Posts Tagged ‘zinc’

Smallholder wheat production can cut Africa’s costly grain imports

This blog by Mike Listman was originally posted on CIMMYT.org.

International scientists are working with regional and national partners in sub-Saharan Africa to catalyze local wheat farming and help meet the rapidly rising regional demand for this crop.

The specialists are focusing on smallholder farmers in Rwanda and Zambia, offering them technical and institutional support, better links to markets, and the sharing of successful practices across regions and borders, as part of the project “Enhancing smallholder wheat productivity through sustainable intensification of wheat-based farming systems in Rwanda and Zambia.”

“Work started in 2016 and has included varietal selection, seed multiplication, and sharing of high-yielding, locally adapted, disease-resistant wheat varieties,” said Moti Jaleta, a socioeconomist at the International Maize and Wheat Improvement Center (CIMMYT) who leads the project. “Our knowledge and successes in smallholder wheat production and marketing will also be applicable in Madagascar, Mozambique, and Tanzania.”

Harvesting wheat at Gataraga, Northern Province, Rwanda.

Maize is by far the number-one food crop in sub-Saharan Africa but wheat consumption is increasing fast, driven in part by rapid urbanization and life-style changes. The region annually imports more than 15 million tons of wheat grain, worth some US$ 3.6 billion at current prices. Only Ethiopia, Kenya, and South Africa grow significant amounts of wheat and they are still net importers of the grain.

“Growing more wheat where it makes sense to do so can help safeguard food security for people who prefer wheat and reduce dependence on risky wheat grain markets,” Jaleta explained. “We’re working in areas where there’s biophysical potential for the crop in rain-fed farming, to increase domestic wheat production and productivity through use of improved varieties and cropping practices.”

In addition to the above, participants are supporting the region’s wheat production in diverse ways:

  • Recommendations to fine-tune smallholder wheat value chains and better serve diverse farmers.
  • Testing of yield-enhancing farming practices, such as bed-and-furrow systems that facilitate efficient sowing and better weed control.
  • Testing and promotion of small-scale mechanization, such as power tillers, to save labor and improve sowing and crop establishment.
  • Exploring use of hand-held light sensors to precisely calibrate nitrogen fertilizer dosages throughout the cropping season.

Innocent Habarurema, wheat breeder in the Rwanda Agriculture and Animal Resources Development Board (RAB), cited recent successes in the release of improved, disease resistant wheat varieties, as well as engaging smallholder farmers in seed multiplication and marketing to improve their access to quality seed of those varieties.

“The main challenge in wheat production is the short window of time between wheat seasons, which doesn’t allow complete drying of harvested plants for proper threshing, Habarurema explained. “Suitable machinery to dry and thresh the wheat would remove the drudgery of hand threshing and improve the quality of the grain, so that it fetches better prices in markets.”

Millers, like this one in Rwanda, play a key role in wheat value chains.

Critical wheat diseases in Zambia include spot blotch, a leaf disease caused by the fungus Cochliobolus sativus, and head blight caused by Fusarium spp., which can leave carcinogenic toxins in the grain, according to Batiseba Tembo, wheat breeder at the Zambian Agricultural Research Institute (ZARI).

“Developing and disseminating varieties resistant to these diseases is a priority in the wheat breeding program at Mt. Makulu Agricultural Research Center,” said Tembo. “We’re also promoting appropriate mechanization for smallholder farmers, to improve wheat production and reduce the enormous drudgery of preparing the soil with hand hoes.”

Participants in the project, which runs to 2020, met at Musanze, in Rwanda’s Northern Province, during February 5-7 to review progress and plan remaining activities, which include more widespread sharing of seed, improved practices, and other useful outcomes.

“There was interest in trying smallholder winter wheat production under irrigation in Zambia to reduce the disease effects normally experienced in rainfed cropping,” said Jaleta, adding that the costs and benefits of irrigation, which is rarely used in the region, need to be assessed.

