Virus-resistant wheat varieties released, farmers to get seed

Wednesday February 3 2016

A wheat field at a research station. Efforts to

A wheat field at a research station. Efforts to breed stem-rust resistant varieties are enhanced by international collaborations. PHOTO BY LOMINDA AFEDRARU 

By Lominda Afedraru

National Agricultural Research Organisation (Naro) is to make available a couple of disease-resistant wheat varieties to farmers for the next planting season.
The three recently released varieties are resistant to UG99 stem rust virus and were developed by Buginyanya Zonal Agricultural Research and Development Institute (BugiZARDI).
They have been intensively tested and evaluated for several factors: Cultivation by farmers, yield potential and baking quality characteristics, stability, distinctiveness, and uniformity.
This was carried out by the Crop Protection Department, Ministry of Agriculture before the official release in November last year. Wheat varieties were bred by scientists in BugiZARDI in collaboration with their colleagues in Kenya and Austria.

Dr Arthur Wasukira, the Institute’s director, said the varieties released are named as NARO Wheat1 (Sipi), NARO Wheat2 (Elgon) and NARO Wheat3 (Nyonyi).

It is expected that the seed will be available from the next rainy season. The team is using the farmer approach for seed multiplication in Bukwo, Kween and Manafwa districts as well as on-station multiplication at Buginyanya.

Since the disease has proved a global threat, research institutes in UK and US are also breeding resistant varieties.
UG99 stem rust is one of the most devastating wheat diseases in the world and can cause 60–100 per cent yield loss in susceptible wheat varieties.
That is the reason why scientists are breeding resistant varieties to resolve yield loss arising from this disease.

Dr Wasukira explains that NARO Wheat1 takes 98 days to mature and has good characteristics for extended storage, is not easily damaged by pests and yields 2.8 tonnes per hectare.
NARO Wheat2 yields up to 2.2 tonnes per hectare, takes 110 days to mature and does well under low-moisture conditions.
NARO Wheat3 takes 100 days to mature. It is the most stable across several environments and yields up to 2.5 tonnes per hectare.

Quality characteristics
The new wheat varieties have reddish brown grains with 10 per cent flour protein and can produce good flour, which indicates good quality gluten content.
Gluten gives elasticity to dough, helping it to rise and keep its shape and often gives the final product the necessary texture.

The varieties were developed from a process called mutation breeding. A selected farmer-preferred variety Pasa was obtained from International Maize and Wheat Improvement Centre (CIMMYT), and a sample subjected to Gamma radiation in laboratories at the International Atomic Energy Agency in Austria.

This irradiated sample was then grown in Uganda—in a controlled field in Kalengyere and Kabale over two seasons. And through mass selection of plants with no symptoms of the disease, bulked at Buginyanya for another two seasons before being tested for yield and other properties in multiple locations.

These included Kisoro, Kabale, Mbarara, Bulambuli, Kapchorwa, Kween and Bukwo districts. In all seasons, the varieties were tested alongside Nkungu and Pasa, which proved to be superior in many aspects.

Multiple locations
The process from irradiation to release of the varieties by the ministry lasted from 2009 to 2015. Before the breeding process, the varieties were subjected to intense disease pressure at Moi University, from which successful varieties were selected for further trials in Uganda.
In order to establish which variety grows well in which area, the breeding team led by Dr William Wagoire conducted multi-locational trials for three years—2012 to 2015—covering six seasons with two seasons per year.

These trials were conducted in Bukwo, Kween, Kapchorwa, Bulambuli, Mbarara, Kabale, Kanungu and Kisoro. The varieties released were found to be stable in all the locations.
Wheat research in Uganda is at a relatively small scale but gaining momentum through capacity building plus regional and international collaborations.

Wheat in Uganda

Statistics from Naro indicate that Uganda imports 95 per cent of wheat for food, which costs up to $121m annually. But Uganda has potential to produce wheat in West Nile, Mt Elgon, in the south-west and parts of northern region particularly Lamwo District.

Wheat is a short-term maturing crop that can provide both food and income to improve the livelihoods of people in these locations.
The crop is considered to be an important food and non-traditional cash crop prioritised to address household income and food security specifically in the highland areas of Mt. Elgon and south-western region.

The total production in the country is 20,000 metric tonnes from 14,000 hectares of land utilised by smallholder farmers.
Wheat is mostly imported and processed in the country for export as flour to neighbouring countries. Several milling industries have been set up, which indicates increase in market opportunities in the country.

However, access and availability to seed of improved varieties is also limited, justifying the need to develop improved high-yielding disease-resistant varieties, which are suitable for Ugandan agro ecological conditions.