گزينش مناسب ترين پايه براي دو رقم گريپ فروت در منطقه دزفول

SELECTION OF THE BEST ROOTSTOCK FOR TWO GRAPEFRUIT CULTIVARS IN DEZFUL REGION

Dezful region has a suitable climate for grapefruit production. Exporting this product to neighbor countries has been increased in recent years. In order to select the best rootstocks for commercial cultivars, an experiment was conducted from 1997 to 2001 at Safiabad Agricultural Research Center. Two cultivars of grapefruit, `Ruby Redʹ and `Marsh Seedlessʹ, were bud grafted on eight rootstocks namely: Cleopatra mandarin, Citrus amblycarpa, Kin mandarin, Citrus volkameriana, Swingle Citromelo, Carizo Citrange, Citrus aurantium and Troyer citrange. The experiment was arranged in a split plot (with cultivars in the main plots and rootstocks in subplots) layout with complete randomized block design. The results were evaluated from fifth year when trees commercially productive. The results revealed that there was a significant yield differences between rootstocks at 1% level of probability. Citrus volkameriana and Carizo citrange showed better performance than other 6 cultivars. `Roby Redʹ on these two rootstocks produced 18211 and 16459 kg ha^-1. yield and compared to Citrus aurantium there was an increase of 111.81 and 91.44 percent, respectively. ʹMarsh seedlessʹ on volkameriana rootstocks produced 1ʹ5006 kg ha-I. and on Carizo citrange produced 11793 kg ha^-ʹ yield compared to sour orange rootstocks showed an increase of 43.83 and 13.04 percent.