• Title/Summary/Keyword: tropics

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Effect of Plant Population Densities on the Severity of tate Leaf Spot and Rust of Groundnut

  • Pande, S.;Rao, J.Narayana
    • The Plant Pathology Journal
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    • v.18 no.5
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    • pp.271-278
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    • 2002
  • The effect of five plant population densities [5 (D$_1$), 10 (D$_2$), 20 (D$_3$), 30 (D$_4$), and 40 (D$_{5}$) plants/m$^2$] of four groundnut cultivars [ICGV 86699, ICG (FDRS) 10, ICGS 11 and TMV 2] and fungicide application (Kavach, chlorothalonil) to manage late leaf spot (LLS) and rust were studied in a field experiment during the 1995 and 1996 rainy seasons. LLS and rust severities were low in fungicide sprayed plots in all the cultivars irrespective of plant densities. Severities of LLS and rust, and percentage defoliation caused by LLS were significantly more in higher plant densities (D$_4$, D$_{5}$) than in lower plant densities (D$_1$, D$_2$, D$_3$) in fungicide sprayed and unsprayed plots in all the cultivars. All the cultivars gave significantly higher haulm and pod yields in fungicide sprayed plots than in unsprayed plots. Haulm and pod yields were significantly higher in higher plant densities than in lower plant densities. A combination of higher plant densities (D$_4$, D$_{5}$) and fungicide protection against LLS and rust gave maximum yield.yield.

The Relationship between Growth Duration and Yield in Soybean in the Sub-tropics (아열대 지역의 콩생육기간과 수량과의 관계)

  • Kim, S.D.;Toung, T.S.;Shanmugasundaram, S.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.4
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    • pp.469-472
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    • 1983
  • Seasonal variations influence the growth duration and yield of soybeans in the tropics and subtropics. Results of different yield trials were used to determine the relationship between yield with days to R$_1$ and R$_{8}$ in different seasons. Similarly relationship for 100 seed weight was examined. Multiple regression equations suggest that increase in yield can be obtained by increasing the days to R$_{8}$ regardless of seasons. However, increasing the days to R$_1$ invariably reduced the yield. The longer the time from R$_1$ to R$_{8}$, the higher the 100 seed weight. Since the population examined was heterogeneous for photoperiod sensitivity, the need to examine photoperiod sensitive and insensitive selections separately is discussed.

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On the Breeding of “CSR18${\times}$CSR19”- A Robust Bivoltine Hybrid of Silkworm, Bombyx mori L. for the Tropics

  • Kumar, N.Suresh;Basavaraja, H.K.;Kumar, C.M.Kishor;Reddy, N.Mal;Datta, R.K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.5 no.2
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    • pp.153-162
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    • 2002
  • Earlier breeding experiments undertaken at Central Sericultural Research and Training Institute, Mysore, India since a decade had resulted in the development of many productive and qualitatively superior bivoltine hybrids. However, the hot climatic conditions of tropics prevailing particularly in summer are not conducive to rear these high yielding bivoltine hybrids. This has necessitated breeding of compatible bivoltine hybrids for year-round rearing. Accordingly, the Japanese hybrid, B2Ol ${\times}$ BCS12 which was found to be tolerant to high temperature was used as breeding resource material. Following hybridization and selection rearing of silkworms was taken up in SERICATRON (Environmental chamber with precise and automatic control facilities for uniform maintenance of temperature and humidity) at high temperature of $36{\times}1^{\circ}C$ and 85${\times}$5% RH in fifth instar and the control batches at $25{\times}1^{\circ}C$ and 65{\times}$5% RH. Directional selection was resorted to the batches reared at 36$\pm$1$^{\circ}C$ till F$_{5}$ keeping pupation rate as important selection criteria. From $F_{2}% onwards the experiment was modified in such a way as to conduct normal rearing every alternate generation to regain the lost vitality due to continuous exposure to high temperature and high humidity stress. At $F_{2}$ , Oval and dumb-bell cocoons were separated out and designated as CSR18 and CSR19, respectively. By utilizing these lines at $F_{12}$, the hybrid CSR18$\times$CSR19 was prepared and studied for the thermotolerance by subjecting to stress condition at high temperature of 36$\pm$1$^{\circ}C$ and 85$\pm$5% RH in fifth instar and the control batches at $25{\times}1^{\circ}C$ and 65${\times}$5% RH. The better performance of CSR18${\times}$CSR19 (survival > 88%) at $36{\times}1^{\circ}C$ clearly indicates the general superiority of CSR18${\times}$CSR19 with regard to high temperature tolerance over the productive hybrids and CSR18$\times$CSR19 can perform well in varied agro-climatic conditions of the tropics with optimum qualitative and quantitative characteristics.s.

