Haripriya Anand M. author Byju G. author text journal article 2008 A field experiment was conducted with two cassava cultivars and eight levels of nitrogen to examine the relationship between extractable chlorophyll (Chl) content of cassava leaves and both the Chl meter value (SPAD) and leaf colour chart (LCC) score. The SPAD, LCC, and Chl a+b content were influenced by leaf position, growth stage, cultivar (cv.), and N fertilization. The cvs. and N fertilization had significant effect on SPAD, LCC, and Chl a+b content of youngest fully expanded leaf (leaf 1) blade in most cases. An F-test indicated that common equations pooled across cvs., N fertilization, and growth stages could be used to describe the relationships between Chl a+b content and LCC and between SPAD and LCC, but not between SPAD and Chl a+b content. Relationships between tuber yield and SPAD, LCC, and Chl a+b content were significant (p<0.05) and positive at 30 and 60 d after planting. Thus LCC and SPAD can be used to estimate leaf Chl content which is an indicator of leaf N status. cultivar; Manihot esculenta; N fertilization; SPAD 10.1007/s11099-008-0087-8 https://ps.ueb.cas.cz/artkey/phs-200804-0005.php https://ps.ueb.cas.cz/artkey/phs-200804-0005.php continuing 46 4 511 516 2008 03003604 periodical academic journal