1,720,959 research outputs found
Efficacy of combining Niger seed oil with malathion 5% dust formulation on maize against the maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae)
No full textThe combined effects of Niger seed oil and malathion, 5% dust, against the maize weevil, Sitophilus zeamais, were evaluated to determine the minimum effective rate(s) of the combinations that can provide adequate protection to maize seed against attack by weevils. Niger seed oil at the rates of 0%, 10%, 20%, 30%, 40%, 50% and 100% of the recommended application rate, 5 ml kg(-1), was combined with malathion at the respective rates of 100%, 50%. 40%. 30%, 20%, 10% and 0% of the recommended application rate, 0.5 g kg(-1). All combinations provided complete protection to maize seed from the maize weevil up to 90 days after infestation. To determine the residual effects of the treatments, weevils were reintroduced to the grain that had been treated 90 days previously. In addition to 100% malathion, 10% Niger seed oil+50% malathion, and 20% Niger seed oil+40% malathion, were fully effective in controlling S. zeamais for a further 156 days after this re-infestation. Therefore, these combinations could be considered as a potential component in an effort to establish integrated management of the maize weevil. Residual performance of both oil and malathion against the weevils was primarily affected by the dose of malathion, with higher doses of malathion providing greater protection for a longer period. Niger seed oil treatment lowered the level of seed germination at the application rate of 5 ml per kg of maize. (C) 2008 Published by Elsevier Ltd
Infestation and Yield Losses Due to Sesame Webworm (Antigastra catalaunalis, (Duponchel) on Different Sesame Varieties in Western Tigray, Northern Ethiopia
No full textSesame (Sesamum indicum L.) is the most important oilseed crop in Ethiopia. It is basically grown during the summer season in different regions of the country and produced mainly in the northern and northwestern lowlands of Ethiopia. The production of sesame is low because of insect pests such as sesame webworm, sesame seed bug and gall midge. Among these pests, sesame webworm is one of the most important insect pests and it attacks the crop at all growth stages and causes a significant yield loss. Therefore, the present study was aimed to assess the infestation and avoidable yield losses of sesame due to sesame webworm on different released sesame varieties at field conditions. A field experiment was conducted to assess the infestation and yield losses with respective cost-benefit of nine released sesame varieties to sesame webworm in paired plots (treated with Diazinon 60% EC and untreated) in RCBD with three replications in 2016 production year. There was a significant difference (p<0.001) between the protected and unprotected plots of each variety in leaf, flower and capsule injury. Protection of sesame from the webworm with insecticide effectively reduced leaf (0.02%), flower (<2%) and pod (<1%) damage to very low levels, On the other hand, the unprotected sesame had high levels of infestation. The highest capsule injury was recorded on BaHa-Necho (9.68%) and varieties Adi, Setit-2 and Borkena sustained <5% capsule injury. Grain yield was also increased significantly (p<0.001) in the protected plots of the nine varieties as compared to their corresponding unprotected plots. Maximum yield was obtained from Setit-2, Setit-1, Humera-1 and Higher in both treated and untreated plots. The highest avoidable yield losses were obtained from Adi, Gonder-1, BaHa-Necho, and BaHa-Zeyit with respective cost-benefit ratio 2.27, 2.02, 2.12 and 2.03. Therefore integration of sowing the varieties Setit-2, Setit-1, Humera-1 and Hirhir and spraying with Diazinon 60 EC, at a rate of one liter per hectare at 2, 4 and 6 weeks after crop emergence (WAE) has potential to reduce the yield losses of sesame due to sesame webworm infestation and to increase yield of sesame
Farmer’s pesticide uses and risks in onion fields in the central rift valley of Ethiopia
Full text linkImproper use of pesticides has been the most problematic factor in affecting the environment and pollinating insects. Therefore, this research was conducted to assess farmers’ awareness and usage of insecticides for the protection of onion pests in the Central Rift Valley of Ethiopia from January to May 2022. A purposive sampling method was used to select onion growers in the study area. The respondents revealed that damage caused by pests and diseases led to yield loss in onions, and their choice was applying insecticide chemicals without training in the application technique of the chemical. A very high proportion of farmers (60%) in Adami Tullu Jido Kombolcha and Bishan Guracha (44%) never wear personal protective equipment (PPE) at the time of insecticide application. The result also demonstrated that only 44% of respondents from Adami Tullu Jido Kombolcha and 25% from Bishan Guracha had attended formal training. They also revealed that they purchased pesticide chemicals without knowing their safe use or disposal methods. Due to this, farmers fail to follow the label for pesticide rate, spray volume, and wearing personal protective equipment. The results of this study suggest that farmers in the study area need training and inspection on the safe use and hazardous effects of insecticides.
