My raspberry plant has lots of crumbly fruit and yellowing leaves, so may have the virus. Should I throw out all the canes? Can I reuse my bed? Should I try to move everything? Is the soil contaminated? Some canes are on my neighbour’s property. Will they recontaminate my canes is I buy all new?
Take a look at an earlier Q&A posted on our website a few weeks ago: Problems with raspberry canes. In short, the problem needs a definitive diagnosis, and a sample should be collected and sent to a reliable laboratory for testing. For example, the symptoms you describe could be from iron deficiency, or could be caused by the raspberry bushy dwarf virus (“RBDV”) or the tomato ring spot virus. Or perhaps something else. Let’s assume your plants are infected with a virus.
Once a plant has signs of RBDV, it is too late to treat it, and the only way to stop the spread of the virus is to remove the affected plants – including the roots. Discard the plants with city waste, don’t compost them at home. Get rid of all of the possibly contaminated plants (even those in your neighbour’s garden!) – don’t leave any behind, as reinfection is a concern. The virus is believed to be primarily transmitted via pollen, so you should be able to replant in the same area, as long as all the infected plants have been removed. Use healthy plants that are certified to be virus-free. This is likely a good time to amend the soil – raspberries like sandy loamy soil that contains lots of organic matter. Remember to sterilize the tools you use before planting new stock.
The tomato ringspot virus (which affects only red raspberries) is transmitted through the soil to the roots of the bushes by the dagger nematode (an evil-sounding beast, if ever there was one). If this virus is the culprit – and you can have the soil tested for presence of the nematodes – don’t replant in that area until the nematodes have been destroyed. As this may be difficult to achieve, it may be wisest just to select a new site at least 16 metres away from the old planting area for your new raspberries.
If you do select another site to plant your next raspberry crop, avoid areas where eggplant, potatoes, tomatoes or strawberries have been grown, as these spots may have root diseases that can infect the raspberries.
The BC government has a good publication that should help you – RBDV – frequently asked questions. This publication lists several varieties of raspberry that are resistant to the virus. Another good reference is OMAFRA’s Notes on raspberry disease: viruses. Ohio State University’s Virus diseases of raspberries is also very informative.
As well, OMAFRA’s Raspberries and Blackberries for Home Gardens provides good information on the selection, planting and care of raspberries.