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21.
Pearl millet (Pennisetum glaucum) is the most important cereal in crop-livestock production systems in arid and drier semi-arid environments valued for its grain and dry stover. The conventional approach of improving grain yield through greater partitioning of biomass to the grain and decreased stover yield is not a viable strategy for arid regions where biomass also needs to be improved. The current research tested the hypothesis whether biomass can be improved without extending the crop duration. The 232 F5 lines derived from a cross (J28 × RIB 335/18) were evaluated in their testcross form along with three commercial hybrids under arid zone conditions. Biomass, grain and stover yields, panicle number, grain size and grain number panicle−1 varied 1.8 to 2.7 fold in progeny testcrosses. Variation in duration of flowering time accounted for only 2% of variation in biomass, indicating that considerable scope existed for selection of testcrosses, and by implication, of F5 progenies with high biomass independent of crop duration. Stover yield accounted for 72% of differences in total biomass with remaining accounted for by grain yield. From among 92 and 132 testcrosses that had flowering time comparable to two early checks, most had significantly higher biomass, grain and stover yields than these early checks but none of the testcrosses had earliness on par with extra-early maturing hybrid HHB 67. Mean superiority of best 5% testcrosses over early checks was 58% for biomass, 68% for stover yield and 53% for grain yield. The results indicated that there are good prospects of improving biomass in arid zone pearl millet without significantly compromising crop duration.  相似文献   
22.
In South Asia, foliar blight of wheat (Triticum aestivum L.) is a disease complex caused by Cochliobolus sativus (the spot blotch pathogen) and Pyrenophora tritici-repentis (the tan spot pathogen) which can reduce yields by >30?%. Little is known about the effects of wheat genotypes and their planting time on foliar blight epidemics. Field experiments were conducted to determine the infection potential and epidemic development of C. sativus and P. tritici-repentis on two susceptible (Sonalika and BL1473) and two tolerant (NL750 and Milan/Shanghai-7) wheat genotypes under optimum (November 26) and late (December 11 and December 26) planting conditions. The dynamics of airborne conidia were studied using air samplers. The highest aerial concentrations of conidia and disease incidence of both pathogens on all four wheat genotypes were detected during the first 3?weeks of March under both optimum and late seeding conditions in both years. Compared to optimum sowing time (i.e. November 26), wheat genotypes had higher disease severity when planted late on December 11 and 26. The disease complex reduced grain yield by 20.5, 27.2 and 37.3?% for November 26, December 11 and December 26 plantings, respectively in 2004. The corresponding differences were 17.7, 23.6 and 30.2?% in 2005. The findings of this study provide valuable information on the epidemiology of spot blotch and tan spot, which could help in developing strategies for managing these diseases in South Asian region through the selection of suitable genotypes and planting dates.  相似文献   
23.
Universally, trees have been recognized as an important component of urban landscapes for millennia because they provide a wide range of benefits to society. Although the planting of trees has been an integral and important part of human settlements in Nepal, the concept of urban forestry is poorly understood and often neglected. This paper investigates urban peoples?? perceptions towards urban forests as well as the perceived benefits related to the use and existence of urban forests in Lalitpur, Nepal. A survey was conducted among residents and visitors to an urban park. Most respondents held positive attitudes towards urban forests and were aware of the benefits provided. Despite involvement of various agents from both government and non-governmental organizations in promoting urban forests, greenery was declining in the city. The loss and degradation of urban forests adversely affected the ecosystems because the city is suffering from water, air and soil pollution. In recent years, the local government has promoted urban greenery; however, there are no accompanying legislation or regulations governing urban forestry. Therefore, concrete scientific and professional knowledge is required in order to manage the forestry in the city.  相似文献   
24.
Journal of Crop Science and Biotechnology - Drawing upon consequentially growing food insecurity in mid-hills attributed to poor adoption levels inter alia inflicted by narrow range of locally...  相似文献   
25.
Severe losses of yaks (Bos grunniens) were investigated in the most eastern region of Bhutan. The most serious disease was a fatal chronic skin disease with emaciation and anaemia. Post mortem examinations revealed major lesions in the liver, consisting of hepatic megalocytosis, bile duct proliferation, fibrosis and remodelling of the hepatic structure. There was also renal megalocytosis, ascites and mild to moderate icterus. Pyrrolizidine alkaloid poisoning was diagnosed and confirmed by demonstrating sulphur-bound pyrrolic metabolites of the alkaloids in preserved liver tissue. Skin lesions with hyaline parakeratosis were an important feature. Similar lesions were found in the mucosa of the oral cavity. No records could be found of such skin lesions in any other species or disease. Pyrrolizidine alkaloid poisoning seriously affects the livelihood of the local population which depends almost entirely on the yak. Various control measures are discussed. The key to be found is the identification of the toxic plants.  相似文献   
26.
