Root rot diseases of sugar beet (Beta vulgaris L.) as affected by defoliation intensity
2006
Karadimos, D.A. (Hellenic Sugar Industry SA, Larissa (Greece). Larissa Factory, Department of Plant Protection) | Tsialtas, J.T. | Maslaris, N. | Papakosta, D.
The aim of this work was to study the effect of sugar beet re-growth after water stress defoliation on root rots of three cultivars (Europe, Rival, Corsica), which were spring sown in Thessaly, central Greece, for two growing seasons (2003-2004). At the beginning of July, sugar beets were subjected to water deficit with irrigation withholding. A month later, three defoliation levels (control - C, moderate - MD, severe - SD) and irrigation were applied. Thus, sugar beets were forced to re-grow and three harvests (15, 30 and 40 days after defoliation - DAD) were conducted. Rotter roots per hectare were counted and pathogens were identified. Data were analyzed as a four-factor randomized complete block design with years, defoliation levels, sampling times and cultivars as main factors. The number of rotted roots was increased with the defoliation level and was significantly higher for SD sugar beets (3748 roots/ha). No significant differences were found between C and MD treatments (1543 and 2116 roots/ha, respectively). Rival was the most susceptible cultivar to root rots. Sugar beets were more susceptible to rotting 15 and 40 DAD (2778 and 2998 roots/ha). The causal agents of root rots were the fungi, Fusarium spp., Rhizopus stolonifer, Macrophomina phaseolina and Rhizoctonia solani.
显示更多 [+] 显示较少 [-]