Managing the risk of transferring particular plant diseases (pathogens) through irrigation water sourced from surface storage has been an ongoing field of investigation. It is a known problem, disease organisms in water, and there are a range of solutions offered by various products and systems with various results to the effectiveness on the plant diseases.

Most nursery operators would define an efficient irrigation system as one that waters their plants evenly, with a minimum of hand watering being required. The nursery industry has developed benchmarks that define an efficient irrigation system based on a standard test, allowing systems to be compared against the benchmarks.

Biofilms can create many problems in production nurseries including, reducing flow in irrigation pipes, blocking emitters, harbouring plant diseases and producing slimy surfaces. While attempts can be made to eradicate biofilm by the treatment of pipes and surfaces, there are a number of features of biofilms that make it difficult to entirely remove these organisms from a system. It’s important to remember that biofilm control must be done continuously, not intermittently, and that plants mustn’t be damaged or killed in the process.

Onsite visits regularly reveal irrigation installations that do not meet nursery industry Best Management Practice (BMP) benchmarks. Irrigation supply outlets are extremely competent in the design, supply and installation of pumping and distribution systems for irrigation, but many have little experience in designing irrigation systems that meet the requirements of modern production nurseries.

Technology advancements and deterioration of components mean that an irrigation system can’t be installed and expected to operate to industry best practice for the next 20 years. What can be done is to
constantly monitor all facets of the system, and apply maintenance programmes to ensure it remains at the cutting edge.