Seed health of organic peas and faba beans and its effects on the health of the harvested grains

A survey was conducted in Germany during 2009–2012 on seed health of organic pea and faba beans and their harvested progeny seed on up to 32 organic farms per year. Seeds were either basic seeds intended for production of certified seeds (Basic), certified organic seeds (Certified) and on-farm organically produced seeds but not certified (Uncertified). The frequency of Ascochytapisi or A. fabae, Didymella pinodes, Peyronellaea pinodella and Fusarium spp. was determined. For peas, 17 out of 71 and for faba beans 2 out of 48 seed lots had >10% infestation of Ascochyta blight complex pathogens, a level considered problematic. Ascochyta levels at harvest were >10% for 30 of the pea and four of the faba bean samples. As well for A. pisi as for D. pinodes, the mean percentage of infected seeds was significantly higher in uncertified pea seeds than in certified and basic seed lots. In most cases, the faba bean seeds were infected with one pathogen only, however, a combination of pathogens regularly occurred on peas. Overall, highly infested seed lots resulted in highly infested harvest lots. However, high infestations also occurred in lots originating from clean seed pointing to the importance of local soil- and air-borne infection sources. The relationships between the level of seed lot infestation, environmental factors and infestation levels of harvested progeny seeds were weak for both crops. For an overall improvement of pea and faba bean health in organic farming, there is a need to assure healthy seeds in addition to the reduction of soil- and potentially air-borne inoculum.