• 제목/요약/키워드: Tropics

검색결과 173건 처리시간 0.022초

Combined Application of Pseudomonas fluorescens and Trichoderma viride has an Improved Biocontrol Activity Against Stem Rot in Groundnut

  • Manjula, K.;Kishore, G.Krishna;Girish, A.G.;Singh, S.D.
    • The Plant Pathology Journal
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    • 제20권1호
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    • pp.75-80
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    • 2004
  • In an attempt to develop effective biocontrol system for management of stem rot disease in groundnut, 57 bacterial isolates and 13 isolates of Trichoderma spp. were evaluated for their antagonistic activity against Sclerotium rolfsii. The antagonists were selected based on their ability to inhibit the external growth of S. rolfsii from infected groundnut seeds. Four isolates of Pseudomonas fluorescens, GB 4, GB 8, GB 10 and GB 27, and T. viride pq 1 were identified as potent antagonists of S. rolfsii. T. viride pq 1 produced extracellular chitinase and parasitized the mycelium of S. rolfsii. Under controlled environment conditions, P. fluorescens GB 10, GB 27, T. viride pq 1 and the systemic fungicide Thiram(equation omitted) reduced the mortality of S. rolfsii inoculated to groundnut seedlings by 58.0%, 55.9%, 70.0% and 25.9%, respectively compared to control. In vitro growth of P. fluorescens GB 10 and GB 27 was compatible with T. viride pq 1 and Thiram(equation omitted). Integrated use of these two bacterial isolates with T. viride pq 1 or Thiram(equation omitted) improved their biocontrol efficacy. Combined application of either GB 10 or GB 27 with T. viride pq 1 was significantly effective than that with Thiram(equation omitted) in protecting groundnut seedlings from stem rot infection.

열대 지역 Gross Moist Stability 특징 분석 및 미래 변화 (Characteristics of the Gross Moist Stability in the Tropics and Its Future Change)

  • 김혜원;서경환
    • 대기
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    • 제24권2호
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    • pp.141-150
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    • 2014
  • This study investigates the characteristics of the Gross Moist Stability (GMS) over the tropics. The GMS summarizes the relationship between large-scale entropy forcing due to radiation and surface fluxes and the response of smaller-scale convection. The GMS is able to explain both to where moist entropy is advected by the atmospheric circulation and how deep the moisture flux convergence is in the tropical region. In the deep convective region, positive GMS appears over the warm pool region due to the strong column-integrated moisture convergence and the ensuing export of moist entropy to the environment. The vertical advection of moist entropy dominates over the horizontal advection in this region. Meanwhile, over the eastern tropical ITCZ region, which is characterized by shallow convective area, import of moist entropy by horizontal winds is dominant compared to the vertical moist entropy advection. Future changes in the GMS are also examined using the 22 CMIP5 model simulations. A decrease in the GMS appears widely across the tropics, but its increase occurs over the western-central equatorial Pacific. It is evident that the increased GMS region corresponds to an increased region of precipitation, implying that strengthened convection in the future due to increased entropy forcing exports the enhanced moist energy to stabilize the environment.

Recent Breakthroughs in Sericultural Technology in India to Match the Requirement of Silk Industry in Tropics

  • Datta, R.K.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제1권2호
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    • pp.79-86
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    • 2000
  • Strengthening of R & D components of sericulture in India since the sixties has led to a quantum jump in silk production and presently India is the second largest producer in the world. This achievement is primarily due to a number of breakthroughs in R & D to match the requirements of tropics, by way of introduction of improved mulberry varieties and silkworm breeds, better mulberry cultivation and rearing management practices suited to tropical conditions. Of late, new approaches in molecular biology and biotechnology have also been vigorously pursued to strengthen the current conventional strategies. The present paper attempts to provide an overview of the present status of silk production in both mulberry and non-mulberry sectors, breakthroughs achieved through new approaches of biotechnology and the future prospects for maximizing silk productivity in India.

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Preliminary Experiment of Gravel Contact Oxidation Process in the Tropics

  • Abdullah Keizrul bin;Omachi Toshikatsu
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2006년도 학술발표회 논문집
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    • pp.12-17
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    • 2006
  • Natural rivers have water purification functions called Gravel Contact Oxidation Process, which decontaminate river water by biological absorption, oxidation and degradation on riverbed gravels. This function has been developed and applied to many small/medium-sized urban rivers in Japan as one of the direct river water purification methods. However the method hasn't been verified in the tropics, which have different climate conditions and river characteristics. A preliminary experiment carried out at a polluted urban tributary in the outskirts of Kuala Lumpur, Malaysia where an increasing attention has been paid to river environment, showed a good applicability to the tropical conditions as a technically practical water purification measure with some maintenance cares for sludge management.

