Impact of Rice Nursery Nutrient Management, Seeding Density and Seedling Age on Yield and Yield Attributes

To help farmers in the mid hills of Nepal improve their crop management and rice yields, we conducted a study testing different nursery management options and their effect on grain yield and yield components under rainfed conditions. The experiment was conducted in a farmer’s field during the cropping season 2009 and 2010 at Sundarbazar, Lamjung, Nepal, using a 3-factor factorial RCB design with 3 replications. The three management factors tested were 1) fertilizer management in the nursery, 2) seeding density, and 3) seedling age at transplanting, using the rainfed lowland rice variety Radha-4. There were eight treatment combinations, consisting of two levels of fertilization (0 and 20:20:0:13 kg NPKS ha-1 at 15 DAS), two levels of seeding density (607 and 303 g·m-2) and two seedling ages (20 and 40 days old). Two years’ results showed that top-dressed fertilizer in the nursery had no consistent effect on grain yield. However, lower seeding density (303 g·m-2) resulted in taller plants, more productive tillers m-2, less sterility and higher grain yield. In addition, older seedlings (40 days) produced taller plants, more productive tillers, more filled grains, and a higher grain and straw yield. The interaction analysis between both factors indicated that 40 days old seedling with a low seeding density produced the highest grain yield, both in the drought season 2009 and the high-yielding season 2010. The economic analysis confirmed that the treatment with low seeding density and 40 days old seedlings produced by far the highest net returns and B:C ratio in both seasons, independent of the fertilizer treatment. The combination of these two management components is therefore economically viable and profitable, and can be recommended to farmers. However, the results need to be confirmed for other varieties used by farmers in the region.

Effect of row spacing and direction of sowing on yield and yield attributing characters of wheat cultivated in Western Chitwan, Nepal

A field experiment was conducted to study the growth and productivity of wheat as affected by row spacing and direction of sowing at Rampur, Chitwan, Nepal during the 2007-2008 wheat growing season. The experiment was carried out in 3-factors factorial randomized complete block design comprising two varieties (Gautam and BL-2800), three row spacings (15, 20 and25 cm) and two row directions of sowing (east-west and north-south). The effects of variety and row direction of sowing on grain yield were significant (p < 0.05), but the grain yield was not affected by the row spacing treatment. BL-2800 variety produced higher grain yield (3.53 t·ha-1) as compared to Gautam (3.11 t·ha-1). Both wheat varieties yielded about 11% higher (p < 0.05) grain in the north-south sowing as compared to the eastwest sowing.

Study of Fruit Diversity and Selection of Elite Acid Lime (<i>Citrus aurantifolia Swingle</i>) Genotypes in Nepal

Acid lime (Citrus aurantifolia) fruits are cultivated in terai, mid hill and high hill districts of Nepal. It is cross-pollinated crop and has a high variation in fruit characters within the species. Fruit character is the main basis of genotype selection. Study of fruit diversity is of utmost importance to select the elite genotypes for breeding and variety development program. Therefore, total of 620 fruit samples were collected and evaluated in the main production season of the year 2010 and 2011, from 62 bearing trees. Samples were collected from three agro-ecological domains, representing terai, mid hill and high hill areas of eastern Nepal. Elite landraces were selected on the basis of scoring fruit characters. High variation in vitamin C was observed between the terai (57.4 mg) and high hill (72.5 mg) samples. Amount of juice was 36.8% in mid hill and 44.1% in terai samples. Higher percent of juice and total soluble solids (TSS) observed in terai samples but tritable acidity (TA) and vitamin C was low as compare to high hills. There was significantly negative correlation found in fruit weight, fruit diameter, juice percent and seed number, whereas significantly positive correlation was in pulp and vitamin C, with altitude range. Total landraces were separated in five major cluster group. Variation in the level of similarity was observed among the cluster groups. The variability distance of fruit characters was highest in cluster group II (–17.45%) and lowest in cluster group V (58.5%). On the basis of scoring number of fruit characters, total four elite genotypes i.e. LD-49 from mid hills, LD-23 and LT-17 from higher hills and LM-44 from terai were selected for conservation, breeding and variety development purpose.

