Effect of benzyladenine on grafting of grapefruit ( Citrus paradisi Macf. )

Abstract

The experiments were conducted at Shambat Research Station , Agricultural Research corporation (ARC) , Khartoum North , Sudan. The effect of different concentration of benzyl adenine (BA) as pre – budding treatment were tested on scion budtake in 10 – year old field grown grapefruit trees (Citrus paradise Macf.) cv. “ Redblush”. Five concentrations ( 0 , 100 , 200 , 400 , 800 mg / l ) were used and were applied by foliar spraying on attached vigorously growing branches , two weeks prior isolation and insertion of scion bud onto the rootstock or by soaking of detached budwood for 1hr before the budding process. Sour orange (Citrus aurantium L .) was used as a rootstock in this study. The budded seedlings were incubated under plastic house conditions. All concentrations promoted budtake , scion shoot elongation and leaf number ; however percent budtake , shoot length and number of leaves depend on concentration (highest values for the three variables measured) was 400 mg / l which increased the number of budtake , leaves and shoot elongation compared to the control or branches or budwood treated with lower or higher concentrations. BA – effects were highest with the soaking than the foliar application. Budwood soaked once during late July through November increased budtake , scion shoot elongation and leaf number. The degree of response increased with increasing BA concentration , the greatest effect being obtained with 40 mg / l. The treatment duration seemed to have no effect on the effectiveness of BA. However all BA treated scion buds swelled within 8 to 12 days after treatments and new scion shoots were visible within 3 weeks and developed normally. In a few cases secondary shoots originating from the same scion buds were observed.