INSV (impatiens necrotic spot virus) is a disease with
many faces: it can produce many different kinds of symptoms on many
different herbaceous plants, including the stem cankering shown here
on alstroemeria. Other symptoms typical of INSV include chlorotic mottle,
yellow or brown spots or ringspots, and stunting of the new growth.
If you suspect that a crop may be infected with INSV, send a sample
to your university diagnostic lab, or purchase in-house test kits from
Agdia. In addition to watching for
suspicious virus-like symptoms in your crops, the other keys to INSV
management are to monitor for Western flower thrips year-round, and
to keep the greenhouse weed-free.