Effect of the Irrigation Interval and Nitrogen Rate on Yield and Yield Components of Onion (Allium cepa L.) at Arba Minch, Southern Ethiopia

Table 6

Interaction effect of the irrigation interval and N rate on yield and yield components of onion.

Treatment		Bulb length (cm)	Bulb diameter (cm)	Average bulb weight (g)	Total biomass (t ha^−1)	Marketable bulb yield (t ha^−1)	Unmarketable bulb yield (t ha^−1)	Total bulb yield (t ha^−1)	Harvest index (%)
Irrigation interval (day) N (kg·ha^−1)
3	0	5.13	5.51^de	62.13^c	29.35^f	21.54^d	3.56	25.10^d	82.65
	50	5.71	6.17^c	70.6^b	36.48^b	28.86^b	2.78	31.65^b	86.75
	100	7.02	6.18^a	79.6^a	41.59^a	33.70^a	2.57	36.27^a	87.22
	150	7.48	6.83^a	82.00^a	41.84^a	34.12^a	2.63	36.75^a	87.87
6	0	5.11	5.54^dc	64.53^c	29.72^f	23.23^d	2.43	25.67^d	82.19
	50	5.27	6.13^c	73.10^b	36.64^b	30.31^b	2.01	32.33^b	88.20
	100	6.27	6.44^b	78.47^a	40.31^a	33.56^a	1.76	35.34^a	87.66
	150	7.01	6.58^ab	80.76^a	40.69^a	33.20^a	2.02	35.22^a	86.58
9	0	4.57	4.54^g	40.86^g	26.12^h	18.61^e	3.29	21.90^e	78.43
	50	5.11	5.37^e	46.23^ef	31.52^de	22.61^d	2.52	25.13^d	79.73
	100	5.83	5.58^ed	49.86^ed	33.27^c	25.99^c	1.77	27.76^c	83.40
	150	6.28	5.66^d	53.10^d	32.54^cd	25.87^c	2.13	28.00^c	86.15
12	0	4.04	3.66^h	31.57^i	22.34^i	15.14^f	3.18	18.32^f	76.68
	50	4.45	4.62^g	35.46^hi	27.65^g	18.37^e	3.29	21.67^e	78.34
	100	5.34	5.03^f	39.93^gh	29.69^f	21.72^d	2.45	24.17^d	81.52
	150	5.53	5.38^e	42.53^fg	30.54^ef	21.43^d	2.46	23.89^d	77.64
CD (<0.05)		NS	0.09	1.6	0.65	0.79	NS	0.85	NS
SEM (±)		0.08	0.02	4.91	0.80	1.21	0.12	1.41	8.05
CV (%)		5.15	2.45	3.81	2.69	4.32	13.48	4.24	3.41

Means followed by the same letter within a column are not significantly different at a 5% probability level according to Duncan’s multiple range tests, CD = critical difference, SEM = standard error of mean, CV = coefficient of variation, and NS = nonsignificant.