GROWTH RESPONSE OF PALM TRESS TO THE FREQUENCY OF IRRIGATION BY BUBBLERS IN KHUZESTAN, IRAN

摘要

Based on the shortage of water resources in Iran and the high evapotranspiration rate inrnKhuzestan region (2044 mm/year), an irrigation system on Estamaran palm tree in thernExperimental Farm of Shahid Rajaee of Omidiyeh plain was conducted.rnThis study had two purposes, namely irrigation frequency and suitable depth of irrigationrnapplication of the Estamaran palm trees in Omidiyeh region. This study had two objectives.rnIrrigation frequency was the primary treatment and the evapotranspiration estimating methodsrnwas the secondary treatment. Three irrigation levels. i.e. one day long (A1), two day long (A2)rnand three day long (A3), were used as irrigation frequency. Also the evapotranspirationrnestimating methods used were, Penman-Montith 100% (B1), Penman- Montith 70% (B2), classrnA pan 100% (B3) and class A pan 70% (B4). Since this study had three replications, 36 palmrntrees were selected for this experiment. Cropwat software V.4 for windows, was applied for thernevapotranspiration estimating from Penman-Montieth method. Irrigation scheduling was donernaccording to SCS recommendations. Experimental design was according to split plot method in arnrandomized block. Finally by measuring the different growth indices of palm trees (leaf number,rnbarb number and leaflet length) at a definite time, the best treatment was determined. The resultsrnshowed that as a whole all the treatments in this experiment did not show a significant differencern(up to 5% level) for the indicated indices. However, at the end of 4 month since the beginning ofrnthis study, the growth indices of trees in A2B1, A1B2 and A1B1 increased compared to otherrntreatments. The result also indicated that, A1B2 was the best treatment of all. In comparison withrnthe traditional irrigation by local farmers, using A1B2 treatment for all the palm trees (from Augrnto Nov), will have 28422.34 m~3 water saving in 3.87 hectare per month.