Dean Malvick, plant pathologist at the University of Minnesota speaking the Soybean Symposium told the audience that SCN can influence the outbreak of BSR (brown stem rot) and SDS (suddden death syndrome). And we know that SDS has seen a resurregence the last few years with cool and moist weather and is not occurring in more states than ever before (is SCN partly to blame).

With both diseases, their frequence and severity is much greater when SCN is presence in the soil, and the higher the egg count and population the greater the problem. And what is even more serious, according to Malvick is that plant BSR resistance actually seems to be overcome in the presence of SCN.

And SCN enhances early season infection with SDS and overall SDS severity. So with the rapid spread of SCN and buildup of populations with inadequate plant resistance its no wonder that we are seeing more SDS than ever before.

Malvick said the SDS organism lives and overwinters in cysts and can be transported with cysts. However he points out that SCN isn’t required for SDS to develop for it can facilitate rapid spead.

How SCN can transfer SDS to the soybean plant? SCN’s effect is both physical transport and wounding that allows entry into the plant, and like with BSR, SCN might be affecting plant’s resistance to SDS. And Malvick concluded that SCN has helped spread SDS in Minnesota.