Algae
Thursday, 09 March 2006 15:54
Over watering and compacted growing media, especially in newly planted bedding plants and hanging baskets, often leads to the buildup of algae on the surface of the growing media. Train employees on proper watering practices so that the upper surface of your media dries out between watering.
Avoid excessive fertilization, runoff and puddling water on floors, benches, and greenhouse surfaces to discourage algae growth. Proper drainage is needed so that water, especially water containing fertilizer, does not stand on the floor.
A number of different algaecides are commercially available. Read the labels carefully before use. Many algaecides including Green-Shield, GreenClean and Triathlon are only labeled for use on greenhouse surfaces.
ZeroTol, Physan 20, and TerraCyte have broader uses listed on their labels so may be used on both greenhouse surfaces and plants - but read the labels carefully for plant safety use restrictions. For example, Physan 20 is only labeled for use on orchids, roses and African violets. According to the Terracyte label, it states to test a small section of plants at labeled rates for potential phytoxicity before large-scale use. Repeated applications of TerraCyte can also raise the soil pH.
Many growers have reported good results using Selectrocide. Phytotoxicity may occur at concentrations above 20 ppm so the shock treatment to clean irrigation lines needs to be done between crop cycles when the greenhouse is empty of plants. Once the lines have been cleaned, the continuous dose is below the 20 ppm level.
For more information see:
www.griffins.com/tech_service/pdfs/selectrocide_faqs.pdf
Leanne Pundt
