|
Available articles
Genetic Base of Wheat Cultivars Recommended in Nepal / Umesh R. Rosyara in Nepal Agriculture Research Journal, Vol. 6 (2005)
Title : Genetic Base of Wheat Cultivars Recommended in Nepal Material Type: printed text Authors: Umesh R. Rosyara, Author ; Joshi, Bal K., Author Publication Date: 2005 Article on page: 1-9 p. Languages : English (eng) Keywords: Coefficient of parentage, diversity, Triticum aestivum, wheat breeding Abstract: Plant breeding success is dependent, in part, upon the genetic diversity found within genetic
resources. The genetic base of wheat (Triticum aestivum L.) cultivars recommended in Nepal is not
well characterized. Therefore this study was carried out to quantify the genetic base of Nepalese
wheat cultivars by coefficient of parentage (COP). Analysis of pedigree information was based on
International Wheat Information System of the International Center for Maize and Wheat
Improvement (CIMMYT), which consists of WCOP for calculation of COP and WPDEND for
generating Mendelgram with contribution of ancestors to the cultivar if fully expanded. One
hundred eighteen ancestors from 23 countries were identified in the pedigree of 24 recommended
Nepalese cultivars. Of these, 32 ancestors contributed at least 1% each to the genetic base of
Nepalese cultivars, with a total contribution of 79%. Ancestors originating from USA contributed
19.8% of the genes, India 11.2%, Japan 9.5%, Argentina 7.5%, Kenya 7.5% Australia 6.2%, Brazil
5.6%, Canada 5.5%, Italy 4.1% and remaining from other countries. At 30% similarity, 18 clusters
were formed with largest cluster of five members. None of Nepalese landraces were traced in the
pedigree of these cultivars. Relatively large amount of diversity in Nepalese cultivars exits based on
their genetic background although small number of cultivars is recommended for cultivation.Link for e-copy: http://elibrary.narc.gov.np/?r=55
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 1-9 p.[article] Genetic Base of Wheat Cultivars Recommended in Nepal [printed text] / Umesh R. Rosyara, Author ; Joshi, Bal K., Author . - 2005 . - 1-9 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 1-9 p.
Keywords: Coefficient of parentage, diversity, Triticum aestivum, wheat breeding Abstract: Plant breeding success is dependent, in part, upon the genetic diversity found within genetic
resources. The genetic base of wheat (Triticum aestivum L.) cultivars recommended in Nepal is not
well characterized. Therefore this study was carried out to quantify the genetic base of Nepalese
wheat cultivars by coefficient of parentage (COP). Analysis of pedigree information was based on
International Wheat Information System of the International Center for Maize and Wheat
Improvement (CIMMYT), which consists of WCOP for calculation of COP and WPDEND for
generating Mendelgram with contribution of ancestors to the cultivar if fully expanded. One
hundred eighteen ancestors from 23 countries were identified in the pedigree of 24 recommended
Nepalese cultivars. Of these, 32 ancestors contributed at least 1% each to the genetic base of
Nepalese cultivars, with a total contribution of 79%. Ancestors originating from USA contributed
19.8% of the genes, India 11.2%, Japan 9.5%, Argentina 7.5%, Kenya 7.5% Australia 6.2%, Brazil
5.6%, Canada 5.5%, Italy 4.1% and remaining from other countries. At 30% similarity, 18 clusters
were formed with largest cluster of five members. None of Nepalese landraces were traced in the
pedigree of these cultivars. Relatively large amount of diversity in Nepalese cultivars exits based on
their genetic background although small number of cultivars is recommended for cultivation.Link for e-copy: http://elibrary.narc.gov.np/?r=55
Title : Rice Gene Pool for Tarai and Inner Tarai Areas of Nepal Material Type: printed text Authors: Joshi, Bal K., Author Publication Date: 2005 Article on page: 10-22 p Languages : English (eng) Keywords: Ancestor, Landrace, Nepalese rice cultivar, Rice gene pool, Tarai and Inner Abstract: Knowledge on crop gene pool helps to develop varieties, to know the potential sources for
breeding materials and to develop strategy for sustainable use and conservation. The amount of
genetic diversity presents depends on the number and diversity of the original ancestors
involved in the creation of a germplasm pool, existing landraces and wild species. The objective
of this research was to study the diversity of rice gene pool present in the Nepalese improved
rice cultivars and landraces adapted to Tarai and Inner Tarai ( Nepalese rice cultivars were examined and surveyed the literature for distribution of landraces
and wild relatives of rice. Crosses among indica rice gene pool are more common and use of
japonica and nivara species were less common. There are 28 improved rice cultivars, >500
landraces, and 6 wild species and relatives of rice adapted to Tarai and Inner Tarai. Eight
countries are the origins for 28 cultivars. In Nepal 4 cultivars were bred and developed using a
local landrace and exotic genotypes. A total of 35 ancestors originated in 11 different countries
were used to develop these 28 cultivars. Highest number of ancestors was from India. Use of
ancestors of both sativa and nivara species having indica and japonica types indicated the
collection of wide gene pool. Most of the ancestors were sativa (60.00%) and indica (65.71%).
Genetic erosion is observed in rice diversity therefore, in situ, on farm and ex situ conservations
are necessary for maintaining the genetic variation. Utilization of local landraces in breeding
program may be the good way of genetic resources conservation. Gene pool from these
landraces along with international gene pool could make towards success in developing high
yielding cultivars with wide adaptability and/or site specific. In this study, cultivars and
landraces surveyed represent a wide range of variation for different areas of origin and
adaptation. This genetic diversity is very useful for further rice improvement and should be
conserved both ex situ and in situ.Link for e-copy: http://elibrary.narc.gov.np/?r=56
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 10-22 p[article] Rice Gene Pool for Tarai and Inner Tarai Areas of Nepal [printed text] / Joshi, Bal K., Author . - 2005 . - 10-22 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 10-22 p
Keywords: Ancestor, Landrace, Nepalese rice cultivar, Rice gene pool, Tarai and Inner Abstract: Knowledge on crop gene pool helps to develop varieties, to know the potential sources for
breeding materials and to develop strategy for sustainable use and conservation. The amount of
genetic diversity presents depends on the number and diversity of the original ancestors
involved in the creation of a germplasm pool, existing landraces and wild species. The objective
of this research was to study the diversity of rice gene pool present in the Nepalese improved
rice cultivars and landraces adapted to Tarai and Inner Tarai ( Nepalese rice cultivars were examined and surveyed the literature for distribution of landraces
and wild relatives of rice. Crosses among indica rice gene pool are more common and use of
japonica and nivara species were less common. There are 28 improved rice cultivars, >500
landraces, and 6 wild species and relatives of rice adapted to Tarai and Inner Tarai. Eight
countries are the origins for 28 cultivars. In Nepal 4 cultivars were bred and developed using a
local landrace and exotic genotypes. A total of 35 ancestors originated in 11 different countries
were used to develop these 28 cultivars. Highest number of ancestors was from India. Use of
ancestors of both sativa and nivara species having indica and japonica types indicated the
collection of wide gene pool. Most of the ancestors were sativa (60.00%) and indica (65.71%).
