Browsing by Author "Chabari, Kithaka Samson"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Assessment of Selected Physico-Chemical Parameters of Groundwater in Chuka Igambang’ombe Constituency, Kenya
    (Chuka University, 2022) Maweu, Bonface K.; Chabari, Kithaka Samson; Nguku, James Kyalo; Chuka, University
    Groundwater is an essential source of water for drinking and other domestic uses. Recently, there has been high dependence on groundwater due to water shortage as a result of changing climates, and higher costs of accessing piped water. An occurrence of the physico-chemical parameters of the groundwater in levels past the WHO highest permissible limits can cause serious health implications to the consumers of the groundwater. This study therefore, assessed the extent of the physico-chemical parameters concentration of the groundwater in Chuka, Igambang’ombe constituency. A total of five samples was collected from 5 boreholes in the Mucw’a and Ndagani regions surrounding the Chuka University main campus. Selected physical parameters were recorded onsite by use of portable apparatus. Samples for testing chemical parameters were collected and transported in cooler boxes to Chuka University laboratories for analysis. Physical parameters determined onsite were dissolved oxygen (DO), temperature, and the pH. Dissolved Oxygen meter, mercury thermometer, and pH meter were the equipment used to test the respective physical parameters. UV- spectrophotometry was used to analyze the chemical parameters: nitrates, and phosphates, where absorbance was recorded at a wavelength of 220-820 nm and 880nm respectively. The assessment was conducted during the relatively dry months of January to March. The temperature of the water ranged from 22.8-25.20C. The pH levels ranged from 4.50 – 9.50. The high altitude nitrate levels were 2.4mg/L, and 7.37mg/L at the low altitude. The phosphate concentrations were below detectable limits. The results were then compared with WHO standards for the highest permissible levels for the tested parameters to determine the suitability of the water for consumption. All the tested parameters lied within the WHO permissible limits for drinking water except for the pH levels.
  • Thumbnail Image
    Item
    IN-VITROEVALUATION OF FUNGICIDES SENSITIVITY OF TOMATO LEAF BLIGHT PATHOGENS ISOLATES Alternariasolani and Phytophthorainfestans
    (Chuka University, 2021) Nyakinywa, Ruth; Ogolla, Fredrick O.; Chabari, Kithaka Samson
    Tomato early and late blight diseases caused by Alternaria solani(Ellis & Martin) Sorauer and Phytophthora infestansrespectively hinder tomato production globally. Use of fungicides in management of blight diseases has become a priority among farmers. However, indiscriminate or use of sub lethal doses negate disease management efforts. Despites the knowledge of possible occurrence of fungicide insensitive phyto-pathogens, farmers has continued using fungicides without periodic evaluation of their effectiveness. This study was carried out to evaluate an in-vitro sensitivity of tomato leaf blight pathogens (Alternaria solaniand Phytophthora infestans) against selected fungicides mostly used by tomato farmers along River Ruguti in Tharaka Nithi County in Kenya.Fungicides evaluated included, Mancozeb (640 g kg-1 ) + Metalaxyl (40 g kg-1 ), mancozeb 640 g/kg + metalaxyl 80 g/kg, Mancozeb, Propineb700 g/kg + Cymoxanil 60g/kg, Carbendazim and Triticonazole at different concentration (25%, 50% and 75%). Poison food method was used for evaluation. Complete Randomise design was used for the experiment. Per cent data on mycelia growth inhibition by various fungicides at different concentration were analysed using General Linear Model (α=.05) and significant means separated using Least significant difference (LSD) in Scientific Analysis System version 9.4. All the tested fungicides significantly (P≤ 0.05) inhibited the mycelial growth of tested pathogen. However, among tested fungicides, Carbendazim (89.83%) and Propineb700g/kg +Cymoxanil 60g/kg were superior over other fungicides with Carbendazim being the least. Mycelia growth inhibition increased with an increase in fungicide concentration. Mycelia growth inhibition of Alternaria solaniwas 81.78% as compared to Phytophthora infestans at 69.78%.