Cannabis Guide - 2022 - 16

DISEASE MANAGEMENT
INFECTED
HEALTHY
and protects it on the surface, " says
Hernandez. " You're not destroying the
viroid. You're just sealing it away for
potential future infection. "
Hydrogen peroxide and peroxyacetic
acid do have some efficacy but are not as
effective as bleach and heat sterilization.
Treat your crop as if every plant
was infected. If you have not tested
your crop, you must assume that
everything is infected, says Hernandez.
Treat everything like you're trying to
stop the spread from plant to plant.
On-site propagation offers the benefit
of being able to control any potential
outside factors.
" Starting from seed is one way to
Hop latent viroid-infected plants may appear smaller than others in the crop and produce fewer
trichomes. Photo: Dark Heart Nursery
INFECTED
HEALTHY
manage virus because seed transmission
of virus or viroid is really only about
10% with hops latent viroid, " says
Hernandez. " If you're producing seeds
from an infected plant, you already
know that you're reducing the virus or
viroid load by 90%. "
Outgrow the virus. Growers can take
fresh cuttings from an infected plant,
root them and try to grow them at a
faster rate to get vegetative growth fast.
" Then they'll take very fresh, very young
cuttings from the plant and [growers]
repeat this process over and over again
with the idea that the newest, youngest
growth has the lowest viroid load, "
says Hernandez.
Growers can either reduce or
" Christmas tree branching " is a possible symptom of plants with hop latent viroid. Dark Heart Nursery,
a cannabis nursery and tissue culture lab, offers online resources to help growers learn more about
HpLVD. Photo: Dark Heart Nursery
unfortunately with hop latent viroid, the
latent part in the name really comes into
play here because plants can be infected
with this viroid and not show any
symptoms at all. But they would still be
capable of transmitting and propagating
this viroid. "
Symptoms tend to show up under
times of stress or as the plant gets
further into the flowering stage as
harvest approaches. HpLVD is also
responsible for phenomena growers are
calling " dudding, " where some plants do
not grow as big as genetically identical
clones that are all around them. Lower
trichome production in these smaller
plants will make them look noticeably
less frosty. Some growers have reported
" Christmas tree branching " as a
symptom, Hernandez notes. This causes
a 90-degree angle where branches meet
the stem rather than an upward angle.
Hernandez recommends the
following preventative controls and
treatment methods for HpLVD.
Sanitation is vital. Any material that's
coming into contact with potentially
infected plants should be aggressively
sterilized. Alcohols should be avoided
when working with HpLVD.
" [Alcohols are] actually a really bad
idea because it precipitates the viroid
16 2022 GUIDE TO CANNABIS PRODUCTION
completely eliminate the viral load
through these successive growing and
cutting cycles. Hernandez stresses the
need to test in order to confirm
that the disease has been eradicated
from your crop.
" Any management practice, any
sort of trying to get your facility to
bounce back from hop latent viroid
infestation, requires access to reliable
testing, " she says.
The most reliable is QPCR
(Quantitative polymerase chain reaction)
testing, according to Hernandez.
Various companies offer this testing as
a lab service or are producing QPCR
machines for purchase that growers can
use on-site. Test strips are a popular
testing method with viruses, but at this
time viroid testing and HpLVD testing
with test strips is not as reliable yet. v

Cannabis Guide - 2022

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