Traditional crop breeding cultivates drought tolerance faster and more efficiently than genetic modification

(NaturalNews) Traditional plant breeding techniques are dramatically outperforming genetic engineering in the quest to develop crop verities that can be grown in more marginal conditions, according to researchers from the International Maize and Wheat Improvement Center (CIMMYT) in Mexico City.

Researchers have expressed concern that, as global warming leads to higher temperatures and lessened rainfall, more and more food crops will need to be drought-resistant. For example, drought has been shown to reduce corn yields in African by as much as 25 percent.

In addition, ongoing degradation of topsoil and rising chemical agriculture costs are driving a need for crops that can better tolerate nutrient-poor soils.

New, non-GM varieties have 30 percent higher yield

In 2006, the Drought Tolerant Maize for Africa project was launched, in partnership with CIMMYT and the International Institute for Tropical Agriculture in Ibadan, Nigeria. Researchers searched CIMMYT's seed bank for drought-tolerant corn varieties, then crossed these varieties. These new varieties were then cultivated, and seed was saved from the most drought-tolerant individuals. That seed was then grown and crossed with other corn varieties already known to thrive in Africa.

"It is a painstaking and expensive process," said Kevin Pixley, director of CIMMYT's genetic resources program.

In spite of the difficulty of the process, the project has already developed 153 new corn varieties suitable for cultivation in 13 countries. Field trials have shown that, under good rainfall conditions, these varieties match or surpass the yield of existing crop varieties. Under drought conditions, the new varieties outperform existing varieties by as much as 30 percent.

According to recent analysis, published in The Journal of Developing Areas, the extra yields from these 153 varieties could reduce the number of people living in poverty by 9 percent in the 13 countries. This would amount to more than half a million people in Zimbabwe alone.

In contrast, CIMMYT's efforts to produce drought-resistant genetically modified (GM) corn (in collaboration with six other research groups and Monsanto) have yet to produce a single viable variety. That's because most plant traits, including drought tolerance, involve multiple genes. Genetic engineering technology is only able to work on a single gene at a time.

Reducing fertilizer dependence

CIMMYT has also been working to develop corn varieties able to tolerate nitrogen-poor soils. According to CIMMYT corn breeder Biswanath Das, one of the biggest problems African farmers have is that they are only able to afford about 10 percent of the fertilizer recommended for their fields.

Globally, soil quality is diminishing and topsoil is vanishing. Indeed, a study conducted by researchers from the University of Sydney and presented at the Carbon Farming conference in 2010 found that all the topsoil on Earth will be gone by 2110, if farming practices do not change. Factors contributing to soil depletion include overuse of synthetic fertilizers, overuse of plowing and poor erosion control. All of these factors are reported to be intensified by global warming and are expected to contribute to a food crisis as the planet's population continues to grow.

Since 2010, CIMMYT researchers have been working on the Improved Maize for African Soils (IMAS) project in collaboration with the Kenya Agricultural Research Institute, the South African Agricultural Research Council and DuPont Pioneer to develop new corn varieties. The IMAS project uses both conventional breeding and genetic engineering to try and develop corn varieties that can thrive in nitrogen-poor soil.

In just four years, IMAS has already developed 21 such varieties through conventional breeding techniques suitable for eight countries. Field trials show that in nitrogen-poor soil, these varieties produce an extra metric ton of yield per hectare than currently available varieties.

Yet IMAS researchers say that a GM corn variety suitable for nitrogen-poor soil is still at least 10 years away.

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