Dry matter yield: Effects of the different irrigation treatments by average from all nitrogen application (Table 1) were found that after the 1st harvest in 8th week, applying 0.5 x ET0 and 1.0 x ET0 could positively affect dry matter yield of Napier grass at the 2nd and 3rd harvest date and the total dry matter yield. However, dry matter yield at 2nd harvest did not differ between 1.0 x ET0 and