Study the effect of Azolla (Azolla pinnata) based organic fertilizer enriched with Eppawala Rock Phosphate and Rice Husk Ash on growth and yield of Chilli (Capsicum annum)

Abstract

The excessive utilization of inorganic fertilizers can result in severe human and environmental risk. The study was conducted to evaluate the effect of an organic fertilizer derived from Azolla in its dry form blended with Rice husk ash (RHA) and Eppawala rock phosphate (ERP) on the growth and yield performance of Green Chilli variety MICH HY 01. This study was conducted as a pot experiment at the Faculty of Technology, University of Ruhuna. The basal growing media was prepared by using compost, sand, and coir dust at 2:1:1 ratio. The experiment followed a complete randomized design with four treatments and four replicates. The treatments comprised of Azolla: ERP: RHA ratio as follows, T1 (control - 0g: 3g: 3g), T2 (3g: 3g: 3g), T3 (6g: 3g: 3g), and T4 (9g: 3g: 3g). Growth parameters (plant height, number of leaves, number of branches, leaf length, leaf width, stem diameter) and yield parameters (number of days to first flowering, number of flowers, number of pods, pod length, pod girth, fresh weight of pods) were recorded. Results revealed that the application of the fertilizer at a ratio of 9g: 3g: 3g of Azolla: ERP: RHA (T4) per plant significantly enhanced both growth and yield of Chilli. Applying Azolla as a fine powder with ERP and RHA resulted in significant difference (P<0.05) in plant height (88.25±1.65 cm), number of leaves (196±4.35), number of branches (82±4), leaf length (15.075±0.189) cm, leaf width (6.00 cm), stem diameter (7.535±0.149 mm) in T4. The minimum number of days to first flowering were recorded in T4 as 60.00±0.00 days, and highest number of flowers per plant (84.25±6.30), number of pods per plant (45.75±3.52), greatest pod length (12.375±0.11 cm), pod girth (10.360±0.15 mm) the highest total yield per plant were recorded (108.69±5.19 g) in T4. Comparatively, the control treatment (T1) with 0g: 3g: 3g of Azolla: ERP: RHA exhibited significantly lower yields. Therefore, the application of Azolla, Eppawala rock phosphate, and Rice husk ash at a rate of 9g: 3g: 3g per plant proved to be most suitable for achieving high yield in Chilli cultivation.