As the world population grows, one of the greatest concern is maintaining food sources vital to man's survival. 

The humble grain of wheat is the second most important staple worldwide.  For this reason, scientists have been developing new varieties that can withstand both pests and disease. 

A new scourge however, could seriously threaten our most valuable crop.  A fungus, called a rust threatens to wipe out nearly all existant wheat varieties.  Wheat rust, as it is commonly known, is on the march. 

First detected in Africa, it has slowly spread to most of Asia, thanks in small part to global commerce, but mostly to global warming and shifting climatic conditions, and now stands to conquer the rest of the world.  Without wheat, the world could experience the greatest famine and threat to security the world has ever known. 

The rust was first detected more than half a century ago in North America.  At that time it wiped out almost half of the entire yearly crop. 

With the development of GMO wheat, many pests and disease have been circumvented, but not wheat rust.  The rush to create a rust resistant variety is on, and the quicker it is developed, the better.  
In a cruel twist of fate the rust has mutated, and has become much more infectious in the past 15 years.  The discovery of the new strain was made in Uganda in 1999, and sent scientist scurrying to meet the apparent deadline that would be a worldwide epidemic of the wheat rust.  

Since then, the rust has been detected worldwide and has been observed undergoing further mutations.  What that means, is that the fungus has not only adapted to be more infectious, but it also has mutated to become able to infect more varieties of the grain, so that nearly all wheat varieties and crops are completely vulnerable to the disease.  

Just a year ago, Germany detected an outbreak for the first time in half a century.  What the German scientists concluded, was that global warming is accelerating the rate of infection and providing a friendly environment for the rust to strengthen and spread.  

Cooler springs, but hotter summer are an ideal condition for molds and rusts.  

Less than 6 months ago, the rust caused crop failurs in Ethiopia, which decimated farms to the tune of 50% losses of the usual crop yields.  In some areas, the failure rate surpassed the 70% mark. 

What scientists fear the most, then, is the fact that the rust is now able to cause high rates of failure at incredible speed.  Some scientists compare them to forest fires, to exemplify both the degree of destruction, and man's inability to stop the spread.  

Rusts do not need man to spread.  Apart from the obvious contamination when wheat is shipped abroad, the best friends rust has is the wind and warmth.  Spores are carried very far by the wind.  Rust also are able to produce spores in the millions, and therefore able to persist and to be pervasive. 

To make matters worse, wheat production is threatened and highly dependent on climate.  As climate patterns change with global warming, so do the microclimates of different areas.  Where there once was sufficient rain, now the same areas are in deep drought. The converse in true in other areas, where rains are copious in places where it once was scarce, causing both soil erosion and flooding.  

What that mean to scientists, is that the race to develop new varieties is not only pressing but crucial.  International agencies are pressing wealthier countries to step up to the plate and fund the necessary research to ensure that wheat does not disappear from the food chain.  

The UK has made significant investments in the research already.  The John Innes Center, in Norwich, is already leading world efforts to develop the new wheat varieties.  It is also important, scientists note, that the research concentrates on the development not of more potent fungicides, but new varieties of the grain, since the pollution generated by the chemicals will be met by the fungus' ability to mutate.  

One of the research's main aim is to cross breed the wheat with barley, which is completely immune, so far, to the rust, and with other wild grasses that have adapted to be resistant to the pathogen. 

Another tool developed by the researchers is a mathematical model that can help them identify possible outbreaks locales, where they can intervene before the fungus can spread and take hold.  One of the way the models are developed, is through the use of metereological data.  The preliminary models show that the countries most vulnerable to the disease at the moment are Ethiopia, the Middle East and greater Africa.  

The researchers also predict that if a fungus outbreak will occur, it will most probably begin in the Middle East and from there spread to the horn of Africa and beyond. 

Researchers are also noticing that the new strain of the fungus is affecting locales where the pathogen was previously unknown, like South Asia and North AFrica.  And that is because in the previous decades, those areas had an unfavorable climate. This again, reiterates the danger posed by a world that is in the throes of climate change.  

The rust is also an extremely quick pathogen.  From onset to destruction of its host, less than 15 days elapse.  By the time the visible signs of the fungus appear on the stems, the plant is already doomed. 

If anyone has any doubt what a worldwide rust epidemic could mean to the world, one can only harken back to the Irish potato blight, which killed millions of people and spurred one of the greatest diasporas in history.


Source: Times of India:  4.20.14


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