Non-symbiotic Seed Germination and In vitro Plant Development of Pholidota articulata

Pholidota articulata is an epiphytic orchid mostly used in ornamental cut/pot flower and in traditional medicine. As it has high ornamental and medicinal values, its population from natural habitats is decreasing, therefore, it is listed in the Appendix-II of Convention on International Trade in Endangered Species (CITES). The objective of the present study is to obtain the in vitro plants of P. articulata from seed culture to conserve its germplasm. The in vitro seed germination was carried out in different strengths of Murashige and Skoog (MS) and Knudson C (KnC) medium supplemented with various plant hormones. On the half-strength of MS medium, seeds were started to germinate after 4 weeks of primary culture and they were developed into protocorms with first leaf primordium earlier than on the other medium. Therefore, in vitro developed protocorms were sub-cultured on the half-strength of MS medium supplemented with different concentrations of 6-benzylaminopurine (BAP), gibberellic acid (GA3) and α-naphtalene acetic acid (NAA). They were successfully developed into shoots on the 1.5 mg/l BAP supplemented half-strength of MS medium. Later, they were inoculated on the half-strength of MS medium supplemented with different concentration of α-napthalene acetic acid (NAA), indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) for the root formation, where IBA supplemented medium was found effective for the development of roots. Thus, this study provides a reliable protocol for non-symbiotic seed germination and plant production, and reveals that seed-derived protocorms are good explants for the in vitro mass propagation for conservation and sustainable utilization in horticulture.

Effect of Grafting Dates on Success and Growth of Kumquat (Fortunella japonica Swingle) Sapling

An experiment was carried out to study the effect of grafting dates on the success and growth of kumquat sapling during 2017-18 at Banepa, Kavre to standardize suitable grafting time. The experiment was conducted in a single factor completely randomized design with five treatments and three replications. The treatments consisted of five grafting dates which viz., 25th November, 10th December, 25th December, 10th January and 25th January. Scion collected from the mother plant of kumquat was grafted onto two years old trifoliate orange rootstock by side veneer method at 15 days intervals under screen house. The data were recorded at every 30 days interval and found a significant effect of grafting dates on most of the economically important parameters such as graft success percent, the mortality of sprouted grafts, sapling height, number of leaves per sapling and leaf area. The result revealed that 100% graft success was observed on the grafts prepared in January. The highest mortality (13.68±0.58%) was reported on 25th November grafted sapling. The sapling height (39.68±3.68 cm), number of leaves per sapling (23.12±3.43) and leaf area (16.34±1.05 cm2) were found superior for 10th January grafted sapling while the number of primary and secondary branches per sapling were found non-significant for all grafting dates. Therefore, the study revealed that 10th January was the most suitable time for grafting of kumquat under Kavre, Nepal conditions.

Effect of Grafting Dates on Graft-take Success and Sapling Growth of Persian Walnut (Juglans regia L.) Under Open Field Condition of Jumla, Nepal

A field experiment was carried out at Horticultural Research Station, Rajikot, Jumla to determine the best grafting date of walnut for the highest graft-take success and sapling growth. The experiment was conducted during the two consecutive years 2017, and 2018. Two varieties namely ‘Hartley’ and ‘Payne’ and four different dates of grafting viz. 15th March, 22nd March, 29th March, and 5th April were used as the treatment and the experiment was laid out in split-plot design. Each treatment was assigned with ten grafts with five replications per treatment. The measured parameters for the experiments included graft-take success (%), final scion diameter (cm), growth on scion diameter (%), number of primary branches per plant, plant spread (cm), and number of leaf per plant. The pooled value of observation for two years showed highly significant effect of variety and grafting date on grafting-take. ‘Hartley’ variety showed maximum graft-take success (73.2%) and ‘Payne’ with the least success (54.0%). The pooled value of two successive years showed the highest graft-take success (70.0%) on 15th of March, significantly at par with 22nd March (64.5%) and 29th March (67.0 %) grafting. Grafting on 15th March was also superior in terms of number of leaves (31.7), and least was observed for grafting on 29th March (20.5). In essence, variety ‘Hartley’ was found to record higher graft-take success with 15th March as the optimum grafting date under Jumla condition.

