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PRIMARY PRODUCTION
yield for each hectare of vegetables, flowers and fruit. The department advises livestock farmers on modern methods of animal production, helps them in the supply of improved and exotic breeds of pigs and poultry, and provides an artificial insemination service for pigs. Fisheries research covers marine resources, aquaculture, hydrography and marine pollution problems. In marine resources research, emphasis is placed on recommending new fish stocks for commercial exploitation within the range of the Hong Kong fleet, and on monitoring the performance of existing capture fisheries. The newly commissioned 565 GRT fisheries research vessel Tai Shun was inter-calibrated in a trawling exercise with the fishing power of the F.R.V. Cape St. Mary to maintain future comparability of past reseach data, before the latter vessel was retired after more than 20 years of service. The Tai Shun will be used to conduct acoustic surveys of pelagic fish in the northern part of the South China Sea, and related fisheries hydrographic research, as well as exploratory fishing on the edge of the northern continental shelf.
Of the other facets of fisheries research being conducted, aquaculture is concerned with developing more efficient culture systems; hydrographic investigations are designed to supply environmental information for an assortment of biological programmes; and marine pollution research is aimed at assessing the impact of pollution on aquatic ecology and to recommend means of ameliorating water qualities for fisheries.
Developing Farming and Fishing
Owing to the shortage of farm labour in Hong Kong and its rising cost, the main develop- ment in the agricultural industry in recent years has been the introduction of labour-saving devices, Farmers use pre-emergence herbicides for weed control in market garden crops and there is widespread use of small farm machines and sprinkler irrigation. At the end of 1981, there were 3 200 rotary cultivators and 2 100 sprinkler units in use on vegetable farms.
The plastic net house, designed to aid vegetable growing in adverse weather, is the subject of an active development programme by the department. The net houses which are particularly suited for leafy green vegetables protect crops from bad weather, insects and birds. Technical assistance, agricultural loans and related services have been made available to farmers to promote their use.
Straw mushroom cultivation has gained considerable popularity in recent years which is reflected by the increased number of local mushroom farms from 40 in 1979 to 60 in 1981. The locally produced mushroom has about 30 per cent of its share of the local market.
Teams of argicultural development officers are posted throughout the New Territories to deal with farming and pollution problems, and with co-operative societies and rural associations. Both credit facilities and technical advice are available to farmers and the agricultural development officers also assist them in land development and rehabilitation.
In the rural development programme during the year, more than 223 farmers attended farm discussion groups led by professional and technical officers from the Agriculture and Fisheries Department. Some 21 field demonstrations of chemical weed control methods were conducted in the main vegetable-growing areas for the benefit of farmers. Officers also made more than 58 000 visits to farmers and co-operative societies, and many farmers visited government experimental farms and farming projects.
Fisheries development work involves modernising fishing craft and introducing more efficient fishing gear and navigational aids. An advisory service on hull design and deck arrangement is provided for fishermen, while experiments and demonstrations are conducted to test the suitability of new fishing gear. Fisherman's training classes in navigation, steering and engine operation are organised in the main fishing ports.