Cleaning and disinfecting greenhouses between crops

The best way to avoid diseases being transferred from one crop to the next is to clean and disinfect the greenhouse between crops.

The protected cropping industry in Australia is growing, with more and more producers using greenhouses to grow vegetables and flowers.

One of the benefits of growing under cover is that it’s possible to readily exclude and control pests and diseases. An important pest control point in the cropping cycle is the changeover period between one crop and the next.

Once a crop grown in a greenhouse is finished, it is important to completely clean out the greenhouse in preparation for the next crop. This is the best way to avoid diseases being transferred from one crop to another.

A video on cleaning and disinfecting greenhouses – one of the Protected Cropping Toolkit – gives step-by-step instructions on how to do this.

The videos were developed to support the protected cropping industry as part of a VegNET NSW project in partnership with Hort Innovation, in partnership with Applied Horticultural Research.

How to clean and disinfect a greenhouse

Before you start, lower the greenhouse temperature to provide easier conditions for workers. Also, ventilate the greenhouse, and make sure workers are wearing appropriate PPE when handling chemicals.

• Remove supporting clips and all of the old crop, cutting away the organic material from the support lines and the substrate bags.
• Collect all plant material and move it to an area well away from the greenhouse.
• Remove the drippers from the substrate bags and collect the old bags of substrate.
• Collect remaining fruit or plant material by hand.
• Sweep with a broom or use a blower to remove residual vegetation and loose material.
• Rinse out the rows with clean water.
• Flush and disinfect the irrigation system, removing sensors on the lines when doing this.
• Fill the irrigation lines with a chlorine solution and leave for 12 to 24 hours.
• Thoroughly flush to system with fresh water to remove all traces of chemicals.
• Wash all walls, floors, internal structures and drains with a high-pressure cleaner and detergent, and then disinfect all surfaces. Electronic equipment should be protected during this process because they can be damaged by the chemicals.
• Clean irrigation storage tanks, fertigation systems and filters.

After cleaning and disinfecting

Once fully cleaned, only people who are dressed in appropriate PPE should be allowed to enter the greenhouse.

Once fully cleaned, the greenhouse should be treated as sterile. Only people who are dressed in appropriate PPE should be allowed to enter. New growing media, plant material and clean trolleys should only be placed in the greenhouse after they have been cleaned and disinfected.

Other videos in the Protected Cropping Toolkit series cover greenhouse layout, planning and setup, irrigation, nutrient management and key pests and diseases. The video series can be watched on YouTube.

Links

Protected Cropping Toolkit video series

Protected Cropping Toolkit – Episode 5 – Cleaning & Sanitation

Applied Horticulture Research

VegNET

Hort Innovation