Fusarium head blight by cereals

Fusarium head blight (FHB) predominantly caused by Fusarium graminearum and Fusarium culmorum belongs to the most damaging diseases, particularly in years with intensive rainfall. The fungus reduces substantially grain yield and affects grain quality. Mycotoxin contamination of human food and animal feed became a more important feature than the direct yield losses that often occur irregularly. Response to artificial infection with Fusarium was studied in wheat and barley. Different techniques of inoculation with isolates of Fusarium culmorum and Fusarium graminearum were applied. Relatively higher content of DON was obtained with spike surface inoculations (for type I of resistance) than with single floret inoculations in wheat or use of "brushing" technique in barley (for type 11). Genotypes with resistance to DON accumulation (Sumai 3, Arina, Petrus) were detected in wheat with the help of both methods. Barley varieties Chevron, Cl 4196 (sources of resistance), Jersey, Olbram and Scarlett showed lower DON content in trials with spike surface inoculation. No significant differences in mycotoxin content were found between barley varieties by "brushing" method. High or moderate resistance was detected in wheat varieties Sumai 3, SG-V NB x MM Sum 3, F201 R, SG-U 513, SG-U 466, Arina, Bizel, Petrus, and Nela. There were found differences between fungus isolates ill both aggressiveness and mycotoxin production. Isolate 821 (from Poland) could be classified in wheat as the most strong DON Producer, while isolate 608 was predominant NIV producer. Response to artificial infection with Fisarium culmorum and fungicide treatment was studied in winter wheat and spring barley cultivars in field experiments at the location Prague-Ruzyne in three year period (2001, 2002 and 2003). Fungicide treatment caused oil average 39% reduction of DON content in wheat and 53% reduction in barley. The survey of mycotoxin content was carried out in Czech Republic in the four year period in wheat, barley and rye. The limit value (2 ppm) was exceeded only in one sample of barley and three samples of wheat. Fusarium graminearum became in recent years the prevailing toxicogenic species.