Wheeiie Green: The Development of a Mobile Unit to Produce Rooted Cuttings of EucalyptusJree Species

摘要

A first prototype of a mobile unit to produce rooted cuttings has been developed at CSSR NRE.The development of such a unit has two main objectives. Firstly to develop a low-tech unit in which cuttings can be rooted in infrastructure-poor conditions at nurseries based in rural areas. Such a unit needs to maintain the basic conditions conducive to the survival and rooting of the cuttings. The second objective is to develop the unit into a scientific experimental unit in which different conditions canbe simulated to determine specific conditions needed to root diff icult-to-root hybrid clones. This paper reports on the progress of the development of the unit to date and the results obtained during the first rooting experiment. For this experiment hedge plants of an Eucalyptus grandis X E. camaldulensis clone were grown in the glasshouse at the University of Pretoria. Micro cuttings were placed in two media, namely a vermiculite medium and air to test for aerial rooting. The cuttings were "washed" inBenomyl (Benzidimazole) to prevent fungus infections and the cut edge was dipped in a rooting hormone, Seradix B2, before placement. Survival decreased rapidly within the first 5 days to about 54% plant survival.The first roots were observed 15 days after placement; at this stage plant survival stabilized at 44%. After 18 days the rooting percentage of the surviving plants was 6% for aerial rooting and 53% for the surviving cuttings placed in vermiculite. During this experiment the floor heating pads could not be used. However, the heat generated by the T5 Extra high output fluorescent tubes was enough to maintain an average temperature of 27 deg C in the chamber. Temperatures never went below 25 deg C or above 30 deg C. The average relative humiditywas 81 %. The results of this experiment indicate that there is sufficient potential for successful rooting of cuttings to warrant further development of this mobile propagation unit.