Powdery mildew: Aristocratic disease of wheat

Abstract

Powdery mildew of wheat, caused by Blumeria graminis f. sp. tritici, is common disease in all the wheat growing areas, including the territory of Serbia. It occurs each year in a lower or higher intensity. It is considered as a high-risk pathogen because of its significant potential for adaptability and change in the virulence structure of its population. Breeding for resistance to this pathogen is an important task of wheat breeding programs worldwide. A large number of the powdery mildew pathotypes have been described, and a large number consistently forms. For that reasons wheat resistance to this pathogen is most often shortlived. Given that this pathogen has a great potential in spreading to significant distances, the risk of loss of resistance is even greater. However, the type of resistance which is characterized as a partial, allowing pathogenic development to the extent that does not affect yield losses, has been achieved in some wheat varieties that are now successfully grown across the world. Also, the cultural practices which ensure optimal crop canopy is an important measure that keeps the pathogen under control, given that the powdery mildew is a disease of rich, thick heavy crops. Fungicide treatment is recommended when preventive measures do not provide effective results.

Prouzrokovač pepelnice (Blumeria graminis f. sp. tritici) se javlja u svim proizvodnim područjima pšenice širom sveta, pa tako i na teritoriji Srbije, svake go dine u slabijem ili jačem intenzitetu. Smatra se visoko rizičnim patogenom zbog značajnog potencijala za adaptabilnost i promenu u virulentnosti populacije. Rad na selekciji na otpornost pšenice prema ovom patogenu je važan zadatak oplemenjivačkih programa širom sveta. Veliki broj patotipova ovog patogena je do sada opisan, i veliki broj se konstantno stvara, te je otpornost pšenice najčešće kratkotrajne prirode. S obzirom da se radi o patogenu velikog potencijala širenja na značajne udaljenosti, rizik od gubitka otpornosti sorti je utoliko veći. Ipak, tip otpornosti koji se karakteriše kao parcijalan, odnosno koji dozvoljava patogenu razvoj u meri koja ne nanosi značajne štete, postignut je kod nekih sorti koje se danas uspešno gaje širom sveta. Takođe, primena agrotehničkih mera koje obezbeđuju optimalni biljni sklop omogućava adekvatnu kontrolu ovog patogena, s obzirom da je pepelnica oboljenje bogatih useva, gustog sklopa. Tretiranje fungicidima se preporučuje onda kada preventivne mere ne daju efikasne rezultate.