Genetic erosion is observed in rice diversity therefore, in situ, on farm and ex situ conservations
are necessary for maintaining the genetic variation. Utilization of local landraces in breeding
program may be the good way of genetic resources conservation. Gene pool from these
landraces along with international gene pool could make towards success in developing high
yielding cultivars with wide adaptability and/or site specific. In this study, cultivars and
landraces surveyed represent a wide range of variation for different areas of origin and
adaptation. This genetic diversity is very useful for further rice improvement and should be
conserved both ex situ and in situ.Link for e-copy: http://elibrary.narc.gov.np/?r=56
Title : Correlation and Path Coefficient Analyses in Sugarcane Material Type: printed text Authors: Chaudhary, R.R., Author ; Joshi, Bal K., Author Publication Date: 2005 Article on page: 24-27 p Languages : English (eng) Keywords: Cane yield, correlation, path coefficient, sugarcane Abstract: This study was conducted to determine the contribution of different traits to cane yield in
sugarcane (Saccharum officinarum L). Sixty-five clones were evaluated in a replicated field
experiment at Sugarcane Research Programme, Jitpur, Nepal in 2003 for six morphological characters
under irrigated conditions. Analysis of variance revealed significant differences for all the
characters studied. Cane yield showed positively and highly significant correlation with single
cane weight, stalk length and millable cane number. There was also positively significant
correlation of cane diameter and number of internode with cane yield. Length of internode had
positive non-significant correlation with cane yield. Single cane weight had the highest positive
direct effect on cane yield followed by millable cane number. Stalk diameter and stalk length was
positively and significantly correlated with cane yield, which was due to indirect effect of single
cane weight. Results indicate that the genotypes should be selected on the basis of single cane
weight and millable cane number for getting higher sugarcane yield.Link for e-copy: http://elibrary.narc.gov.np/?r=57
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 24-27 p[article] Correlation and Path Coefficient Analyses in Sugarcane [printed text] / Chaudhary, R.R., Author ; Joshi, Bal K., Author . - 2005 . - 24-27 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 24-27 p
Keywords: Cane yield, correlation, path coefficient, sugarcane Abstract: This study was conducted to determine the contribution of different traits to cane yield in
sugarcane (Saccharum officinarum L). Sixty-five clones were evaluated in a replicated field
experiment at Sugarcane Research Programme, Jitpur, Nepal in 2003 for six morphological characters
under irrigated conditions. Analysis of variance revealed significant differences for all the
characters studied. Cane yield showed positively and highly significant correlation with single
cane weight, stalk length and millable cane number. There was also positively significant
correlation of cane diameter and number of internode with cane yield. Length of internode had
positive non-significant correlation with cane yield. Single cane weight had the highest positive
direct effect on cane yield followed by millable cane number. Stalk diameter and stalk length was
positively and significantly correlated with cane yield, which was due to indirect effect of single
cane weight. Results indicate that the genotypes should be selected on the basis of single cane
weight and millable cane number for getting higher sugarcane yield.Link for e-copy: http://elibrary.narc.gov.np/?r=57
Title : Performance of Different Size True Potato Seed Seedling Tubers at Khumaltar Material Type: printed text Authors: Adhikari, R.C., Author Publication Date: 2005 Article on page: 28-34 p Languages : English (eng) Keywords: Desiree, seedling tuber, tuber size, yield Abstract: A field study was carried out at Khumaltar-Lalitpur, during 2002-2004 to evaluate and compare
the performance of different sizes of seedling tubers (1-5 g, 5-10 g, 10-20 g and 20-40 g) of true
potato seed (TPS) with whole and half cut seed tubers of Desiree of 20-40 g size at 60- 25-cm
spacing. Percent emergence, plant height, ground cover by foliage, stems/plant, number of tubers
per plant, marketable and total yields were significantly increased with the increase in seedling
tubers weight as compared to whole and half cut seed tubers of Desiree. Late blight
(Phytophthora infestans L.) disease was quite low in the TPS crops than Desiree. Both whole
and half cut seed tubers of Desiree produced significantly higher average per tuber weight.
Uniformity of the tubers harvested from different sizes of seedling tubers was statistically
similar and tubers from Desiree were statistically uniform as compared to seedling tubers. The
three years result suggests that more than 1 g size seedling tubers can be successfully used for
potato production as from the seed tubers of any standard variety.Link for e-copy: http://elibrary.narc.gov.np/?r=58
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 28-34 p[article] Performance of Different Size True Potato Seed Seedling Tubers at Khumaltar [printed text] / Adhikari, R.C., Author . - 2005 . - 28-34 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 28-34 p
Keywords: Desiree, seedling tuber, tuber size, yield Abstract: A field study was carried out at Khumaltar-Lalitpur, during 2002-2004 to evaluate and compare
the performance of different sizes of seedling tubers (1-5 g, 5-10 g, 10-20 g and 20-40 g) of true
potato seed (TPS) with whole and half cut seed tubers of Desiree of 20-40 g size at 60- 25-cm
spacing. Percent emergence, plant height, ground cover by foliage, stems/plant, number of tubers
per plant, marketable and total yields were significantly increased with the increase in seedling
tubers weight as compared to whole and half cut seed tubers of Desiree. Late blight
(Phytophthora infestans L.) disease was quite low in the TPS crops than Desiree. Both whole
and half cut seed tubers of Desiree produced significantly higher average per tuber weight.
