Infection must have happened after my visit in December, unless plants were already infected but were not yet showing symptoms. |
Rust spores can be carried by wind currents hundreds or even thousands of miles, even across oceans. They are eventually brought down to earth by rain, and a leaf that's been wet for several hours is needed in order for a spore to germinate and infect a plant. |
Surveying these fields will provide information to get the big picture of how this fungus behaves in this part of the world. We know it's caused major losses in Asia and other parts of the world, but we don't really know how it will affect crops here. The weather and prevailing winds this spring will play a big role in what happens, but if South Texas bean crops have a rough year with soybean rust, there will be the potential for a bad year further north. |
This finding in South Texas is probably a new introduction. And what it suggests is that soybean rust could take the so-called 'rust corridor' to points possibly as far north as Canada. |