Research Highlights (2005-2006)

Through its partnership with national programs, WARDA concentrated its effort on the three major rice production systems, namely upland, lowland and irrigated. At the same time activities were undertaken in processing; dissemination of research results; policy and marketing issues; natural resource management, particularly impoverishment of soil fertility; water use efficiency; integrated pest management; and technology uptake. Issues such as the high cost of inputs, the unstable market, weak institutional policies and capacity building were addressed. A new area, which received increased attention, was the theme of drought.

Integrated Rice Production Systems (Program 1)

Unexpected severe drought in 2005 trials in Benin highlighted promising material with potential to confer drought tolerance. The drought stress during the reproductive stage of plant development was so severe in the seven advanced yield trials sown at Naouli in Benin that the mean yield over the trials of four elite varietal checks, namely IRAT136 (released in Benin), WABC165, NERICA1 and NERICA4, was reduced to a meager 536kg/ha, 604 kg/ha, 484 kg/ha and 586 kg/ha, respectively.

Although the 300 test lines in the trials had not been rigorously selected previously for drought tolerance, 97 lines significantly (P≤0.05) outyielded one or more of checks. The mean yield of those lines with a significant yield increase over each check was either just over or under double that of the checks at 964kg/ha, 1086 kg/ha, 998 kg/ha and 1090 kg/ha, respectively. And the percentage yield increase of the top yielding lines over each of the checks ranged from 176% over WABC165 to 253% over IRAT136. These 97 lines provide a valuable pool of material to assist alleviation of yield loss and stability of yield under severe drought conditions and will be disseminated widely to NARS for evaluation in sub-Saharan Africa.

The NERICA Promotion Project supported by IFAD in the Democratic Republic of Congo (DRC) showed that upland NERICA varieties are well adapted in the Bumba zone (Eastern Province and Equator Province). Among the seven NERICAs evaluated in the two provinces, NERICA4, NERICA6 and NERICA7 are the most adapted. NERICA4 gave the highest yield, followed by NERICA7 and NERICA6 in the Eastern Province, whereas in the Equator Province NERICA7 gave the highest yield (5 t ha-1) followed by NERICA4 (4 t ha-1) and NERICA6 (3 t ha-1). From 220 new NERICAs, 18 upland types were selected as the best adapted. Eleven out of 72 NERICA lowland varieties evaluated gave good results. Some of the seventy-two lowland types were noted to be sensitive to iron toxicity.

In collaboration with national partners, five new irrigated rice varieties were released in the Senegal River valley. These varieties will further increase the genetic diversity and offer varietal choices in addition to the three Sahel varieties that now occupy more than 70 percent of the total irrigated rice area in the region. Three interspecific (irrigated NERICAs) and 1 intraspecific varieties were also identified for release in The Gambia.

The successful application of a methodology for combined agronomic and socio-economic on-farm research resulted in pinpointing yield and productivity gaps among farmers, and identifying key constraints to improving production efficiency. The methodology has also enhanced elaboration of the concept of options for Integrated Crop Management (ICM), and the optimization of resources along the intensive lowland-irrigated continuum as a means for improving irrigated rice performance in Africa.

Pertinent results for Program 1 included:

1. New NERICAs with better characteristics associated with weed competitiveness than the first generation NERICAs were identified;

2. Identification of an O. glaberrima line showing shorter growth duration than CG 14, the O. glaberrima parent of all commercial upland NERICAs;

3. Transfer to NARS partners of the screening methodology developed at WARDA to identify durable blast resistance varieties;

4. Development was completed in Senegal of a prototype small-scale harvester to address the bottleneck of labor shortage for harvest and post-harvest operations;

5. 72 potential parents were characterized for drought tolerance/resistance both at vegetative and reproductive stages of plant development;

6. Genetic and QTL assessment in NERICA was completed;

7. Experiments found fewer deadhearts on rice intercropped with maize as a trap crop than on monocropped rice or maize;

8. Development of habitat management strategy to control the African rice gall midge (AfRGM) in Nigeria by using plants of Paspalum scrobiculatum around rice fields as a reservoir of AfRGM parasitoids;

Rice Policy and Development (Program 2)

The program was actively involved in promoting the development of complementary technologies to enhance sustainable production in rice-based farming systems throughout West and Central Africa.

The ARI and ROCARIZ networks contributed significantly to the objectives of the Africa Rice Center: 11 new upland and 60 lowland NERICA lines were named; more than 2,000 tonnes of NERICA seed were produced in seven ARI pilot countries and distributed to farmers; passport data of eight released NERICAs compiled to facilitate their adoption and use; and 46 NARS scientists trained in impact assessment. The newly named materials are mainly extra early (NERICA 8, 9, etc).

Besides the ARI Coordination Unit’s direct contribution to seed production, it also facilitated seed production in pilot and non-pilot countries through ARI national coordination and partnership with several NGOs.

Pertinent results included:

1. The introduction of more than 400 NERICA lines to farmers through the participatory varietal approach;

2. Training of 20 NARS technicians and more than 200 farmers in seed production;

3. Study tours of PVS and CBSS in NERICA production countries, including Guinea, for scientists from the Democratic Republic of Congo and Uganda;

4. Workshop on HIV/AIDs and Agriculture: Implications for food security in West and central Africa;

5. Regional rice policy and food security workshop attracted 80 participants from 20 countries;

6. Agricultural Policy Research and Advocacy Group (APRAG) was formed with partners in Nigeria, Mali, Burkina Faso and Niger;

7. A study on gender-differentiated impact of collective action governance in semi-collective irrigated rice schemes in Benin was completed

8. A farmer-training video on an improved rice parboiling technique and equipment was developed in collaboration with local artisans.