Effect of Planting Methods on Growth of Onion ( Allium cepa var. Cepa )

The experiment was conducted at Melkassa center of the Ethiopian Institute of agricultural Research for two season to investigate the effect of different onion planting methods on growth parameters and canopy development of onion cultivars. The experiment consisted of three planting methods of onion, namely direct seeding to the field, transplanting of seedlings and planting sets, and three onion cultivars (Adama Red, Bombay Red and Nasik Red). The experimental design was split plot with three replications; cultivars were assigned to the main plot and planting methods to sub-plot. Data were collected at 55, 70, 85 and 100 days after planting. Leaf area index were significantly (P<0.05%) higher on sets and transplants at all dates of observation. The correlation analysis results show highly significant (P<0.001) association between plant height, leaf area, LAI and shoot fresh and dry weight, with correlation coefficient ranging between 0.89 and 0.99. This indicates that any one of these parameters can be used for yield estimator depending on the condition and the facilities available. Regression analysis of total yield on leaf area index showed stronger dependence at 85 days after planting than the other dates as observed by a higher value of coefficient of determination (R2 = 0.80). This study indicated that planting method has significant effect on the growth and performance of onion cultivars.