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.
