PRIMARY PRODUCTION
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production may reach 1.8 metric tons on average land, and over two metric tons on better soils.
The most important disease of paddy is blast, caused by the fungus Piricularia Oryzae, and farmers are making more use of blast-resistant varieties recommended by the Agriculture and Forestry Department. The department also selects seed within varieties, but only a limited amount of such improved seed is available. Traditionally the manurial treatment of rice consists of adding only very small dressings of dry animal manure, but the use of balanced artificial fertilizers is becoming increasingly important.
A narrow range of fruit and field crops is prepared for export to overseas Chinese. Although quantities are not large they provide a useful source of income and include water chestnut, Japanese apricot, lemon, taro, bitter cucumber, white cabbage, ginger, radish, lychee, wampei, mushroom, lotus root, olive, turnip, yam and mustard. The value of these crops in 1963 was over $1 million. The water chestnut crop, in particular, has greatly improved in quality in recent years and a larger proportion is now being ex- ported as 'first grade'. Crops exported to the United States and to certain other countries must be accompanied by a Comprehensive Certificate of Origin.
Pond Fish Production. The number of fish ponds in the New Territories continued to increase and the total area is now 1,300 acres, situated mostly along the Deep Bay coastline, near Yuen Long. The most important species reared is grey mullet which requires water with a salinity above 0.1 per cent. Fry are found in local coastal waters, in February and March, and the supply in 1963 was sufficient to meet local requirements, more than 7 million being collected. Fry of four other important species, silver carp, grass carp, big head and mud carp, were obtained from China between May and August, about 7 million being imported. Com- mon carp and edible goldfish are bred locally and, respectively, some 1,600,000 and 100,000 fry were raised to meet trade require- ments. Edible goldfish require fresh water (less than 0.4 per cent salinity), and common carp tolerate up to one per cent salinity. Total pond fish production, for the year, was estimated at 844 tons, valued at some $4 million, which represented about 8.5 per