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Yield Loss and Economic Threshold Level of Soybean due to Leaf Roller (Apoderus Cyaneus Hope) in Nepal / Gyawali, Bishnu K. in Nepal Agriculture Research Journal, Vol. 6 (2005)
[article]
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 Population dynamics of insect pests of rice at RARS Tarahara: a light trap survelliance / G.S Bhandari
in Proceedings of the 27th National Summer Crops Workshop, held at Rampur, Chitawan, 18-20 April 2013, Vol. II / Giri, Y.P.
Title : Population dynamics of insect pests of rice at RARS Tarahara: a light trap survelliance Material Type: printed text Authors: G.S Bhandari, Editor ; B. Chaudhary ; B Sapkota, Author ; D.N Mahato, Author ; S.K Upadhyaya, Author Pagination: 310-314 p. Keywords: Beneficial organism ; Economic threshold level insect pests population dynamics Abstract: Economic loss due to insect pests is one of the major problems for rice production. There
may be a lot of beneficial insects present in the field. Fanners apply chemical pesticides
heavily that may destroy beneficial organisms. There is immense need of studying the
seasonal occurrence of harmful and beneficial insects for their proper management. A
survey of major insect pests of rice was conducted for three years from 20 lO to 2012 with
the objective of assessing seasonal occurrence of major insect pests of rice and beneficial
insects to plan future insect management strategy. Abundance records of insects namely
White Stem Borer, Yellow Stem Borer, Pink Stem Borer, Leaf Folder, Case Worm, Rice
Gundhi Bug and Tiger Beetle were made from January 2010 to December 2012. The study
revealed the overall abundance of pink stem borer as highest followed by yellow stem borer
and Gundhi bug. The relation between population buildup of rice gundhi bug and tiger
beetle found non-significant. The peak population of gundhi bug recorded in the August to
November. However, peak population of tiger beetle was from July to August thus,
reduction in population of gundhi bug was non-significant during its peak period. The study
suggests that the insect management priority be set as per the abundance rank of the studied
insect pests. The study recommends that the judicious use of pesticides be followed for
insect pest management to have increased population of beneficial natural enemies.Link for e-copy: http://elibrary.narc.gov.np/?r=959 Population dynamics of insect pests of rice at RARS Tarahara: a light trap survelliance [printed text] / G.S Bhandari, Editor ; B. Chaudhary ; B Sapkota, Author ; D.N Mahato, Author ; S.K Upadhyaya, Author . - [s.d.] . - 310-314 p.
in Proceedings of the 27th National Summer Crops Workshop, held at Rampur, Chitawan, 18-20 April 2013, Vol. II / Giri, Y.P.
Keywords: Beneficial organism ; Economic threshold level insect pests population dynamics Abstract: Economic loss due to insect pests is one of the major problems for rice production. There
may be a lot of beneficial insects present in the field. Fanners apply chemical pesticides
heavily that may destroy beneficial organisms. There is immense need of studying the
seasonal occurrence of harmful and beneficial insects for their proper management. A
survey of major insect pests of rice was conducted for three years from 20 lO to 2012 with
the objective of assessing seasonal occurrence of major insect pests of rice and beneficial
insects to plan future insect management strategy. Abundance records of insects namely
White Stem Borer, Yellow Stem Borer, Pink Stem Borer, Leaf Folder, Case Worm, Rice
Gundhi Bug and Tiger Beetle were made from January 2010 to December 2012. The study
revealed the overall abundance of pink stem borer as highest followed by yellow stem borer
and Gundhi bug. The relation between population buildup of rice gundhi bug and tiger
beetle found non-significant. The peak population of gundhi bug recorded in the August to
November. However, peak population of tiger beetle was from July to August thus,
reduction in population of gundhi bug was non-significant during its peak period. The study
suggests that the insect management priority be set as per the abundance rank of the studied
insect pests. The study recommends that the judicious use of pesticides be followed for
insect pest management to have increased population of beneficial natural enemies.Link for e-copy: http://elibrary.narc.gov.np/?r=959 E-copies
http://nkcs.org.np/narc/dl/?r=959URL