Effect of Nutrient Enriched Organic Liquid Fertilizers on Growth of Albemonchus esculentus

Considerable amounts of fish and fruit wastes are produced on a daily basis due to the fish processing and postharvest handling of fruits. The proper management of organic waste by converting into valuable resources is of utmost importance, in order to reduce their adverse impacts on the environment. This study was aimed to assess the utilizing potential of fish waste hydrolyzed with fruit wastes of papaw (Carica papaya) and pineapple (Ananas comosus) to enhance the nitrogen content of organic liquid fertilizers. Ripe fruit peel + crown leaves of A. comosus, ripe fruit peel + leaves of C. papaya and (1:1w/w) combination were used to extract the protease enzymes bromelain, papain and both enzymes respectively. They were mixed separately with 400 g of powdered fish waste and incubated for two days at room temperature. Six different fertilizer combinations were prepared by mixing enzymatically-digested fish waste with eight-week decomposed plant leaves and immature stems of Tithonia diversifolia, Mikania scandens, Chromolaena odorata and Gliricidia sepium with coconut husk ash and allowed to decompose for another two weeks. Nutrients of the resulting fertilizers were analyzed. Albemonchus esculentus plants were foliar sprayed twice a week for three months. Results revealed that, the nitrogen content was higher in fertilizers enriched with fish waste hydrolyzed by papain (0.49%), bromelain (0.38%) and the mixture of both enzymes (0.35%) compared to the control (0.30%). Fish waste hydrolyzed with papain recorded the highest phosphorus (0.05%), potassium (0.34%), calcium (0.26%) and magnesium (0.04%) levels. Fish waste hydrolyzed with papain enzymes recorded the highest number of leaves (16.0±0.8), shoot height (55.9±0.5 cm) and number of pods (19.5±0.5), fruit weight (33.1±1.4 g) followed by the bromelain enzyme and the mixture of both enzymes for the growth of A. esculentus. Findings of this study recommend the use of the above organic waste in production of organic liquid fertilizers which would in turn be a low-cost and an eco-friendly alternative for the chemical fertilizers while helping for the sustainable nutrient management and recycle of wastes.