Chiranjivi Regmi - Academia.edu (original) (raw)

Papers by Chiranjivi Regmi

Research for development, 2023

International Organization of Citrus Virologists Conference Proceedings (1957-2010)

International Organization of Citrus Virologists Conference Proceedings (1957-2010), 1993

The shoot tip grafting (STG) technique has been applied in different countries for supplying dise... more The shoot tip grafting (STG) technique has been applied in different countries for supplying disease-free citrus. The objectives of these studies were to modify the existing techniques to obtain more successful grafts. The combination of three conditions: a) exposure of seedlings to room light conditions, 12 hr daily for 3-9 days prior to grafting, b) benzyl aminopurine (BAP) treatment of the grafts at 0.5 mgiliter Murashige and Skoog (MS) medium for shoot development of the scion and c) transfer of successful grafts to the control MS medium (without any growth hormone) for 10-15 days prior to transferring to soil, have increased the number of successful grafts of one mandarin and one sweet orange variety gafted to rough lemon rootstock.

International Organization of Citrus Virologists Conference Proceedings (1957-2010), 1988

Population dynamics of the greening vector was monitored randomly in selected Eureka Lemon trees ... more Population dynamics of the greening vector was monitored randomly in selected Eureka Lemon trees over a period of 5 yr in a citrus orchard at Pokhara (altitude 935 m). It was observed that the Diaphorina citri population reached its maximum in May, June, and July before the monsoon, and its minimum during the winter. The progression of the disease in the orchard was 12% per year.

International Organization of Citrus Virologists Conference Proceedings (1957-2010), 2010

Poverty in Nepal, largely a rural phenomenon, is widespread, with 30.8% of the population living ... more Poverty in Nepal, largely a rural phenomenon, is widespread, with 30.8% of the population living below the poverty line. Agriculture is the main source of livelihood of the Nepalese people who are living below poverty. Citrus, the first cash crop, is grown in small to very small orchards producing less than 10 tons/ha. More than 90% of the trees are seedlings of a local mandarin and therefore they are essentially free of most graft-transmissible diseases. Huanglongbing (HLB) and the Asian psyllid vector, Diaphorina citri, were reported in Nepal in the mid-1960s and, in the absence of any control measures, have continued to spread ever since. Here we report the information available regarding the presence of HLB in several important citrusgrowing areas (Armalakur,

Nepal Journal of Science and Technology, 2002

A study was carried out to isolate indigenous lepidopteran-toxic Bacillus thuringiensis strains ... more A study was carried out to isolate indigenous lepidopteran-toxic Bacillus thuringiensis strains from the soils collected from different regions of Nepa1.A total of 350 soil samples were collected from far western, mid western, western, central and eastern regions covering 33 districts in Nepal.Three thousand eight hundred colonies recovered after acetate selection, were screened for bipyramidal crystal morphology Eight strains of B. thuringiensis were isolated and bioassayed for their effectiveness against the cabbage butterfly, Pieris brassicae nepalensis Doubleday and the cotton bollworm, Helicoverpa armigera Hubner . Results showed the prevalence of B. thuringiensis from an altitude ranging from 72 to 5050 m. above sea level (masl) in the soils. Among the eight B, thuringiensis strains isolated, Chit-5 isolated from uncultivated land in Chitwan (400 masl) proved to be the most efective against the third instar larvae of both the above insects. The other isolates showed varying d...

Nepal Journal of Science and Technology, 2003

Huanglongbing disease (HLB) or citrus greening disease (CGD) is the number one threat to the citr... more Huanglongbing disease (HLB) or citrus greening disease (CGD) is the number one threat to the citrus production of Nepal. The greening organism produces leaf mottle symptoms, but they are not specific for confirmative diagnosis. The pathogen cannot be cultured in artificial medium that makes its diagnosis more complicated. In this context quick and reliable polymerase chain reaction (PCR)-based molecular diagnosis of this disease is crucial. In the present investigation, two PCR-based assays viz. one based on 16S ribosomal DNA (rDNA) and another based on ribosomal protein gene from the b operon (rpl KAJL-rpoBC) of HLB oganism were used to diagnose HLB disease in suspected citrus samples collected from 10 districts of Nepal. Out of 198 samples tested, 38 were detected positive for HLB. Of the 10 districts studied, eight were found infested with HLB disease. Result of the present preliminary study on distribution of HLB disease in Nepal highlights the alarming potential threat to citr...

Citrus canker, caused by the bacterium Xanthomonas citri (Hasse) occurs in large areas of the wor... more Citrus canker, caused by the bacterium Xanthomonas citri (Hasse) occurs in large areas of the world’s citrus growing countries including Nepal. Though the disease has serious effect in Nepal, this is the first detailed study carried out to isolate the pathogen and confirm it by available biochemical tests and pathogenicity test. Furthermore, the study was intended to find the proper and economical control measure to combat disease in citrus orchards. The causative agent of the disease was isolated from the diseased plants and pure culture was obtained. The isolated pure culture was subjected to Gram staining, catalase test, oxidase test, O-F test, starch hydrolysis, nitrate reduction test, methylred test, Voges-prausker test, indole production test, urease test and carbohydrate utilization test. To re-confirm it, pathogenicity test was conducted on host plant and after the appearance of the typical citrus canker lesion on host, the bacteria was re-isolated, thus proving the Koch’s p...

