SCANGRAPH: a program for digitization of graphs using an image scanner

The program SCANGRAPH has been developed for vectorizing anydrawing or graph in the form of a single continuous line. Withthe use of the software, the raster image of a graph in theTIFF format as generated from an optical scanner or digitizingvideo system can be converted to the corresponding digitizedgraph with x and y coordinates given. The digitized data canbe output in the ASCII format for importing to other softwarepackages. Options for peak identification, data smoothing andcompression, and graph comparison are also provided for datamanipulation.     

Can Fish Control Planthopper and Leafhopper Populations in Intensive Rice Culture?

Planthoppers and leafhoppers are important rice pests. We tried to find out whether a polyculture of silver barb, common carp and Nile tilapia could control hoppers in intensively cropped rice fields. We used the data of five rice-fish experiments conducted between 1995 and 1998 at the Co Do rice-fish research station, Can Tho province, Mekong Delta, Vietnam. Our results showed that the number of Nilaparvata lugens (Stål), Sogatella furcifera (Horváth), Nephotettix virescens (Distant) and Recilia dorsalis (Motschulsky) was the same in fields with and without stocked fish. We concluded that the three stocked fish species are not able to control hopper numbers. Other, predatory fish species might be more effective in hopper control.