Presently, air layering (syn.- Gootee, marcottage, pot layerage) is a common commercial and most accepted method of propagation of litchi. The best time of air layering in India is at beginning of monsoon i.e. June- July. However, the literature suggests that litchi can be air-layered all the year round in Hawaii with best results during spring (on non-flowering branches) before active growth commences. In the several experimental attempts, it has been revealed that the success of air layers and establishment in the main field required to have further integration of innovative approach and scientific skill to develop an efficient and effective method with the consistent outcome.
Very limited efforts to date have been made to propagate litchi in the off-season and standardization of its technology is still lacking. The critical study of the air layering technique in litchi revealed the fact that the success of air layers is very much influenced by Season, thickness/ diameter of branches, physiological mature condition of shoot, width of ring/girdle, rooting medium and its wrapping, treatment with rooting hormones, existing environmental factors (Temperature-Humidity- Rainfall), Orientation of branches, skill and tool used for Gootee making, foliage on detached layers and placement of air layers in nursery.
The traditional method of air layering has few advantages and more disadvantages. In many cases, the development of adventitious roots in air layered shoot is completed after the rainy season is over and that leads
to poor establishment in the nursery as the planting season is over. The season’s effect has been found to have pronounced effect in the regeneration of roots in air layering.
Normally under delayed rooting condition, the air-layered rooted plants are detached from the mother plant and are kept in the nursery at the onset of winter season which requires special attention and care for its survivability and prolonged maintenance period, till the next planting season. The exogenous application of root hormones (auxin) has been found to hasten the initiation of roots, increase the percentage of rooting and number of roots per layer. The wrapping material has also been observed to influence the vigour and success in making air layers in litchi.
Hence, taking the commercial practice, an attempt made to propagate litchi during the off-season (February-March) with the integration of some most important factors mainly slight modification in the atmospheric condition, compared with traditional one to find out the experimental feasibility and commercial viability of off-season propagation endeavour through air layering in litchi. The main intention of this technique is to reduce the nursery period and maintenance cost with continued plant availability in planting season.
National Research Centre for Litchi