poster - International Conference of Agricultural Engineering

TABLE 1: Irrigation depth and actual evapotranspiration of onion for each treatment.
Irrigation depth (mm)
Actual evapotranspiration (mm)
Year Treatment
P1 P2 P3 P4 Total P1 P2 P3 P4 Total
2008 T1 78 46 212 a 0 337 a 25.0 112 199 a 21 357 a
T2 63 60 71 b 0 194 b 25.9 105 108 b 18 256 b
T3 47 60 27 c 0 134 c 23.0 84 77 b 17 200 c
2009 T1 69 72 185 a 0 326 a 29.0 102a 204 a 23 a 358 a
T2 47 49 115 b 0 210 b 30.0 77 ab 138 b 25 a 270 b
T3 54 41 13 c 0 109 c 31.9 62 b 95 c 10 b 199 c
*P1, P2, P3, P4 means different growth stages of onion, which were initial, development,
mid-season, and late season, respectively. *Values in a column under the same year with
different letters are statistically significant by Duncan’s multiple range test at p < 0.05.
TABLE 2: Values of crop coefficient for onion at initial, mid-season and late season stages
K c K c ini K c mid K c end
2008 0.71 1.19 0.75
2009 0.75 1.37 0.66
Average 0.73 1.28 0.70
FAO 56 suggested 0.70 1.05 0.75
TABLE 3: ET a , bulb yield, WP, and IWP of onion under different irrigation treatments
Treatment
Irrigation (mm) ET a (mm) Yield (t ha -1 ) WP (kg m -3 ) IWP (kg m -3 )
2008 2009 2008 2009 2008 2009 2008 2009 2008 2009
T1 337 a 326 a 357 a 358 a 68.2 a 56.0 a 19.3 a 15.6 20.5 17.2
T2 194 b 210 b 256 b 270 b 41.9 b 40.8 b 16.3 a 15.3 22.0 20.5
T3 134 c 109 c 200 c 199 c 15.8 c 27.2 c 8.0 b 13.7 11.8 25.2
Values in a column with different letters are statistically significant by Duncan’s multiple range
tests at p < 0.05.
ETa (mm)
500
400
300
200
100
2008 2009
Fitted
y = 0.7306x + 118.7
R 2 = 0.9995
0
0 100 200 300 400
Irrigation depth + Precipitation (mm)
FIGURE 1: Relationship between ET a and irrigation depth + precipitation in 2008 and 2009.