Uniformity of the tubers harvested from different sizes of seedling tubers was statistically
similar and tubers from Desiree were statistically uniform as compared to seedling tubers. The
three years result suggests that more than 1 g size seedling tubers can be successfully used for
potato production as from the seed tubers of any standard variety.Link for e-copy: http://elibrary.narc.gov.np/?r=58
Title : Response of Wet Seeded Rice Varieties to Sowing Dates Material Type: printed text Authors: Mishri L. Shah, Author ; Bhurer, K.P., Author Publication Date: 2005 Article on page: 35-38 p Languages : English (eng) Keywords: Grain yield, seeding dates, wet rice Abstract: The experiment was conducted at Regional Agriculture Research Station, Parwanipur in two
consecutive years to find out the suitable rice varieties for wet seeding conditions in relation to
sowing dates. Yield components like tillers number/m2, number of filled grains/panicle and
1000-grain weight were found in the decreasing trend from the seeding of 15 of June onward. The
percent decrease in the grain yield was 14.1, 31.8 and 50.6 in 1998/99 where as 4.8, 7.9 and
49.6 in 1999/00 on June 29 to July 14 seeding dates respectively as compared to 15 June seeding
date. Radha 4 in the first and Chaite 2 in the second year recorded the highest grain yield of
3757 and 4197 kg/ha respectively. Interaction effect of the sowing dates and varieties was highly
significant. Radha 4 produced the highest grain yield of 5039 kg/ha in 1998/99 where as Radha 4 and
Chaite 6 were found at par in 1999/2000 seeded on 15 June. Radha 4 was the best variety for wet
seeded conditions when seeded on 15 June. Chaite 2 had been observed good yielder in all seeding
dates among the tested varieties.Link for e-copy: http://elibrary.narc.gov.np/?r=59
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 35-38 p[article] Response of Wet Seeded Rice Varieties to Sowing Dates [printed text] / Mishri L. Shah, Author ; Bhurer, K.P., Author . - 2005 . - 35-38 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 35-38 p
Keywords: Grain yield, seeding dates, wet rice Abstract: The experiment was conducted at Regional Agriculture Research Station, Parwanipur in two
consecutive years to find out the suitable rice varieties for wet seeding conditions in relation to
sowing dates. Yield components like tillers number/m2, number of filled grains/panicle and
1000-grain weight were found in the decreasing trend from the seeding of 15 of June onward. The
percent decrease in the grain yield was 14.1, 31.8 and 50.6 in 1998/99 where as 4.8, 7.9 and
49.6 in 1999/00 on June 29 to July 14 seeding dates respectively as compared to 15 June seeding
date. Radha 4 in the first and Chaite 2 in the second year recorded the highest grain yield of
3757 and 4197 kg/ha respectively. Interaction effect of the sowing dates and varieties was highly
significant. Radha 4 produced the highest grain yield of 5039 kg/ha in 1998/99 where as Radha 4 and
Chaite 6 were found at par in 1999/2000 seeded on 15 June. Radha 4 was the best variety for wet
seeded conditions when seeded on 15 June. Chaite 2 had been observed good yielder in all seeding
dates among the tested varieties.Link for e-copy: http://elibrary.narc.gov.np/?r=59
Title : Planting Materials Seed Systems of Finger Millet, Rice and Taro in Jumla, Kaski and Bara Districts of Nepal Bimal Material Type: printed text Authors: Baniya, B.K., Author ; ,Tiwari, R.K., Author ; Chaudhary, Pashupati, Author ; Shrestha, Surendra K., Author Publication Date: 2005 Article on page: 39-48 p Languages : English (eng) Keywords: Seed flow, seed production, selection, storage, system Abstract: Formal and informal seed supply systems of rice (Jumla, Bara and Kaski), finger millet and taro
(Kaski) were studied in three ecosites of Nepal during 1999-2001 to understand the processes of
seed flow, seed production, seed selection and storage systems. A survey was conducted at 48 to
96 households. Informal seed supply was the only system in Jumla and Kaski and formal system
existed only in Bara. The main sources of seed were farmer’s own saved seed (67-91%), seed
from neighbors and relatives. Exchange of germplasm was the main basis of fulfillment from other
sources. All farmers obtained seed from their own village, while farmers introduced
materials occasionally from outside village. Most of the farmers followed seed selection before
or after crop harvest. Rice field selection and plant selection based on a fixed set of criteria
was the common practice. Non lodged plants with more grain per panicle, bold grains, well-matured
and uniform plants, long panicle, true to type, good looking grains, free from diseases and insects
were the main rice seed selection criteria. All farmers from both sites stored rice seeds by local
methods in the locally available containers. Mor and Mudkothi are the special straw containers to
store rice seed in Bara. Dhara is a special mud structure used to store rice seeds in Jumla. Finger
millet seed supply system was mostly similar to that of rice seed system. Ninety one percent
farmers saved seed for their own use; however, many of them changed finger millet seeds lots or
varieties regularly for their particular plot. Ears selection during harvest by set criteria for
seed purpose was the common practice. Farmers stored finger millet seed carefully in small locally
available containers and tried their best to maintain the quality of seed during different stage of
seed production. Taro has diverse planting materials: cormels, corms with eyes, suckers and corm
with small cormels. Taro planting materials management is totally informal and almost 89% farmers
saved these materials for their use and replaced them mostly after 3 years. Farmers had fixed
criteria of corms and cormels selection for planting purpose and focus and more on disease
free. Storage of planting materials was locally by using local materials and methods.
Understanding of seed system in various crops helps to develop conservation strategy.Link for e-copy: http://elibrary.narc.gov.np/?r=60
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 39-48 p[article] Planting Materials Seed Systems of Finger Millet, Rice and Taro in Jumla, Kaski and Bara Districts of Nepal Bimal [printed text] / Baniya, B.K., Author ; ,Tiwari, R.K., Author ; Chaudhary, Pashupati, Author ; Shrestha, Surendra K., Author . - 2005 . - 39-48 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 39-48 p
Keywords: Seed flow, seed production, selection, storage, system Abstract: Formal and informal seed supply systems of rice (Jumla, Bara and Kaski), finger millet and taro
(Kaski) were studied in three ecosites of Nepal during 1999-2001 to understand the processes of
seed flow, seed production, seed selection and storage systems. A survey was conducted at 48 to
96 households. Informal seed supply was the only system in Jumla and Kaski and formal system
existed only in Bara. The main sources of seed were farmer’s own saved seed (67-91%), seed
from neighbors and relatives. Exchange of germplasm was the main basis of fulfillment from other
sources. All farmers obtained seed from their own village, while farmers introduced
materials occasionally from outside village. Most of the farmers followed seed selection before
or after crop harvest. Rice field selection and plant selection based on a fixed set of criteria
was the common practice. Non lodged plants with more grain per panicle, bold grains, well-matured
and uniform plants, long panicle, true to type, good looking grains, free from diseases and insects
were the main rice seed selection criteria. All farmers from both sites stored rice seeds by local
methods in the locally available containers. Mor and Mudkothi are the special straw containers to
store rice seed in Bara. Dhara is a special mud structure used to store rice seeds in Jumla. Finger
millet seed supply system was mostly similar to that of rice seed system. Ninety one percent
farmers saved seed for their own use; however, many of them changed finger millet seeds lots or
varieties regularly for their particular plot. Ears selection during harvest by set criteria for
seed purpose was the common practice. Farmers stored finger millet seed carefully in small locally
available containers and tried their best to maintain the quality of seed during different stage of
seed production. Taro has diverse planting materials: cormels, corms with eyes, suckers and corm
with small cormels. Taro planting materials management is totally informal and almost 89% farmers
saved these materials for their use and replaced them mostly after 3 years. Farmers had fixed
criteria of corms and cormels selection for planting purpose and focus and more on disease
free. Storage of planting materials was locally by using local materials and methods.
