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. They may harbor the virus. Such a measure may prevent an epidemic in the greenhouse. C Submit suspect plants to a diagnostic clinic for testing, especially for crops where the losses have been greatest. Flower Nasturtium Zinnia Table 2.