Comparative Studies on the Agriculture of Japan and China.

宇都宫大学共11人来华访问，中国杭州浙江农业大学共10名中国科学家赴日进行中日农业比较研究。研究主要集中在水稻生产、稻田杂草防治、动物生产、蔬菜（特别是水生物种栽培）、蚕桑养殖、基础和应用植物病理学等方面。1. 浙江省和日本目前都有一个共同的问题，即农村人口严重减少。该省需要大幅度增加粮食生产。高产水稻品种是最可取的，中国迫切需要除机械化以外的节约劳动力。研究了日本和中国稻田杂草种类和群落的变化、杂草防治的方法和效果以及目前稻田杂草管理存在的问题。杂草防治的主要问题是建立杂草管理制度、保护稻田生态系统和开发新的无除草剂杂草防治方法。3. 在动物生产方面，通过对日本、中国全国和浙江省的实地调查，比较研究了动物产业的现状和生产技术。研究了中日两国在莲藕、水竹等水产蔬菜栽培技术和商品化生产方面的差异。5. 注意到中日两国蚕茧质量和产量的差异。中国蚕桑养殖体系的改进可能需要借鉴日本的经验。6. 在浙江省和日本收集了多种可能是病毒或支原体病因的植物材料。通过合作研究，找出每种材料的病原菌。从具有黄色症状的假丝念珠菌中分离出一段16S核糖体DNA，并对其序列进行分析。建立了一种有利于促进两校合作学习的模式。少

Total of 11 persons of Utsunomiya University visited China, and total of 10 Chinese scientists of Zhejiang Agricultural University, Hangzhou, China, visited Japan to perform comparative studies on the agriculture of Japan and China. The studies were focused on rice production, weed control in patty field, animal production, vegetables, especially aquatic species cultivation, sericulture, and basic and applied plant pathology. 1. Zhejiang Province and Japan have a current problem in common that the rural population has been decreasing seriously. The Province needs essential increase in food production. Rice varieties bearing high productivity are most desirable, and saving of labor other than machanization is required urgently in China. 2. Weed species and community changes in paddy field, methods and effect of weed control, and present problems in weed management in Japan and China were studied. Major problems in weed control are establishment of weed management, protection of paddy fi … More eld ecosystem and development of new weed control methods without herbicide. 3. In the field of animal production, the present status of animal industry and the production techniques were comparatively studied by the field survey in Japan, whole China and Zhejiang Province. 4. Differences of culturing techniques and commercial production of aquatic vegetables including lotus root and water bamboo etc. between Japan and China were studied. 5. Differences in the quality and productivity of cocoon between Japan and China were noticed. Improvement of sericulture system in China might be needed after Japanese experience. 6. A variety of plant materials which had possible virus or mycoplasma etiology were collected in Zhejiang Province and in Japan. Cooperative studies were done to find out the pathogen of each material. A segment of 16S ribosomal DNA was isolated in Zephyranthes candida with yellows symptoms, and the sequence of the DNA was analyzed. A model was established which will contribute to the promotion of cooperative studies between two colleges. Less