Understanding of seed system in various crops helps to develop conservation strategy.Link for e-copy: http://elibrary.narc.gov.np/?r=60
Title : Resistance in Rice Breeding Lines to the Blast Fungus in Nepal Material Type: printed text Authors: Bedananda Chaudhary, Author ; Sundar M. Shrestha, Author ; Sharma, R.C., Author Publication Date: 2005 Article on page: 49-56 p Languages : English (eng) Keywords: Blast resistance, field condition, greenhouse assay, Pyricularia grisea, rice lines Abstract: A total of 36 rice breeding lines including checks were evaluated for resistance to blast at
Rampur during 2000-2001. The experiments were conducted under both field condition and
greenhouse inoculated condition. Qualitative resistance in rice to blast was assessed based on
lesion type, whereas quantitative resistance was assessed based on area under disease progress
curve (AUDPC) in the upland field condition. The number of sporulating lesions and the number
of leaves with at least one sporulating lesion per plant were considered as measures for
evaluation of quantitative resistance in the greenhouse assay. The lesion type, neck blast
percentage and AUDPC data suggest that most of the rice lines possess higher level of resistance
to leaf and neck blast. The rice lines varied for the number of sporulating lesions and the number
of leaves with sporulating lesion per plant. Some lines were incompatible to virulent blast
isolates, showing major resistance genes. NR 1558, NR 601-1-1-9, BW306-2 and CN 836-3-10
were promising lines for quantitative resistance to both leaf and neck blast. Radha 12, Sabitri,
Janaki possess higher level of quantitative resistance to blast, hence these could be promoted for
cultivation in blast-prone environments. These genotypes could also be utilized as donor parents
for breeding durable blast resistant varieties. The most virulent blast isolate could be used for
evaluation of both qualitative and quantitative resistance to blast in early generation in the
greenhouse so that workload could be cut down in future works.Link for e-copy: http://elibrary.narc.gov.np/?r=61
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 49-56 p[article] Resistance in Rice Breeding Lines to the Blast Fungus in Nepal [printed text] / Bedananda Chaudhary, Author ; Sundar M. Shrestha, Author ; Sharma, R.C., Author . - 2005 . - 49-56 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 49-56 p
Keywords: Blast resistance, field condition, greenhouse assay, Pyricularia grisea, rice lines Abstract: A total of 36 rice breeding lines including checks were evaluated for resistance to blast at
Rampur during 2000-2001. The experiments were conducted under both field condition and
greenhouse inoculated condition. Qualitative resistance in rice to blast was assessed based on
lesion type, whereas quantitative resistance was assessed based on area under disease progress
curve (AUDPC) in the upland field condition. The number of sporulating lesions and the number
of leaves with at least one sporulating lesion per plant were considered as measures for
evaluation of quantitative resistance in the greenhouse assay. The lesion type, neck blast
percentage and AUDPC data suggest that most of the rice lines possess higher level of resistance
to leaf and neck blast. The rice lines varied for the number of sporulating lesions and the number
of leaves with sporulating lesion per plant. Some lines were incompatible to virulent blast
isolates, showing major resistance genes. NR 1558, NR 601-1-1-9, BW306-2 and CN 836-3-10
were promising lines for quantitative resistance to both leaf and neck blast. Radha 12, Sabitri,
Janaki possess higher level of quantitative resistance to blast, hence these could be promoted for
cultivation in blast-prone environments. These genotypes could also be utilized as donor parents
for breeding durable blast resistant varieties. The most virulent blast isolate could be used for
evaluation of both qualitative and quantitative resistance to blast in early generation in the
greenhouse so that workload could be cut down in future works.Link for e-copy: http://elibrary.narc.gov.np/?r=61
Title : Economic Management of Late Blight (Phytophthora infestans L.) of Potato in Eastern Tarai of Nepal Material Type: printed text Authors: Prem C.P. Chaurasia, Author Publication Date: 2005 Article on page: 57-61 p Languages : English (eng) Keywords: Eastern Tarai, economic spray, Dithane M-45, late blight management, potato Abstract: Field experiments were carried out at Regional Agriculture Research Station, Tarahara in three
consecutive years (1997-2000) during winter season to know the economic sprays of different
fungicides to manage late blight disease of potato. Late blight susceptible cultivar of potato
Kufri Sindhuri was used for the experiment. Krinoxyl gold (metalaxyl 8% and mancozeb 64%)
at the rate of 1.5 g/l, Dithane M- 45 (mancozeb 75%) @ 0.3% and Bordeaux mixture @ 10 g
copper sulfate and 10 g lime/l of water and their different combinations were tested in
randomized complete block design with three replications. Terminal disease severity was the
highest (7.9) on 0-9 scale disease rating in unsprayed check and it was significantly higher than
those of other fungicides sprays. Plots with three sprays of Dithane M- 45 @ 0.3% recorded the
lowest (2.4) terminal disease severity. Disease development was the fastest in the unsprayed plot
compared to all other treatments. Similarly apparent infection rate was the highest in unsprayed
treatment. Area Under the Disease Progress Curve was also the highest in unsprayed plot and it
was significantly higher than those of other treatments. Tuber yield was the lowest (3.93 kg/4.5
m2 plot in unsprayed and the highest (6.08 kg), in the plot receiving four sprays of Dithane M-45
@ 0.3 % and this was at par with the tuber yield of plots receiving two and three sprays of
Dithane M-45. Benefit cost ratio was the highest (1.54) in case of two sprays of Dithane M-45
@ 0.3% at 10 days intervals. All others fungicide spays were uneconomical under Eastern Tarai
condition.Link for e-copy: http://elibrary.narc.gov.np/?r=62
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 57-61 p[article] Economic Management of Late Blight (Phytophthora infestans L.) of Potato in Eastern Tarai of Nepal [printed text] / Prem C.P. Chaurasia, Author . - 2005 . - 57-61 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 57-61 p
Keywords: Eastern Tarai, economic spray, Dithane M-45, late blight management, potato Abstract: Field experiments were carried out at Regional Agriculture Research Station, Tarahara in three
consecutive years (1997-2000) during winter season to know the economic sprays of different
fungicides to manage late blight disease of potato. Late blight susceptible cultivar of potato
Kufri Sindhuri was used for the experiment. Krinoxyl gold (metalaxyl 8% and mancozeb 64%)
at the rate of 1.5 g/l, Dithane M- 45 (mancozeb 75%) @ 0.3% and Bordeaux mixture @ 10 g
copper sulfate and 10 g lime/l of water and their different combinations were tested in
randomized complete block design with three replications. Terminal disease severity was the
highest (7.9) on 0-9 scale disease rating in unsprayed check and it was significantly higher than
