Cercospora leaf spot caused by Cercospora violae, can damage the overall appearance of pansies and reduce their marketability and value. The disease is favored by extended periods of high humidity with nighttime leaf-wetting and daytime drying. The disease can come in through infected seed or weeds of the Viola family. The fungus overwinters in seed, infected crop residues, or in weeds of viola family. A few infected plants can produce large amounts of inoculum causing a lot of plants in the house to be infected.
Another complicated situation in spring is how one handles growth when different species are mixed in the same container.
Plant growth regulator (PGR) recommendations vary from species to species & with plant age but from a practical matter growers need to control plant growth across a wide range of plant species at the same time and as efficiently as possible. In practice, growers face two complicated situations on a regular basis (1) relatively small plantings of many different species and or varieties are in the same house at the same time, and (2) relatively small of plantings at different stages of development are present in the same house at the same time.
During the spring crop production season growers often need to use plant growth regulators (PGRs) for a variety of reasons. Most often the purpose to control plant vigor is during the grow-out stage.
For a number of years I’ve studied the use of organic fertilizers for growing commercial greenhouse crops. To start I chose to evaluate fertilizers that could be mixed and applied using methods familiar to growers using traditional water-soluble or granular slow-release chemical fertilizers.