Performance Evaluation of Sesame under Regulated Deficit Irrigation Application in the Low Land of Western Gondar, Ethiopia

Table 4

Crop water requirement and depth of irrigation water application (mm) on weekly bases.

Date	DAS	ETo (mm/day)	Kc	CWR (mm)	Net irrigation applied (mm/period)
					UO	DI	DD	DM	DL	50	75	120
17/02	—	—	—	25	25	25	25	25	25	25	25	25
21/02	4	4.5	0.60	18.9	18.9	4.7	18.9	18.9	18.9	9.5	14.2	22.8
28/02	11	4.5	0.60	18.9	18.9	4.7	18.9	18.9	18.9	9.5	14.2	22.8
7/03	18	5.89	0.60	24.7	24.7	6.2	24.7	24.7	24.7	12.4	18.6	29.6
14/03	25	5.89	0.68	28.8	28.8	22.8	13.8	28.8	28.8	14.0	21.0	34.6
21/03	32	5.89	0.80	33.0	33.0	33.0	8.3	33.0	33.0	16.5	24.7	39.6
28/03	39	5.89	0.91	37.5	37.5	37.5	9.4	37.5	37.5	18.8	28.1	45
4/04	46	6.59	1.03	47.5	47.5	47.5	11.9	47.5	47.5	23.8	35.6	57
11/04	53	6.56	1.10	50.5	50.5	50.5	28.9	34.2	50.5	25.3	37.9	60.6
18/04	60	6.59	1.10	50.7	50.7	50.7	50.7	12.7	50.7	25.4	38.1	60.6
25/04	67	6.59	1.10	50.7	50.7	50.7	50.7	12.7	50.7	25.4	38.1	60.6
2/05	74	6.23	1.10	48.0	48.0	48.0	48.0	12	48.0	24.0	36.0	57.6
9/05	81	6.23	1.10	48.0	48.0	48.0	48.0	16.9	48.0	24.0	36.0	57.6
16/05	89	6.23	0.98	42.7	42.7	42.7	42.7	42.7	10.7	21.4	32.1	51.2
23/05	96	6.23	0.55	24.0	24.0	24.0	24.0	24.0	3.4	12.0	18.0	30.0
30/05	End	6.23	0.25	0	0	0	0	0	0	0	0	0
Total				548	548	496	423	389	496	287	417	654

DAS, days after sowing; ET_o, reference crop evapotranspiration (mm/period); K_c, crop coefficient; CWR, crop water requirement (mm/period); NI, net irrigation requirement (mm/period); 100, optimum irrigation (ET_a); UO, uniform optimum application (100% ET_c); DI, 75% deficit at the initial stage; DD, 75% deficit at the development stage; DM, 75% deficit at the midseason stage; DL, 75% deficit at the late stage; 50-50%, uniform deficit; 75-75%, uniform deficit; 120-20% (ET_c), over irrigation water application.