Plant propagation signifies the multiplication of plants, which plays a vital role in fruit culture and can be accomplished by a variety of ways depending upon the kinds of plant involved and the purpose of propagation. Litchi (Litchi chinensis Sonn.), is one of the most important evergreen, subtropical fruit crop, which has been identified as the crop having high export potential. The slow area expansion rate at one side and availability of quality planting material of suitable cultivars/varieties having high yield with quality production at the other, clearly indicates that this crop has been meagerly exploited for its rapid multiplication technique either through sexual or vegetative means.
Fortunately, litchi can be propagated by sexual as well as by various vegetative methods. The attempts of different methods of litchi propagation have been made in almost all the litchi producing countries, but till date, the results obtained are not consistent as they came with the varied success at different places. The methods vary concerning uniformity and size of the new plants, the quality of the root system produced, time to bear, multiplication rate, cost and the need for special techniques and equipment.
Apart from these environmental factors, the influence of some hormones and co-factors also play an important role in the propagation of litchi. The complexities in litchi propagation lie with the fact that its success is the function of the interaction of so many interdependent factors, which needs thorough investigation with systematic and concerted efforts. The other practical problem in litchi is low rooting potential, high transplanting shock and poor field establishment which leads to scarcity of plants in the market at reasonable price. There is still need of more efficient and commercially accepted method of propagation for consistent performance in litchi.
1.The existing commercial method – Air layering…read more
2.Technical procedure of air layering….read more
3.Establishment and maintenance of mother block….read more
4.Establishment of shelter house facilities….read more
The results of the off-season trial of air layering in litchi were found very encouraging as after recording the days to maximum root development and browning; the successful air layers were cut off, the polythene films also unwrapped and gotten soaked in water and planted/potted. After severing the gootee from the mother tree, they shaped and pruned to retain about 25- 30 leaflets on each gottee and these gottees planted in the polybags, nursery bed under shade house (net) and open field in the orchard under partial shade in the soil, never be planted in full sun.
It recorded the thickest, healthiest and short roots in the treatment having moss grass wrapping and found as the preferred rooting medium.The moss grass wrapping for rooting medium with etiolated IBA (@ 5000 ppm) treatment had more nutrients and provided an ideal condition for the growth of roots. The best result with maximum survival percentage (90.06) was recorded in e treatment having poly cover + moss grass + IBA, which followed by the treatments having poly cover + soil medium + IBA and main season practice having the survivability of 74.33 % and 74.00 % respectively.
The maintenance duration of the plant in the nursery by survivability percentage has been found to be reduced from seven (7) months to one (1) month compared to traditional main season attempt. Maintenance duration (month) for off-season propagated plants through air layering is one month only as compared to main season propagation through air layering which is almost seven months while the cost of planting material per unit comes to Rs. 6.00 during main season in comparison to Rs. 6.40 per unit during off-season propagation.
The field establishment was also better in the case of off-season propagated plants compared to main season. The economics calculated and the cost benefit ratio was found highest (1:3.52) in the treatment of off-season air layering propagation
Handling of elite/genuine planting material
The planted air layers are kept under the shade-net house (50% shade) and have regular irrigations which are essential.The moment new roots begin as envisaged by visual observation, the young plants soon start to flourish after a few weeks. Propagated plants gradually are hardened off, and it may be then ready for field planting within a month time gap of hardening. The use of bags for potted plants with enriched potting mixture also adds the value w.r.t. Endure transportation jerks, higher field establishment, rapid, healthy growth and eventually for high and sustained quality production.
Conclusion and recommendations
The off-season air layering in non-bearing shoots significantly reduced the juvenility period (in the case of treatment having poly cover + vegetative branch + Moss grass wrapping) and higher survival percentage.The initial cost of off-season propagation may be little high, but in due course, it may prove cheaper, if the activity is made as an annual phenomenon. The treatments imposed during offseason have caused a significant effect. The treatment having poly cover + Moss grass wrapping + IBA proved significantly superior to most of the desirable traits and also recorded highest survival percentage. The period of maintenance duration reduced from seven (7) months to one (1) month and found convenient.
The earmarked plus trees may be utilized, and the phenomenon may be made regular for nurseries which are involved in the commercial.
The off-season air layering propagation method with precise, specific treatments emerged as the economically viable and improvement over traditional method in litchi propagation
As farmers/growers face the deficiency in obtaining good quality and sufficient planting material of litchi, there is immense need to motivate nurserymen/plant propagators and to increase their awareness about the improved method of propagation techniques for the high rate of success and profitability.
- National Research Centre for Litchi