1. Official release of eight cassava varieties in the Lake zone of Tanzania
Kulembeka HP, Jeremiah SC, Mkamilo G, Ngendello T, Ndyetabula I, Merumba S.M, Legg JP and Kanju EE.

2. Importance of cassava Tanzania is 4th cassava producer in Africa
Total root production is 7 M tons from 670,000 ha
Cassava is 2nd most important staple after maize
Of the total cassava production in Tanzania (7M tons), Lake zone contributes about 40%

5. Fig. Cassava production (MT) in each zone in 2007/2008

6. Major biotic constraints in the Lake zone
Cassava yields lake zone 7.3 t/ha, national average 10.5 tons/ha (FAO, 2007)
Low yields were mainly due to susceptibility of local varieties to major diseases and pests: CMD, CBB and CGM
The emergence of CMD pandemic in Lake zone in 1998 wiped out all cassava varieties resulting into food crisis
Five varieties in the pipeline for official realease in 2005 also succumbed to CMD_UgV

7. Yield losses up to 100%

8. Mitigation of CMD pandemic
To address CMD pandemic about 900 breeding line were introduced from Uganda in 2001 with support from IITA, EARNET, GOT and USAID-OFDA
Introduced through open quarantine facility and put under inspection for one year
Materials screened against CMD-UgV, root yield and other root traits with the support of USAID-OFDA and GOT
Participatory evaluation resulted into identification of 8 (eight) promising lines for high yield, resistance to CMD and other farmer preferred traits

9. Participatory variety selection

10. Application for official Release
In May 2008 proposal for official release of eight promising was submitted to Tanzania Official Seed Certification Institute (TOSCI)
TOSCI conducted National Performance Trial (NPT) and Distinctiveness Uniformity and Stability (DUS) test,
NPT and DUS results were presented and discussed at NPT Technical Committee and National Variety Release Committee in December 2009
All eight varieties were accepted for official release on 22nd December 2009.
NPT and DUS were supported by AGRA

11. Name under which tested
Description of Released varieties
Name under which tested
Proposed names
Merits
MM96/8450
Kyaka
Yield potential (22t/ha); CMD resistant, CGM tolerance, CBB tolerance, Maturity (11-12 months), bitter
MM96/4684
Mkombozi
Yield potential (20t/ha); CMD resistant, CGM tolerance, Maturity (10-12 months), good mealing quality, sweet
MM96/5725
Nyakafuro
Yield potential (20t/ha); CMD resistant, CGM tolerance, Maturity (10-12 months)
MM96/3075B
Belinde
Yield potential (20t/ha); CMD resistant, CGM tolerance, Maturity (9-12 months), good for intercropping, sweet
MM96/4619
Meremeta
Yield potential (20t/ha); CMD resistant, CGM tolerance, Maturity (9-12 months), sweet
MM96/8233
Rangi mbili
Yield potential (23t/ha); CMD resistant, CGM tolerance, Maturity (10-12 months), sweet
95NA/00063
Kasala
Yield potential (22t/ha); CMD resistant, CGM tolerance, Maturity (11-12 months), sweet, mealy
TMS191/0067
Suma
Yield potential (17t/ha); CMD resistant, CGM tolerance, Maturity (10-12 months), good for intercropping, sweet

12. Dissemination
By support of BMGF through GLCI project and SIDO (MUVI project) the released varieties have been widely disseminated to farmers in the Lake zone of Tanzania particularly in:
Bukoba, Muleba, Biharamulo, Misenyi, Misungwi, Ukerewe, Bunda, Musoma, Kwimba, Geita and Serengeti districts

13. Cassava Multiplication

14. CHALLENGES
By the time the eight varieties were released for resistance to CMD-UgV, CBSD was not important in the Lake zone.
Most of the released varieties succumb to CBSD infection therefore increasingly threatening cassava production and food security in Lake zone.
Current efforts are geared towards breeding for dual resistance to CMD and CBSD

15. ACKNOWLEDGEMENT IITA USAID-OFDA EARRNET AGRA TOSCI
GOVERNMENT OF TANZANIA
CASSAVA RESEARCH TEAM
FARMERS
GCP21-II

16. THANK YOU