Abstract:
Inadequate grafting take of some of the rose cultivars may cause economic losses. The study was conducted to determine the effects
of cutting position (top, middle and bottom) of Rosa hybrida rootstocks (‘Natal Briar’ and ‘Rosa Progress’) and auxins (0 %, 0.4 %
IBA and 0.2 % NAA) on rooting and grafting take of rose cultivar ‘Inca’. Changes in endogenous carbohydrate content during rooting
were measured on days 0, 3 and 7 after sticking. The experiment was factorial in a completely randomized design. Interaction between
cutting position and rootstock was significant (P ≤ 0.05) for most of the parameters measured. The shoot height, root number, percent
rooting and grafting take increased towards the basal position in ‘Rosa Progress’. In ‘Natal Briar’, the shoot and root growth parameters
increased towards the top though non significant except grafting take that significantly increased towards the basal position. The auxin
treated cuttings recorded significantly (P ≤ 0.05) higher grafting take and rooting percentage than the control. 0.4 % IBA exhibited
higher shoot height, leaf number and root number than 0.2 % NAA. The rootstock ‘Natal Briar’ recorded significantly (P ≤ 0.05)
higher rooting percentage and grafting take than ‘Rosa Progress’. Middle and top position cuttings of ‘Rosa Progress’ and ‘Natal Briar’
recorded higher carbohydrate content, respectively than bottom position cuttings. Bottom position recorded higher sucrose content on
day 3 than days 0 and 7 after planting in ‘Rosa Progress’. ‘Natal Briar’ exhibited significantly (P ≤ 0.05) higher carbohydrate content
than ‘Rosa Progress’. The increase in growth with top position cuttings of ‘Natal Briar’ could be attributed to high carbohydrate content.
The high growth responses in bottom position cuttings of ‘Rosa Progress’ could be attributed to high sucrose content on day 3 after
planting. The stem cuttings of rootstocks for top grafting rose cultivar ‘Inca’ should be taken from bottom position cuttings of both
rootstocks, and auxins should be applied to increase rooting and grafting take.
