Results – Seed Borne Diseases

Results showing the survival of seed borne plant diseases are shown in figure 10. The initial infection level of the seed borne pathogens varied considerably among the different crop species included in the experiment (Figure 10). However, after 35 years of storage in permafrost the infection levels were in general only slightly changed in most of the samples, although some variation in the levels were observed over the years.

All investigated pathogens were still detected after 35 years of storage also when the initial infection level was low, as for B. allii and Fusarium spp. in onion, A. dauci and A. radicina in carrot, Fusarium spp. in barley and wheat, U. nuda f. sp. tritici in wheat, and LMV in lettuce. For some of the pathogens with higher infection levels, like D. dictyoides in meadow fescue and P. nodorum in wheat, a trend towards reduced level was observed, whereas for Phoma betae in beet a trend towards increased infection was observed, compared to the level at the start of the experiment.