Assessment of Radish (Raphanus sativus L.) Cultivars for its Yield and Yield Attributing Characters at Central Mid-Hill (Kathmandu Valley) Conditions of Nepal

A varietal study on five open pollinated cultivars of Radish viz Mino Early, Okura, Pusa Chetki, Forty Days and Miyasige with an objective to find the most superior variety was conducted at Horticultural Research Division, Khumaltar, Lalitpur in winter season for 3 years from 2016 in consecutive years. Mino Early and Forty Days are widely adopted varieties and kept as local check varieties. The trial was conducted under Randomized Complete Block Design (RCBD) with four replications. Out of the five cultivars, Okura gave significantly the highest of Root wt. (326 g), Root yield (53.85 t/ha), Root length (25.5 cm), Root diameter (53.9 mm), and Leaf wt per plant. (268 g), Days to harvest (63 days) followed by Miyasige which had Root wt (259 g), Root length (23.4 cm) Root diameter (51.9 mm), Days to harvest (66 days). Okura had 49 percent yield increment followed by Miyasige with 21.9 percent as compared to Mino Early. Hence, these two cultivars are found superior and recommended for cultivation in central mid-hills like Kathmandu valley conditions in Nepal.

Evaluation of Growth and Yield Characters of Garden Pea Genotypes at Dailekh, Mid-Western Nepal

Knowledge of phenotypic variation among the germplasm is important for the breeding program of garden pea. This study was conducted to evaluate the growth and yield traits of garden pea genotypes and to identify high yielding, and powdery mildew resistant genotype at Horticulture Research Station (HRS), Dailekh, Mid-western Nepal. Eleven garden pea genotypes were evaluated in the main production season (2018-2019) and compared with 'Sikkim Local' as standard variety, and the experiment was laid out in randomized complete block design with three replications. The analysis of variance revealed that genotypes had significant variation for all the traits studied except few insignificant traits. Significantly higher number of green pod/plant, green pod yield/plant, seed number/pod and seed yield/plant were recorded in genotypes DGP-12-18-2 and DGP-12-18-1 as compared with other studied genotypes. Genotype DGP-12-18-2, and DGP-12-18-1 exhibited resistant (2) to powdery mildew disease and these genotypes showed 45.8% and 16.6% yield advantage over the standard check 'Sikkim Local' variety. Therefore, genotypes DGP-12-18-2 and DGP-12-18-1 can be recommended to produce for fresh green pod and seed yield at on-farm condition of Mid-Western Nepal.

Effect of Postharvest Application of Edible Coatings and Packaging on Acid Lime Fruit var. SunKagati 1 Quality at Ambient Storage Condition

Sunkagati-1 is one of the commonly grown acid limes recommended for terai region of Nepal with main season production from Shrawan to Poush. In recent year, area of acid lime is increasing while no appropriate technology of postharvest is available for it. An experiment was carried out with an objective to assess the influence of edible oil coatings and packaging on storage life of acid lime fruit. Fruits were harvested at physiologically mature stage with smooth and shiny appearance and treated with four edible oils (coconut oil, mustard oil, sesamum oil and castor oil), liquid paraffin 10% wax emulsion and 25 micron low density polyethylene (LDPE) packaging. The study was conducted in completely randomized block design (CRD) with seven treatments and three replications. Fruits were kept at ambient condition (20±1.55 ºC, 65±6.5 % RH) till 24 days and analyzed for various postharvest physical, chemical and physiological parameters after 8th, 16th and 24th days of storage. The result showed that LDPE packaging has significant effect on reduction of physiological loss in weight (1.69 %), spoilage loss (5.17 %), higher vitamin C content (60.11 mg/100g), Titratable acidity (6.71 %) and development of marketable color viz., 100% yellow color. Also, coconut oil showed significantly better postharvest quality retention with reduced physiological loss in weight (10.83 %) and spoilage loss (10.45 %). This study concluded that LDPE packaging and coconut oil coating are the appropriate method to extend the storage life of acid lime in ambient condition of mid hills situation.

Assessment of Inter-varietal Cross Lines of Gladiolus on Vegetative and Floral Traits for Selection and Promotion in Nepal

Artificial crossing between species and varieties has been effective in producing new gladiolus cultivar with desirable traits. The seeds obtained from the total of twelve inter-varietal cross lines were raised in nurseries in 2013. The corms and cormels were selected yearly from the first phase to the fourth phase of selection. Forty seven inter-varietal cross lines and one check genotype were assessed in preliminary non-replicated trial in 2017 in the field of Regional Agricultural Research Station, Lumle, Nepal. A total of twenty five inter-varietal cross lines of gladiolus was selected, and assessed to develop new productive and attractive varieties of gladiolus on the basis of sixteen traits: the first spike emergence, complete spike emergence, the first floret loosening, maximum number of floret opening at a time, floret diameter, number of florets /spike, days to the seventh floret wilting, flower life, plant height, spike length, rachis length, number of spikes/ mother corm, number of marketable spikes /mother corm, number of filled capsules/spike, number of unfilled capsules/spike and total number of capsules/spike. Forty six inter-varietal cross lines were selectively reduced to twenty five inter-varietal cross lines after they had been assessed in the preliminary trial. Eventually ten cross lines: HRSDG-013-2.17(A), HRSDG-013-7.4(B), HRSDG-013-7.8(A), HRSDG-013-7.8(B), HRSDG-013-8.5(A), HRSDG-013-8.16(A), HRSDG-013-9.12(A-2), HRSDG-013-10.24, HRSDG-013-11.7(B) and HRSDG-013-11.17(B-2) are likely to be promoted for replicated trial so as to develop new desirable varieties in future.