those of other fungicides sprays. Plots with three sprays of Dithane M- 45 @ 0.3% recorded the
lowest (2.4) terminal disease severity. Disease development was the fastest in the unsprayed plot
compared to all other treatments. Similarly apparent infection rate was the highest in unsprayed
treatment. Area Under the Disease Progress Curve was also the highest in unsprayed plot and it
was significantly higher than those of other treatments. Tuber yield was the lowest (3.93 kg/4.5
m2 plot in unsprayed and the highest (6.08 kg), in the plot receiving four sprays of Dithane M-45
@ 0.3 % and this was at par with the tuber yield of plots receiving two and three sprays of
Dithane M-45. Benefit cost ratio was the highest (1.54) in case of two sprays of Dithane M-45
@ 0.3% at 10 days intervals. All others fungicide spays were uneconomical under Eastern Tarai
condition.Link for e-copy: http://elibrary.narc.gov.np/?r=62
Title : Role of weather on Alternaria Leaf Blight Disease and its effect on Yield and Yield Components of Mustard Material Type: printed text Authors: Sundar K. Shrestha, Author ; Lisa Munk, Author ; Mathur, S.B., Author Publication Date: 2005 Article on page: 62-72 p Languages : English (eng) Keywords: Alternaria brassicae, epidemics, iprodione, mancozeb, mustard, oil content Abstract: Alternaria leaf blight disease caused by Alternaria brassicae in mustard (Brassica juncea (L)
Czern and Coss) was studied in two crop seasons, 1992 and 1993 in Nepal at Nawalpur, Sarlahi
(Tarai) and Khumaltar, Lalitpur (mid hill). At Nawalpur, epidemics of the disease was recorded for
both seasons. Weather conditions like humidity, temperature and frequent rainfall played key role
for the epidemics. In experimental fields, the disease appeared first in mid-December when the
relative humidity was more than 80% with maximum temperature ranging between 18-250C and minimum
between 10-140C. At Khumaltar, incidence of the disease was low in both seasons due to low average
temperature from December to February. Among cultivars, Krishna and Pusabold were less susceptible
than Varuna. Both mancozeb and iprodione had effectively reduced disease in the sprayed plots and
increased seed yield by 48% and 130% respectively. The correlation between disease severity and
yield, and yield components was negative and highly significant. Average yield loss was estimated
to be in the range of 32 to 57%. Seed infection was also significantly higher in non sprayed
treatment than sprayed one. The disease showed a negative effect on oil content causing losses on
oil between 4.2 to 4.5%.Link for e-copy: http://elibrary.narc.gov.np/?r=63
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 62-72 p[article] Role of weather on Alternaria Leaf Blight Disease and its effect on Yield and Yield Components of Mustard [printed text] / Sundar K. Shrestha, Author ; Lisa Munk, Author ; Mathur, S.B., Author . - 2005 . - 62-72 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 62-72 p
Keywords: Alternaria brassicae, epidemics, iprodione, mancozeb, mustard, oil content Abstract: Alternaria leaf blight disease caused by Alternaria brassicae in mustard (Brassica juncea (L)
Czern and Coss) was studied in two crop seasons, 1992 and 1993 in Nepal at Nawalpur, Sarlahi
(Tarai) and Khumaltar, Lalitpur (mid hill). At Nawalpur, epidemics of the disease was recorded for
both seasons. Weather conditions like humidity, temperature and frequent rainfall played key role
for the epidemics. In experimental fields, the disease appeared first in mid-December when the
relative humidity was more than 80% with maximum temperature ranging between 18-250C and minimum
between 10-140C. At Khumaltar, incidence of the disease was low in both seasons due to low average
temperature from December to February. Among cultivars, Krishna and Pusabold were less susceptible
than Varuna. Both mancozeb and iprodione had effectively reduced disease in the sprayed plots and
increased seed yield by 48% and 130% respectively. The correlation between disease severity and
yield, and yield components was negative and highly significant. Average yield loss was estimated
to be in the range of 32 to 57%. Seed infection was also significantly higher in non sprayed
treatment than sprayed one. The disease showed a negative effect on oil content causing losses on
oil between 4.2 to 4.5%.Link for e-copy: http://elibrary.narc.gov.np/?r=63
Title : Yield Loss and Economic Threshold Level of Soybean due to Leaf Roller (Apoderus Cyaneus Hope) in Nepal Material Type: printed text Authors: Gyawali, Bishnu K., Author Publication Date: 2005 Article on page: 73-77 p Languages : English (eng) Keywords: Economic threshold level, leaf roller, physiological growth stages, yield loss Abstract: Yield loss in soybean due to leaf roller (Apoderus cyaneus Hope) was studied at Khumaltar during
1985 and 1986 seasons. Field experiments were conducted during vegetative as well as reproductive
stages of soybean. Rolled leaves of soybean with eggs, grubs and pupae were collected from the
field and reared in the laboratory for adults. Adults were introduced into nylon cages installed at
the central rows of each plot just after germination of soybean. Insects were maintained at
population density of 25, 50 and 100 per m2. At maximum (100) adult density, the potential grain
yield loss of cultivar, Ransom soybean in its vegetative and reproductive stages were 103 and 48 mg
per day respectively from each adult of A. cyaneus. Percentages of yield losses were 36.2, 45.2,
and 58.0 during vegetative and 37.5, 48.5 and 66.0 during reproductive stages from the insect
population of 25, 50 and 100, respectively which, was
not in accordance with the level of two and four fold increased population density of insect. Yield
reduction was higher (260 and 108 mg per day) from each adult beetle at lower population level (25)
in both vegetative and reproductive stages of soybean.Link for e-copy: http://elibrary.narc.gov.np/?r=64
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 73-77 p[article] Yield Loss and Economic Threshold Level of Soybean due to Leaf Roller (Apoderus Cyaneus Hope) in Nepal [printed text] / Gyawali, Bishnu K., Author . - 2005 . - 73-77 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 73-77 p
Keywords: Economic threshold level, leaf roller, physiological growth stages, yield loss Abstract: Yield loss in soybean due to leaf roller (Apoderus cyaneus Hope) was studied at Khumaltar during
1985 and 1986 seasons. Field experiments were conducted during vegetative as well as reproductive
stages of soybean. Rolled leaves of soybean with eggs, grubs and pupae were collected from the
field and reared in the laboratory for adults. Adults were introduced into nylon cages installed at
the central rows of each plot just after germination of soybean. Insects were maintained at
population density of 25, 50 and 100 per m2. At maximum (100) adult density, the potential grain
yield loss of cultivar, Ransom soybean in its vegetative and reproductive stages were 103 and 48 mg
per day respectively from each adult of A. cyaneus. Percentages of yield losses were 36.2, 45.2,
and 58.0 during vegetative and 37.5, 48.5 and 66.0 during reproductive stages from the insect
