Wheat rust dates back almost to when wheat was first domesticated. It clings to the stalk of the plant draining its nutrients. It was brought under control in the 1950′s by scientists who created hybrid crops having strong disease resistance. This solution, however, also brought about complacency as the rust organism has continued to evolve and mutate, emerging again as potent as ever.
There has been excessive speculation over the past six years by commodity index traders in wheat futures contracts. The statistics and report was submitted in an article by the Senate Committee on Homeland Security & Governmental Affairs in June of 2009.
Ironic it is that 2011 has brought a wheat rust, Ug99 (Uganda in 1999), to the stems of wheat. A fungi that if gone unchecked can wipe out 80% of the world’s wheat crop. The use of fungicide sprays has been the only solution for most farmers to keep the spores from rotting the stems. There are wheat farmers that can’t afford the extra doses of spray required to save their crops.
The fungus grows a mycelium in about ten days at each infection then produces spores that break through the stem. This phase is referred to as the ‘repeating stage’ and this particular rust spore is the only one that can harm the plant. Multiple and repeated infections of the same plant and surrounding wheat plants can create an epidemic when environmental conditions are in their favor.
Prevailing southern springtime winds carry the spores (urediniospores) north into the central Great Plains where they infect winter wheat plants. The cold weather in winter prohibits stem rust infections from developing. The stem rust disease cycle in the North ends at harvest time.
The disease cycle begins on southern crops from spores infecting the winter wheat seedlings from the fall planting. The rust disease on wheat plants in the winter was spread from volunteer plants that sprouted during the summer and became infected. Spring plantings in the North are harvested in August which is long before the winter crop has sprouted in the South.
Overwintering spores as the source show as a heavy infection in the lower leaves with less infection on the younger leaves higher on the plant. Infections that are scattered mainly on the top leaves indicate that airborne spores were carried onto the field by winds. Urediniospores produce in one to two weeks allowing for multiple generations during one growing season.
Wheat rust takes in the nutrients from the tissues that are important for a healthy plant to develop and breaks through the layers affecting transpiration. The plants become more vulnerable to the invasion of other fungus or bacteria. It’s probable that the grains will be shriveled and due to the infection in the stem, plants can fall over in heavy winds and rain causing mechanical harvesting to be impossible.
Thousands of experimental hybrids have been created from labs around the world. The stages are numerous and time consuming. It may not be until 2016 before new resistant varieties are available for commercial use around the world as they need to be subjected to cross-breeding for qualities beyond resistance and yield.
In the mean time, the genetically modified seed corporations have been anxiously waiting in the wings to push their wheat frankenseed onto the unsuspecting masses. They may use the media to convince people that their frankenseed is the only solution. Not only is it not the only solution, it causes much more harm than any good it could possibly offer. GMO wheat will also endanger the bee population worse than it already is.
source:
apsnet.org
pbs.org/newshour
