As the harvest gets under way, we look back at the 2011-12 crop season at ICARDA’s headquarters, the Tel Hadya research station in Syria. Rainfall (450 mm to date) was 35% above the long-term average; temperatures were 2-3 degrees lower than normal. The barley harvest was exceptional, providing a benchmark for yield under rainfed conditions. The cold winter provided a good test for cold and frost tolerance in all crops. Depending on the timing of dry spells in relation to crop phenology, the season also provided valuable data on the ability of improved varieties − spring bread wheat in particular − to cope with moisture stress during the grain-filling and maturity stages.
Tel Hadya represents only a small part of ICARDA’s global research. Nevertheless, this update illustrates the breadth of the research portfolio, and how the results are helping to improve food security and livelihoods in dry areas.
ICARDA’s barley program is developing varieties adapted to the many different environments where the crop is grown. The new varieties offer high and stable yields, as well as drought and/or cold tolerance, disease resistance and other traits. Several thousand genotypes of spring and winter barley are being tested, with field plots at Tel Hadya extending over 40 hectares.
In winter barley, more than 16,000 genotypes are being evaluated in nurseries, yield trials and breeding plots. Research covers both 2-row and 6-row types; the former for drought-prone environments, the latter generally for high-input irrigated production. Multi-environment testing has allowed breeders to significantly improve a range of traits: yield, drought and cold tolerance, earliness, plant height (to facilitate mechanized harvesting), disease resistance and grain quality. For example, drought tolerance trials at Tel Hadya, combined with cold tolerance screening in highland areas in Iran and Turkey, are helping to develop varieties that combine both traits. A number of genotypes have performed extremely well this season, including Sadik-01/… (2-row) and Kc/Mullers/Heydla//… (6-row).
In spring barley, breeders work with an extremely diverse range of genotypes: 2- and 6-row, black- and white-seeded, and different spike shapes. The aim is to improve yield and resistance to biotic and abiotic stresses in feed, forage and food types (including the so-called ‘naked barley’). Other target traits include malting quality and input-responsiveness (varieties that can give very high yields under favorable conditions). This season, a number of varieties yielded more than 8.5 tons per hectare on large-scale demonstration plots.
ICARDA breeders are developing new varieties of spring, winter and facultative bread wheat that combine high yield potential and high water use efficiency – giving bumper yields in good years and acceptable yields in dry years.
Experiments on spring wheat at Tel Hadya cover about 40 hectares. Some 1500 genotypes are being evaluated in advanced yield trials. Despite the lack of rainfall during the grain-filling stage, several genotypes are expected to yield substantially more than most currently available varieties. The difference could be as high as 50% under rainfed conditions and 30% under irrigation. Many more genotypes are being evaluated for drought and cold tolerance, and resistance to yellow rust – the biggest disease threat to wheat crops in West Asia and North Africa.
The same genotypes are also being evaluated in Egypt, Ethiopia, Morocco and Sudan. This ensures that breeders have large, reliable datasets from multiple environments: on yield potential (from irrigated environments in Egypt); Hessian fly and Septoria resistance (from hot-spots in Morocco); stem and yellow rust resistance (Ethiopia); and Septoria resistance and heat tolerance (Sudan).In facultative/winter wheat, several highly promising genotypes were identified, giving yields of up to 6.5 t/ha with limited amounts of irrigation, and 2.5 t/ha under rainfed conditions. They combine high yield potential, drought tolerance, yellow rust resistance and good grain quality. These genotypes are also being tested by national research programs in more than 20 countries. This approach, facilitated by ICARDA’s international nurseries program, accelerates testing, sharing of results, and eventual release of new varieties.
ICARDA’s durum wheat program focuses on yield, quality, and resistance to a range of stresses: heat, drought, rust diseases (stem, stripe and leaf rust), Septoria, root rot, Hessian fly and sawfly. Nearly 2000 genotypes are being evaluated in advanced yield trials at Tel Hadya. Some of these genotypes yielded more than 7 t/ha under rainfed conditions (Tel Hadya) and 11 t/ha under irrigation (Egypt). Other trials − 219 genotypes, 50 test sites across the Mediterranean − are evaluating yield and adaptation to different environments.
Three new high-yielding durum varieties were released this season in Algeria, Ethiopia and Turkey. The two Ethiopian varieties are resistant to all three rust diseases. The third variety (Ammar 6, released in Algeria and Turkey) has outstanding grain quality (gluten strength and carotene).
The durum program also includes a major biotechnology component. In collaboration with INRA-Morocco and Rothamsted-UK, novel genes for Hessian fly resistance were identified (surprisingly, from a susceptible variety) using the TILLING technique. Research on salt and drought tolerance, in partnership with Tuscia University in Italy, focused on DREB (Dehydration Responsive Element Binding Factor) genes. Allelic variants of DREB genes were detected in several ICARDA durum lines. In addition, SNPs (Single Nucleotide Polymorphisms) were identified in a highly salt-tolerant durum line. These discoveries will help to understand the mechanisms through which durum plants respond to drought and salt stresses; and to develop new primers for marker-assisted selection.
For more information contact Dr Miloudi Nachit, durum wheat breeder, email M.Nachit@cgiar.org
ICARDA scientists and engineers, working with the private sector in Syria, have developed new technologies for faba bean mechanization. In 2010, the team developed the first mechanized seeder suitable for research plots. A second model is being trialed this season, designed to plant single rows of material of single-seed descent. It can simultaneously plant three single-row plots. These tractor-mounted devices can be easily adjusted to accommodate a range of seed sizes (which, in experimental genotypes, can vary by a factor of ten), planting depths and row spacings. Another unique feature is their pointed tines, allowing seeds to be precision-planted into standing stubble for zero-tillage (conservation agriculture) experiments. The first experiments, integrating faba bean into conservation agriculture systems, began this season.
