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Evaluation of biological control option for Bagrada bug (Bagrada hilaris (Burmeister)) in Kenya
43-47.Views:84Brassica production is important for economic development of Kenya. Bagrada bug, a significant pest of brassicas, affects their yields and quality, currently posing a threat to both local and commercial vegetable production in Kenya. Biological control of bagrada bug using natural enemies is a cheaper and environmentally friendly method. The study aimed to identify native egg parasitoid species in Kenya. A field prospection survey of the bagrada bug egg parasitoid was done by a series of bagrada bug egg exposure in different parts of the country. Freshly laid bagrada bug eggs in cards were exposed for possible parasitism in the field for three days. The eggs were later carried to the laboratory at NSRC to await hatching. Two egg parasitoid species Trissolcus basalis (Hymenoptera, Scelionidae) and Gryon sp. were identified during the study after a period of bagrada bug egg exposure in Machakos and Kisumu. Two cards with parasitized bagrada bug eggs were recovered from Machakos from which one card yielded four parasitoids of one species Trissolcus basalis and the other yielded two parasitoids Trissolcus basalis and Gryon sp. One card with two parasitized eggs by Trissolcus basalis was recovered from Kisumu, however, there were no parasitoids identified in Nanyuki, Naivasha and Kitengela where bagrada bug is also prevalent. Results showed parasitoid presence in fields with high bug populations compared to areas with few or no Bagrada bug infestations. Conducting trials in both laboratory and field settings is recommended to obtain clear data on the effectiveness of the identified egg parasitoid in managing the bagrada bug population.
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Effect of biochar and inorganic fertilizer on the quality of beetroot (Beta vulgaris L.) in Kenya
7-13.Views:207Despite its health benefits, the production and quality of beetroot is still low in Kenya due to the application of non-recommended rates of fertiliser and soil amendment. This research aimed at contributing to the improvement of the beetroot quality in Kenya. It was designed to determine the effects of biochar and NPK (17-17-17) on the quality of beetroot in Kenya. An RCBD factorial experiment was conducted at Egerton University farm, Kenya, for two seasons. Biochar (0, 5, 10 t/ha) and NPK (0, 200, 300 and 400 kg/ha) were applied together before planting. Data were collected on beetroot diameter, total phenolics, total soluble solids, calcium, iron and phosphorus contents and analysed using SAS statistical software. The co-application of biochar and NPK significantly (p≤0.05) increased the beetroot diameter, iron, calcium, phosphorus, TSS and phenolics content in season two and not in season one. The sole application of biochar showed a significant increase in the iron content of beetroot in season one. However, biochar did not have a significant effect on beetroot diameter, mineral content, TSS and phenolics content of beetroot in season two. The sole application of NPK at 200, 300 and 400 kg/ha significantly (p≤0.05) increased the diameter of beetroot and iron content in both seasons one and two and also significantly improved the calcium and phosphorus content in season two. These NPK levels were not statistically different from each other, but different from the control. It is therefore recommended to apply NPK and biochar for quality beetroot.
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Effects of biochar and inorganic fertiliser on the growth and yield of beetroot (Beta vulgaris L.) in Kenya
37-45.Views:285Beetroot (Beta vulgaris L.) is a root vegetable packed with many nutritional benefits such as minerals and vitamins. Despite its importance in Kenya, farmers get about 30-35 t/ha which is significantly lower than the potential yield (68 t/ha). This is mostly attributed to low soil fertility. This study aimed to determine the response of the beetroot growth and yield on biochar and NPK. A 3×4 factorial experiment was carried out at Egerton University farm over two seasons to test the effects of biochar and NPK (17-17-17), under supplemental irrigation. Biochar (0, 5, 10 t/ha) was combined with NPK (0, 200, 300, 400 kg/ha). The combination of Biochar and NPK increased significantly (p ≤ 0.05) beetroot growth and yield in two seasons. Treatment B10N400 showed the tallest plants (79.2 cm) at 90 days in season two, while the control resulted in the shortest (27.6 cm). Treatment B10N200 showed the biggest (213.2 cm2) leaves at 90 days. The treatment B5N300 recorded the highest marketable yield (84 t/ha) in season two and the lowest was B0N0 with 2.6 t/ha. Sole application of NPK rates (200, 300, 400 kg/ha) increased significantly the growth and yield of beetroot compared to the control in both seasons. In season one, N300 (300 kg/ha) had 61.9 t/ha of the total yield, the control had the lowest. In season two, 300 kg/ha had 83 t/ha of total yield. Biochar increased beetroot growth and yield in season 2. Treatment B5 recorded the highest marketable yield of 61.2 t/ha, while the control showed the lowest of 53 t/ha.