LCQ14 : New herbicide to control spreading of Mikania micrantha
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     Following is a question by the Hon Albert Chan and a written reply by the Secretary for the Environment, Transport and Works, Dr Sarah Liao, at the Legislative Council meeting today (November 10) :

Question:

     In reply to my question on November 26, 2003, the Administration advised that it had adopted a number of measures to curb the proliferation of Mikania micrantha in rural areas. However, it is learned that Mikania micrantha is still spreading, blocking other plants from sunlight and strangling many plants which have withered as a result. In this regard, will the Government inform this Council:

(a)  of the locations and total area where Mikania micrantha has proliferated over the past 12 months;

(b)  of the new measures adopted to prevent Mikania micrantha from harming trees;

(c)  of the results of its joint study with the Guangdong Forestry Bureau to curb the spread of Mikania micrantha; and

(d)  whether more effective measures will be drawn up to curb the proliferation of Mikania micrantha; if so, of the details; if not, the reasons for that?

Reply:

Madam President,

(a)  in general, Mikania micrantha has not affected any planting in the urban landscaped areas managed by various Government departments. The spreading of the weed in country parks and ecologically sensitive areas is not serious either and has been kept under control. Mikania micrantha usually grows in abandoned fields, roadsides, hillside and fringe of woodland where there is ample sunlight. The weed could be found at Yuen Long, North District, Pokfulam and in country park areas at Pat Sin Leng, Tai Tam, Lantau and Sai Kung. This year, we have cleared a total of 35 hectares of land in country parks, Sites of Special Scientific Interest and other landscaped area in the rural areas that were affected by Mikania micrantha;

(b)  the best way to protect trees from damage by Mikania micrantha is to closely monitor the situation with regular maintenance to ensure that there is no infestation of this weed. In this respect, relevant departments have regularly inspected areas under their management. They have also instructed their front-line staff and the maintenance contractors to remove and control the proliferation of Mikania micrantha, as soon as practicable once the weed is found. The above measure is found to be effective and as a result, the growth of Mikania micrantha has been kept under control;

(c)  the joint study carried out by the Agriculture, Fisheries and Conservation Department and the Guangdong Forestry Bureau on control of Mikania micrantha has been completed. The study has identified a herbicide "Sulfometuron-methyl", which is effective in killing the weed but not other local plants. We have carried out large scale field trials on the application of this herbicide and so far the results are satisfactory. Upon further monitoring of its performance, we would consider make wider use of this herbicide to control spreading of the weed in country parks. Although, there is no existing measure that can permanently eliminate Mikania micrantha, the Administration would continue to explore other means to curb its growth; and

(d)  the Administration will step up efforts in clearing Mikania micrantha in country parks and sites of high ecological value with all practical measures. We have tried out the use of the new herbicide as mentioned above. We will closely monitor its performance over a longer period of time. If found satisfactory, we will consider adopting the new measure more widely.

Ends/Wednesday, November 10, 2004
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