From too wet, too cold, to too dry and too hot. It seems like Ohio has seen quite a range of conditions this spring. All of these conditions can influence stand. The following is a summary of potential issues that will affect stands.
The pathogens: for those fields that received saturating rains the most common seedling pathogens are the water molds, a mix of Pythium spp. and Phytophthora sojae and Phytophthora sanosmeana. These will infect the roots when the soils are saturated and can cause brown to tan lesions on the roots and the most common symptom at this time of year is damping-off or skips in the rows.
Other seedling pathogens that we may see this year due to the drier conditions will be Rhizoctonia, which is another seedling pathogen. This pathogen has a brick red color at the base of the stem and can also have lesions on the roots. Fusarium spp. and Macrophomina phaseolina can also infect roots in these spots.
Watermolds: Pythium spp. Phytophthora sojae Phytophthora sansomeana |
Rhizoctonia solani |
Phythium spp. <25 Phytophthora sojae Phytophthora sansomeana |