• Journal of Forest and Environmental Science
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• 제38권2호
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• pp.75-89
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• 2022

The negative impact of monoculture rubber plantations on biodiversity and associated ecological processes/ecosystem services has led to suggestions on the use of integrated land use systems for rubber cultivation and production in order to ensure environmental sustainability. However, there is paucity of information on the effect of such integrated land use systems on the diversity and abundance of the rubber plantation undergrowth. We evaluated and compared undergrowth plant species composition, richness, abundance, diversity and interaction, in three integrated systems (Rubber-Strelitzia reginae Integrated System - RSrIS, Rubber-Podocarpus nagi Integrated System - RPnIS & Naturally Managed Rubber Plantation - NMRP) with three Rubber Monoculture Plantations (RMP₁, RMP₂ & RMP₃) adjacent to the integrated systems, respectively, at the Investigation and Experiment Station of Tropical Crops, Danzhou, Hainan, China. Undergrowth species density was higher in the rubber monocultures than in the integrated systems except in RSrIS. Species richness and diversity were also higher in the monocultures except in NMRP. Species similarity/interaction between the monocultures and the integrated systems was highest between RMP₃ and NMRP. The NRMP proved to be the best model of natural rubber integrated system for the conservation of undergrowth species richness, diversity and interspecific interaction. However, the conservation of undergrowth species in other forms of integrated natural systems can be enhanced by considering the ecology of species to be integrated in terms of their growth characteristics, competitive nature, and ability to grow in association with other species.

• Animal Bioscience
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• 제37권3호
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• pp.481-491
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• 2024

Objective: This study determined fermentation characteristics of commonly used feedstuffs, especially tropical roughages, for dairy cattle in Southeast Asia. This information is considered relevant in the context of the observed low milk fat content and milk production in Southeast Asia countries. Methods: A total of 29 feedstuffs commonly used for dairy cattle in Vietnam and Thailand were chemically analysed and subjected to an in vitro gas production (GP) test. For 72 h, GP was continuously recorded with fully automated equipment and methane (CH₄) was measured at 0, 3, 6, 9, 12, 24, 30, 36, 48, 60, and 72 h of incubation. A triphasic, nonlinear, regression procedure was applied to analyse GP profiles while a monophasic model was used to obtain kinetics related to CH₄ production. Results: King grass and VA06 showed a high asymptotic GP related to the soluble- and non-soluble fractions (i.e. A1 and A2, respectively) and had the highest acetate to propionate ratio in the incubation fluid. The proportion of CH₄ produced (% of GP at 72 h) was found to be not different (p>0.05) between the various grasses. Among the selected preserved roughages (n = 6) and whole crops (n = 4), sorghum was found to produce the greatest amount of gas in combination with a relatively low CH₄ production. Conclusion: Grasses belonging to the genus Pennisetum, and whole crop sorghum can be considered as suitable ingredients to formulate dairy rations to enhance milk fat content in Vietnam/Thailand.

• The Plant Pathology Journal
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• 제28권2호
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• pp.123-136
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• 2012

Diseases caused by begomoviruses (family Geminiviridae, genus Begomovirus) constitute a serious constraint to tropical and sub-tropical agro-ecosystems worldwide. In recent years, they have also introduced in temperate regions of the world where they have great impact and are posing a serious threat to a variety of greenhouse crops. Begomoviral diseases can in extreme cases reduce yields to zero leading to catastrophic losses in agriculture. They are still evolving and pose a serious threat to sustainable agriculture across the world, particularly in tropics and sub-tropics. Till recently, there have been no records on the occurrence of begomoviral disease in South Korea, however, the etiology of other plant viral diseases are known since last century. The first begomovirus infected sample was collected from sweet potato plant in 2003 and since then there has been gradual increase in the begomoviral epidemics specially in tomato and sweet potato crops. So far, 48 begomovirus sequences originating from various plant species have been submitted in public sequence data base from different parts of the country. The rapid emergence of begomoviral epidemics might be with some of the factors like evolution of new variants of the viruses, appearance of efficient vectors, changing cropping systems, introduction of susceptible plant varieties, increase in global trade in agricultural products, intercontinental transportation networks, and changes in global climatic conditions. Another concern might be the emergence of a begomovirus complex and satellite DNA molecules. Thorough understanding of the pathosystems is needed for the designing of effective managements. Efforts should also be made towards the integration of the resistant genes for the development of transgenic plants specially tomato and sweet potato as they have been found to be widely infected in South Korea. There should be efficient surveillance for emergence or incursions of other begomoviruses and biotypes of whitefly. This review discusses the general characteristics of begomoviruses, transmission by their vector B. tabaci with an especial emphasis on the occurrence and distribution of begomoviruses in South Korea, and control measures that must be addressed in order to develop more sustainable management strategies.

• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.495-503
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• 1992

The internal and external outputs of the agricultural sub-systems of mixed livestock-crop farms in Pabna Bangladesh were analysed, to clarify the multiple functions of cattle in farm systems. Production systems with grazing areas were relatively more productive than those with no grazing. There was a tremendous variation in farm income, largely because of land area. An increase of one ha in land area was estimated to boost farm income by about 50%. Number of cattle, cattle off-take percentage and milk off-take per average cow related positively to farm income. As land area decreased the relative importance of cattle production increased. Crops were dominant in producing food for home consumption. Cattle contributed only 5-6 per cent to home consumption. Cattle supplied a significant cash income: 45 per cent in the villages with grazing areas and 57 per cent in the other villages. In future, the cash output from cattle will decline and emphasis will shift to the role of cattle in supporting crop production. Any research or development strategy for livestock needs to focus first on the importance of the complex relation between livestock and crops.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.19-19
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• 2020

The Cassava(Manihot esculenta Crantz) is a tropical root crop, originally from Amazonia, that provides the staple food of an estimated 800 million people worldwide. It belongs to the family Euphorbiaceae which also includes rubber (Hevea brasiliensis) and castor bean (Ricinus communis). Among tropical crops, rice, sugarcane, maize and cassava are the most important sources of calories for human consumption. Problems in the propagation of cassava are virus diseases and low rates of seed germination. So we tried to optimize protocols for mass production of somatic embryo amenable to large-scale vegetative propagation of Cassava. After in vitro eight-week culture of leaves of Cassava, the medium which contained the 2,4-D, BAP and IBA showed the highest callus induction rate, embryogenesis callus formation rate and somatic embryo formation in Cassava culture. In the medium with GA₃ and myo-inositol, shoots were most vigorously regenerated from somatic embryos of Cassava. Our experiments confirmed that in vitro growth and multiplication of plantlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

• 한국초지조사료학회지
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• 제44권3호
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• pp.157-164
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• 2024

Sorghum-Sudangrass hybrids (SSH) is a grass cereal hybrid crop with a high yield potential under different climatic conditions. The aim of this study was to evaluate the growth characteristics, dry matter yield and nutrient content of the SSH cultivars such as Dairy Mens Dream, Superdan and Supergreen from 2021 to 2023 in Jeju Island, Korea. Among the three cultivars, Superdan grew significantly taller with a larger stem diameter at both harvest times. In contrast, Dairy Mens Dream had least height and less stem diameter, but the dry matter yield was greater for Dairy Mens Dream than other cultivars. Furthermore, the crude protein content at the first cut was higher than 8.5% compared to the second cut (6.5 - 7.0%). The neutral detergent fiber (NDF) and acid detergent fiber (ADF) content was higher in the second harvest of all cultivars compared to the first harvest of SSH in 2021. The SSH cultivation in 2021 and 2023 had higher ADF and NDF content than in 2022, possibly due to the average precipitation and optimum temperature suitable for SSH production in 2021 and 2023. The selected three SSH cultivars showed significant growth characteristics, dry matter content, and nutritional value. The overall data suggested that all three SSH showed significant productivity and nutritional content in the Jeju region of sub-tropical climatic condition.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1621-1621
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• 2001