population of 25, 50 and 100, respectively which, was
not in accordance with the level of two and four fold increased population density of insect. Yield
reduction was higher (260 and 108 mg per day) from each adult beetle at lower population level (25)
in both vegetative and reproductive stages of soybean.Link for e-copy: http://elibrary.narc.gov.np/?r=64
Title : Development and Evaluation of Improved Feeders for Goats Suitable to Stall-fed Management System Material Type: printed text Authors: Chet R. Upreti, Author ; Kuwar, Bahadur Singh, Author ; Panday, S.B., Author Publication Date: 2005 Article on page: 78-83 p Languages : English (eng) Keywords: Contamination, cost effective, feed saving, small farmer, stall-feed, suitable feeders Abstract: Five different types of feeders were designed and tested on goats to find out their effectiveness
in reducing feed wastage and cost fabrication. Experiment was conducted at Agriculture
Research Station (ARS)-Bandipur for two years. Tested feeders were hexagonal, rectangular, hay
rack, chain barrel and conventional wooden Tatnu. Feeders were fabricated using iron bars and
woods. They were tested with the adult goats for feed wastage and feed contamination. Experimental
feeds were fodders twigs (Tanki), forage (Stylo, Napier), crop residue (straw from black bean) and
commercial concentrate. Chain barrel type of feeder was also tested at farmer’s field at Baradi.
Rectangular feeders have significantly lower (P other tested feeders. The fabrication cost was NRs 3200, 1700, 700, 900, and 150 for hexagonal,
rectangular; hay rack, chain barrel and conventional wooden Tatnu respectively. The rectangular
feeder is suitable for goats feeding in Tarai and in the hills of Nepal. It has provision for
feeding fodders, grasses, crop residues and concentrates together at the same time. Chain barrel
type had comparatively higher wastage (10.7% for fodder) than the rectangular but was preferred by
the farmers due to its low fabricating cost, portable in size, small space required and easy to
handle. Therefore, the rectangular feeder is recommended for middle level farmers and chain barrel
for small farmers who rear few goats.Link for e-copy: http://elibrary.narc.gov.np/?r=65
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 78-83 p[article] Development and Evaluation of Improved Feeders for Goats Suitable to Stall-fed Management System [printed text] / Chet R. Upreti, Author ; Kuwar, Bahadur Singh, Author ; Panday, S.B., Author . - 2005 . - 78-83 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 78-83 p
Keywords: Contamination, cost effective, feed saving, small farmer, stall-feed, suitable feeders Abstract: Five different types of feeders were designed and tested on goats to find out their effectiveness
in reducing feed wastage and cost fabrication. Experiment was conducted at Agriculture
Research Station (ARS)-Bandipur for two years. Tested feeders were hexagonal, rectangular, hay
rack, chain barrel and conventional wooden Tatnu. Feeders were fabricated using iron bars and
woods. They were tested with the adult goats for feed wastage and feed contamination. Experimental
feeds were fodders twigs (Tanki), forage (Stylo, Napier), crop residue (straw from black bean) and
commercial concentrate. Chain barrel type of feeder was also tested at farmer’s field at Baradi.
Rectangular feeders have significantly lower (P other tested feeders. The fabrication cost was NRs 3200, 1700, 700, 900, and 150 for hexagonal,
rectangular; hay rack, chain barrel and conventional wooden Tatnu respectively. The rectangular
feeder is suitable for goats feeding in Tarai and in the hills of Nepal. It has provision for
feeding fodders, grasses, crop residues and concentrates together at the same time. Chain barrel
type had comparatively higher wastage (10.7% for fodder) than the rectangular but was preferred by
the farmers due to its low fabricating cost, portable in size, small space required and easy to
handle. Therefore, the rectangular feeder is recommended for middle level farmers and chain barrel
for small farmers who rear few goats.Link for e-copy: http://elibrary.narc.gov.np/?r=65
Title : Growth, Efficiency of Feed Utilization and Economics of Different Rearing Periods of Turkeys Material Type: printed text Authors: Mukesh Karki, Author Publication Date: 2005 Article on page: 84-88 p Languages : English (eng) Keywords: Economics, feed utilization, growth, rearing period, turkey Abstract: The present study on body weight and feed efficiency for growth was carried out on 112 turkey
poults from day of hatch to 28 weeks of age during May to November 2002 at Poultry Research
Unit of Regional Agricultural Research Station (RARS)-Parwanipur. Layer starter ration
supplemented with 6% fish meal + 0.3% lysine + 0.125% methonine was fed up to 8 weeks of
age, then after layer finisher diet was fed. The body weight, feed consumption was observed at 4
weekly interval and feed efficiency and economics of rearing period in terms of income over
feed and poults cost was calculated. Significant increase in body weight was recorded up to 28
weeks in male and 20 weeks in female. Male turkey had significantly higher body weight than
that of female in all ages. Feed efficiency is best at earlier age but up to 16 weeks it is 3.77 for
male after that it detoriates progressively. Male turkey exhibited better feed efficiency than that
of female for all weeks. Significantly higher return per bird was obtained from male than that of
female in all age. The profit per bird for both male and female was found maximum in 16 weeks
of rearing, followed by 20 weeks and 24 weeks. Therefore, instead of waiting for highest body
weight, it is better to sell turkey at 16 to 20 weeks of age to take maximum advantage of higher
weight gain, higher efficiency of feed utilization and higher profit.Link for e-copy: http://elibrary.narc.gov.np/?r=66
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 84-88 p[article] Growth, Efficiency of Feed Utilization and Economics of Different Rearing Periods of Turkeys [printed text] / Mukesh Karki, Author . - 2005 . - 84-88 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 84-88 p
Keywords: Economics, feed utilization, growth, rearing period, turkey Abstract: The present study on body weight and feed efficiency for growth was carried out on 112 turkey
poults from day of hatch to 28 weeks of age during May to November 2002 at Poultry Research
Unit of Regional Agricultural Research Station (RARS)-Parwanipur. Layer starter ration
supplemented with 6% fish meal + 0.3% lysine + 0.125% methonine was fed up to 8 weeks of
age, then after layer finisher diet was fed. The body weight, feed consumption was observed at 4
weekly interval and feed efficiency and economics of rearing period in terms of income over
feed and poults cost was calculated. Significant increase in body weight was recorded up to 28
weeks in male and 20 weeks in female. Male turkey had significantly higher body weight than
that of female in all ages. Feed efficiency is best at earlier age but up to 16 weeks it is 3.77 for
male after that it detoriates progressively. Male turkey exhibited better feed efficiency than that
of female for all weeks. Significantly higher return per bird was obtained from male than that of
