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a) Coppice Shoots
Coppice shoots are the best juvenile material for mass propagation of Eucalyptus hybrid by cuttings. To obtain coppice shoots, the trees should be coppiced about 15 cm above the ground level in the month of February. The cut portion should be given antifungal treatment (1g red lead + 1g copper carbonate in 1 litre seed oil). The coppice shoots may be harvested after 6-8 weeks.
The coppice shoots are collected in the early hours of morning and made into bimodal leafy cuttings. The leaves are trimmed to half the original size and treated with talc preparation of 5000 ppm IBA. The base of the cuttings may be treated with 0.1% bavistin or any other suitable fungicide to prevent fungal attack. Treated cuttings are planted in plastic trays or root trainers filled with sterilized vermiculate, perlite or coarse sand. These are maintained under high humidity (RH 80%) in mist chamber and about 30ºC temperature is adequate for quick rooting. The cuttings develop good rooting system within about 35 to 45 days (Piare Lal et al., 1992). The rooted cuttings are transferred from plastic trays to polythene bags filled with soil and sand in 1:1 ratio. These are retained in the mist chamber for another week and subsequently shifted out for hardening.
The rooted cuttings hardened under partial shade of trees or in the manipulated shade conditions under net house. Initially these are maintained under frequent misting but the frequency of misting is slowly reduced to nil over a period of 6 weeks. At the end of hardening period, the rooted cuttings are treated with 100 ppm N, 100 ppm P and 50 ppm K for boosting their growth. The stock is then handled in the routine way until planted out.
The limitations in this method are that the tree has to be coppiced and very mature trees coppice very poorly.
b) Epicormic Shoots
Very young epicormic shoots collected from near the basal region of the main stem are generally easy to root. These epicormic shoots should be collected in summer or rainy season. These are treated like the coppice shoots for making cuttings, rooting, hardening etc. Though these are comparatively lesser juvenile than coppice shoots, these can be used if coppicing of the tree is not possible due to any reason.
c) Semi Hardwood Cuttings
Non-leafy semi hardwood cuttings of seedlings less than l year old can be rooted by treating with 100 ppm IBA by basal dip method or 5000 ppm IBA in talc preparation. Rainy season is the most suitable season for propagation by this method. This method has only limited applications. |
