哈密瓜细菌性果斑病及其防治

内蒙古巴彦淖尔盟 1991年从新疆引种种植哈密瓜 ,1996年发现细菌性果斑病 ,近几年发生严重。巴盟地区 5月上旬播种哈密瓜 ,6月上旬见到病斑 ,7月份严重。小瓜表面见不到病斑 ,大瓜上病斑清楚可见。病菌在瓜上糖后进入瓜体内部 ,侵染瓜肉 ,成熟时腐烂。气候对病害发生有较大影响 ,干旱年份发病轻 ,高温、多雨潮湿年份发病重。品种抗病性有差异 ,感病的有皇后系列、86系列 ,抗病的有西域系列和甘密宝。栽培方式对发病有影响 ,起垄栽培发病轻 ,平地栽培发病重。该病为害叶片和果实。叶部病斑圆形至多角形 ,水浸状 ,灰白色 ,后期病斑中间变薄 ,…     

The control of bovine tuberculosis in New Zealand

Mycobacterium bovis was probably introduced into New Zealand with cattle imported in the early 19th century. A tuberculosis control programme was introduced for cattle in 1945. However, the control of tuberculosis in cattle and deer in New Zealand over the past two decades has been hampered by the presence of an important wildlife reservoir, the Australian brushtail possum (Trichosurus vulpecula). While the importance of this source of infection has been suspected by the Ministry of Agriculture for some time, scientific proof has been lacking until recently. A new control programme is currently being finalized with the following objectives: to reduce the prevalence of herd infection in vector free areas to internationally accepted levels, to prevent the establishment of tuberculous vectors in new areas, to decrease the number and size of existing areas where tuberculous vectors exist, and to encourage land-owners to take action against tuberculosis on their properties and in their herds.     

Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in Sediments from Siskiwit Lake, Isle Royale

Polychlorinated dibenzo-p-dioxins and dibenzofurans were found in sediment from Siskiwit Lake on Isle Royale, Lake Superior, a location which can receive only atmospheric inputs. The source of these compounds is the atmospheric transport of dioxins and furans formed by combustion of domestic and chemical waste.