female in all age. The profit per bird for both male and female was found maximum in 16 weeks
of rearing, followed by 20 weeks and 24 weeks. Therefore, instead of waiting for highest body
weight, it is better to sell turkey at 16 to 20 weeks of age to take maximum advantage of higher
weight gain, higher efficiency of feed utilization and higher profit.Link for e-copy: http://elibrary.narc.gov.np/?r=66
Title : Socioeconomic and Agroecological Determinants of Conserving Diversity On-farm: The Case of Rice Genetic Resources in Nepal Material Type: printed text Authors: Gauchan, Devendra, Author ; Melinda Smale, Author ; Maxted, N., Author Publication Date: 2005 Article on page: 89-98 p Languages : English (eng) Keywords: Diversity indices, dominance, evenness, on-farm conservation, rice diversity, richness Abstract: Conservation of crop genetic resources presents a challenge of identifying specific determinants
driving maintenance of diversity at farm and agroecosystems. The objectives of this study were to
identify socioeconomic, market and agroecological determinants of farmers’ maintenance of rice
diversity at the household level and derive implications for policies in designing on-farm
conservation programs. We assess spatial rice diversity at farm level using household survey
data. A household decision making model is conceptualised using microeconomic theory to assess
and identify factors influencing on-farm rice diversity. The model is then tested econometrically by
using various factors affecting farmers’ variety choice and diversity decisions. The findings show
that household-specific socioeconomic, agroecological and market factors are important in
determining on-farm rice diversity. The significant variables in explaining richness and evenness of
rice diversity include distance to the nearest market, subsistence ratio, modern variety sold, land
types and adult labour working in agriculture. The statistical signs of the factors determining rice
diversity are consistent in explaining the richness, dominance and evenness among rice varieties.
Finally, the study implies that the cost-effective means of promoting and sustaining on-farm
conservation programmes is to target them in market isolated geographic locations of high crop
diversity where farm households have more heterogeneity of agroecological conditions and more
active family adult labour working on-farm.Link for e-copy: http://elibrary.narc.gov.np/?r=67
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 89-98 p[article] Socioeconomic and Agroecological Determinants of Conserving Diversity On-farm: The Case of Rice Genetic Resources in Nepal [printed text] / Gauchan, Devendra, Author ; Melinda Smale, Author ; Maxted, N., Author . - 2005 . - 89-98 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 89-98 p
Keywords: Diversity indices, dominance, evenness, on-farm conservation, rice diversity, richness Abstract: Conservation of crop genetic resources presents a challenge of identifying specific determinants
driving maintenance of diversity at farm and agroecosystems. The objectives of this study were to
identify socioeconomic, market and agroecological determinants of farmers’ maintenance of rice
diversity at the household level and derive implications for policies in designing on-farm
conservation programs. We assess spatial rice diversity at farm level using household survey
data. A household decision making model is conceptualised using microeconomic theory to assess
and identify factors influencing on-farm rice diversity. The model is then tested econometrically by
using various factors affecting farmers’ variety choice and diversity decisions. The findings show
that household-specific socioeconomic, agroecological and market factors are important in
determining on-farm rice diversity. The significant variables in explaining richness and evenness of
rice diversity include distance to the nearest market, subsistence ratio, modern variety sold, land
types and adult labour working in agriculture. The statistical signs of the factors determining rice
diversity are consistent in explaining the richness, dominance and evenness among rice varieties.
Finally, the study implies that the cost-effective means of promoting and sustaining on-farm
conservation programmes is to target them in market isolated geographic locations of high crop
diversity where farm households have more heterogeneity of agroecological conditions and more
active family adult labour working on-farm.Link for e-copy: http://elibrary.narc.gov.np/?r=67
Title : Data Analysis Methods Adopted under In situ Global Project in Nepal Material Type: printed text Authors: Joshi, Bal K., Author ; ,Upadhyay, Madhusudan, Author ; Bimb, Hari P., Author ; Gauchan, D., Author ; Baniya, B.K., Author Publication Date: 2005 Article on page: 98-110 p Languages : English (eng) Keywords: Data analysis methods, on farm research, station subject areas Abstract: Synthesizing data analysis methods adopted under in situ global project in Nepal along with
variables and nature of study could be guiding reference for researchers especially to those
involved in on farm research. The review work was conducted with the objective to help in utilizing
and managing in situ database system. The objectives of the experiment, the structure of the
treatments and the experimental design used primarily determine the type of analysis. There were 60
papers of this project published in Nepal. All these papers are grouped under 8 thematic groups
namely 1. Agroecosystem (3 papers), 2. Agromorphological and farmers’ perception (7 papers), 3.
Crop population structure (5 papers), 4. Gender, policy and general (15 papers), 5. Isozyme and
molecular (6 papers), 6. Seed systems and farmers’ networks (5 papers), 7. Social, cultural and
economical (11 papers) and 8. Value addition (8 papers). All these papers were reviewed basically
for data type, sample size, sampling methods, statistical methods and tools, varieties and
purposes. Descriptive and inferential statistics along with multivariate methods were commonly used
in on farm research. Experimental design, the most common in on station trial was least used. Study
over space and time was not adopted. There were 5 kinds of data generated, 45 statistical tools
adopted in eight different crop species. Among the 5 kinds of data under these eight subject areas,
categorical type was highest followed by discrete numerical. Binary type was least in frequency.
Most of the papers were related to rice followed by taro and finger millet. Cucumber and pigeon pea
were studied least. Descriptive statistics along with 2, multivariate analysis and regression
approaches would be appropriate tools. Similarly SPSS and MINITAB may be good software. The best
one among a number of statistical tools should be selected and utmost care must be exercised while
collecting data.Link for e-copy: http://elibrary.narc.gov.np/?r=68
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 98-110 p[article] Data Analysis Methods Adopted under In situ Global Project in Nepal [printed text] / Joshi, Bal K., Author ; ,Upadhyay, Madhusudan, Author ; Bimb, Hari P., Author ; Gauchan, D., Author ; Baniya, B.K., Author . - 2005 . - 98-110 p.
