more on Crinum viruses
Mon, 19 Jan 2004 05:53:26 PST

There are two well documented viruses that affect Crinum, and which can cause 
symptoms such as you describe.  Both are similar viruses and both can 
apparently infect Hippeastrum.  

Both viruses come from a group, that is almost invariantly spread by 
mechanical inoculation (e.g., cutting shears) or by insects (e.g., various aphid 
species).  The insects that spread viruses in these groups are usually very 
specific and if the insect is not in your area you will not get insect spread.  

Plant to plant transmission is not known for these two viruses (I think it is 
not known).  So, plants in the same flower bed will not infect each other 
unless the insect vector is present.  You can infect a plants with contaminated 
pruning shears, but leaves touching those of nearby plants should not be a 
problem (probably).  Likewise, the viruses are not known to be seed or pollen 

I don't think it has been determined for sure that the Crinum mosaic 
potyvirus (CMPV) can be insect spread, but I'd bet it is.  Since the insect is not 
known, we can't determine if it occurs in your part of the world.  There is a 
good chance the insect vector for CMPV is not common in your area--there is no 
way to tell right now.    

The Hippeastrum mosaic potyvirus (HMPV) causes similar symptoms on Crinum as 
does  CMPV, and is known to be spread by a few insect species as well as by 
mechanical transmission.  

These two viruses are not typically found in home garden plants, but do 
occur.  They can cause severe problems for the plant, weakening it enough that it 
may not bloom or it may become susceptible to other diseases.  Sometimes they 
cause no symptoms and are quiescent.  There is no cure.  

The best thing to do, if you have plants with the symptoms, is to root up the 
plants and discard them.  If you can't bring yourself to do that, at least be 
very careful with pruning tools.  If you have virus symptoms in your garden, 
never use shears on two different plants (even symptom-free plants) without 
washing them with soap and water.   I would guess that virus particles on yard 
tools will loose infectivity in 3-5 days at temperatures around 70-80 F.  If 
you have the symptoms you may well have the infection, but you cannot be sure.  

Having said all of this, it should be pointed out that most Crinum growing in 
back yards are not virus infested, and you can keep the infection at bay if 
you watch your plants and act as needed.  For sure, if you have new plants that 
are showing symptoms I'd keep them as far away from my established plants as 
possible, or I'd consider tossing them.  It may be that your state 
agricultural university can do a diagnostic test for you, perhaps for a small fee.  

Generally, Crinum viruses will only be expected to cause problems on closely 
related plants (other members of the Amaryllidaceae) and your other garden 
plants will not be affected. 

Link:  Symptoms of CMPV on Crinum sp.…

Link:  Information, HMPV… 


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