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Distribution of Tropical Tropospheric Ozone Determined by the Scan-Angle Method applied to TOMS Measurements

  • Kim, Jae-H.;Na, Sun-Mi;Newchurch, M. J.;Emmons, L.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.7-11
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    • 2002
  • This study introduces the first method that determines tropospheric ozone column directly from a space-based instrument. This method is based on the physical differences in the Total Ozone Mapping Spectrometer (TOMS) measurement as a function of its scan-angle geometry. Tropospheric ozone in September-October exhibits a broad enhancement over South America, the southern Atlantic Ocean, and western South Africa and a minimum over the central Pacific Ocean. Tropical tropospheric ozone south of the equator is higher than north of the equator in September-October, the southern burning season. Conversely, ozone north of the equator is higher in March, the northern burning season. Overall, the ozone over the southern tropics during September-October is significantly higher than over the northern tropics. Abnormally high tropospheric ozone occurs over the western Pacific Ocean during the El Nino season when the ozone amounts are as high as the ozone over the Africa.

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온대와 열대에서 생태형이 다른 수도품종의 수량 및 생육형질의 변이 III. 열대적도지역에서 묘대일수에 따른 한국품종의 반응 (Variations of Yields and Growth-related Characteristics shown by Different Ecotype of Rice Varieties in the Temperate and Tropical Zones III. Response of Korean Varietes on Different SeedJing Age in Equatorial Tropics)

  • 노건길;이은웅;임무상
    • 한국작물학회지
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    • 제32권1호
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    • pp.1-4
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    • 1987
  • 인도네시아 발리에서 한국 4개품종을 묘대일수와 재배법을 달러하여 공식한 결과 20일묘와 30일묘간에는 이앙후 출수기까지의 일수, 생육과 수양형질 및 수량에서 차이가 없었으며 시비량이 많고 재식밀도가 낮은 한국재배법이 수량 및 수량 구성요소가 유의성 있는 좋은 성적을 보였다.

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Evolution of a Productive Bivoltine Hybrid of Silkworm Bombyx mori L.(SD7${\times}$SD12) with Shorter Larval Duration

  • Rao, P.Sudhakara;Basavaraja, H.K.;Kalpana, G.V.;Naik, V.Nishitha;Mahalingappa, K.C.;Pallavi, S.N.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제8권1호
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    • pp.27-32
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    • 2004
  • With an objective of evolving quantitatively and qualitatively superior bivolitine silkworm hybrid of Bombyxmori L. for tropics with shorter larval duration without compromising on productivity traits, a breeding programme was initiated at this institute during 1997 by utilizing breeding resource material from the institutes Germplasm collection. The breed SD7 is characterized with plain larvae spinning white oval cocoons and SD12 is characterized by sex-limited larval markings spinning white dumb-bell cocoons. After fixation, these breeds along with other newly evolved breeds were subjected for hybrid evaluation in the laboratory. Based on the hybrid studies, the hybrid SD7${\times}$SD12 was selected and evaluated for one year comprising three major sea- sons (6 trials) of tropics viz., Pre-monsoon (characterized by high temperature, low humidity and without any rain fall), Monsoon (characterized by moderate temperature, heavy rain fall with high humidity) and post-monsoon season (characterized by low temperature and low humidity with frequent rain fall) to know the fluctuations in the larval duration. The evaluation studies indicated that the hybrid is having shorter larval duration with productive merits. The hybrid SD7${\times}$SD12 recorded survival percent of 92.74, shell weight of 46.7 cg, shell ratio % of 24.0 and filament length of 1,200 meters with a shorter larval duration of 24 hrs; when compared to productive hybrid CSR2${\times}$CSR5(control). The breeding methodologies and hybrids usefulness for tropics were discussed.

Factors Affecting High Mortality Rates of Dairy Replacement Calves and Heifers in the Tropics and Strategies for Their Reduction

  • Moran, John B.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권9호
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    • pp.1318-1328
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    • 2011
  • The tropics is not an ideal location for calf rearing as the high temperatures and humidities introduce many potential disease problems to milk fed calves. In addition, the type of dairy farming (generally poorly resourced small holder farming) and the general lack of awareness of the long term implications of poorly reared stock do not encourage farmers to pay close attention to their calf and heifer rearing systems. Surveys of calf rearing systems in Asia, tropical Africa and South America highlight the high calf and heifer mortalities. A range of 15 to 25% pre-weaning calf mortality is typical on many tropical dairy farms. It is often as high as 50%, indicating very poor calf management. This contrasts with US findings of less than 8% mortality from birth to 6 months while surveys of Australian farmers report only 3% losses. Simple extension programs on farms in Sri Lanka and Kenya have drastically reduced calf mortalities and improved pre-weaning growth rates. Improved management strategies leading to lower calving intervals, higher calving rates, reduced still born and pre-weaned calf mortalities and fewer non pregnant heifers can supply many more dairy herd replacements than currently occurs. Such strategies can increase the number of replacement heifer calves in the herd from 15 to over 35%, thus allowing farmers to increase their herd sizes through natural increases. Simple management procedures such as ensuring adequate intake of good quality colostrum within the first 12 hours of life, housing and good hygiene to minimise disease transfer, providing clean drinking water, developing appropriate feeding protocols to encourage early rumen development and paying closer attention to climate control and animal health can all lead to improved calf vigour and performance. Good record keeping is also important so farmers can more easily identify susceptible calves and quickly treat potential problems.