Nepalese Horticulture

An experiment was carried out to study the effect of grafting dates on the success and growth of ... more 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 mortalit...

Nepal Journal of Science and Technology, 2010

Citrus canker, caused by the bacterium Xanthomonas citri (Hasse) occurs in large areas of the wor... more Citrus canker, caused by the bacterium Xanthomonas citri (Hasse) occurs in large areas of the world's citrus growing countries including Nepal. Though the disease has serious effect in Nepal, this is the first detailed study carried out to isolate the pathogen and confirm it by available biochemical tests and pathogenicity test. Furthermore, the study was intended to find the proper and economical control measure to combat disease in citrus orchards. The causative agent of the disease was isolated from the diseased plants and pure culture was obtained. The isolated pure culture was subjected to Gram staining, catalase test, oxidase test, O-F test, starch hydrolysis, nitrate reduction test, methylred test, Voges-prausker test, indole production test, urease test and carbohydrate utilization test. To re-confirm it, pathogenicity test was conducted on host plant and after the appearance of the typical citrus canker lesion on host, the bacteria was re-isolated, thus proving the Koch...

Nepal Journal of Science and Technology, 2013

Biomass such as agricultural and forestry residues are important resources for energy in Nepal. T... more Biomass such as agricultural and forestry residues are important resources for energy in Nepal. This biomass can be converted into densified soild biofuel by briquetting fuel technology which can address handling, transportation, and storage problems. In addition, it helps to increase a number of applications and enhance its utilization efficiency. The purpose of this study is to quantify the physical and chemical properties of different biomass, such as sawdust, banana stem, rice straw, etc. and combustion in order to investigate clear options. Additionally, it helps to provide the efficiency of stoves available at Nepal Academy of Science and Technology (NAST) laboratory. Among the feedstock tested, Mikania micrantha char had highest fixed carbon of 45.92% which clearly shows that it is a good source for biomass briquetting. Out of four stoves tested, Baked Ceramic 4 BHB Stoves had highest efficiency of 33.4% with Banmara briquettes. The study also showed reduced emission of harmf...

Science, technology and innovation indicators in …, 2007

Research for development, 2023

International Organization of Citrus Virologists Conference Proceedings (1957-2010)

International Organization of Citrus Virologists Conference Proceedings (1957-2010), 1993

The shoot tip grafting (STG) technique has been applied in different countries for supplying dise... more The shoot tip grafting (STG) technique has been applied in different countries for supplying disease-free citrus. The objectives of these studies were to modify the existing techniques to obtain more successful grafts. The combination of three conditions: a) exposure of seedlings to room light conditions, 12 hr daily for 3-9 days prior to grafting, b) benzyl aminopurine (BAP) treatment of the grafts at 0.5 mgiliter Murashige and Skoog (MS) medium for shoot development of the scion and c) transfer of successful grafts to the control MS medium (without any growth hormone) for 10-15 days prior to transferring to soil, have increased the number of successful grafts of one mandarin and one sweet orange variety gafted to rough lemon rootstock.

International Organization of Citrus Virologists Conference Proceedings (1957-2010), 1988

Population dynamics of the greening vector was monitored randomly in selected Eureka Lemon trees ... more Population dynamics of the greening vector was monitored randomly in selected Eureka Lemon trees over a period of 5 yr in a citrus orchard at Pokhara (altitude 935 m). It was observed that the Diaphorina citri population reached its maximum in May, June, and July before the monsoon, and its minimum during the winter. The progression of the disease in the orchard was 12% per year.

International Organization of Citrus Virologists Conference Proceedings (1957-2010), 2010

Poverty in Nepal, largely a rural phenomenon, is widespread, with 30.8% of the population living ... more Poverty in Nepal, largely a rural phenomenon, is widespread, with 30.8% of the population living below the poverty line. Agriculture is the main source of livelihood of the Nepalese people who are living below poverty. Citrus, the first cash crop, is grown in small to very small orchards producing less than 10 tons/ha. More than 90% of the trees are seedlings of a local mandarin and therefore they are essentially free of most graft-transmissible diseases. Huanglongbing (HLB) and the Asian psyllid vector, Diaphorina citri, were reported in Nepal in the mid-1960s and, in the absence of any control measures, have continued to spread ever since. Here we report the information available regarding the presence of HLB in several important citrusgrowing areas (Armalakur,

