Abstract:
Onion (Allium cepa L.) is member of the family Alliaceae and the most widely grown
herbaceous biennial vegetable crop. Quality planting material is one of the major inputs to
successful vegetable production. However, it is one of the major constraints in Ethiopia.
Northeastern Ethiopia has suitable agro-climatic condition for onion seed production.
However, onion seed production packages, including its appropriate planting time, are not
yet determined. Evidences on effects of the different planting time on quality and yield level is
not well explored. Therefore, this experiment was conducted at Jari small scale irrigation
scheme from September 2015 to April 2016 to determine an appropriate planting time for a
better plant growth, yield components, seed yield and quality of Adama red onion variety. The
experiment was laid out in randomized complete block design with three replications.
Treatments were nine planting dates: 1st September, 16th September, 1st October, 16th
October, 31st October, 15th November, 30th November, 15th December and 30th December.
Data were collected on growth, yield components, seed yield and quality parameters and
analyzed using SAS version 9.2 statistical software. Analysis of variance revealed that plant
height, number of leaves per plant, number of scapes per plant, scape diameter, scape height,
days to 50% flowering and maturity, umbel diameter, number of seeds per umbel, 1000-seed
weight, seed yield and germination percentage were significantly influenced by planting time.
The highest seed yield (1032.7kg/ha) as well as the highest germination percentage (94.3%)
were recorded from onion planted early (1st September). On the other hand, the lowest seed
yield (29.7kg/ha) and germination percentage (15.3%) recorded from onion planted late
(December). Growth, yield components, seed yield and quality parameters were negatively
and significantly correlated with planting time. Therefore, 1st September is recommended as
appropriate planting time for onion seed production at Jari, Northeastern Ethiopia. Since this
result is based on one season work, in order to give conclusive recommendation, further
investigation is needed at Tehuledere district and other locations with similar agro-ecological
conditions in the region.
