Six varieties of cassava, including Rayong 1(R1), Rayong 5 (R5), Rayong 60 (R60), Rayong
90 (R90), Kasetsart 50 (KU 50) and CMR 33-57-81 were planted under identical field conditions in 1996 at Nakorn Ratchasrima, Thailand. A split–split plot randomized complete block (RCB) design with three replications was employed.
Roots were manually harvested at 6, 8, 10 and 12 months and immediately analyzed for solid content,which was expressed as percentage starch.