Helminthosporium leaf blight (HLB), a complex of spot blotch caused by Cochliobolus sativus and of tan spot caused by Pyrenophora tritici-repentis, is a major wheat disease in South Asia. This 2-year study elucidated HLB development and its impact on yield. Symptoms caused by C. sativus and P. tritici-repentis were first observed at the seedling and tillering stages, respectively. The number of airborne conidia and leaves infected by the two pathogens remained low for several weeks under lower temperatures, followed by a sharp rise as temperatures increased. The number of airborne conidia of C. sativus and incidence of infection by C. sativus were higher compared with P. tritici-repentis. The disease complex caused an average 30% reduction in yield, with greater losses under delayed seeding. Delayed seeding increased disease severity even in resistant genotypes and caused higher yield losses. 'Milan/Shanghai-7' was the most resistant among six genotypes evaluated. Despite higher disease severity, 'BL 1473' showed relatively lower yield losses, indicating its tolerance to foliar blight. The findings of this study bear implications for integrated foliar blight management in the warmer areas of South Asia by combining optimum seeding date, seed treatment and foliar spray of fungicides, and resistant wheat genotypes.

Background Pneumonia is a leading cause of mortality among children under-five years of age globally. The WHO (2014) has reported that indoor air pollution caused by cooking and heating with biomass fuel, living in crowed homes and parenting smoking are risk factors of pneumonia.Objectives The objective of the study was to identify the risk factors for pneumonia among children under-5 years of age.Methods A case control study was carried out among the mothers having under-5 years children who were admitted in the paediatric ward of Dhulikhel Hospital in 2012/13. A convenience sampling technique was used to select 50 children with pneumonia and 150 children with non-pneumonia diseases matched on age, sex and setting. A semi-structured interview consisting of questions related to risk factors for pneumonia was used to collect data from mothers of both cases and controls.Results Sex of the child did not differ by case/control group whereas the children with pneumonia were slightly older with 26% cases and 15% controls older than 3 years of age. Mother’s education was similar in both groups as was family income. Living in a household with a chulo with smoke increased the odds of having pneumonia significantly, with the risk almost 4 times greater if the chulo was located within the same building (OR: 3.76, 95% CI: 1.20-11.82, p=0.02). Children who had diarrhea in the past 3 months were protected from pneumonia (OR: 0.38, 95% CI: 0.18- 0.82, p=0.01). An increasing trend of pneumonia was observed among children of tobacco smoking parents with greater risk if both parents smoked; it was, however, not statically significant (OR: 2.21, 95% CI: 0.56-8.82, p=0.26).Conclusion The present study suggests that two factors related to smoke, presence of a smoky chulo in a household and both parents smoking, are modifiable risk factors related to pneumonia in young children. Reliable longitudinal studies, interventions, and programs to educate parents in prevention are important for reducing mortality and morbidities related to acute respiratory illnesses in Nepal.Kathmandu University Medical Journal Vol.12(4) 2014; 247-252

An experiment was conducted to determine the host resistance of potato against Phytophthora infestans for twenty-five potato genotypes in 2010 and 2011 at Khumaltar, Lalitpur, Nepal using four assays: three for foliage resistance (field, whole-plant and detached leaf) and one for tuber resistance (tuber slice). An isolate of P. infestans collected from Lalitpur (LPR-1) was used for inoculation at a concentration of 3 x 10 3 sporangia ml -1 in all assays. Infected foliage area in the field and whole-plant assays, lesion size on detached leaves, and colony growth on tuber slice were all individually converted to 0-9 interval scale for susceptibility. Field assessment, considering the most robust measure of resistance, was used as benchmark for comparing the other assays. Sixteen of the genotypes had very little disease in the field (scale value <1) indicating they were probably expressing race-specific resistance, which has historically been short lived. Susceptibility levels measured in the whole-pant assay were highly correlated (r = 0.90) with converted field scale values, although the correlation was lower for the detached leaf assay (r = 0.63) and least for tuber-slice assay (r = 0.46). Low correlation in the detached leaf assay was assumed to represent lower resolution of the single-cycle assay. Low correlation in the tuber assay may have also reflected genetic differences as foliage and tuber blight resistance are not always correlated. Genotypes with extreme resistance in the field were frequently identified as having partial resistance in the other assays, which could mistakenly be interpreted as more durable field resistance. The consequences for selecting durable resistance are discussed.

A study was carried out to address distribution of some heavy metals in deep groundwater resources of the Kathmandu Valley. Groundwater samples were analyzed for pH, ORP, EC, iron, manganese, zinc, and arsenic in 41 deep groundwater wells during pre monsoon and post monsoon seasons for two consecutive years. The study showed elevated concentrations of iron and manganese in the groundwater of the valley. The occurrence of elevated concentrations of arsenic was also exhibited and observed up to 0.160 mg/L. The spatial distribution patterns demonstrated elevated levels of EC, iron, manganese, zinc, and arsenic in central groundwater district (CGWD) of the valley. The monitored parameters except ORP are not significantly correlated with studied time series, inferring similar distribution of the metals. Correlation analysis and principal component analysis (PCA) were performed to find out relationships among examined parameters and metals. The ORP has strong negative correlations with iron, manganese, and arsenic, suggesting reductive mobilization mechanism of the metals in the groundwater. PCA results showed that iron and manganese with high positive loading factors were due to common natural source of origin of these metals in the groundwater, while negative loading factors of pH and ORP indicated that iron and manganese mobilization was favorable in low pH and reducing environment. Cluster analysis (CA) evidenced high mineralization in most of the wells in the CGWD.

The landraces of rice (Oryza sativaL.) possess wide diversity, which needs to be properly characterized for their use in genetic improvement. Replicated field studies were conducted in 1998, 1999 and 2000 at two sites in Nepal to determine diversity in 183 landraces of rice adapted to the lowlands and the hills in Nepal. Fourteen improved genotypes were also used for comparison. Thirteen agronomic traits were investigated. Shannon–Weaver diversity index (H) and Simpson's index of diversity (D) were estimated to determine the level of genetic richness among the landraces. The landraces differed significantly for all traits. Except for plant height and maturity, at least one of the landraces compared well with the performance of improved cultivars. A principal component analysis separated the lowland- and hill-adapted landraces into two broad groups.

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