Project participants may also include in selection trials wheat varieties that have been bred to contain enhanced grain levels of zinc, a key micronutrient missing in the diets of many rural Africa households.

“The project will also push for the fast-track release and seed multiplication of the best varieties, to get them into farmers’ hands as quickly as possible,” Jaleta said.

In addition to CIMMYT, RAB, and ZARI, implementing partners include the Center for Coordination of Agricultural Research and Development for Southern Africa (CCARDESA). Generous funding for the work comes from the International Fund for Agricultural Development (IFAD) and the CGIAR Research Program on Wheat.

Researchers find “hotspot” regions in the wheat genome for high zinc content

The reported work by wheat scientists paves the way for expanded use of wild grass species, such as Aegilops tauschii (also known as goat grass; pictured here) as sources of new genes for higher grain zinc in wheat. (Photo: CIMMYT)

An international team of scientists applied genome-wide association analysis for the first time to study the genetics that underlie grain zinc concentrations in wheat, according to a report published in Nature Scientific Reports on 10 September.

Analyzing zinc concentrations in the grain of 330 bread wheat lines across diverse environments in India and Mexico, the researchers uncovered 39 new molecular markers associated with the trait, as well as 2 wheat genome segments that carry important genes for zinc uptake, translocation, and storage in wheat.

The findings promise greatly to ease development of wheat varieties with enhanced levels of zinc, a critical micronutrient lacking in the diets of many poor who depend on wheat-based food, according to Velu Govindan, wheat breeder at the International Maize and Wheat Improvement Center (CIMMYT) and first author of the new report.

“A collaboration among research centers in India, Australia, the USA and Mexico, this work will expedite breeding for higher zinc through use of ‘hotspot’ genome regions and molecular markers,” said Govindan. “It also advances efforts to make selection for grain zinc a standard feature of CIMMYT wheat breeding. Because varieties derived from CIMMYT breeding are grown on nearly half the world’s wheat lands, ‘mainstreaming’ high zinc in breeding programs could improve the micronutrient nutrition of millions.”

More than 17 percent of humans, largely across Asia and Africa, lack zinc in their diets, a factor responsible for the deaths of more than 400,000 young children each year.

Often used in human disease research, the genome-wide association approach was applied in this study to zero in on genome segments — known as quantitative trait loci (QTLs) — that carry genes of interest for wheat grain zinc content, according to Govindan.

“The advantages of the genome-wide association method over traditional QTL mapping include better coverage of alleles and the ability to include landraces, elite cultivars, and advanced breeding lines in the analysis,” he explained. “Our study fully opens the door for the expanded use of wheat progenitor species as sources of alleles for high grain zinc, and the outcomes helped us to identify other candidate genes from wheat, barley, Brachypodium grasses, and rice.”
Farmers in South Asia are growing six zinc-enhanced wheat varieties developed using CIMMYT breeding lines and released in recent years according to Ravi Singh, head of the CIMMYT Bread Wheat Improvement Program.

Financial support for this study was provided by HarvestPlus (www.HarvestPlus.org), a global alliance of agriculture and nutrition research institutions working to increase the micronutrient density of staple food crops through biofortification. The views expressed do not necessarily reflect those of HarvestPlus. It was also supported by CGIAR Funders, through the Research Program on Wheat and the Research Program on Agriculture for Nutrition and Health. Research partners in India and Pakistan greatly contributed to this study by conducting high-quality field trials.

Moving zinc-enriched wheat into the mainstream

By Matthew O’Leary/CIMMYT

EL BATAN, Mexico (May 30,2017)– In an effort to stamp out hidden hunger, scientists are calling for support to make zinc-biofortification a core trait in the world’s largest wheat breeding program.

At least 2 billion people around the world suffer from micronutrient deficiency, or hidden hunger, which is characterized by iron-deficiency anemia, vitamin A and zinc deficiency.

Zinc deficiency remains a crucial health issue in sub-Saharan Africa and South Asia. As a key nutrient in red meat, zinc deficiency is prevalent in areas of high cereal and low animal food consumption.