Abstract

An experiment to asses the Effect of plant density (intra-row spacing) on yield and yield components (bulb diameter, bulb weight, marketable and unmarketable bulb yield and total bulb yield Q/ha) of onion (Allium cepa l.) varieties (Bomby red, Adama red and Nasic red) were conducted in 2007 and 2008 at Adami Tulu Agricultural Research center, on horticulture research field, in mid rift valley of Ethiopia with the objective of; to identify optimum spacing between two consecutive plants and to recommend the best spacing combination for those three morphologically different varieties independently. The experiment was conducted using randomized complete block design with three replicates. Area occupied by a single plot is 4 x 3 m and with a spacing of 1.5 x 1 m between block and plot respectively. There are a total of 12 treatments. The analyzed result using SAS soft ware shows significance difference among those varieties with different spacing level like (4, 6, 8, 10 cm) by using 10 cm as check or control. For Adama red, A4 gave best marketable yield (220.55 ± 84 q/ha) followed by A6 (201.45 ± 60 q/ha) and for Bomby red B4 out yielded much better than the rest spacing (301.58 ± 77 q/ha). For the third variety N4 gave (324 ± 65 q/ha) marketable yield followed by N6 (251.5 ± 126 q/ha).Generally evaluating the three varieties with different spacing, Nasic red (N4) performs better followed by bomby red (B4). Among the three varieties, Adama red (A8) gave less yield performance than the rest varieties.

Key words: Intra row, marketable, spacing, yield.