Comparison of surface and drip irrigation regimes for banana (musa AAA)cv. grand nain in Gezira, Sudan

The experiment was established in the Horticultural Research Centre Farm, Agricultural Research Corporation, Wad Medani, Sudan during16th November 2009 and 16th October 2011. The soil used on the experimental site is silty clay loam soils with high silt content (68%). A drip irrigation system was designed and installed on an area of 2145 square m. The system was evaluated for its performance relative to the conventional surface irrigation method. Three months old planting material propagated by tissue culture was transplanted in the field on 16th of November, 2009 at spacing of 3 x3 meter (1111 mother plants/ha). Three months after planting two sucker were left (2222 plants/ha) and population was maintained thereafter. Five irrigation treatments were applied under drip irrigation system. These were 40%, 60%, 80%, 100% and 120% of crop evapotranspiration (ETc). The traditional surface irrigation was used as a control. Irrigation interval in drip irrigation system was applied every other day. In surface irrigation method, irrigation scheduling was every 3 days at the beginning, and then the interval was increased gradually to every 5-10 days depending on the prevailing weather conditions. The treatments were replicated four times in a randomized complete block design (RCBD) and four plants represented experimental plot. The parameters measured included plant height, plant girth, number of green leaves, leaf area, number of days from planting to shooting and harvesting, yield and yield components and total water applied. Irrigation water productivity, nutrients use efficiency and economic analyses were determined. The results on the hydraulic characteristic of drip irrigation system gave 7.92 1/h for average emitters discharge, 90.9% field emission uniformity, 91% absolute emission uniformity, 91.9% design emission uniformity and 81.9% irrigation efficiency. Growth parameters varied depending on the quantity of water applied under drip irrigation system. Applying water at 100% and 120% of ETc under drip irrigation resulted in either higher or equal performance on all growth parameters tested relative to the surface irrigation. However, bunch weight for the mother plant and the first ratoon crops of banana were significantly variable by drip irrigation. The highest bunch weight was obtained with 120% and 100% of ETc compared to surface irrigation. The drip irrigation treatments 100% of ETc increased yield by 23% and at the same time saved irrigation water by 74% compared to surface irrigation. The highest irrigation water productivity (1.43 and 1.40 kg/mE3) was obtained with 120% and 100% of ETc under drip irrigation and the lowest was (0.30 kg/mE3) with surface irrigation. The highest marginal rate of return was obtained from the 100% of ETc treatment under drip irrigation system