Other control methods. Frequent chlorination is known to interfere with iron nutrition through breakdown of iron chelates. UV light treatment was also shown to provide only partial kills of spores and viruses, and in addition also interferes with iron chelates. The best possibilities for solution treatment at present remain ultra-filtration and heat pasteurisation. Runia has suggested a practical heat pasteurisation scheme for nutrient solutions with heating to 95 for 10 seconds and suggests that such treatment does not interfere with iron or some fungicides in the solutions.
Biological control is still in the early research stage.
In New Zealand Trichoderma is available as Trichopel granules which have been used fairly widely and in some liquid preparations which not been used widely by our clients. Finck-Jensen,D and J.Hockenhull. Goldberg,N.P. and M.E.Stranghellini. Hockenhull,J and D.Funck-Jensen. Kennedy,R and G.F.Pegg.