Hygiene and hygiene protocols in their widest sense are always demanding, emotive and largely site-specific issues. Future alternatives will depend even more extensively upon greater practical imposition of designated routine tasks, as more registered products, especially fungicides and disinfectants are and will potentially be removed from use on farms. Surviving the many challenges to keep upgrading sanitary measures often holds real sensitivities on farms for both growers and their staff. Achievement can be brought about by upgrading the primary aspects of cleaning, waste removal, building integrity, pest exclusion and staff awareness. Specific fundamental refinements can then be selected rationally to raise and modify the overall level of crop health related to any site's overall hygiene protocol, without compromising current measures. Just like health and safety, a culture of ownership and responsibility needs to prevail to ensure better standards universally.
However, the current pandemic has meant there is an unprecedented new level of awareness concerning spread factors which has revealed how effective some simple physical boundaries can be. The use of protective clothing, disposable gloves and the ubiquitous face masks becoming the new norm for everyone everywhere. During a site sanitation breakdown many of the more fundamental aspects can be too easily overlooked whilst a more academic path can emerge due to the immediate impact to farm and crop hygiene. Disease outbreaks can be persistent (Cobweb), irregular (Mycogone), triggered by seasonal vectors (Lecanicillium), weed moulds can be recycled and nourished by improper climate management. Weather conditions can attract pests raising cultural risks to raw material deliveries. We are all aware of the devastating effects, difficulties and cost ramifications that result. So, a candid approach is essential for meaningful resolution going forward.
Realistically how functional and well policed is a farm’s hygiene protocol in practical terms and what value does it deliver on a continuous basis for protective purposes physically? Where are the stress points? Does the current monitoring expose unofficial short cuts such as the movement of contaminated packaging into new crops for example? How much organic waste material gets combined with picking waste during clean-up operations? For example, when the staff cross over can unwittingly become additional vectors of constant recycling of spores, mycelial fragments, and necrotic tissue from mature crops to new crops. Equally, segregating waste skips is as important as preventing different staff groups intermingling. In reality it can be difficult and too costly to achieve the ideal situation but it is an integral element of farm hygiene.
As with a climate control computer, performance is only as good as the information inputted. The critical point being the understanding of the values and settings sought at different stages of growth. The parallel being the buy-in of staff as, if they are not able to understand the importance of why work has to be carried out in a specific manner, it is unlikely that they can fully grasp the impact of inadequate sanitation in its widest sense therefore they become less dedicated to the task in hand. Spores can be sticky or dry so their transmission can be promoted in similar as well as different ways. That is the fundamental point in what can develop into an increasingly complex situation because the increased disease pressure is unseen until it is too late. Rigorous cleaning in conjunction with more astute waste management is the benefit from a raised profile of what may appear tedious and mundane at first sight.
Then it becomes easier to identify neglected weak points that can be bolstered practically. Consider how this can be done more effectively within the bounds of current practice by breaking down what really happens. This involves no additional chemical or sanitary products. Any organic debris is a potential habitat for flies and mites which can be complicated on some farms where other operations take place adjacent to mushroom growing. Such pests do not have to be specific to mushroom growth. It is their movement and ability to transfer mycelial fragments, diseased tissue, dust particles, and spores whilst introducing mites and expanding their presence on site. That is what needs acknowledgement rather than another chemical solution. They are serious vectors worthy of much deeper consideration as to their functionality. How can they be isolated and their habitats removed? The importance of good estate management, drainage, and controlled waste streams can prevent a build-up of unwelcome organic residues. Clearance without interruption is paramount.
The relentless pressure on farms regarding labour availability, recruitment costs and staff retention alongside the endless cost increases make it difficult to raise much enthusiasm to consider further adjustments and increase pressure on existing staff. In all probability, it is to the staff that any change in methods and monitoring will fall. However, re-evaluating risks and expanding know-how to overcome hygiene limitations can result in higher levels of solidarity.