Effects of Rumen Undegradable Protein and Minerals Proteinate on Early Lactation Performance and Ovarian Functions of Dairy Cows in the Tropics

  • Kanjanapruthipong, J.;Buatong, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.6
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    • pp.806-811
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    • 2002
  • A 90 d study was designed to investigate the effects of rumen undegradable protein (RUP) and a mixture of Cu, Zn and Mn proteinate (CZMP) on milk yield and composition and ovarian functions during rainy months. Twenty four Holstein${\times}$ indigenous cows in their 2nd and 3rd lactation were randomly allocated to total mixed rations (TMR) containing soy bean meal (SBM) as a source of rumen degradable protein (RDP), SBM plus CZMP, and formalin treated SBM (FSBM) as a source of RUP. Maximum and minimum temperature humidity index during the experimental period were 83.6-84.7 and 75.4-76.1. There were no differences (p>0.05) in intakes of dry matter, crude protein and net energy and in contents of butterfat, lactose and minerals. Cows on TMR containing FSBM not only lost less weight (-278, -467 and -433 g/d) with more intake of RUP (0.92, 0.58 and 0.59 kg/d) but also produced more milk (19.27, 18.23 and 18.13 kg/d) and 4% fat corrected milk (18.57, 17.57 and 17.51 kg/d) with more protein (3.06, 2.81 and 2.80%), solids-not-fat (8.69, 8.38 and 8.38%) and less milk urea N (9.3, 15.4 and 15.0 mg/dl) compared with those on TMR containing SBM and SBM+CZMP, respectively (p<0.01). However, cows on TMR containing SBM and SBM+CZMP did not differ in these respects (p>0.05). Whereas incidence of cystic ovaries at 20 and 90 d pospartum was less (p<0.01) in cows on TMR containing SBM+CZMP (37.3 and 12.5%) than those on TMR containing SBM (62.5 and 25%), it was nil for cows on TMR containing FSBM. Cows in all three group differed (p<0.01) from each other for the recurrence of first observed estrus with those on TMR containing FSBM having least days (22, 36 and 47 d) compared with their counterpart on TMR containing SBM+CZMP and SBM, repectively. The results suggest that RUP is one of the limiting factors affecting milk yield and its composition and ovarian functions during early lactation of dairy cows in the tropics.

Cave communities and the future

  • Chapman, Phil
    • Journal of the speleological society of Korea
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    • no.4
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    • pp.51-58
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    • 1996
  • Caves abd the life they contain face constant pressure from a worldw demand for cement. hydro-electric power and land for building a agriculture. The 8th International Congress of Speleology held in Kentu two years ago passed a resolution on behalf of the IUCN "Cave Speci Group" which called for "...biological surveys of threatened caves. mos in the tropics, and ecological studies to solve specific managem provlems on the causes of endangerment and how these can be remov or mitigated". This final article in the "Cave Life" series explains the n for an ecological approach to cavelife conservation.

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Vegetation Indices for Selective Logging Detection in Tropical Forest of East Kalimantan

  • Bhandari, S.P.;Hussin, Y.A.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.289-291
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    • 2003
  • Selective logging is currently a widely adopted management practice throughout the tropics. Monitoring of spatial extent and intensity of such logging is, therefore, becoming an important issue for sustainable management of forest. This study explores the possibility of using vegetation indices and Landsat 7 ETM+ image for this purpose. Two dataset acquired on 2002 and 2000 of Labanan concession area East Kalimantan, Indonesia were used. Three different vegetation indices (MSAVI, SAVI and NDVI) slicing and differentiating methods were tested. The results showed that the MSAVI is superior with overall accuracy of 77% and kappa 0.64.

