http://ir.bdu.edu.et/handle/123456789/17407 2026-10-13T01:48:21Z http://ir.bdu.edu.et/handle/123456789/17449 Seasonal Population Dynamics of White Mango Scale (Aulacaspis tubercularis (Hemiptera: Diaspididae) on mango in North Gojam, Amhara Region, Ethiopia Yeshiwas, Birhanu In Ethiopia, mango (Mangifera indica L.) is the most widely grown fruit crop. Including the study area, Mango production in Ethiopia is damaged by various insect pests, one of them is the white mango scale, which is the most significant insect pest that causes severe damage to mango tree. It spread and now causes a loss between 50% and 100% to the production of mangoes by affecting the financial gains of mango growers. Therefore, the objective of this study was to examine the population dynamics of the white mango scale, as well as the impact of some basic climatic factors on the population density of the white mango scale in the study areas. The study on the dynamics of Aulacaspis tubercularis was carried out in the north Gojjam administration zone of Ethiopia from December 2022 to November 2023. Bahir Dar zuria and North Mecha district were purposefully selected for the study of this investigation. From each woreda, two representative sites or orchards were selected for the study. From each site/orchard, five mango trees were purposefully selected, and twelve mango leaves were plucked monthly from each mango tree (four at the upper, four at the middle, and four at the lower portion) at each of the four cardinal directions of the tree (female male, egg, crawlers were counted and recorded). Data related to meteorology, including maximum and minimum temperatures, mean temperature, relative humidity, and rainfall, was obtained from the Ethiopian National Meteorological institute and analyzed using R-Statistics software version 4.3.1. The results of the study confirmed that white mango scale was identified in all sampled study areas throughout the study period with a fluctuating population density. The mean number of white mango scale showed significant differences (p< 0.05) among the study months in each location, tree directions and canopy positions. The population density of white mango scale was significantly higher at Dek than in the rest of the study areas (p<0.05). There was a marked increase in white mango population density from March to mid-June with the general trend of slight to moderately increased precipitation. In contrast, there was a swift decrease in the white mango population from mid-June to September, followed by prolonged heavy precipitation. The correlation coefficient between the white mango scale population and some basic weather factors, including maximum temperature, minimum temperature, and relative humidity, showed a weak to very strong positive correlation and a weak positive to weak negative correlation with rain fall in the four study areas. The results of the study showed that white mango scale is distributed in all four cardinal directions, with the white mango scale insect preferring the southern cardinal direction. Furthermore, the study investigated whether the buildup and decline of the white mango scale are affected by basic climatic factors such as temperature and rainfall, relative humidity, and cardinal direction differences, where the other contributing factors need to be investigated further. 2024-06-01T00:00:00Z http://ir.bdu.edu.et/handle/123456789/17448 Evaluation of aqueous extracts of Botanicals to manage Cabbage Aphid (Brevicoryne brassicae L. (Hemiptera: Aphididae) on Cabbage (Brassicae oleraceae L.) at Koga Irrigation Scheme, North Mecha District, Ethiopia Ayenew, Wubayehu Cabbage is one of the most important vegetable crops that grown throughout the world, especially in Africa including Ethiopia. Cabbage aphid is one of the most important a sap sucking insect pest that damage cabbage crops. The aim of this study was to evaluate the efficacy of botanicals aqueous extract against cabbage aphids. The field experiment was carried out at Koga irrigation scheme, North Mecha district, Ethiopia. The experiment was conducted in Randomized Complete Block Design (RCBD) with 14 treatments along with standard check Dimethoate 40% E.C and untreated control with three replications. Four types of botanical extracts such as Nicotiana tabacum L, phytolacca dodecadra, Otostegia integrifolia and Dodonaea angustifolia leave extracts were applied at intervals of one week in the concentration of 2.5%, 5% and 7.5% respectively. But Dodonaea angustifolia leave extracts were applied at intervals of one week in the concentration of 7.5%, 10% and 12.5% respectively. "Copenhagen." Varity was used as a test crop and SAS version 9.4 was used to evaluate the data after it was entered. These research finding shown that all botanical concentrations were completely assuring in terms of their effects on aphid infestation, efficacy on cabbage aphid population, production of cabbage heads, plant canopy spread, plant height, Yield and yield loss. In terms of cabbage aphids, every plant based treatment was harmful. In this study, the Endod leaves (5 and 7.5%) concentration produced the best results among the treatments. Less yield loss was seen in the cabbage crops, a lower infestation level, a greater efficacy level, and a maximum marketable yield that was comparable with standard check. A 68.8% yield loss was recorded in untreated plots. Endod leaves extract with a concentration of 5% and 7.5% are the best for the management of cabbage aphid. Further studies should be conducted on effectiveness of these botanicals in different season. 