The devastating Ug99 stem rust has spread to South Africa, Nature magazine reported May 26.
It quoted a study saying that the two South African forms of the disease are able to overcome the effects of two resistance genes in wheat that normally prevent stem rust from taking hold.
Named because of its discovery in Uganda in 1999, Ug99 can overcome resistance in about 90 per cent of the world’s wheat varieties. It has since spread to Kenya, Ethiopia, Sudan, Yemen and Iran and scientists expect it to continue moving west and eventually to North America.
The spread could be even quicker due to “the 747 effect” – inadvertent transmission by travellers.
The fungus can devastate harvests: for example, farmers in the Narok region of Kenya lost up to 80 per cent of their wheat crop due to Ug99 in 2007.
Combined grassy and broadleaf weed control
Thumper Total, a new broadleaf and grassy herbicide for spring wheat from Bayer CropScience, gives cereal growers more rotation flexibility, the company says in a release.
“Thumper Total gives them the freedom to get back into pulse crops such as lentils, dry beans and field peas the year following application,” says Lauren Davis, manager of cereal crop herbicides.
Thumper Total combines the active ingredients found in Velocity (Group 2 thiencarbazone) and Thumper (Group 6 bromoxynil and Group 4 2,4-D). It controls Group 1-resistant wild oats and Group 2-resistant broadleaf weeds like kochia and cleavers.
It can be applied up to the six-leaf stage and the emergence of the third tiller.