27.
Rumen ciliate composition of river-type water buffalo and goat in Nepal was surveyed. As the result of survey, 13 genera representing 52 species and 20 formae of the ciliates were identified. Of them 13 genera with 44 species and 9 formae were found from the water buffalo and 8 genera with 21 species and 12 formae from the goat. The present paper shows the first report of Hsiungella triciliata, Entodinium brevispinum, E. convexum, E. javanicum, E. rectangulatum f. rectangulatum, E. rectangulatum f. lobosospinosum, Diplodinium nanum, D. psittaceum, D. sinhalicum and Ostracodinium quadrivesiculatum from water buffalo and Epidinium ecaudatum f. parvicaudatum from goat.  相似文献   
28.
The composition of the essential oil of Lindera neesiana Kurz fruit was examined by GC-MS, 1H, 13C and bidimensional NMR techniques (HMQC, HMBC, COSY, TOCSY). Forty compounds were identified, representing approximately 86% of the oil: Z-citral (15.08%), E-citral (11.89%), eucalyptol (8.75%), citronellal (6.72%), α-pinene (6.63%) and β-pinene (5.61%) were the major components. The essential oil of L. neesiana fruit showed significant antimicrobial activity against Staphylococcus aureus and Candida albicans at non-cytotoxic doses in human keratinocytes, suggesting possible topical applications.  相似文献   
29.
Fungal leaf spot diseases of wheat (Triticum aestivum L.) in Nepal cause significant yield reduction. Although field testing has identified a few partially resistant cultivars, most wheat grown in Nepal lacks adequate resistance to leaf spot diseases. During 2009–2010, 116 local and commercial spring wheat cultivars and advanced breeding lines were selected from multi-year field experiments in Nepal and evaluated for seedling resistance to three leaf spot diseases: spot blotch, Stagonospora nodorum blotch (SNB) and tan spot races 1 and 5 (two of the most prevalent races) in the growth chambers at North Dakota State University, Fargo, ND, USA. The wheat cultivars and lines were artificially inoculated with individual pathogens or races at the two-leaf stage and disease reactions were evaluated 6 to 10 days after inoculation (DAI). Results indicated that 30%, 31%, 19% and 10% of the tested wheat cultivars and lines were resistant to spot blotch, SNB, tan spot races 1 and 5, respectively. Six advanced breeding lines (SW89-5422, BL 2127 = DANIAL88/HLB30//NL297, BL 3033, FILIN/IRENA/5/CNDO/R143//ENTE/MEXI-2/3/AE. SQUA (TAUS)/4WEAVER, GAN/AE.SQUARROSA (236)//DOY1/AE.SQUARROSA(447)/3/MAIZ/4/INQALAB91, Mayoor//TK SN1081/Ae. Squarrosa (222)/3/FCT, were resistant to spot blotch, SNB and tan spot race 1. Similarly, two wheat cultivars Chirya 3 and Chirya 7 were resistant to spot blotch, and tan spot races 1 and 5. The resistant wheat lines identified in this study represent potentially useful and untapped sources of resistance to multiple leaf spot diseases and should be utilized in wheat breeding programs in Nepal in order to develop wheat cultivars with broad-spectrum resistance.  相似文献   
30.
An outbreak of virulent footrot was investigated in a flock of 605 Merino cross-bred sheep in Bhutan. Conventional control methods in the preceding eight years had reduced its prevalence from 36-79% in different components of the flock to about 15% overall. Only one serogroup (B) of Dichelobacter nodosus was identified among 40 isolates cultured from affected sheep. A vaccine prepared from this strain was used in a pilot trial to compare the response of 14 treated and 14 untreated sheep. All affected, vaccinated animals in this trial healed quickly and were protected against re-infection while additional cases developed among untreated sheep during a period favourable for the spread of footrot. The serogroup B vaccine was administered to the whole flock for two successive years. No other footrot treatment was given during these or subsequent years. The whole flock was examined three times, foot by foot, for two years and twice yearly for another two years. When vaccination began there were 88 affected sheep in the flock, an affected sheep being defined as an animal with a foot-score of 2 or greater in one or more feet. There were neither affected sheep in the flock 30 days after the first dose of vaccine nor were any identified in later inspections. Virulent footrot, originating from the farm under investigation, persisted in neighbouring village flocks during this period. It was concluded that whole flock specific D. nodosus vaccination made a major contribution to the elimination of all clinical signs of footrot from the flock of 605 sheep where the condition had previously persisted for 10 years.  相似文献   
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