Nepal Journal of Science and Technology, 2002

A study was carried out to isolate indigenous lepidopteran-toxic Bacillus thuringiensis strains ... more A study was carried out to isolate indigenous lepidopteran-toxic Bacillus thuringiensis strains from the soils collected from different regions of Nepa1.A total of 350 soil samples were collected from far western, mid western, western, central and eastern regions covering 33 districts in Nepal.Three thousand eight hundred colonies recovered after acetate selection, were screened for bipyramidal crystal morphology Eight strains of B. thuringiensis were isolated and bioassayed for their effectiveness against the cabbage butterfly, Pieris brassicae nepalensis Doubleday and the cotton bollworm, Helicoverpa armigera Hubner . Results showed the prevalence of B. thuringiensis from an altitude ranging from 72 to 5050 m. above sea level (masl) in the soils. Among the eight B, thuringiensis strains isolated, Chit-5 isolated from uncultivated land in Chitwan (400 masl) proved to be the most efective against the third instar larvae of both the above insects. The other isolates showed varying d...

Nepal Journal of Science and Technology, 2003

Huanglongbing disease (HLB) or citrus greening disease (CGD) is the number one threat to the citr... more Huanglongbing disease (HLB) or citrus greening disease (CGD) is the number one threat to the citrus production of Nepal. The greening organism produces leaf mottle symptoms, but they are not specific for confirmative diagnosis. The pathogen cannot be cultured in artificial medium that makes its diagnosis more complicated. In this context quick and reliable polymerase chain reaction (PCR)-based molecular diagnosis of this disease is crucial. In the present investigation, two PCR-based assays viz. one based on 16S ribosomal DNA (rDNA) and another based on ribosomal protein gene from the b operon (rpl KAJL-rpoBC) of HLB oganism were used to diagnose HLB disease in suspected citrus samples collected from 10 districts of Nepal. Out of 198 samples tested, 38 were detected positive for HLB. Of the 10 districts studied, eight were found infested with HLB disease. Result of the present preliminary study on distribution of HLB disease in Nepal highlights the alarming potential threat to citr...

Citrus canker, caused by the bacterium Xanthomonas citri (Hasse) occurs in large areas of the wor... more Citrus canker, caused by the bacterium Xanthomonas citri (Hasse) occurs in large areas of the world’s citrus growing countries including Nepal. Though the disease has serious effect in Nepal, this is the first detailed study carried out to isolate the pathogen and confirm it by available biochemical tests and pathogenicity test. Furthermore, the study was intended to find the proper and economical control measure to combat disease in citrus orchards. The causative agent of the disease was isolated from the diseased plants and pure culture was obtained. The isolated pure culture was subjected to Gram staining, catalase test, oxidase test, O-F test, starch hydrolysis, nitrate reduction test, methylred test, Voges-prausker test, indole production test, urease test and carbohydrate utilization test. To re-confirm it, pathogenicity test was conducted on host plant and after the appearance of the typical citrus canker lesion on host, the bacteria was re-isolated, thus proving the Koch’s p...

Nepalese Horticulture

An experiment was carried out to study the effect of grafting dates on the success and growth of ... more 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 mortalit...

Nepal Journal of Science and Technology, 2010

Citrus canker, caused by the bacterium Xanthomonas citri (Hasse) occurs in large areas of the wor... more Citrus canker, caused by the bacterium Xanthomonas citri (Hasse) occurs in large areas of the world's citrus growing countries including Nepal. Though the disease has serious effect in Nepal, this is the first detailed study carried out to isolate the pathogen and confirm it by available biochemical tests and pathogenicity test. Furthermore, the study was intended to find the proper and economical control measure to combat disease in citrus orchards. The causative agent of the disease was isolated from the diseased plants and pure culture was obtained. The isolated pure culture was subjected to Gram staining, catalase test, oxidase test, O-F test, starch hydrolysis, nitrate reduction test, methylred test, Voges-prausker test, indole production test, urease test and carbohydrate utilization test. To re-confirm it, pathogenicity test was conducted on host plant and after the appearance of the typical citrus canker lesion on host, the bacteria was re-isolated, thus proving the Koch...

Nepal Journal of Science and Technology, 2013

Biomass such as agricultural and forestry residues are important resources for energy in Nepal. T... more Biomass such as agricultural and forestry residues are important resources for energy in Nepal. This biomass can be converted into densified soild biofuel by briquetting fuel technology which can address handling, transportation, and storage problems. In addition, it helps to increase a number of applications and enhance its utilization efficiency. The purpose of this study is to quantify the physical and chemical properties of different biomass, such as sawdust, banana stem, rice straw, etc. and combustion in order to investigate clear options. Additionally, it helps to provide the efficiency of stoves available at Nepal Academy of Science and Technology (NAST) laboratory. Among the feedstock tested, Mikania micrantha char had highest fixed carbon of 45.92% which clearly shows that it is a good source for biomass briquetting. Out of four stoves tested, Baked Ceramic 4 BHB Stoves had highest efficiency of 33.4% with Banmara briquettes. The study also showed reduced emission of harmf...

Science, technology and innovation indicators in …, 2007