Abstract

 Cassava (Manihot esculanta. Cratz) is one of the most important food crops that constitute a considerable portion of the daily diet of the people and also serves as one of the major source of carbohydrate. Despite its importance, production of cassava in Ethiopia has different constraints and opportunities. Among which, shortage of improved varieties is the first and the most important one. It is mainly cultivated by small resource poor farmers on smallholding plots of land. Average storage root yield obtained per a given plot of cassava is as low as 100 tons per hectare despite the potential yield of 600 tons per hectare per year. This low yield might be due to the cultivation of local, low yielding, late maturing cultivars. To contribute to alleviating the problem and provide farmers other alternative varieties, Hawassa Agricultural Research Center, in collaboration with Jimma and Sekota Agricultural Research Centers, conducted evaluation of cassava clones in potential and moisture stressed agroclimatic conditions of the country. Jima and Hawassa sites represent potential agroclimatic condition, while Amaro and Sekota represent moisture stressed areas. A total of seven cassava clones namely AWC-1 (MM 96/5280), AWC-2 (MM 90/5280), AWC-3 (MM 96/7151), AWC-4 (MM96/1871), AWC-5 (MM96/3868) and Kello (standard check) were evaluated by using randomized complete block design replicated three times. The evaluation was carried out for two consecutive years, from 2012 to 2014. The combined analysis result indicated that there was statistically significant difference among the clones tested and the locations where the experiment was conducted. The clone AWC-1 (37.17 t/ha) followed by AWC-2(35.52 t/ha) and AWC-5 (35.51 t/ha) gave the highest storage root yield but there was no statistically significant difference in the total storage yield among the clones AWC-2, AWC-3 and AWC-5. In the same way, the highest dry matter content was recorded from the clones AWC-2 (51.8%), AWC-3 (48.5%) and Kello (49.1%). Among the locations tested, the best result was obtained from Amaro (35.14 t/ha) which is characterized by its low moisture stress, indicating that cassava can resist/tolerate low moisture stress and give comparative yield provided that other factors are not limited. Thus, those clones with the highest storage root yield and dry matter content were promoted for variety verification and will be released for wider production.   

Key words: Cassava, moisture stress, potential, storage root, dry matter