Evaluation of Cucumber Hybrids for Yield and Quality Under Plastic House and Open Field Conditions

Low yield of off-season cucumber due to use of open-pollinated varieties with high male to female ration, long gestation period and high incidence of diseases are the major problems of cucumber production in Nepal. The use of imported hybrids varieties during the off-season and plastic film technology has shown to lead to enhanced growth and higher yield in recent years. However, there is a little work on hybrid cucumber research and their testing in Nepal. Therefore, experiments were conducted at the National Horticulture Research Center (NHRC), Directorate of Agricultural Research (DoAR), Tarahara and Farmer's field in Dhankuta district accordingly to select best hybrids. Sixteen genotypes including best Indian hybrid Dynasty and 3 open-pollinated check genotypes were evaluated at NHRC, Khumaltar during the years 2018 and 2019 in Randomized Complete Block Design (RCBD) with three replications under the plastic house. Previously selected seven genotypes were evaluated in DoAR, Tarahara in 3 replications and best hybrid was compared with farmers' varieties in Dhankuta at open field conditions. Tested genotypes showed a significant difference in yield and other parameters like male to female ratio, early flowering, vine length, disease scoring etc. both under the plastic house and open field conditions. The new hybrids HRD CUM 009 x 003 (107.05 mt/ha), HRD CUM 006 x 003 (91.55 mt/ha) and HRD CUM 004 x 001(88. 10 mt/ha) were promising due to higher yield, earlier to 50% female and male flowering, a greater number of female flowers, short vine length, higher number of fruits per plants and earliness harvesting than other cultivated varieties. Most of the tested hybrids produced more than double yield than open-pollinated genotypes.

Evaluation of Radish (Raphanus sativus L.) Varieties under Shade-net Condition for Yield and Quality

This experiment was carried out in a shade net house at the horticultural research farm of Agriculture and Forestry University, Chitwan, Nepal during spring 2018 to identify the suitable radish (Raphanus sativus L.) variety having high yield potential with better quality roots for off season. The experiment was laid out in Randomized Complete Block Design (RCBD) with eight treatments, i.e. five improved (Vedetar Local, Miyasinge, Tokinasi, Pusa Chetki and All Season) and three hybrid varieties (Mino Early Long White F1, Ivory White F1 and MAHY 22 F1) of radish with four replications. Radish seeds were seeded in the third week of February. Miyasinge variety showed the highest plant height (43.91 cm), biomass yield (73.22 t ha-1) and fresh shoot weight per plant (127.15 g) whereas the highest number of leaves per plant (20.54) was recorded in MAHY 22 F1. Ivory White F1 variety showed the highest root length (19.51 cm), root circumference (9.31 cm), root to shoot ratio per plant (1.29) and fresh root yield (30.87 t ha-1). The highest root skin thickness (0.27 cm) was found in Miyasinge, the highest TSS (6.20 ºBrix) was observed in Mino Early Long White F1. Ivory White F1 showed the highest ascorbic acid content (19.51 mg 100 g-1), dry matter of root (7.62 %) and score (8.36) from the consumers’ acceptability test for pungency. Ivory White F1 showed superior growth, yield and quality attributes under shed net conditions.

Opportunity and Challenges of Sweet Orange (Citrus sinensis L. Osbeck) Production in Sindhuli and Ramechhap Districts

Household survey and focus group discussion (FGD) were carried out in year 2017/18 in Sindhuli and Ramechhap districts in order to identify scope and constraints for better sweet orange production. A semi-structured questionnaire acquiring household and orchard information, production, post-harvest operation as well as marketing situation was administered in the survey of 60 and 62 households in Sindhuli and Ramechhap, respectively. Prior to household survey, a FGD was carried out in each site of Sindhuli and Ramechhap to collect general information and cross check the individual response. Poor orchard management, lack of irrigation, infestation of a number of insects including fruit fly, infection of a number of diseases as well as lack of financial facilities were reported as key constraints to grow sweet orange industries in these districts. The yield of sweet orange was found less than national average yield in both survey sites. Various measures to increase production and to improve post-harvest quality of fruits have been suggested based on situation analysis.