This article will aim to answer many of the important questions asked by disinfectant users over the years and I hope that it may be of benefit. I have specifically mentioned our own product Sporekill as a disinfectant example where there is an important advantage point.
“Cooking Out” is always the first line of defence wherever possible.
Disinfection is vital if you don’t cook out, but still very important even if you do because the floors for example do not reach much higher than 35°C, so most pathogens can still survive in this area. Fortunately, Sporekill is particularly good in this area; but more about that later.
The key to controlling mushroom diseases is always to look for the source of the problem, not try to ‘Band Aid’ the symptoms. For this reason, I am focussing this document on the emptying and filling stages.
What should be my procedure when I empty a room?
Before starting close down the inlet fans in adjacent rooms.
If not cooking out, wet down the surface of the casing, preferably the night before emptying with water, or better still with 2% solution of Sporekill in a large volume of water. This stops spores from casing zone spreading so much as it breaks up over the emptying winch; due to its ‘sticky soap like’ nature.
Less spores around the farm to start with means less spores to infect new rooms …its all a numbers game!
Once empty, get compost off site as quick as possible. Ensure floors are wetted down with disinfectant before scraping and brushing up fallen debris, so you are not raising dust (especially important when you are not cooking out).
Wash down all surfaces with water with high volume spray or pressure washer.
Once surfaces are clean, we recommend always using a 2-3% solution of sodium hypochlorite (bleach) for initial disinfection and for restoring floor colour. It will allow you detect floor hygiene issues more easily. It is also very low cost and because your surfaces are now cleaner, your disinfectant can be used sparingly and effectively.
Outside wash down with water, making sure drains are clear taking away waste water and then disinfect with hypochlorite or Sporekill which has minimal effect on outside environment.
Also clean down forklifts and machinery associated with filling operations with plenty of low pressure water making sure no debris is left trapped behind box sections that can reinfect the next time you use. When clean apply disinfectant at 1-2%.
The effect of hypochlorite is ‘short and sweet’ which is why you must use a disinfectant for residual protection. Sporekill has the additional benefit in this regards, because it forms a protective film over the surfaces trapping any remaining debris or spores etc that may be around or more importantly that settles after the filling process.
The disinfectant (Sporekill), should be applied a couple of hours after the hypochlorite bleaching while surfaces are wet so that it spreads easily and ‘films’ into all the nooks and crannies.
When filling a room, get the job done as quickly as possible with minimum of ‘breaks’, so you can get the doors closed from outside contaminants. Re disinfect all the machinery again prior to next use with Sporekill which will be kinder to machinery.
Once the room is filled and closed, the floors should be washed with low pressure hoses to avoid splash on bottom shelves. Once clean, you can apply Sporekill to the walls and door frames for fly control and additionally to the floor to give you peace of mind that gaps and bumps in concrete are filled with Sporekill film thus preventing physical movement of any trapped spores later. It also has additional benefit that with the floor being wet and slightly sticky, any spores dropping out from air in filling process will get trapped in the soapy matrix stopping further movement by subsequent footfall and equipment moving in the growing room.
When you do all these points above, it allows you to use your disinfectant more sparingly and effectively at 1-2% instead of 2-3%, this will save you a lot of money (50% of your costs). NOTE if you have a lot of disease pressure, then we would do the above regime but also keep rate of disinfectant high as well, until everything is under control.
Using a good quality specialised mushroom disinfectant like Sporekill in the right way is actually in reality a very low cost at around US$10 for a room, which is pretty small in the big picture of things! It is much easier and infinitely cheaper to control disease by getting good clean start in the room. We all know it does not take long when growing mushrooms for disease levels to grow rapidly resulting in a financial loss due to lost production kgs and diseased/spotted mushrooms.
With increased disease resistance to fungicides, it is doubly important that we focus on better disinfection as well physical aspects such as properly sealed doors.
It is very flexible in many aspects of hygiene (see below) making it a very economical tool for mushroom growers everywhere.