Influence of potting media on the growth and bulb yield of onion (Allium cepa L.)

A trial was conducted in the screen house at the Department of Crop Science, Faculty of Agriculture, University of Benin, Benin City, Nigeria to investigate the effect of different potting media on the growth and yield of Allium cepa L. Five sources of growing media: burnt rice husk (BRH), oil palm refuse bunch (OPRB), cattle dung (CD), poultry manure (PM) and river sand (RS) were used. River sand and the other four sources were combined in ratios of 1:1, 1:2 and 2:1 to make 12 treatments [RS + PM (1:1); RS +PM (1:2); RS +PM (2:1); RS + OPRB (1:1); RS + OPRB (1:2); RS + OPRB (2:1); RS + BRH (1:1); RS + BRH ( 1:2); RS + BRH (2:1); RS + CD (1:1); RS + CD (1:2); and RS + CD (2:1)]. Together with the five main media sources, made up a total of 17 treatments. These treatments were laid out in polybags in a completely randomized design with three replications. Data were collected on leaf length, number of leaves, number of bulbs, weight of fresh bulb, bulb girth and bulb yield. Results obtained indicated that potting media influenced growth and yield of onion significantly. The best yield was obtained from OPRB potting media with 30.00 g fresh bulb per plant, bulb girth (11.83 cm) and bulb yield (19.80 t ha(-1)). In the urban and sub-urban areas constrained with polluted and inadequate land space, potting medium with OPRB could be an innovative approach to good quality, enhanced and sustained onion production.