Because INSV is systemic, it may overwinter in perennials in the roots. Unsold perennials remaining in the greenhouse from year to year may come into contact with a wide variety of crops. Occurrence of thrips provides a dangerous link between infected perennials and healthy plants. The role of perennials as reservoirs may become more significant as the perennials industry grows. Count thrips and change cards weekly.
C Keep ornamental bedding and vegetable plants separated within the greenhouse.
C Do not mix bedding plants with cutting-propagated plants. The disease frequently enters the greenhouse via vegetatively propagated plant material. C Do not hang baskets of cutting-propagated crops over seedlings. Young seedlings are highly susceptible. C Eliminate weeds.