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 98-110 p
Keywords: Data analysis methods, on farm research, station subject areas Abstract: Synthesizing data analysis methods adopted under in situ global project in Nepal along with
variables and nature of study could be guiding reference for researchers especially to those
involved in on farm research. The review work was conducted with the objective to help in utilizing
and managing in situ database system. The objectives of the experiment, the structure of the
treatments and the experimental design used primarily determine the type of analysis. There were 60
papers of this project published in Nepal. All these papers are grouped under 8 thematic groups
namely 1. Agroecosystem (3 papers), 2. Agromorphological and farmers’ perception (7 papers), 3.
Crop population structure (5 papers), 4. Gender, policy and general (15 papers), 5. Isozyme and
molecular (6 papers), 6. Seed systems and farmers’ networks (5 papers), 7. Social, cultural and
economical (11 papers) and 8. Value addition (8 papers). All these papers were reviewed basically
for data type, sample size, sampling methods, statistical methods and tools, varieties and
purposes. Descriptive and inferential statistics along with multivariate methods were commonly used
in on farm research. Experimental design, the most common in on station trial was least used. Study
over space and time was not adopted. There were 5 kinds of data generated, 45 statistical tools
adopted in eight different crop species. Among the 5 kinds of data under these eight subject areas,
categorical type was highest followed by discrete numerical. Binary type was least in frequency.
Most of the papers were related to rice followed by taro and finger millet. Cucumber and pigeon pea
were studied least. Descriptive statistics along with 2, multivariate analysis and regression
approaches would be appropriate tools. Similarly SPSS and MINITAB may be good software. The best
one among a number of statistical tools should be selected and utmost care must be exercised while
collecting data.Link for e-copy: http://elibrary.narc.gov.np/?r=68
Title : Occurrence of Garlic Rust in Mid Hill of Nepal Material Type: printed text Authors: Timila (Dhawa), R.D., Author ; Sharada Joshi, Author ; Gyanu Manandhar, Author ; Sarala Sharma, Author Publication Date: 2005 Article on page: 110-111 p General note: Research note Languages : English (eng) Link for e-copy: http://elibrary.narc.gov.np/?r=69
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 110-111 p[article] Occurrence of Garlic Rust in Mid Hill of Nepal [printed text] / Timila (Dhawa), R.D., Author ; Sharada Joshi, Author ; Gyanu Manandhar, Author ; Sarala Sharma, Author . - 2005 . - 110-111 p.
Research note
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 110-111 p
Link for e-copy: http://elibrary.narc.gov.np/?r=69
Title : Associative Nitrogen Fixation in Lowland Rice Material Type: printed text Authors: Raj K. Shrestha, Author ; Maskey, S.L., Author Publication Date: 2005 Article on page: 112-121 p General note: Review paper Languages : English (eng) Keywords: Key words: Fertilizer, fixation, nitrogen, rice Abstract: Nitrogen (N), a most limiting nutrient, is the input required in the largest quantity for lowland
rice production. The concerns on N economy and efficiency and its impact on environment have
renewed interest in exploring alternative or supplementary N source for sustainable agriculture.
Several studies have indicated the existence of significant rice genotypic differences in N2
fixation stimulating traits (NFS). Rice genotypes with high NFS are desirable because they add N to
the soil-water-plant system without additional farm inputs and reduce dependence on fertilizer.
Large genotypic differences in percent N derived from air (% Ndfa) like 1.5% in Abang Basur, medium
maturing genotype, to 21% in Oking Seroni, late maturing genotype, indicates potential of isolating
genotypes with high NFS for sustainable agriculture. The exogenous supply of nitrogenous fertilizer
to lowland rice significantly inhibited N fixation but improved plant growth. Where as phosphorous
fertilizer did not affect atom % 15N excess and % Ndfa significantly but slight decrease in atom %
15N excess and increase in N2 fixation was observed. Inhibitory effect of exogenous supply of N
fertilizer indicates limited potential of associative N2 fixation to significantly benefit
agriculture. Farmers would have to withhold N fertilizer from their rice crop in order to increase
biological N2-fixation associated with rice. If they do such practice the plants will be N
deficient and might have a lower yield. However, the development of N fixation in response to a
deficiency of available N may well be an integral part of the N cycle of natural ecosystem and low
input farming system there by maintaining a N balance in the environment.Link for e-copy: http://elibrary.narc.gov.np/?r=70
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 112-121 p[article] Associative Nitrogen Fixation in Lowland Rice [printed text] / Raj K. Shrestha, Author ; Maskey, S.L., Author . - 2005 . - 112-121 p.
Review paper
Languages : English (eng)
in Nepal Agriculture Research Journal > Vol. 6 (2005) . - 112-121 p
Keywords: Key words: Fertilizer, fixation, nitrogen, rice Abstract: Nitrogen (N), a most limiting nutrient, is the input required in the largest quantity for lowland
rice production. The concerns on N economy and efficiency and its impact on environment have
renewed interest in exploring alternative or supplementary N source for sustainable agriculture.
Several studies have indicated the existence of significant rice genotypic differences in N2
fixation stimulating traits (NFS). Rice genotypes with high NFS are desirable because they add N to
the soil-water-plant system without additional farm inputs and reduce dependence on fertilizer.
Large genotypic differences in percent N derived from air (% Ndfa) like 1.5% in Abang Basur, medium
maturing genotype, to 21% in Oking Seroni, late maturing genotype, indicates potential of isolating
genotypes with high NFS for sustainable agriculture. The exogenous supply of nitrogenous fertilizer
to lowland rice significantly inhibited N fixation but improved plant growth. Where as phosphorous
fertilizer did not affect atom % 15N excess and % Ndfa significantly but slight decrease in atom %
15N excess and increase in N2 fixation was observed. Inhibitory effect of exogenous supply of N
fertilizer indicates limited potential of associative N2 fixation to significantly benefit
agriculture. Farmers would have to withhold N fertilizer from their rice crop in order to increase
biological N2-fixation associated with rice. If they do such practice the plants will be N
deficient and might have a lower yield. However, the development of N fixation in response to a
deficiency of available N may well be an integral part of the N cycle of natural ecosystem and low
input farming system there by maintaining a N balance in the environment.Link for e-copy: http://elibrary.narc.gov.np/?r=70
