FACTORS AFFECTING THE ROOTING RESPONSE OF FRUIT TREE CUTTINGS TO IBA TREATMENT

Auxin treatment allows expression of a latent rooting potential in cuttings inherent in the genotype or the physiological status of the shoot.
For subjects capable of some degree of rooting the response to applied auxin was increased by severely pruning the stockplant in the previous winter (including reducing the permanent framework), by preventing light reaching the stem during growth, by wounding the stem after cutting collection and by providing an environment conducive to cutting survival and maximum metabolic activity.
Such highly preconditioned cuttings were produced readily in the stooling process which combines ultra-severe annual pruning of the stockplant with the absence of light at the shoot base, and the favourable rooting environment was provided by a base temperature of between 20 and 30°C in a well-drained and hence aerated compost.

Consistent response to IBA applied in organic solvents was obtained by regulating factors that influenced the amount of solution collecting at and being absorbed through the cut base, which included dipping depth, dipping duration and the suction developed at the cut base due to water lost between collection and treatment.

For powder formulations the main variables were those factors determining the amount of powder adhering to the cutting base and epidermis, including pre-dipping in water or an organic solvent, and retaining the powder through careful handling.

V International Symposium on Growth Regulators in Fruit Production

B.H. Howard

https://doi.org/10.17660/ActaHortic.1986.179.144