Many times people ask descriptions of obscure pears and many of those answers come from here http://www.ars-grin.gov/cor/catalogs/pyreurop.html. No-one has put in as much time and effort, let alone resources as Corvallis to grow pears.
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Clark. Thanks for the list. I was reading the descriptions and noticed one of the pears I ordered from them are listed as “Virus Infected”. What exactly does that mean and should I even graft it? Do you think the scions they sent could be carrying the virus and if so why would they even send them?
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Speedster,
Many fruits are virus infected. I don’t intentionally graft virus infected pears but many people do grow them. The virus infected wood they sent you is likely infected with a minor virus but they will tell you which one in their descriptions. Google the virus symptoms and decide if the benefit outweighs the cost. I don’t order the virus infected ones because it sometimes effects growth slightly. If you trade a lot of scions you likely have several viruses over the course of many years. The people most at risk for viruses are those that multigraft trees. Lets say you grafted 4 virus infected pieces of wood on one tree now every scion shared from that tree has 4 viruses. The people recieving those scions don’t know the wood is virus infected in most cases and it’s unlikely the person helping them out realizes either. That’s why I think it’s best if you have the room graft one variety to one tree. I don’t always have the open trees to graft to because rootstocks take at least a year to grow out here. Last year was a wet year so I got away with bench grafting trees.I would highly recommend you read this post Virus free scion wood?
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@speedster1 — sometimes virus infection is a good thing. It can provide a dwarfing effect and gives more precocity. A few of the Merton-Malling apple rootstocks had virus infections that were causing the dwarfing — when the EMLA cleanup of the MM’s was done, the dwarfing effect went away!
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That is all interesting stuff. I knew that a lot of figs have the fig virus and it doesn’t seem to hurt them but wasn’t aware that there were that many viruses for other fruit trees.
Here’s the reference for the comparison of precocity and vigor of EMLA vs MM rootstocks:
Autio, W.R., J.L. Anderson, J.A. Barden, G.R. Brown, R.M. Crassweller, P.A. Domoto,
A. Erb, D.C. Ferree, A. Gaus, P.M. Hirst, C.A. Mullins, and J.R. Schupp. 2001. Location
affects performance of Golden Delicious, Jonagold, Empire, and Rome Beauty apple
trees on five rootstocks over ten years in the 1990 NC-140 cultivar-rootstock trial. J.
Amer. Pom. Soc. 55:138–145
My understanding is the virus Corvallis had was overstated and was quickly corrected. I was extremely relieved by the way they handled the issue and the promptness in resolving the problem. This last year the scions I received from them were exceptional. I’m considering making my order soon for this year. We are very fortunate to have this program available.
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