Int. J. Agril. Res. Innov. Tech. 15(1): 11-21, June 202
Density And Distribution Of Enset Root Mealybugs On Enset
No full textThe enset root mealybug ( Cataenococcus ensete Williams and
Matile-Ferrero) has become the most important insect pest of enset (
Ensete ventricosum ) in southern Ethiopia. The objective of this study
was to determine the distribution and density of enset root mealybugs
on enset plants. The distribution of the enset root mealybug on enset
roots and corms of the 'Genticha' clone was studied in 2005 on farmers'
field at Yirgachefe, southern Ethiopia. An average of 87 adult enset
root mealybugs were collected from roots and corms per plant. The
majority of the mealybugs inhabited the roots (79%), while 21% was
found on the corms. About 99% of the mealybugs were found in the upper
40 cm soil layer. In addition, about 90% of the mealybugs were
collected within a 60 cm radius from the plants. The majority of the
mealybugs (59%) were found on the upper half of the corm. About 63% of
all mealybugs were collected from the corm and on the roots within a 20
cm radius from the corm. Both root and shoot fresh weight had a
negative correlation (r2 = 0.58 and 0.92, respectively) with the enset
root mealybug population density.L'enset mealybug de racine ( Cataenococcus ensete Williams et
Matile-Ferrero) est devenu la peste de l'insecte le plus important
d'enset ( Ensete ventricosum ) dans le Sud d'Ethiopie. L'objectif de
cette étude était de déterminer la distribution et la
densité d'enset mealybugs de racine sur les plantes d'enset. La
distribution de l'enset mealybug sur les racines d'enset et les bulbes
du clone de « Genticha » a été étudiée
dans 2005 sur les agriculteurs › le champ à Yirgachefe, le
Sud d'Ethiopie. Une moyenne de 87 enset adulte mealybugs de racine a
été recueilli des racines et des bulbes par la plante. La
majorité du mealybugs a habité les racines (79%), pendant que
21% a été trouvé sur les bulbes. Environ 99% du
mealybugs ont été trouvé dans la couche du sol de 40 cm.
Par ailleurs, environ 90% du mealybugs ont été recueilli dans
un rayon de 60 cm des plantes. La majorité du mealybugs (59%) ont
été trouvé sur le moitié supérieure du bulbe.
Environ 63% de tout mealybugs ont été recueilli du bulbe et
sur les racines dans un rayon de 20 cm du bulbe. Le poids frais de la
racine et des rejetons a une corrélation négative (r2 = -0.76
et -0.96, respectivement) avec l'enset la densité de population de
mealybug de racines
Pathogenecity of Beauveria bassiana and Metarhizium anisopliae, to the Two Spotted Spider Mites, Tetranychus urticae, (Acari: Tetranychidae) at Different Temperatures and in Greenhouse Condition
Full text linkPathogenecity of entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae isolates of Ethiopian origin on eggs and adults of the two spotted spider mites, Tetranychus urticae, effect of temperature on virulence, as well as potentials of isolates in the greenhouse condition was assessed during October 2008 to May 2009 at Plant protection Research center in Ambo. All the isolates tested (B. bassiana 9614 and 9609, and M. anisopliae MM and PPRC 6) caused high mortality to the eggs of the two spotted spider mites compared to the control groups. Significant differences of pathogenicity were observed among isolates kept at different temperature regimes. Temperature regimes of 25°C and 30°C were suitable for the isolates M. anisopliae MM and B. bassiana 9614 compared to 20°C and 35°C. All the four fungal isolates used caused significantly higher mortality compared with the untreated control groups under the greenhouse condition and the highest mortality was 89.4%. As a consequence leaves treated with the fungal isolates had less damage that may be attributed to fewer number of surviving mites. The study showed that M. anisopliae and B. bassiana are able to kill the two spotted spider mites eggs and adults, and can be used as substitute or complement to synthetic chemicals most of which lack ovicidal activity.Keywords: Entomopathogens; Isolates; Mortality; Temperature; Two Spotted Spider Mites
