Rice farmers in Uganda have increasingly adapted upland varieties in recent years though they mostly grew traditional lowland varieties that yielded well in swampy lands. Along with this trend, cereal breeders at the National Crops Resources Research Institute (NaCRRI) have been releasing New Rice for Africa (Nerica) rice varieties, which strive upland.
Nerica include a group of 18 varieties developed by the African Rice Centre, which is part of the CGIAR Consortium, along with national research organisations in West Africa.
They are based on crosses between the robust African species, Oryza glaberrima, and the higher yielding Asian species, Oryza sativa.
In Uganda, several Nerica varieties were introduced in 2002 and by 2009, they had expanded the area planted with upland rice from 1,500 to over 50,000 hectares.
The Nerica 4 variety dominates and is appreciated for its hardiness, high yields and shorter maturation period of between 90-100 days compared to traditional varieties that take between 120-140 days.
Nerica with off-springs, 1 to 10, have also been released, with seed multiplication by private seed dealers expanding their availability to farmers. Compared to West African countries like Nigeria, Ghana Bukina Faso, Cameroon and Senegal where rice is grown as staple food, in Uganda farmers construe rice as a commercial commodity capable of earning them increased income.
Today, Uganda is one of the leading producers of Nerica 4, and ranks twelfth in Africa for overall rice production.
For the scientists at NaCRRI majoring in breeding cereal crops, this year has been the most exciting. In April, they were in position to release the varieties that are capable of growing in upland and in swampy areas.
“We have been carrying out research in upland rice varieties. We released three varieties in 2002, two in 2007 and four in 2010 which farmers are now growing in lowlands but with little prospect of giving them good yields,” explains Dr Jimmy Lamo, the team leader.
The main disease in lowland rice, which is a challenge to farmers throughout the globe is the rice yellow mottle. According to Dr Lamo, farmers have been relying on Kibimba rice varieties, the K series, which has since succumbed to the disease.
In the research initiative, which began four years ago, the scientists have been breeding these varieties using a collection of high breed rice species both from Africa and Asia.
The team started trials with 300 breeding lines out of which five promising lines where selected. The varieties from Africa were mainly WITA 9 rice varieties, bred in most West African countries, two varieties from Tanzania and others from the International Rice Research Institute (IRRI) breeding centre in Mozambique.
These new varieties were released by the Plant Variety Release Committee at the ministry of Agriculture in the following names: IRRI 1, GSR007 variety released in the brand name Okile, Nerica 6 which is tolerant to the yellow mottle disease, IRRI 522 variety released in the brand name Comboka.
For the latter, the team decided to maintain its Kiswahili name because this variety was first released in Tanzania with the same name. For purposes of serving the interest of farmers in East Africa, it was thought prudent to maintain this name.
“This is the first time we are releasing the four irrigated varieties with the Nerica 6 variety having the potential to grow both upland and lowland. These varieties mature in less than 102 and 120 days compared to the traditional varieties that take 136 days or more to mature,” Dr Lamo says, adding that farmers will be able to harvest four to six tonnes of rice seeds per hectare from the newly released varieties.
NaCRRI is working in collaboration with the Tilda rice scheme to multiply and distribute the seeds to farmers.
Dr Geoffrey Asea, head of the cereal research in Namulonge, feels it was pertinent to breed irrigated varieties to increase rice productivity in Uganda and East African. The consumption level of rice in the country is 250,000 tonnes annually and 33 kg per person.
How the team did it
During the breeding process, the research team picked pollen from the foreign varieties, which they crossed to the traditional varieties thereby coming up with the five high breed lines.
Apart from crossing the pollen, the team at certain stage conducted the breeding through inoculation. Thereafter, they tested the lines in the different farmers’ fields in different geographical locations mainly in the central, Eastern and Northern Uganda to ascertain their performance.