Influence of Organic Enriched Manure and Inorganic Fertilizers on Plant Physiological Processes of Kenyan Tea Clone

Tea (Camellia sinensis L.) is one of the most popular beverages consumed in the world and Kenya is the leading exporter in Africa and only 3rd worldwide after China and India. Nutrient deficiency in soils and poor fertilization are possibly two reasons for low yields and quality of tea. The use of organic matter and mineral fertilizers has been proved to be a sound soil amendment and fertility management strategy. Therefore, this study was conducted to evaluate the possibility of using readily available organic manures in combination of inorganic fertilizers on the physiological processes of tea clones in Kenya. The study was conducted within Timbilil estate, KALRO- Tea Research Institute in Kericho County on variety clone TRFK31/8. It was laid out in a Randomized Complete Block Design (RCBD) and replicated three times. There were 14 treatments that randomly assigned in each block. Data on tea response was determined from photosynthesis rate, transpiration rate and stomatal conductance then recorded and analyzed using GenStat Version 15.1. There were significant differences between the treatments on the transpiration rate, stomatal conductance and the photosynthetic rate in both seasons for all the months recorded. The transpiration rate was highest during the wet season in the months of June, July and August while lower transpiration rates were recorded during the dry season in the months of December, January and February with 0.1 g m−2 s−1 transpiration rates recorded in several treatments in the month of February. Stomatal conductance, photosynthetic rate and transpiration rate were higher where NH4+ was introduced through the organic manure in all the seasons and therefore confirms that it is highly important to incorporate soil amendments with higher organic matter in tea production in Kenya.