2024-03-01T00:00:00Z http://ir.bdu.edu.et/handle/123456789/17447 Management of Tomato Leaf Miner (Tuta absoluta Meyrick) on Tomato (Solanum lycopersicum) Using Botanical and Synthetic Insecticide in Fogera, Northwestern Ethiopia Teshome, Lemat The tomato leaf miner (Tuta absoluta) is an important insect pest affecting Solanaceae plant worldwide. It pose a significant threat to tomato production in Fogera, Northwest Ethiopia. However; study has not yet been made for effective management of this insect by using botanical and synthetic insecticide in these area. Therefore these studies were intended to manage T. absoluta on tomatoes through by using botanical and synthetic insecticide. The study was conducted during 2022 dry season using irrigation in Fogera, Northwest Ethiopia where the tomato variety “Cochoro” was used as a test crop. The experiment consisted of fourteen (14) treatments which are two botanical insecticides, Neem (Azadirachta indica) and Garlic (Allium sativum L.), a synthetic insecticide, Mercury 23 EC 0.14 ml, 0.28 ml and 0.42 ml and an integration of each together through sequential application. The experiment was laid out in Randomized Complete Block Design with three replications. Data on mortality of T. absoluta, infested leaves, tunneled fruit and marketable yield of tomato were collected timely as per their respective standard procedure and analyzed using R-Software version 4.3.1. The results of the study had shown that an integration of botanical with synthetic insecticide influenced most of the tested parameters. Accordingly, the highest mortality of T. absoluta (100%), lowest infested leaves (5.44), lowest tunneled fruit (0.33), highest marketable yield (35.06 ton/ha) and lowest yield loss percentage (<4.10%) were recorded from treatment which consisted of an integration of neem and garlic with Mercury 23 EC 0.28 ml. Similarly this treatments also generated the highest net benefit (350349.94 ETB/ha) with the highest marginal rate of return (553.01%). The yield loss due to T. absoluta was found 81.41%. The current study clearly showed that yield loss positively correlated with infestation of tomato by T. absoluta. Neem and garlic with MERCURY 23 EC 0.28 ml can be recommended as the most effective and economical management of T. absoluta on tomato under irrigation in the study area and areas with similar agro-ecologies. 2024-03-01T00:00:00Z http://ir.bdu.edu.et/handle/123456789/17446 Population Dynamics of White Mango Scale (Aulacaspis tubercularis (Hemiptera: Diaspididae) on Mango (Mangifera indica L.) in South Gondar Administrative zone, Amhara Region, Ethiopia Yeneabat, Tilksew Mango (Mangifera indica L.) is the most important fruit crop grown in Amhara National Regional State of Northwestern Ethiopia for market and family consumption. Mango production is highly affected by several diseases and insect pests. Mango production in the study area is currently constrained by the infestation of white mango scale (Aulacaspis tubercularis). It spread and has become a threat to mango production in the Amhara region and the country at large. Therefore, this research is aim to investigate the population dynamics of white mango scale and its relationship with some ecological factors in Dera District from December 2022 to November 2023. Representative sites were purposively selected for the study. From each site five mango trees were purposively selected, and twelve mango leaves were plucked monthly from each mango tree at the upper, at the middle, and at the lower portion at each of the four cardinal directions of the tree. In the study months, female, male and egg was collected. Annual weather data, maximum temperature, minimum temperature, rain fall and relative humidity was taken from Amhara National Regional Meteorology Station. Micro soft excel was used for data organization and analyzed using R-Statistics software version 4.3.1. The results of the study confirmed that white mango scale was identified in all sampled study areas throughout the study period with a fluctuating population density. The mean number of white mango scale showed significant differences (p< 0.05) among the study months in each location, tree directions and canopy positions. The results indicated that, white mango scale showed population peaks in April and May. There was a high population dynamics recorded in south direction and in the middle between tree canopies. There was a positive correlation between white mango scale with rainfall and temperature. Infested mango leaves by Aulacaspis tubercularis were present in two sampled study areas, with a fluctuating population density throughout the study period. Furthermore, the study investigated whether the build-up and decline of the white mango scale are affected by basic climatic factors such as temperature and rainfall, relative humidity, and cardinal direction differences, where the other contributing factors need to be investigated further for the future. 2024-11-01T00:00:00Z