Virus in bulbs

Alberto Castillo
Mon, 03 Mar 2003 06:22:36 PST
Dear Mary Sue:
                          You are wrong: not all panic at viruses. You can 
still see remarks like “well, it has virus but I like it anyway” too often. 
Fortunately there is a growing concern and you have growers like Diana, Dirk 
Wallace and Dash Geoghegan that spend lots of time and money in taking every 
precaution to sell healthy material.  With time (and no doubt with more 
valuable collections destroyed by viruses) people will learn that it is a 
poor bargain to keep a diseased incurable plant against the rest of the 
collection. We did not invent virus: it is a terrible occurrence that we can 
encounter during our experience as bulb growers. Right now, before our very 
noses, one of the most fantastic projects of our time, the assembling of a 
huge Canna collection has been put to an end by this. Most of you know about 
the National Collections scheme in England. Well, there was a fabulous 
collection of them being assembled and the owner was very happy to have 
found in France 52 cultivars most of which would prove new introductions (to 
the 140 others he was already growing). BUT, in came the Trojan horse! Among 
those plants from France some had a virus that rapidly spread to other so 
far healthy ones. That virus was masked by the plants’ inherent vigor. When 
the owner noticed  the appearance of uncommon yellow mottling in many plants 
had them tested and it gave bean yellow  mosaic and Canna viruses. As  a 
result 70 cultivars (yes, 70!) had to be destroyed at once and the news were 
that he had discontinued the project altogether. So remember this short tale 
every time something shows symptoms and you decide to keep it. In my 
experience in most cases this is a common plant that sooner or later you 
could replace!
One can never overemphasize the need of a quarantine period . Do maintain 
your newly introduced plants away from your collection for a time (two weeks 
at last). Virus symptoms can be masked (there are symptomless and latent 
viruses) but under periods of serious stress (like when you take a plant 
from its “home” and take it somewhere else) symptoms can appear. They are 
more visible (at times ONLY visible) in new growth so watch for the tips of 
new leaves. If they are uniformly green you have many chances that the plant 
is healthy. If it shows mottling in a different shade of green be very 
worried. If you are not convinced do not let it close to your healthy 
collection. For instance if you live in Halifax, send it to Vancouver for 
                       You are right in that there is so little in the web 
on virus symptoms images. In the Ball Guides there are a few images of 
viruses in Liliums, Agapanthus, Canna and in  a number of dicots.
                        There is a lot of virused material in the trade and 
several nurseries have a few cultivars of Crocosmia that are terribly 
virused. Any comments Dave? In my opinion it was viruses who wiped out all 
those fabulous Crocosmias you mentioned of late.

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