RETRACTED: Fusarium development in bread wheat heads under variable humidity conditions

Abstract

Pathogenic models and actual resistance and for analyzing Fusarium head blight (FHB) levels in bread wheat are relied based on environmental conditions near flowering, and breeding for resistance to FHB pathogens generally depends on irrigation before and shortly after anthesis to promote disease development. However, some reports investigated the effects of post-anthesis weather on FHB growth in bread heads. To elucidate this, the effect of moisture on the development of FHB in three bread wheat cultivars of contrasting susceptibility to FHB disease and infected with 16 fungal isolates of diverse aggressiveness of four different fungal species was examined. A pot experiment under natural climatic conditions during the growing season 2022/2023 was designed as split-split-plot with five replicates. Main plots were durations of spray-irrigation of 0, 7, 14, 21, and 28 days; sub-plots were bread wheat cultivars; and sub-sub-plots were the isolates of four Fusarium species with contrasting aggressiveness. Incidence and severity of FHB was determined 21 days after inoculation, and Fusarium-damaged kernel (FDK) percentages were assessed on harvested grain. No significant differences were observed between treatments receiving the least amount of spray-irrigation (0 and 7 days of spray), suggesting that extended moisture enhances disease development and augments grain fungus colonization. 21 or 28 days of spray had the similar impact and were linked with an augmentation in average DI and DS compared with 0 or 7 days of spray, and 14 days of spray was also associated with an increase in means of these pathogenic criteria. Mean FDK percentages at 21 or 28 days of spray were the same and significantly higher than FDK percentages under 0 and 7 days of spray, and 14 days of spray was also linked with an augmentation in mean of FDK. This is the first report to show that extended post-flowering humidity can have a significant enhancing impact on DI, DS and FDK upon infection with F. culmorum, F. solani, F. verticillioides, and F. equiseti, and is in accordance with earlier investiagtions carried out with bread wheat infected with F. graminearum.