg?1 (0.26 % day?1). The weight gain of animals fed 180 and 370 g kg?1 carbohydrate diets were significantly (P < 0.05) lower than those of animals fed 270 and 320 g kg?1. We conclude that about 350 g kg?1 protein and 320 g kg?1 carbohydrate levels could be used for opihi. 相似文献
106.
107.
Phan Thi Cong Tran Dang Dung Tran Minh Hien Nguyen Thanh Hien Abu T.M.A. Choudhury Mihály L. Kecskés Ivan R. Kennedy 《European Journal of Soil Biology》2009,45(1):52-61
Field experiments were conducted during successive rainy seasons in 2006 in the Chau Thanh district of southern Vietnam to evaluate the effects of an inoculant plant growth promoter product called “BioGro” and N fertiliser rates on yield and N and P nutrition of rice. The results indicated that inoculation with BioGro, containing a pseudomonad, two bacilli and a soil yeast, significantly increased grain and straw yields and total N uptake in both seasons, as well as grain quality in terms of percentage N. Nitrogen fertilisation increased grain and straw yields as well as total N and P uptakes significantly in both cropping seasons. The estimated grain yield response to added N was quadratic in nature with and without added BioGro. In the first crop, BioGro out-yielded the control up to 90 kg urea N ha?1 whilst in the second season the beneficial effect of BioGro was observed up to 120 kg urea N ha?1, indicating either an interaction of the inoculant with higher yielding seasonal conditions or a cumulative effect of BioGro application. In the first season, the estimated N rate for maximum grain yield was 103 kg N ha?1 with BioGro while it was 143 kg N ha?1 without BioGro. The maximum estimated grain yields were 3.21 and 3.18 t ha?1 with and without BioGro, respectively. This information indicates that BioGro was able to save 40 kg N ha?1 with an additional rice yield of 30 kg ha?1 in the season. In the second rainy season, the estimated N rates for maximum grain yields were 94 and 97 kg N ha?1 with and without BioGro, respectively. The estimated maximum grain yields were 3.49 and 3.25 t ha?1 with and without BioGro, respectively. The two seasons’ combined results indicate that application of BioGro improved the efficiency of N use by rice significantly, saving 43 kg N ha?1 with an additional rice yield of 270 kg ha?1 in two consecutive seasons at the experimental site. The extra efficiency was shown by the fact that the same yield of rice was obtained with about 40 and 60 kg less fertiliser-N that the maximum yields with urea alone in the two successive harvests on the same plots. 相似文献
108.
Takahiro Fujiwara San Afri Awang Wahyu Tri Widayanti Ratih Madya Septiana Kimihiko Hyakumura Noriko Sato 《Small-Scale Forestry》2018,17(1):41-56
Indonesia is one of the largest teak timber producers in the world. The Javanese State Forest Company has been a major producer of teak timber in Indonesia; however, log production decreased drastically due to severe illegal logging after the collapse of Suharto regime. In contrast, small-scale private forests (PFs) owned by local farmers have expanded and are expected to be a new source of teak timber. Long rotation is a critical factor in producing a larger diameter log with a higher heartwood proportion. However, harvest timing in PFs is traditionally decided based on individual farmers’ needs even if trees are still young and of small diameter. Therefore, traditional harvesting is an obstacle to producing high-quality teak timber. The objectives of this study are to (1) identify the household economies and PF management styles of local farmers, (2) characterize the local farmers who conduct traditional harvesting, and (3) suggest key considerations for PF policymaking. Key informant interviews and semi-structured interviews with local farmers were conducted in three villages in Gunungkidul district, Yogyakarta Special Region. The study identified the household economies, the ownership and management structures, and the traditional harvesting in PFs in the three villages, and reaffirmed diversity and complexity of PFs. It appears that PF management is influenced by topographic and socioeconomic conditions and differs widely across villages. Therefore, it is important to consider the diversity and complexity of PFs in PF policymaking. 相似文献
109.
After years of unsustainable logging, dry deciduous dipterocarp forest (DDDF) has become poor in timber stocks and has been converted to industrial crops such as rubber. The objectives of this study were to assess teak (Tectona grandis L.f.) tree establishment under degraded DDDF conditions and to determine factors that influence the suitability of teak as a forest enrichment tree species. A set of 64 experimental plots of 4 900 m2 each was set up and observed for 4–5 years for testing enrichment planting with teak under various combinations of two groups of factors: ecological conditions and forest status. Weighted, non-linear, multivariate regression models were used to detect key factors that influenced the suitability of teak. The results showed that at the age of 4 years the average dominant tree height (defined as 20% of the tallest trees in the experimental plot) reached 11.2, 7.8, 5.3 and 3.8 m for very good, good, average and poor suitability levels, respectively. Survival rates of planted teak from average to very good suitability levels were over 90%. Six key factors that affected the suitability of teak were waterlogging during the rainy season, altitude, stand volume of the degraded DDDF, soil type, percentage of sand and concentration of P2O5 in the soil. Under the extreme ecological and environmental conditions of the DDDF, enrichment planting with teak gave promising results. 相似文献
110.
Thi Thu Nhan Nguyen Helen M. Wallace Cheng-Yuan Xu Zhihong Xu Michael B. Farrar Stephen Joseph Lukas Van Zwieten Shahla Hosseini Bai 《Journal of Soils and Sediments》2017,17(12):2763-2774