Genetic Diversity Assessment of Acid Lime (<i>Citrus aurantifolia</i>Swingle) Landraces in Nepal, Using SSR Markers

Acid lime (Citrus aurantifolia) is an important commercial fruits crop, cultivated in terai to high hills of Nepal. High variation of acid lime fruits are observed in existing landraces due to crossing within the other citrus species. Determination of genetic variation is important to the plant breeders for development of high yielding variety and hybrids. Therefore, an attempt has been made to study the genetic diversity of 62 acid lime landraces, collected from different altitudinal range in the eastern part of Nepal, using SSR markers. Twelve Simple Sequence Repeat (SSR) primer pairs were used to assess the genetic diversity of acid lime. The average genetic similarity level among the 62 accessions was 0.77, ranging from 0.54 to 1.0 and separated five major cluster groups. Total of 33 alleles were detected by eleven primer pairs and size of alleles ranged from 50 to 225. Average polymorphic information content (PIC) value was 0.50, whereas highest 0.75 and lowest 0.18 was observed in CAT01 and GT03 loci respectively. The results of the study clearly indicated that, SSR markers are highly polymorphic and more informative for the assessment of genetic diversity of acid lime landraces.

Growth and yield responses of broccoli cultivars to different rates of nitrogen in western Chitwan, Nepal

A field experiment was conducted with the objective to determine the optimum rate of nitrogen (N) fertilizer for effective growth and yield of two varieties of broccoli in southern plain of Nepal. The experiment was laid out with two-factorial completely random block design (RCBD) comprising two varieties of broccoli (Calabrese and Green Sprouting) and five N rates (0, 50, 100, 150 and 200 kg ha-1) with three replication in each treatment combinations. The effects of variety and N rate on total curd yield were significant but the interaction effect was non-significant. Green Sprouting produced 11% higher total curd than Calabrese. Similarly, curd production increased N rate up to 200 kg ha-1 reaching a maximum of 14.47 t ha-1. This indicated that optimum level of N could be beyond the rates tested in this study, which needs further experimentation.

Evaluation of Drought Tolerant Rice Cultivars Using Drought Tolerant Indices under Water Stress and Irrigated Condition

Drought is the most critical abiotic factor reducing rice yield in rainfed and drought prone areas. Majority of rice cultivated area in south Asia are under rainfed, where water stress at any of the critical growth stage causes sharp decline in yield. Research was conducted in western Nepal at farmers field around the close vicinity of Regional Agriculture Research Center (RARS) Nepalgunj. Ten different rice cultivars were evaluated under drought stress and non-stress condition during the year 2017 to identify superior stress tolerant cultivars. Different drought tolerance indices like stress tolerance (TOL), Stress tolerance index (STI), Stress susceptibility index (SSI), were tested in screening superior rice cultivars. Significant reduction in mean grain yield was observed under drought stress in all rice cultivars under the study. The rice cultivars with high STI values and low TOL and SSI were identified as superior drought tolerant cultivars. Based on results of different tolerance indices, Sukha series of rice, Sukha Dhan 1-6 and Radha-4 showed low TOL and SSI and high STI values and were identified as drought tolerant cultivars. The present study reveals that selection based on drought tolerance indices can be an efficient tool in identification of superior drought tolerant cultivars with higher yield and stability.

Variation of Physiochemical Components of Acid Lime (<i>Citrus aurantifolia</i>Swingle) Fruits at Different Sides of the Tree in Nepal

Acid Lime (Citrus aurantifolia Swingle) is one of the important commercial fruits cultivated from terai to high hill of Nepal. It is an important source of vitamin “C” (ascorbic acid) for human nutrition. Amount of juice, TSS (Total soluble solids), TA (Titrable acid) and vitamin C are the determining factors of quality of acid lime fruits which may vary according to bearing sides of the trees. The main objective of this study is, to determine the variation of fruit quality at different sides of the tree. Total of 15 bearing trees were selected randomly (5 trees per site) from three different agro ecological domain representing terai (1200 m asl) and samples were collected from the selected trees. Randomly ten fruits (from east, west, centre, north and south sides) were collected from each tree and analyzed for amount of vitamin C, TSS, TA and juice. Highest ascorbic acid 79.6 mg and 69.9 mg was observed in south side fruits whereas lowest 62.8 mg and 55.1 mg was observed in centre fruits in the high and mid hills zone respectively, but in terai, highest ascorbic acid 58.7 mg was observed in north side and lowest 41.8 mg was observed in centre. Highest amount of juice 43.9% was observed in south side fruits and lowest 36.6% in centre fruits, but amount of TSS 8.2% and TA 7.2% was observed in south side fruits and lowest 7.3% TSS and 7.0% TA was observed in centre fruits in high hills. In terai highest TSS 8.3% and TA 7.4% was observed in north side fruits and lowest TSS 7.3% and TA 6.7% was observed in centre fruits. Variation of TSS, TA percent and ascorbic acids was observed according to the agro ecological zone.

