Browsing by Author "Shechambo, L."

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Effects of host availability on seasonal abundance of the fruit fly bactrocera invadens drew, tsuruta & white in Morogoro
(Sokoine Unoversity of Agricultural, 2008) Shechambo, L.
Fruit flies (Diptera: Tephritidae) are listed among the major fruit pests distributed in all fruit growing areas of the world. Fruit flies compete with human beings for food resources by causing direct damage to fruits and vegetables. The damage they cause brings about negative economic and social impacts to man since he depends on fruits for important food nutrients, employment and income. The fruit fly problem in Tanzania and Africa has been aggravated since the invasion of the new fruit fly probably of Asian origin, described as Bactrocera invadens (Drew, Tsuruta and White). The newly invasive fruit fly that was first reported in Kenya in 2003, then in Tanzania in 2004, thereafter from the rest of Africa, has shown ability to spread fast within a short time as it is suspected to displace the indigenous fruit flies in the African region. Earlier studies in Morogoro, revealed that the fruit fly does well in low to medium altitude areas than in high altitude areas of the region. This study was conducted at SUA horticultural unit in Morogoro, to assess the temporal and spatial presences of B. invadens in relation to the fruiting of economically important fruit crop species. To achieve the objective, phenological events of important fruit species and varieties were recorded while fruit fly trapping was also done. At the same time weather parameters including temperature, rainfall and relative humidity were recorded. The data were all recorded at weekly basis for a period of 48 weeks. The phenology recording experiment followed a Randomized Complete Block Design while the trapping experiment followed a split-split plot design. Fruit fly trapping results were analysed using Genstat Statistical Package whereby Analysis of Variance (ANOVA) was performed to determine the efficacy of attractants and the difference in fruit fly catches between sub-orchards. The study results reveal that temperature, rainfall and relative humidity influence phenological events in plants which as a result influence the abundance of fruit flies and that weather has a direct impact on the population dynamics of fruit flies. It is ii therefore recommended that knowledge in fruit phenology can be used as a tool in Integrated Pest Control because of the quick response plants have to weather changes hence become accurate timers as to when to start fighting against fruit flies for effective and inexpensive pest management.
Effects of organic mulch on yield and selected pests of organically grown tomato (Solanum lycopersicum L.) and sweet pepper (Capsicum annuum L.)
(Sokoine University of Agriculture, 2018) Shechambo, L.
The objectives of this study were (i) to determine the effects of Mexican weeping pine (Pinus patula Schelde. ex Schltdl and Cham) and wild lemon grass (Cymbopogon spp.) mulches and time of their application on yield and quality of organically grown tomato (Solanum lycopersicum L.) and sweet pepper (Capsicum annuum L.), (ii) to investigate the effect of pine and wild lemon grass mulch on pests and beneficial arthropods under organic production of tomato and sweet pepper, and (iii) to examine the decomposition rate and chemical products of pine and wild lemon grass. Tomato cv. ‘Tanya’ and sweet pepper cv. ‘California Wonder’ were grown organically at Lushoto and Ubiri wards in Lushoto district, Tanga region, North-Eastern Tanzania. The experiment was laid out in a Randomised Complete Block Design (RCBD) with three replications and repeated for three seasons. The treatments were pine mulch applied 3 days after transplanting (PI), and 21 days after transplanting (PA), grass mulch applied 3 days after transplanting (GI), and 21 days after transplanting (GA) and two unmulched controls weeded and unweeded. Dry pine and wild lemon grass materials were used in compost making, each mixed with forest soil, cow manure, green grass and water. Laboratory analysis was done later on at Sokoine University of Agriculture (SUA) Soil Science laboratories to determine the chemical composition of the composts. Data collected included the number of leaves per plant, plant height, fruit yield, number of fruits per plant, fruit size, marketable and unmarketable fruit weight. Beneficial arthropods were also collected using pitfall traps for the three seasons. In each treatment and location, data on numbers and dry weight of weeds, disease incidences and insect pests were also collected. The time taken for compost to mature and their chemical composition in the period of three and twelve months of composting were recorded. The analysed parameters included organic carbon (OC), total Nitrogen (TN), phosphorus (P), potassium (K), copper (Cu), zinc (Zn), iron iii (Fe), and manganese (Mn). Data were subjected to Analysis of Variance (ANOVA) at P≤ 0.05 and where applicable Post Hoc. Tukey’s (HSD) test was used to compare means. Data analysis was done using R Statistical Package (AGRICOLAE Version 1.2.1). Results showed that both types of mulch had positive influence on yield and quality components regardless of the time of mulch application. Among the three seasons, the highest yields were obtained during the wet and cold season (April – August, 2013). Mulching with either pine or wild lemon grass did not affect the number of trapped arthropods while across the seasons, numbers of arthropods increased significantly (P ≤0.05). In weed control, results revealed that pine and wild lemon grass mulch had similar (P≤0.05) effect as weeding. Laboratory analysis of compost containing pine and wild lemon grass containing compost showed significant changes in OC, TN, Na, Fe and Mn between three and twelve months of composting. In conclusion, application of both pine and wild lemon grass mulch brings higher yields of tomato and sweet pepper than hand weeded practice. Both types of mulch lasted throughout the production period without need replenishment. Types of mulch and time of application did not have a significant influence on yield, weed control, insect and disease attacks instead the presence of mulch reduced numbers of weeds, increased numbers of beneficial arthropods, yield and quality of tomato and sweet pepper. Pine and wild lemon grass containing compost released nutrients as early as three months after heaping. It is therefore recommended, that pine and wild lemon grass can be used as organic mulch three to 21 days after transplanting tomato and sweet pepper seedlings but using pine and wild lemon grass containing compost requires further investigation. It is further recommended for future scholars to also focus on studying beneficial arthropods and their relationship with insect pests where pine and wild lemon grass are used as mulch.