PHD-Department of Agricultural Sciences and Technology

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Browsing PHD-Department of Agricultural Sciences and Technology by Author "Finyange, Pole"

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    Evaluation of Inorganic and Organic Fertilizers on Productivity and Quality of Bixa Orellana in Kwale County, Kenya
    (Kenyatta University, 2024-05) Finyange, Pole
    Bixa (Bixa orellana) is a small evergreen shrub that grows to a maximum height of 20–33 feet (6–10 m). It can grow in a wide variety of tropical to subtropical climates with very little care and low rainfall levels. However, it is faced with a number of challenges: competition with cheap synthetic food colours; low production and productivity; low quality of bixa in terms of bixin levels (less than 2.5% as opposed to 3.5-4.0%). This study was aimed at evaluating the effect of inorganic and organic fertilizers on productivity and quality of bixa orellana in Kwale County of coastal Kenya. A baseline survey was conducted in the major bixa producing areas of Kwale County to determine the status of bixa farming where a structured questionnaire was administered to 300 respondents. Bixa seeds and soils were sampled from farms in each of the sub-counties and subjected to seed quality tests and soil nutrient level analysis respectively. Evaluation trials on the effect of inorganic and organic fertilizers on productivity and quality of Bixa were also conducted through a field trial that was established in an existing bixa plantation at the Kenya Bixa Company Nucleus Farm in Shimoni area of Kwale County. Bixa plants of the red pointed variety, pink rounded and green pointed variety with the same age (5 years old) were subjected to treatments of different levels of organic and inorganic fertilizers in a factorial experimental unit arranged in a randomized complete block design (RCBD) replicated three times. The treatments comprised of two levels of NPK fertilizer (100kgs/ha, 150kgs/ha) and 2 levels of poultry manure (5 tons/ha, 10 tons/ha) as well as a combination of the two at half rates (2.5 tons/ha manure +50 kgs/ha NPK and 5 tons/ha manure +75 kgs/ha NPK) together with a control. Post-harvest handling studies on bixa were also conducted. Data from the experiments was analyzed using R software. A p-value of less than 0.05 was considered significantly different. The results indicated that Bixa farming is a major income generating enterprise for the smallholder farmers in Kwale County. The prices for bixa at the farm gate have been increasing on annual basis as a result of the increased demand for natural food colours in the world markets. The treatments of NPK fertilizers at the rates of 100 kg/ha and 150kg/ha respectively as well as that of manure at the rate of 10t/ha recorded the highest yields and bixin levels in all the three blocks. The drying method that produced the best results in terms of the bixin quality was that of drying at 50% shade conditions. The optimum nutrient levels were realized in the treatment manure at rate of 10t/ha and that of NPK applied at the rates of 100kg/ha and 150kg/ha respectively. On distribution of nutrients in the bixa plant, a majority of the nutrients were found in the leaves followed by roots and then stems respectively. Both the Rhizosphere soil pH and electrical conductivity (EC), improved with the application of organic fertilizer soil amendments, while the EC significantly reduced with increased use of organic fertilizer amendments. In conclusion, the study revealed that the use of organic and inorganic fertilizers can increase yields and bixin levels in bixa. This was also true for the levels of nutrients in the soil as well as the rhizosphere soil pH and soil EC. The study recommends that farmers be sensitized on the importance of soil testing and use of manures to improve soil fertility and yields of quality bixa for increased household incomes. They also need sensitization on proper post-harvest handling procedures for bixa from the time of harvesting to drying and storage. The Kenya Bixa Company should consider motivating farmers by paying them for their produce in terms of the bixin content.