Before 2010, ICARDA’s faba bean trials were all hand-planted. This season, 70% of trials were mechanically planted, slashing time and labor requirements, and allowing breeders to substantially increase the size of research plots and the number and diversity of genotypes tested. The faba bean program has quadrupled the size of experimental plots without increasing labor requirements.
For more information contact Dr Fouad Maalouf, faba bean breeder, email F.Maalouf@cgiar.org
ICARDA has a global mandate for research on kabuli chickpea. A total of 66 field trials were planted at Tel Hadya this season, with 25 hectares of field plots and more than 14,000 genotypes: germplasm, genetic stocks, breeding material and crosses. The program aims to develop new varieties with multiple traits. Two key traits are resistance to ascochyta blight (9012 genotypes screened this season) and fusarium wilt (4442 genotypes). Other target traits include drought, heat and cold tolerance; breeders have identified varieties capable of withstanding sub-zero temperatures for several days.
Yield trials tested another 793 advanced lines, targeted at different environments in West and South Asia, and North and sub-Saharan Africa. Several lines combined high yields (2-3 t/ha) with resistance to ascochyta, fusarium, cold and drought. These lines are now being shared with national plant breeders in partner countries.
Other trials measured physiological traits such as chlorophyll content, chlorophyll fluorescence and stomatal conductance. The results will help relate these traits to drought and heat tolerance, providing breeders with a physiological ‘marker’ to aid selection.
For more information contact Dr Imtiaz Muhammad, chickpea breeder and geneticist, email M.Imtiaz@cgiar.org
Water availability is the biggest limiting factor in dryland agriculture. Several field trials at Tel Hadya are helping to test and promote low-cost innovations to increase water productivity. Rainwater harvesting methods are being tested on a five-hectare demonstration plot that includes micro- and macro-catchment techniques. In the former, runoff water is captured from a small area (a single field, or even the area surrounding a single tree). In the latter, water is captured from a large catchment area and shared by multiple fields. The ongoing experiment tests four types of micro-catchment: contour ridges, semi-circular bunds, small basins and contour strips. The first three are used to ‘irrigate’ forage shrubs; while contour strips are being tested with different crops. Smaller experimental plots measure runoff coefficients under different land uses: weeded crop area, grazed area, undisturbed land. The results will help design the most effective water harvesting system for a given area.
A separate 7000 m2 plot tests the use of deficit irrigation, which trades a small reduction in yield for a very large increase in water productivity. The experiment measures the effects of deficit irrigation on sugar beet, evaluating yield and sugar content under different irrigation levels. Sugar beet is a major irrigated crop in several Middle Eastern countries, so even small increases in water productivity would lead to huge water savings.
Another experiment looks at the potential of obtaining irrigation water from non-conventional sources. Wastewater from ICARDA’s sheep research unit, filtered but not chemically treated, is being used to irrigate olive, pistachio and mulberry trees on a three-hectare plot. The experiment compares fruit and nut yields under wastewater and freshwater irrigation with non-irrigated yields. The results will help determine ‘water quality thresholds’ and design cost-effective, safe and profitable ways to recycle wastewater in agriculture.
For more information contact Dr Theib Oweis, Director, Integrated Water and Land Management Program, email T.Oweis@cgiar.org
Olive trees are a major component of Mediterranean farming systems; but inappropriate land management practices have accelerated soil erosion in many olive production areas, especially those located on sloping land. A new study, which began this season, combines field trials with modeling to examine the benefits of two kinds of interventions: low-cost semicircular stone bunds surrounding individual trees, to harvest runoff water and reduce erosion; and alternative weed control methods to replace the common practice of tillage.
The experimental field is located on a 10-15% slope, and contains 114 ten-year old olive trees. The trial includes six ‘treatments’: trees with and without stone bunds, and three weeding methods (herbicide, a motorized weed cutter, and the common practice of tillage using a cultivator). Researchers used ‘Gerlach troughs’ to measure water runoff and soil loss. Experiments on soil loss and erosion management require several seasons to allow definitive conclusions; but preliminary results show clearly that stone bunds provide substantial benefits for little investment; and that the two new weeding methods cause considerably less soil disturbance and erosion, and are less expensive, than the common practice of tillage.
For more information contact Dr Feras Ziadat, soil conservation and land management specialist, email F.Ziadat@cgiar.org
Two experiments are helping to understand how wheat and barley plants behave under a combination of multiple stresses: drought, heat and nitrogen deficiency. One trial measures the response of 20 barley and durum wheat genotypes to different levels of soil moisture and nitrogen fertilizer rates. The second trial evaluates six durum wheat genotypes under different combinations of moisture (irrigation levels) and temperature (early vs late planting). Both trials evaluate landraces and improved varieties as well as lines under development. The results will help identify agronomic and physiological traits that can be used in breeding programs to develop varieties that use water and nitrogen more efficiently, and tolerate drought and heat stress.
Another study examines nutrient dynamics in a cereal-legume intercrop. Legume crops secrete small quantities of organic acids through their roots, increasing the levels of plant-available soil phosphate, benefiting both components of the intercrop. An experiment conducted in partnership with Tottori University, Japan, tests a bread wheat – faba bean intercrop grown with different levels of phosphorus fertilizer. Preliminary results suggest that intercropping increases phosphorus uptake in wheat during early development. Ongoing research will measure yield effects, and the potential of intercropping systems to increase cereal yields in Mediterranean types of soils.