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Characteristics and Cutability of Farmed Rusa Deer (Cervus timorensis) Carcasses for Marketing of Venison

  • Dahlan, I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.5
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    • pp.740-746
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    • 2009
  • Rusa deer are the only viable commercial tropical deer species for farming in the tropics because of their hardiness, adaptability and prolific characteristics. Twelve entire rusa stags were slaughtered according to halal procedure and used for carcass evaluation and cutability studies. Three carcass categories; large (46 to 55 kg), medium (36 to 45 kg) and small (25 to 35 kg) were developed for rusa stags. This study indicated that entire Moluccan rusa deer stags with mean live weight ranges from 50 to 80 kg and age groups of 15 to 29 months showed dressing percentage of 58 to 62%. Carcass conformation of rusa stags showed significantly (p<0.05) higher forequarters portion than hindquarters for medium (mean weight, 40.8 kg) and large (mean weight, 50.0 kg) carcass categories. The large carcass category was significantly (p<0.05) bigger in hindquarters portion (47.3% vs. 45.4%) than the medium carcass category. This study showed that medium and large carcass categories are more suitable for boneless cuts since the muscles were larger than small carcasses and easy for deboning. Stag carcasses showed higher proportion of the musculature in the high-priced areas of the carcass such as in round cuts. Bone-in cuts are more suitable for small carcasses since the muscles were smaller and difficult to debone (mean weight, 30.5 kg). About 90% of total deer carcasses in the small carcass category were developed into retail bone-in cuts (excluding 9.9% of breast, shank and trimming). The carcass characteristics and cutability information derived from this study can be used as a basis for a venison marketing strategy for deer farming and production in the tropics.

Occurrence of Mycotoxins and Toxigenic Fungi in Groundnut (Arachis hypogaea L.) Seeds in Andhra Pradesh, India

  • Kishore, G.Krishna;Pande, S.;Manjula, K.;Rao, J.Narayana;Thomas, D.
    • The Plant Pathology Journal
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    • v.18 no.4
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    • pp.204-209
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    • 2002
  • Andhra Pradesh is one of the major groundnut growing states in India. A total of 182 groundnut samples collected at harvesting from farmers fields in five districts, namely; Anantapur, Chittoor, Cuddapah, Kurnool, and Mahaboobnagar, during 1999 and 2000 rainy seasons were evaluated for the presence of mycotoxins (both aflatoxins and zearalenone) and toxigenic fungi. In samples collected from each district, average seed infection by Aspergillus flavus and Fusarium spp. was 11.9-18.3% and 5.6-12.8% in 1999, and 9.5-14.1% and 9.4-11.9% in 2000, respectively. Among the samples collected, 20.3% and 16.5% were contaminated with aflatoxin in 1999 and 2000, respectively, and in 11.4% and 8.7% of the seed samples collected in two seasons, the aflatoxin content was >30 $\mu\textrm{g}$/kg. An alarming aflatoxin content of 851.9$\mu\textrm{g}$/kg was found in samples collected from Anantapur district during the rainy season in 1999. Zearalenone was not detected in any of the samples collected in 1999, while 2 out of 103 samples collected in 2000 were contaminated with 35.1 and 129.4$\mu\textrm{g}$/kg. Under in vitro cultural conditions, 35.8% of the 173 A. flavus isolates collected from the groundnut samples produced aflatoxins at concentrations of 94.3-1598.6 ng/$\textrm{m}{\ell}$ and 3% of the 266 Fusarium spp. isolates produced 98.1-847.3 $\mu\textrm{g}$/g of zearalenone. The results emphasize the need for a more systematic and regular monitoring of pre-harvest aflatoxin contamination.

APPLICATION OF BACKSCATTER AND COHERENCE DATA ON C AND L BAND FOR LANDCOVER IDENTIFICATION IN TROPICS

  • Nakayama, Mikiyasu
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.267-270
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    • 1999
  • Use of coherence data from operational satellite based SAR sensors has been experimented both on C and L band to identify landcover in tropics. While coherence data proved useful to improve accuracy in landcover identification, such data are not readily available. On the other hand, integrated use of backcatter data by multiple satellites is readily feasible. The very question to be asked is whether integration of backscatter data on multiple bands (e.g. C and L band) is either inferior or superior to use of coherence data. We therefore still do not have a solid clue to answer to the very question. The aim of this study is to evaluate the performance of "integrated use" of backscatter data on C and L band (by ERS and JERS respectively) to identify landcover, vis-a-vis the same by combination of backscatter and coherence data by single satellite. The study was carried out for an area in the southern part of the Sumatra Island, Indonesia. The area has been intensively converted from natural forest into plantation. Five categories of landcover exist in this study area. By ERS-1, only 2 or 3 classes may be identified with the backscatter data alone, while adding the coherence data could delineate 4 classes. By JERS-1, only 3 to 4 classes may be identified with the backscatter data alone, while 4 classes could be clearly delineated by adding the coherence data. By integrating backscatter data on two bands, 4 to 5 classes may be identified. It represents the best results among cases examined. The outcome of the study suggests that integrated use of backscatter data on two bands by ERS and JERS is as powerful as use of backscatter and coherence data on single band by one of these satellite.

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