Seed potato producers are leaving no stone unturned to slow the proliferation of virus in British stocks, with straw mulches and mineral oils set to compliment systemic insecticides as part of a robust integrated pest management (IPM) strategy this year, write Rob Jones and Lucy de la Pasture in this in-depth article, published by crop production magazine (CPM).
Virus levels in Britain’s seed potato stocks have been increasing in recent seasons, most acutely in English-grown seed but Scotland has also seen infection creeping north. It’s a situation that’s prompting some concern for potato growers.
Seed certification schemes in Scotland and England are designed to reassure ware growers that the seed they buy meets the quality specifications of each grade, including virus levels. Visual inspection of the growing crop has long been used to identify infection before haulm destruction and has historically been a reasonable indicator of infection levels in daughter tubers.
PVY is the most damaging of the potato viruses because of the effect it has on quality and yield. Three major strains of PVY are usually recognized, PVYC (stipple streak strains), PVYN (tobacco veinal necrosis strains) and PVYO.
Potato Virus YN (PVYN), a non-persistent potyvirus, has taken over as the dominant strain from PVYO. The change in dominance has put pressure on the seed inspection system because, unlike the previously dominant strain PVYO, PVYN doesn’t as readily express classic mosaic symptoms in infected plants. This makes visual observation alone a less reliable means of judging primary and virus levels, according to Scottish Agronomy’s Stevie Gray.
Source: CPM. Read Rob Jones and Lucy de la Pasture’s in-depth article here