In this article, we will discuss managing Potato Virus Y (PVY) during the potato growing season. Potato Virus Y, also know as Potato Mottle, is commonly found in potato crops, although it can infect other Solanaceous plants such as tomato, pepper and chili pepper. PVY is one of the most damaging potato viruses, owing to its potential effect on quality and the yield of a crop.
Symptoms of Potato Virus Y
Symptoms vary widely between virus strain and potato variety. Most common symptoms seen in the field will be due to secondary (tuber-borne) infection and include stunting, leaf mottling, crinkling, yellowing and necrosis. Primary (current season) infection usually has mild symptoms or none at all.
The best way of getting a confirmation of the presence of PVY is via diagnosis. This can be achieved by sending samples to an approved laboratory for testing. However, laboratory methods can be time-consuming and take days or weeks. So, it is quicker to use a Potato Virus Y rapid test. These tests provide results in a matter of minutes while still in the field.
Many growers, advisors and inspectors will be familiar with the symptoms of PVY. However, getting a definitive confirmation of the presence of Potato Virus Y is important. Catching the virus before it becomes a bigger problem is something every grower is focused on.
In addition, Potato Virus Y rapid tests can be used at various stages of the growing cycle. That means there is an opportunity to confirm the presence or absence of PVY all the way through the growing season.
Some people may say why get a diagnosis of PVY if I know what the symptoms are? Well, one reason is to show evidence that your plant disease management protocols are robust and that you are being proactive in monitoring any potential outbreak. Another reason is simply to detect PVY quickly so dealing with the presence of the plant disease can start as soon as possible. However, the main reason is that regular testing as part of an overall plant disease management strategy will help to produce a good yield.
Staying One Step Ahead of PVY
As with any plant pathogen, if there is a way around control methods in order to infect its host a plant disease is going to try its best to achieve its goal. Especially PVY, as the virus is mostly carried from plant to plant by aphids. However, there are ways and means of trying to stand in PVY’s path.
As recommended by USDA, ARS & Department of Plant Pathology and AHDB Potatoes the following measures will help to try and produce PVY-free potatoes.
- Only plant potato seed that has been certified by authorised organisations and has been tested for potato pathogens. In addition, by planting certified potato seed it means there is confidence that the potato growing season will start disease-free.
- Remove diseased and unwanted potato plants at the earliest opportunity. This way there is less chance of healthy plants being infected with the disease having it been spread via aphids or transmission on equipment or clothes etc.
- It is advised that all equipment is cleaned and disinfected, with approved disinfectants, on a regular basis as part of a routine. It is also advisable to clean hands, clothing and tools as PVY can be transmitted from an infected plant to a healthy plant via plant sap.
- There are industry approved insecticides available for controlling aphid populations. However, on occasions, this method can be ineffective as aphids still have the potential to spread Potato Virus Y before they succumb to the insecticide.
- Test for the virus using commercially available Potato Virus Y tests. As mentioned above the tests are a good way of monitoring crops on a regular basis.
For further information on managing Potato Virus Y, as well as information on seed certification please contact organisations such as AHDB Potatoes, the Animal and Plant Health Agency or the USDA.