Density And Distribution Of Enset Root Mealybugs On Enset
Full text linkThe enset root mealybug ( Cataenococcus ensete Williams and
Matile-Ferrero) has become the most important insect pest of enset (
Ensete ventricosum ) in southern Ethiopia. The objective of this study
was to determine the distribution and density of enset root mealybugs
on enset plants. The distribution of the enset root mealybug on enset
roots and corms of the 'Genticha' clone was studied in 2005 on farmers'
field at Yirgachefe, southern Ethiopia. An average of 87 adult enset
root mealybugs were collected from roots and corms per plant. The
majority of the mealybugs inhabited the roots (79%), while 21% was
found on the corms. About 99% of the mealybugs were found in the upper
40 cm soil layer. In addition, about 90% of the mealybugs were
collected within a 60 cm radius from the plants. The majority of the
mealybugs (59%) were found on the upper half of the corm. About 63% of
all mealybugs were collected from the corm and on the roots within a 20
cm radius from the corm. Both root and shoot fresh weight had a
negative correlation (r2 = 0.58 and 0.92, respectively) with the enset
root mealybug population density.L'enset mealybug de racine ( Cataenococcus ensete Williams et
Matile-Ferrero) est devenu la peste de l'insecte le plus important
d'enset ( Ensete ventricosum ) dans le Sud d'Ethiopie. L'objectif de
cette étude était de déterminer la distribution et la
densité d'enset mealybugs de racine sur les plantes d'enset. La
distribution de l'enset mealybug sur les racines d'enset et les bulbes
du clone de « Genticha » a été étudiée
dans 2005 sur les agriculteurs › le champ à Yirgachefe, le
Sud d'Ethiopie. Une moyenne de 87 enset adulte mealybugs de racine a
été recueilli des racines et des bulbes par la plante. La
majorité du mealybugs a habité les racines (79%), pendant que
21% a été trouvé sur les bulbes. Environ 99% du
mealybugs ont été trouvé dans la couche du sol de 40 cm.
Par ailleurs, environ 90% du mealybugs ont été recueilli dans
un rayon de 60 cm des plantes. La majorité du mealybugs (59%) ont
été trouvé sur le moitié supérieure du bulbe.
Environ 63% de tout mealybugs ont été recueilli du bulbe et
sur les racines dans un rayon de 20 cm du bulbe. Le poids frais de la
racine et des rejetons a une corrélation négative (r2 = -0.76
et -0.96, respectivement) avec l'enset la densité de population de
mealybug de racines
Efficacy of Ethiopian Beauveria bassiana and Metarhiziumanisopliae isolates on spotted spider mites, Tetranychusurticae (Acari: tetranychidae) under laboratory conditions
Full text linkThe efficacy of six Beauveria bassiana and nine Metarhiziumanisopliae isolates of Ethiopian origin were bioassayed in the laboratory replicated 4 times for their lethal effects against the adult of Tetranychusurticae with the aim to incorporate as bio- agent component for IPM of the two spider mites. All the tested isolates were pathogenic tothe two spotted spider mite at 1x108 conidia ml- concentration, but virulence ranged from 45.4% to 90.0% with LT50 from 3.19 to 11.81 days. Based on the extent of mortality, isolates PPRC 29, PPRC 27, PPRC 19, PPRC 66, and EE of Metarhizium; and GG and HH of Beauveria were moderately virulent (60-80%) and PPRC 2 &PPRC 61 of Metarhizium; and9615 & 9604 of Beauveria are weak (<60%). Four isolates (MM &PPRC 6 of Metarhizium; and 9614&9609 of Beauveria) which caused mortality ranges of 86% to 90%,were categorized as highly virulent and further evaluated at four different doses (1×105, 1×106, 1×107 and 1×108 ml-1). The isolates inoculated at different concentrations significantly differed in their efficacy and the higher concentration (1×108 conidia ml-1) caused higher mortality than the lower (1×105 conidia ml-1). Isolate 9614 showed the least LC50 (1.37×105) followed by MM (1.9×105). Therefore the two isolates, B. bassiana 9614 and M.anisopliae MM, which caused higher mortalities within shorter periods, were promising bioagents for the management of the two spotted spider mites
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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