Browsing by Author "Assenga, Bobnoel"

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Status and effects of insect pests on the cashew (Anacardium occidentale L.) in southern and central zones, Tanzania
(NM-AIST, 2020-06) Assenga, Bobnoel
This study was conducted from February to March and July to August 2019 in twenty-four (24) cashew fields located in the southern and central zones of Tanzania. In each zone, three districts were selected based on cashew production reports, and in each district, four farms were selected. In each farm, ten fully-grown cashew nut trees were randomly selected and assessed for infestation by sucking insect pests. The insect pests were assessed within quadrants of one-meter length placed at the north and south of the canopy of the cashew tree. The total number of insect pests, susceptible shoots and nuts, both clean and damaged were recorded. Insect samples were collected and identified at the Tropical Pesticides Research Institute, Arusha Tanzania. Twenty-seven (27) key informant farmers were interviewed using questionnaires and farmers group discussions in both zones. The study revealed a number of both known and first recorded insect pest’s attacks that cashew nut. The commonly known insect pests identified include Helopeltis sp, Pseudotheraptus wayi, Selenothrips rubrocinctus and Mecocorynus loripes, and newly recorded were Miphetophora sp., Plaesiorrhira sp., Diplognatha gagates, Systates sp, and Aphis sp. The incidence and diversity of these cashew sucking insect pests differed in terms of abundance and distribution within cashew fields. Most abundant insect pests were Helopeltis sp. with incidences of 46.7%. Further research is required in studying biology, ecology population dynamics and abundance of first reported and identified insect pests to determine specific periods for intervention and develop methods (species-specific) for effective pest management in Tanzania.
Status of sucking insect pests in cashew growing locations of South and Central Zones, Tanzania
(International Journal of Biosciences, 2020-04-14) Assenga, Bobnoel; Masawe, Peter; Tarimo, Thadeo; Kapinga, Fortunus; Mbega, Ernest
Cashew (Anacardium occidentale L.) is an economically important cash crop for many rural households in Tanzania. However, its production is constrained by some insect pests and diseases. As a precondition for the development of a more sustainable integrated insect pest management strategy for cashew, information on the incidence and severity of cashew sucking insect pests in a changing environment is required. Field surveys were conducted in the major and minor cashew producing areas of Tanzania in two phases, February to March 2019 during the vegetative season and July to August 2019 during reproduction season. The surveys were conducted in 24 cashew fields in six districts (Liwale, Masasi, Nachingwea, Manyoni, Kongwa and Mpwapwa) in southern and central agricultural research zones in Tanzania. Data on a number of shoots infected by sucking insect pests, i.e. black lesion, leaf damage, dieback level, pest counts and counts of natural enemies were collected from the two zones. Data showed that incidence and diversity of sucking cashew insect pests differed in terms of abundance and distribution within cashew fields in the central and southern zones. Liwale and Kongwa districts recorded higher incidence and severity followed by Mpwapwa, Masasi, Manyoni and Nachingwea districts, respectively. In general, insect pests affecting cashew production in selected locations of southern and central Tanzania have been known in terms of identity (genus level), abundance and distribution; therefore, more efforts on the study should be made on identification to species level to formulate management measures to each specie.