Grain Yield Stability of Quality Protein Maize Genotypes across Diverse Environments of Terai and Mid Hills in Nepal

Maize is produced in diverse environmental conditions in Nepal. National Maize Research Program regularly tests maize genotypes for their grain yield stability in highly diverse environments. The objective of this paper is to estimate grain yield stability of quality protein maize genotypes across different environments. Two quality protein maize genotypes namely Poshilo Makai-1 and S99TLYQ-HG-B along with Farmer’s variety were tested at nine different locations of Nepal in four consecutive years before 2013 under farmer’s fields. Alpha-lattice design with two replications was used. The results of these studies revealed that S99TLYQ-HG-B was more stable followed by Poshilo Makai-1 as compare to Farmer’s variety. The overall higher mean grain yield and regression coefficient (b) near to unity showed that S99TLYQ-HG-B is the most adaptive genotype across the tested environments. However, more than unity regression coefficient (b) indicates that Poshilo Makai-1 could be the recommended variety for better environments under farmers’ management

Productivity of maize (Zea mays L.) as affected by varieties and sowing dates

Genotypic yield potential of maize varieties is greatly affected by sowing dates. In order to investigate the effects of sowing dates and varieties on the grain yield of maize, the field experiment was carried out at research field of National Maize Research Program (NMRP), Rampur, Chitwan, Nepal from April 2009 to March 2010.  Three varieties namely Rampur Composite, Arun-2 and Gaurav were sown at every week. The results of experiment showed that interaction effect of variety and sowing date on grain yield of maize was significant. Rampur Composite produced highest grain yield (6.1 t/ha) in August and lowest yield (2.6 t/ha) in May. Similarly Arun-2 produced highest yield (4.6 t/ha) in August and lowest yield (2.1 t/ha) in May. Gaurav produced highest grain yield (5.1 t/ha) in September followed by 4.9, 4.8 and 4.6 t/ha in February, July and August respectively and lowest yield (1.5 t/ha) in November. The sowing date was highly significant on grain production. The highest grain production was 5.1 t/ha in August followed by in February (4.9 t/ha), September (4.6 t/ha) and March (4.4 t/ha) respectively. The lowest grain yield was produced in May (2.4 t/ha). Therefore it was concluded that August planting was best for higher grain production of maize varieties (Rampur Composite, Arun-2 and Gaurav) in terai region of Nepal

Evaluation of pro-vitamin A enriched maize hybrids for fighting hidden hunger in Nepal

Prevailing vitamin A deficiency is a malnutrition repercussing retarded growth, weak immune system and night-blindness in human beings. Pro-vitamin A enriched maize hybrids could be a strategy for combating vitamin A deficiency, mostly prevailing in children and women of Nepal. With the objective to investigate superior pro-vitamin A enriched ‘bio-fortified’ maize cultivars, twice replicated experiments were laid out in α-lattice design over two consecutive growing seasons of 2019 and 2019/20 at the National Maize Research Program (NMRP), Rampur, Chitwan, Nepal. The results revealed that the difference among tested hybrids was glaring for all agro-morphological, yield, and yield components traits. Among the evaluated traits, days to 50% anthesis and silking, plant and ear height, numbers of kernel rows per cob, grains per row, and grain yield varied significantly among the tested maize hybrids. Effect of planting season was significant for grain yield where winter maize produced 32% higher grain yield than spring maize. HPO16-2, HPO49-3, HPO49-5, and HPO49-2 were the 38-61% high yielding ‘bio-fortified’ maize genotypes than normal hybrid check. Therefore, these hybrids might be the potential higher-yielding future pro-vitamin A enriched maize hybrids to resolve food insecurity, malnutrition, trade deficit on maize grains and specially to combat vitamin A deficiency in Nepal

Heat-tolerant maize for rainfed hot, dry environments in the lowland tropics: from breeding to improved seed delivery

Climate change-induced heat stress combines two challenges: high day- and nighttime temperatures, and physiological water deficit due to demand-side drought caused by increase in vapor-pressure deficit. It is one of the major factors in low productivity of maize in rainfed stress-prone environments in South Asia, affecting a large population of smallholder farmers who depend on maize for their sustenance and livelihoods. The International Maize and Wheat Improvement Center (CIMMYT) maize program in Asia, in partnership with public-sector maize research institutes and private-sector seed companies in South Asian countries, is implementing an intensive initiative for developing and deploying heat-tolerant maize that combines high yield potential with resilience to heat and drought stresses. With the integration of novel breeding tools and methods, including genomics-assisted breeding, doubled haploidy, field-based precision phenotyping, and trait-based selection, new maize germplasm with increased tolerance to heat stress is being developed for the South Asian tropics. Over a decade of concerted effort has resulted in the successful development and release of 20 high-yielding heat-tolerant maize hybrids in CIMMYT genetic backgrounds. Via public–private partnerships, eight hybrids are presently being deployed on over 50,000 ha in South Asian countries, including Bangladesh, Bhutan, India, Nepal, and Pakistan

A bibliography of parasites and diseases of marine and freshwater fishes of India

With the increasing demand for fish as human food, aquaculture both in freshwater and salt water is rapidly developing over the world. In the developing countries, fishes are being raised as food. In many countries fish farming is a very important economic activity. The most recent branch, mariculture, has shown advances in raising fishes in brackish, estuarine and bay waters, in which marine, anadromous and catadromous fishes have successfully been grown and maintained