Using the grafting for propagation the jackfruit and producing the rootstocks for the grafting.
El-Zaher M. H. A.
Author Affiliation: Department of Pomology, Faculty of Agriculture, Cairo University, Cairo, Egypt.
American-Eurasian Journal of Agricultural and Environmental Science 3 : 459-473
Abstract : Field experiments were conducted in Giza governorate, Egypt, during 2004/05, 2005/06 and 2007 to study jackfruit seedling production and grafting. Seedlings were produced from intact seeds or decoated seeds (without outer leathery coat) treated with GA3 [gibberellic acid] at 0.5 ppm for 12 h or at 10 ppm for 10 minutes, or with kinetin at 10 ppm for 6 h or at 100 ppm for 5 minutes. Seeds soaked in tap water for 12 or 24 h, and grown under the shade of mango, red cellophane sheets and sunlight (control) were also evaluated. Top-cleft and saddle grafting were conducted using the apical growth of the current shoots of old trees or the apical growth of seedlings produced in the previous experiment as sources of scions. Girdling was conducted under the graft union, and the scion and graft union were covered or not covered with transparent or black polyethylene bag. Soaking of seeds in tap water for 12 h + 10 ppm GA3 for 10 minutes + 100 ppm kinetin for 7 minutes + shading with mango hastened germination and increased the germination percentage (75.6%, on average), average of intact seeds (66.1%) and decoated seed (85.1%) compared to the control (25.1%). The seed germination percent increased by increasing the time after sowing. Seedlings grown under red cellophane sheets had the highest percentage of seedlings with deeply lobed leaves (56.5%), seedling survival (61.7%) and height (29.6 cm), and in the lowest stem thickness (2.9 mm). Seedlings grown under shaded conditions recorded the highest number of leaves per seedling (5.7) and leaf area (7.6 cm2), while seedlings grown under the sunlight (control) had the greatest stem thickness (4.9 mm). Six-month-old seedlings were superior in height (23 cm) and stem thickness (4.3 mm), but 3-month-old seedlings were superior in terms of survival (51.8%). Seed germination and seedling growth were significantly affected by the light conditions, and these parameters were enhanced under the shade of mango and red cellophane sheets. Nine-month-old rootstocks were superior in terms of grafting success (37.5%), time required for obtaining maximum scion bud sprouting (35.8 days), number of sprouted buds per scion (1.7), length of new shoots (2.9 cm), number of leaves per scion (4.6), and length of scion (12.5 cm). Top-cleft grafting using seedlings as source of scions, girdling under the graft union region, and covering of the graft union area with black polyethylene bags resulted in the highest percentage of successful grafts (75%), number of sprouted buds per scion (3.6), length of new shoots (6.6 cm), number of leaves per scion (8.2) and length of scion (16.6 cm), and in the shortest time to obtaining maximum scion bud sprouting (22.5 days).