71 research outputs found

    Effect of photoperiod and host distribution on the horizontal transmission of Isaria fumosorosea (Hypocreales: Cordycipitaceae) in greenhouse whitefly assessed using a novel model bioassay

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    A model bioassay was used to evaluate the epizootic potential and determine the horizontal transmission efficiency of Isaria fumosorosea Trinidadian strains against Trialeurodes vaporariorum pharate adults under optimum conditions (25±0.5°C, ~100% RH) at two different photoperiods. Untreated pharate adults were arranged on laminated graph paper at different distributions to simulate varying infestation levels on a leaf surface. Four potential hosts were located 7, 14 and 21 mm away from a central sporulating cadaver simulating high, medium and low infestation levels, respectively. Percent hosts colonized were recorded 7, 12, 14 and 21 days post-treatment during a 16- and 24-h photophase. After 21 days, mean percent hosts colonized at the highest, middle and lowest infestation levels were 93 and 100%, 22 and 58%, 25 and 39% under a 16- and 24-h photophase, respectively. From the results, it was concluded that the longer the photophase, the greater the percentage of hosts colonized, and as host distance increased from the central sporulating cadaver, colonization decreased. The use of this novel model bioassay technique is the first attempt to evaluate the epizootic potential and determine the horizontal transmission efficiency of I. fumosorosea Trinidadian strains under optimal environmental conditions at different photoperiods. This bioassay can be used to assess horizontal transmission efficiency for the selection of fungi being considered for commercial biopesticide development

    Efficacy of Major Plant Extracts/Molecules on Field Insect Pests

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    Insect pests are considered the major hurdle in enhancing the production and productivity of any farming system. The use of conventional synthetic pesticides has led to the emergence of pesticide-resistant insects, environmental pollution, and negative effects on natural enemies, which have caused an ecological imbalance of the predator-prey ratio and human health hazards; therefore, eco-friendly alternative strategies are required. The plant kingdom, a rich repertoire of secondary metabolites, can be tapped as an alternative for insect pest management strategies. A number of plants have been documented to have insecticidal properties against various orders of insects in vitro by acting as antifeedants, repellents, sterilant and oviposition deterrents, etc. However, only a few plant compounds are applicable at the field level or presently commercialised. Here, we have provided an overview of the broad-spectrum insecticidal activity of plant compounds from neem, Annona, Pongamia, and Jatropha. Additionally, the impact of medicinal plants, herbs, spices, and essential oils has been reviewed briefl

    Variability of Hot Pepper Genotypes in Ascorbic Acid Content

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    Seeds of twenty nine (29) genotypes from Capsicum species (Family: Solanaceae) of hot pepper were selected from the USDA National Germplasm Collection (Griffin, GA) to represent four hot pepper species: Capsicum annuum L., C. baccatum L., C. chinense Jacq., and C. pubescens Ruiz & Pav. Seedlings of 60 days old were planted in a randomized complete block design (RCBD) under field conditions. At harvest, fruits were collected from each genotypes and analyzed for ascorbic acid content. The main objective of this investigation was to select candidate genotypes for use in commercial pepper production and as parents in breeding for fruit quality characteristics. Hot pepper producers look for pepper varieties that yield large quantities of high-quality peppers. Consumer’s characteristics of interest include fruits with great antioxidants content. The project could help KSU meet its objective of assisting limited-resource farmers who may grow and produce new Capsicum cultivars for use as a cash crop. Our preliminary results revealed that fruits of PI 631144, PI 439420, and PI 209028 contained 583, 566, and 244 µg ascorbic acid per gm fresh fruit, respectively

    Soil Loss Analysis of an Eastern Kentucky Watershed Utilizing the Universal Soil Loss Equation

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    Soil erosion is the displacement of soil’s upper layer(s) triggered by a variation in topography, land use and soil types, and anthropogenic activities. This study selected the Marrowbone Creek-Russel Fork watershed in eastern Kentucky to estimate the mean annual soil loss over eight years (from 2013 to 2020) utilizing the Universal Soil Loss Equation (USLE). We included monthly precipitation, soil survey, digital elevation model (DEM), and land cover data to estimate the parameters of the USLE. The mean annual soil loss for the study area ranged from 1.77 to 2.91 Mg ha−1 yr−1 with an eight-year mean of 2.31 Mg ha−1 yr−1. In addition, we observed that developed land cover classes were less erosion-resistant than undeveloped land cover classes over the observation period. The results of this case study in our small watershed that has been historically impacted by upstream coal-mining activities are comparable to the results from similar studies in other geographic regions. However, we suggest other researchers conduct similar studies using robust data to determine the applicability of the USLE model and validate the results in developing measures to address soil loss issues

    Soil Loss Analysis of an Eastern Kentucky Watershed Utilizing the Universal Soil Loss Equation

    No full text
    Soil erosion is the displacement of soil’s upper layer(s) triggered by a variation in topography, land use and soil types, and anthropogenic activities. This study selected the Marrowbone Creek-Russel Fork watershed in eastern Kentucky to estimate the mean annual soil loss over eight years (from 2013 to 2020) utilizing the Universal Soil Loss Equation (USLE). We included monthly precipitation, soil survey, digital elevation model (DEM), and land cover data to estimate the parameters of the USLE. The mean annual soil loss for the study area ranged from 1.77 to 2.91 Mg ha−1 yr−1 with an eight-year mean of 2.31 Mg ha−1 yr−1. In addition, we observed that developed land cover classes were less erosion-resistant than undeveloped land cover classes over the observation period. The results of this case study in our small watershed that has been historically impacted by upstream coal-mining activities are comparable to the results from similar studies in other geographic regions. However, we suggest other researchers conduct similar studies using robust data to determine the applicability of the USLE model and validate the results in developing measures to address soil loss issues

    Marsland Press Journal

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    Abstract: The paper deals with recent botanical enigma of India's hottest chilli 'Bhoot Jolokia', or 'Bih Jolokia' earlier identified as Capsicum chinense, now identified as Capsicum assamicum Purakyasth et al., as new species from Assam, India. But after the detail investigation as well as literature survey it has been found the new species has no novel characters other than Capsicum chinense Jacq. Hence the establishment of the species is in question
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