This report covers samples taken between 2nd and 9th September.
1063 samples have been received so far this year.
Samples have only been received from Grampian and East Anglia for this period.
Peach-Potato Aphids have been found in samples from Grampian.
Potato Aphids have not been found in any samples this week.
Black-Bean Aphids were found in samples from Grampian and East Anglia - this species is a good vector of PVA.
Grain Aphid was again recorded from Grampian.
Bird Cherry-Oat Aphid was found again in Grampian.
Cabbage Aphids were found in East Anglia this week.
Shallot Aphid was found in Grampian this week.
North Scotland: No samples received.
Grampian: Virus pressure remained moderate. Peach-Potato Aphids were found at 2 sites. No Potato Aphids were found. Other potato virus vectors found: Bird Cherry-Oat Aphid, Black-Bean Aphid, Grain Aphid, Shallot Aphid.
Angus and Perthshire: No samples received.
Borders: No samples received.
Northern England: No samples received.
Midlands: No samples received.
East Anglia: Virus pressure was low. No Peach-Potato Aphids or Potato Aphids were found. Other potato virus vectors found: Cabbage Aphid, Black-Bean Aphid.
South West: No samples received.
Very few samples were received over the last week as most crops have finished, so this will be the last report for this season. Please do keep checking the website though, as we will continue to report results from any samples we receive. Virus pressure, although moderate, is now average for the time of year in Grampian, whilst very low in East Anglia, but could still cause problems for any regrowth. Thank you all for taking part in what has been a challenging growing season, I hope you all have a good harvest and that the information has been of benefit to you. Stay safe!
Along with the results from your aphid trap you need to take into account the following
factors when considering the risk of virus spread.
Mature plant resistance. Crops are generally at their most vulnerable
within the first four weeks from emergence. After this time 'Mature Plant Resistance'
builds up which makes it more difficult to transmit virus within the crop. The crop is
again more vulnerable to virus spread if there is regrowth after dessication.
Cultivar resistance. Different varieties of seed will have different
inherent natural resistance to PVY. Using a more resistant cultivar will reduce the
risk of virus transmission.
Volunteers and seed quality. In most situations it is unlikely that
aphids will bring PVY into your crop (see next note). The greatest risk is from aphids
spreading what little virus may already be present. This can come from two possible
sources. Volunteers from previous potato crops and low levels of virus in the seed
Surrounding crops. The risk of aphids spreading PVY to your crop
from elsewhere is increased when ware crops are grown close to your seed. This is
because there will be greater numbers of aphids and ware crops generally have a
higher incidence of virus present.