Fig. 4. Relationship between leaf color chart (LCC) scores and chlorophyll meter (SPAD) values at panicle initiation (PI), 9 d after PI (PI + 9 d), and flowering (FL) in the wet season (WS) of 2000 and at midtillering (MT), PI, and FL in the dry season (DS) of 2001 across three cultivars and four N rate treatments. Leaf color charts were developed by the International Rice Research Institute (IRRI); Zhejiang Agricultural University (ZAU), China; and the University of California, Davis (UCD), USA.