Variations in root and foliage yields and quality among green mite-resistant cassava clones

The objective of this study was to determine variations in root and foliage yields, crude protein (CP), and dry matter (DM) degradation characteristic s of foliage among 25 cassava clones selected for green mite resistance at Ibadan, south-western Nigeria. Clones were sampled 12 months after planting during the 1994-95 and 1995-96 growing seasons to determine root and folia ge yields. Foliage samples were analysed for CP and degradation characteris tics of DM in rumen-fistulated N'dama (Bos indicus) steers using the nylon bag method. Root yield ranged from 1.26 t DM ha(-1) in clone 92/0397 to 7.6 7 t DM ha(-1) in clone 91/02322, and foliage yield from 0.18 t DM hal in cl one 91/02316 to 2.21 t DM hal in clone 92/0429. Crude protein varied from 2 48 g kg(-1) DM in clone 92/0397 to 303 g kg(-1) DM in clone 92/0067. Variat ions in the soluble (142-325 g kg(-1)) and degradable (519-740 g kg(-1)), f ractions, potential degradability (783-933 g kg(-1)), effective degradabili ty (474-575 g kg(-1)), and rate of degradation (0.0173-0.0565% h(-1)) among clones were significant. Root yield was poorly correlated with foliage yie ld, CP, and effective degradability of foliage quality. Using root and foli age yields and effective degradability of DM as indices for root and foliag e production, some clones, (91/ 00438, 91/002322, 92/0057, 92/0398, and 92/ 0427) appeared to have higher potential than others, (89/00250, 91/02312, 9 1/02319, and 92/0397). The results indicate that both agronomic and nutriti ve value indices of the root and foliage should be considered as selection criteria in future cassava improvement programmes in developing countries.