The quality of sugarcane grown on the NE Australian tropical coast ($16^{\circ}$15'- $18^{\circ}$15' S Lat.) has declined markedly in the past seven years. This has been linked to dilution of mill-supply cane with increasing levels of non mature-stalk material consisting of leaves and sucker culms. The prime research objective was to examine the transition from the pre-harvest, in-field crop to harvested material sent for processing, in terms of quality and crop fraction proportions. A secondary objective was to quantify the effects of preharvest-season crop habit and culm condition on crop quality. Ten quadrat samples from each of 54 random crop sites (17 in 1999 and 37 in 2000), covering a wide range of variables (cultivar, crop class, and edaphic, topographic, climatic, and temporal factors) were collected immediately before harvest. Samples were partitioned into four fractions:- sound and unsound mature stalks (culms), sucker culms, and extraneous matter (leaves). Material harvested from each site was sampled and partitioned into four fractions:- sound and unsound billets (culm pieces), culm-spindle pieces, and leaf. In 2000, before harvest, 14 additional sites were sampled monthly, on three occasions, from March - June. Erect and non-erect culms were divided into sound and unsound classes. All samples were disintegrated and presented to a remote reflectance module of a scanning spectrophotometer using the BSES large cassette module. Near infra-red spectroscopic (NIS) analyses were developed for the rapid determination of quality components (Brix, commercial cane sugar (CCS), fibre, moisture, and polariscope reading). Calibrations for three material groups (culm (n = 639), non-culm (n = 496), and combined) were developed for all components using the 1999 data set. Two sub-sets (n = 178, and 190) of about 10% of the preharvest-season and harvest populations scanned in 2000 also were subjected to full routine laboratory analyses. The 1999 combined calibrations were excellent, but the culm calibrations produced consistently lower standard errors. Non-culm calibrations were marginally better than the combined for only CCS and pol. reading. Analysis of the 2000 culm data with calibrations using all 1999 and 2000 culm data resulted in better predictions relative to the 1999 culm calibrations. This also was true for the combined calibrations. Assessment of quality components in pre- and post-harvest sugarcane using NIS calibrations was more cost effective than using routine laboratory techniques. Outcomes from this NIS-facilitated research will have important economic consequences for the Australian sugarcane industry. Potential CCS present in mature culms is being discounted by dilution with leaves and sucker culms, threatening farm viability. The results question the efficacy of current harvesting technology. The CCS of harvested cane is improved only marginally over that of the in-field crop. Current harvesting technology requires either supplementary, innovative pre-mill processing or a design revolution to improve mill-supply cane quality, and therefore whole of industry economics. NIS-facilitated analyses, before the harvest season, highlighted the benefits of growing erect, sound crops. Loss of CCS then, can be minimized only by a combination of crop improvement and agronomic solutions, applied as part of sound on-farm management.

• 생물환경조절학회지
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• 제25권3호
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• pp.212-217
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• 2016

본 시험은 청과용 그린 파파야 무가온 생산시 육묘기간이 생육 및 수량특성에 미치는 영향을 구명하고자 'Red lady' 품종을 이용하여 수행하였다. 육묘기간은 3개월부터 13개월 까지 6처리로 하였으며 2015년 4월 15일 무가온 하우스내에 정식하였다. 육묘기간에 따른 정식 전 파파야 묘의 초장, 마디수, 생체중 등은 육묘기간이 긴 묘일수록 높았으며, 13개월 육묘에서 가장 생육이 좋았다. 첫 수확일수는 육묘기간이 짧아질수록 길어졌으며 13개월 육묘에서 137일(8월 18일)이 소요되었고 3개월 육묘에서 184일(10월 2일)로 가장 길었다. 과일특성은 육묘기간이 짧았던 3개월 육묘에서 과장과 과경이 가장 작았으나 나머지 처리 간에는 차이를 보이지 않았다. 수량은 육묘기간에 따라 영향을 받았으며 상품수량 역시 육묘기간이 길어짐에 따라 증가하였다. 13개월 육묘에서 가장 많았으며(3,172kg), 다음이 11개월(2,247kg) 및 9개월(2,357kg) 이었다. 7개월과 5개월에서 각각 1,942kg 및 1,787kg 이었으며, 3개월 육묘에서 1,443kg으로 가장 적었다. 특히 7개월 육묘 이하에서 상품수량은 1,942kg 이하로 크게 감소되었다. 이상의 결과 청과용 그린 파파야 무가온하우스 재배시 수확기를 앞당기기 위해서는 11개월 육묘가 유리하겠으나, 경영비 등을 고려한다면 9개월 정도 육묘가 바람직할 것으로 생각된다.