Potato Review

www.potatoreview.com POTATO REVIEW MARCH/APRIL 2021 41 APHID CONTROL Where is the IPM potential for virus-vectoring aphid pests? Addressing the increasing virus problem faced by seed potato growers may call for a re-think on how drills are planned and the implementation of e ective IPM strategies to help combat the risk of virus-vectoring aphids developing insecticide resistance. R ESEARCH led by Eric Anderson of Scottish Agronomy has shown sowing spring barley around headlands and wild owers along tramlines of seed potato elds can help to reduce virus incidence. Eric said: “Virus health is one of the industry’s most important challenges. e main culprit is PVY, principally the PVYN strain, but PLRV has also increased albeit from a very low base. “ ere are concerns that visual observation is becoming a less reliable method of assessing plant health. “PVYN may easily go undetected, partly because less aggressive PVYN recombinants might have been selected for by the action of “Natural enemies take time to build their numbers.” roguing out PVYO with obvious eld symptoms.” Other concerning factors are the growth in popularity of asymptomatic (tolerant) cultivars, loss of insecticides and rises in late season infection due to loss of desiccants slowing down haulm destruction and allowing more frequent regrowth. He notes that the incidence of aphid- vectored mosaic viruses tend to be higher on the perimeter edges of elds or adjacent to blank separation beds. “Previous research has shown that long wavelength light re ected from the soil and the contrasting green crop attracts winged aphids to the boundaries between the planted eld and the dark-soil of blank beds. Eric Anderson of Scottish Agronomy says we are seeing shifts in sensitivity to pyrethroids. Long wavelength light reflected from the soil and the contrasting green crop attracts aphids. Teagasc Research O cer Dr Lael Walsh uncovered some aphid sensitivity. ➜