RESEARCHES ON THE COMPORTMENT OF SOME FOREIGN WINTER WHEAT TO THE ATTACK OF THE PATHOGEN DRECHSLERA TRITICI REPENTIS (DIED.) SHOEMAKER PUBLISHEDOtilia COTUNA, Veronica SĂRĂŢEANU, Mirela PARASCHIVU, Carmen DURĂU, Lavinia MICU
Wheat tan spot produced by Drechslera tritici repentis (Died.) Shoemaker fungus is a foliardisease spread in many areas of the world where wheat is cultivated; having great economic importancedue to loses that can be produced at great attack intensities. This pathogen is present in Romania byabout 15 years. In Banat region was first reported in 2007, with the suspicion that the fungus was presentalready before in wheat crops. The harvest loses produced by this pathogen are in direct relationshipwith the inoculum amount, the resistance of the cultivated variety, with the climatic conditions and withthe wheat plants phenophase at the moment of the infections. In 2011 there have been monitored 13winter wheat varieties, respectively 11 varieties of common wheat (Apache, Kalango, Azimut, Soissons,Renan, Karolinum, Esperia, Bilancia, Centauro, Sagittario and Alcione) and 2 varieties of durum wheat(Normanno and Maestrale). The climatic conditions from the spring of 2011 have influenced positivelythe pathogeny of Drechslera tritici repentis (Died.) Shoemaker fungus. The virulence of the pathogen wascomprised between 45% and 75%. The most sensitive variety from the trial was Apache (control), wherethe attack intensity was 75%. The attack severity in the Italian varieties was between 48.33% (Esperia)and 66.66% (Normanno and Centauro). The lowest virulence from the trial was registered in the varietyKalango (I% = 45%). Due to the favourable climatic conditions, the infection has been spread to the flagleaf too. The flag leaf was affected in proportion of 15% (Maestrale and Bilancia varieties) and 33.33%(variety Apache). At the moment when the infection reaches the flag leaf the grains are susceptible to theinfection. The evolution of Drechslera tritici repentis (Died.) Shoemaker fungus was assessed by the useof AUDPC (area under the disease progress curve). The greatest values of AUDPC have been registeredin the varieties Centauro (1370.56), Renan (1359.84), Apache (1333.28), Normanno (1306.56), and thelowest values in the varieties Kalango (917.28), Azimut (954.56) and Esperia (959.84). The values ofAUDPC are strongly correlated with the values of intensity registered in the trial field.
wheat tan spot, Drechslera tritici repentis (Died.) Shoemaker, AUDPC, winter wheat, severity.