STABILITY STUDY OF SOME CASSAVA (Manihot esculenta Crantz) VARIETIES RELATIVE TO THE HARVEST PERIOD IN CÔTE D’IVOIRE

Cassava (Manihot esculenta Crantz) is the second largest food crops in Côte d’Ivoire after yam, with annual production of 4.2 million tons in 2014. It is both a subsistence crop and income for producers. However, climate hazards and the harvest period influence the yield and quality (dry matter content and starch content) tuberous roots. In addition, assessment of varieties for starch, a very marketable product, was not yet completed. In this context, the study relating to the determination of stable cassava varieties for yield, the dry matter content and the starch content were made from 2007 to 2008. The plant material is composed of 30 cassava varieties. The stability parameters used in eight (8) environments (4 harvest dates combined with two years) are those of Francis and Kannenberg. The harvest date had a significant effect on tuberous root parameters. The harvest at 12 months yielded the best compromise between yield, dry matter content, starch content and time. The stable clones and high yield were 9941, 9971, I158, IM89, 9620, 9039 and 9122 with yields ranging from 46 to over 64 t/ha. The most stable varieties with high dry matter content were 9941, 9971, CM52, Yacé, 9614, I158, Boun, Bon2, TMS4, Im93 and Bonk with rates oscillating between 37% and 42%. The stable varieties with high starch content were CM52, 971, 9941, 9620 and Anan with rates varying from 18% to 21%. Otherwise, the varieties 9941 and 9927 were the most stable and performing.