Puccinia – the name might evoke pleasant associations for lovers of classical music. But not for wheat farmers! Their association is “rust”. Recently, they have been particularly worried about Puccinia graminis f. sp. tritici (stem rust). For a long time the stem rust pathogen was assumed to have been beaten. But at the end of the last century, it suddenly reappeared in the form of a new physiological strain. After first being characterized in Uganda in 1999 (and thus christened Ug99 by the specialists), this particularly aggressive and dangerous strain has since spread through North Africa.
World’s wheat harvest under threat
When it appeared in Yemen as an even more aggressive mutant in 2007, the world Food and Agriculture Organisation (FAO) sounded the alarm, warning that the pathogen could pose a serious threat to the global harvest should it eventually reach the major areas of wheat cultivation. The main concern at the moment is that the pathogen might continue its travels in the direction of major wheat producers such as Pakistan and India. North African countries are also under threat. Europe, on the other hand, is not much threatened.
Resistant varieties take time to develop
As it develops, Ug99 fungus impacts negatively to wheat plant metabolic processes. This results in stunting of plant growth and eventually reducing yield. The wheat grains that are harvested tend to be smaller and lighter, and are often shrivelled and of lower quality. Ninety percent of all commercial wheat varieties are susceptible to this aggressive strain of the pathogen. Researchers have identified the first resistance genes already. But it will be a few years before robust wheat varieties will be available for widespread cultivation.
Established fungicides can help
There is good news from Kenya, though. Over a two year period, the Kenya Agricultural Research Institute (KARI) ran a series of wheat field trials. Researchers tested the efficacy of nine registered fungicides. The results showed that the use of fungicides resulted in an economically significant yield increase. “KARI’s final report states that Ug99 can be controlled successfully with the appropriate fungicides”, explains Francis Miano, Technical Manager for Bayer CropScience in Region East Africa. Of the nine fungicides tested, the two most effective products were from Bayer CropScience’s portfolio: FolicurŽ 250EC and SilvacurŽ 250EC. KARI has now officially recommended both products for the control of Ug99 in Kenya. Folicur has been one of the most effective rust-control products on the world market for many years – and has proven its worth in more than 60 countries. Should Ug99 really spread further into Asia, then the good news is that Folicur is already registered in countries such as Pakistan and India, and is well-established there for use on wheat crops.
Download: ( 302 KB pdf)