Exploring potentialities of avian genomic research in Nepalese Himalayas

Nepal,a small landlocked country in South Asia,holds about 800 km of Himalayan Mountain range including the Earth's highest mountain.Within such a mountain range in the north and plain lowlands in the south,Nepal provides a habitat for about 9%of global avian fauna.However,this diversity is underrated because of the lack of enough studies,especially using molecular tools to quantify an-d understand the distribution patterns of diversity.In this study,we reviewed the studies in the last two decades(20002019)that used molecular methods to study the biodiversity in Nepal to examine the ongoing research trend and focus.Although Nepalese Himalaya has many opportunities for cutting-edge molecular research,our results indicated that the rate of genetic/genomic studies is much slower compared to the regional trends.We found that genetic research in Nepal heavily relies on resources from international institutes and that too is mostly limited to research on species monitoring,distribution,and taxonomic validations.Local infrastructures to carry out cutting-edge genomic research in Nepal are still in their infancy and there is a strong need for support from national/international scientists,universities,and governmental agencies to expand such genomic infrastructures in Nepal.We particularly highlight avian fauna as a potential future study system in this region that can be an excellent resource to explore key biological questions such as understanding eco-physiology and molecular basis of organismal persistence to changing environment,evolutionary processes underlying divergence and speciation,or mechanisms of endemism and restrictive distribution of species.

Foot-and-Mouth Disease Outbreak at Bageshwori Gaushala,Chitwan,Nepal

Cow being the national animal of Nepal has special place in the society.Religious institutions have since prehistoric time reared and cared for cattle herds and the tradition still continues.The Bageshwori Gaushala(cow shelter),initiated by the Hindu Rastraguru Yogi Narhaharinath in mid-1990s is one of the largest of such nucleus indigenous cattle herds in Nepal.Indigenous cattle conservation strategy of Nepal has recognized the importance of this nucleus herd,kept by grazing in the surrounding forest.Ethnoveterinary approaches of managing the herd health is in practice and vaccination was never done.Occasional outbreak did happen in past but overall the herd never suffered severe impact.In April 2018,an outbreak of foot-and-mouth disease(FMD)occurred at Bageshwori,Gaushala,Devghat,Bharatpur Metropolitan-1,Chitwan district of Nepal.In the bovine herd studied,80(53.33%)out of 150 affected animals presented characteristics FMD symptoms as vesicular lesions,drooling salivation,foot lameness,high fever and weakness.Following prompt supportive treatment,the condition improved.The complete recovery of infected herd was observed after 45 d.Laboratory analysis showed the presence of Aphthovirus serotype O in the clinical sample.The present study attempts to provide fresh insights into the recent FMD outbreak,clinical signs,their effective treatment protocol and preventive measures that must be practiced following FMD outbreak.

Response of Stubble Shaving Times on Ratoon Yield of Different Sugarcane Genotypes

Ratooning is common practice done in sugarcane with purpose of reducing the total cost of cultivation and early cane maturity.More than 35%of sugarcane productivity is lost due to improper attention of the farmers towards ratoons.Majority of farmers reported that the ratoonability wasn’t good when harvested in December-January.This experiment was carried out to find the appropriate ratoon shaving time with response to different varieties in sugarcane ratoon crop in the year 2018/19 at national sugarcane research project,Jitpur,Bara.The experiment was conducted in split plot design with four levels of cane genotypes as Co–0238,CoLk–94184,Co–0233 and CoS–07250 as the main plot factor while four harvesting dates as sub plot factor with three replications.Observations of a number of millable canes,single cane weight,plant height and single cane diameter were recorded,tabulated and analyzed in R-studio.Ratoon stubble shaving in the month of November had the highest number of millable canes(88079/ha)which wasn’t significantly different from the stubble shaving in the month of December,January.Likewise,highest cane yield(60.04 mt/ha),single cane weight(0.757 kg),cane diameter(2.11 cm),plant height(1.82 m)were found in early stubble shaving dates.Cane Yield and various yield parameter shows better performance in early ratoon shaving periods i.e.from November to January than late ratoon shaving dates.