IRRI Annual Report 1974

This thirteenth annual report covers the work accomplished during the 1974 calendar year. The various sections of the report deal with the interdisciplinary approach to problem areas. The department (or departments) which performed the research is (or are) identified in italics in parentheses following the topic heading, i.e., "Machinery Development and Testing" (Agricultural Engineering Departmena In those cases where more than one department cooperated in a particular major problem area, where only one of the departments carried out one phase of the research, the department a identified in italics following the name of this subtonic. For example, the departments of Agronomy, Agricultural Economics, and Statistics cooperated in a major project -Quantifying Effects of Biological Inputs" (Agronomy, Agricultural Economic, and Statistics Departments), and where the Statistics Department bore single responsibility for one phase of this effort, the name of that department follows the subtopic thus, 'Management package experiments at IRRI' (Statistics). Date in the report are given in metric units. e.g. "t/ha" means metric tons per hectare. Unless otherwise stated, "control" means untreated control. grain yield is calculated as rough rice at 10 percent moisture, and protein content is calculated as a percentage of brown rice at 10 percent moisture. A single asterisk (.) means significant at the 5.percent level, a double asterisk (vv) means significant at the 1% level, bur if value for a control is given, a single asterisk means significantly different from the control at the 5% level and a double asterisk means significantly different from the control at the I% level. The system for indicating pedigrees uses a slam bar (/) rather than the multiplication sign (x ). For example IR22 x IR24 is now written 1R22/1R24. The sequence of crosses is indicated by the number of slant bars: (1E22 x 1R24) x CR94-13 is now written 1R22/1R24//CR94.13. The fourth and further crosses are designated /4/, /5/, and so on. Backcrosses are indicated by a superscript numeral. The report frequently mentions three fundamental types of rice culture. Upland culture means rice grown without irrigation in fields without bonds. Rainfed paddy culture means rice grown without irrigation but in fields that are bonded, to impound rainfall. Irrigated or flooded culture means rice grown with irrigation in bonded fields. A detailed table of contents is furnished at the beginning of each major section, in addition to the general table of contents at the beginning of the report. The thumb index on the back cover provides quick access to each section. To use it, bend the book in half and follow the margin index to the page with the black-edge marker