When a more primary approach is undertaken then everyone must be acquainted with logical reasoning to understand how to upgrade the overall strategy on a practical basis. It is not uncommon to come across the view that we are doing all that we can. The essential information needs to not only be provided but reinforced with supporting visual aids, documentation, written codes and where relevant additional languages as is indeed commonplace on many farms. Could the initial training be upgraded, should staff be updated about ongoing issues to solve on a more regular basis? When advances evolve are they passed back to those involved? Historically I found when discussing sensitive hygiene aspects with my own and other farm’s staff that they always raised objective points which were being overlooked. Harvesting teams see all the cropping surfaces, zones most regularly infected and areas of irregular production. Outdoor work crews see all visitors and external movements in combination with how they clean, wash and disinfect yards, working zones and equipment. So where are the pressure points and how can they be exposed to accomplish improved sanitation? The answer is internally with their involvement. As an example, the use of simple coloured plastic (and washable) markers can not only identify infected sectors and prevent spread but can be used to collect valuable information to monitor levels, changes and the effectiveness of controls at all working levels.
A recent project required a hygiene audit but had to be carried out remotely due to health protocols and travel restrictions. I found an impressive, very well managed farm growing quality, profitable yields with a paramount range of industry standard hygiene measures including a crop care programme with a fungicide, UV fly traps and nematode programme. All areas including staff rest rooms and toilets being regularly cleaned and swabbed for monitoring spore type and levels. The entire site and its surroundings also being audited on a regular internal/external basis historically. Growing rooms, services, equipment and outside machinery all being cleaned, disinfected and in a good state of repair. Crops were cooked out and empty rooms were given a shortened additional cook before filling. On paper and in theory there was little else that could be raised or suggested to overcome a persistent but irregular disease incidence. However, we were able to uncover a series of interconnected and unintentional failings.
These faults were all physical shortcomings and associated with the prevailing weather conditions. There was also a significant but irregular and improper storage of recycled packaging. Interestingly there were some previously unrecognised staff movements and mixing that became apparent during room fills. Though staff were supposed to be wearing the correct footwear, gloves and overalls with the provision of disinfectant foot dips this was not consistently adhered to. As a further example, during the operations some of the sweepings were added to the casing conveyor and hand tools, supposedly designated to external tasks only, could be mixed between other areas on the farm. The basic features were exposed by filming operations of how the work was carried out and then compared to how the work was intended to be managed. Simple segregation of pre and post-harvest tools by colour coding is visual, highly effective and supervision is bolstered accordingly. So too is the use of separate skips and colour coding to prevent contamination from picking waste skips.
The prepared, washed and disinfected yards also dried out during filling/casing so depending upon the ambient conditions the infection risks altered. Keeping yards damped down during these operations is essential. This also promotes a good mentality with regard to achieving the aims of hygiene standards and raising alertness to changing weather conditions. When the time came to clean up the pressure washer ‘moved and mixed’ any spores and lighter material around the site to resettle at some point with a further risk to staff, crops, and fresh materials. This is not an exhaustive list but an illustration of how basic features can be easily overlooked. Such situations can become dangerously routing when left unaddressed with real consequence.
Moving beyond common practice the most pertinent adjustment will likely be the loss of a principal fungicide. It has long been globally considered as the foremost barrier applied to the casing layer for protection against the main fungal diseases most especially Lecanicillium. There are other allowable products available and research continues to source a commercial and effective replacement. To date these alternative levels of protection, have not always been as beneficial. Some consideration must continually be given to the widening social media impact tendency to promote food safety ahead of production values, influencing sales trends dramatically. So, this too must be evaluated whilst formulating revised hygiene measures and goals. This is the underlying reason to encourage the primary function of better physical management. Greater recognition of why the on farm practical aspects involved need to evolve and elevate to the forefront any targets to accomplish a more robust profile. Such progress can significantly help to further restrict re-infection routes whilst lowering a farm’s internally contained spore loading. The exclusion and continuous prevention of all infection types associated with mushroom growing and their agents of dispersal have to become more vulnerable to a determined physical methodology.
The work undertaken recently by Helen Grogan and her Teagasc colleagues regarding the ineffectiveness of hand washing with soap proved spore retention for continued transmission. The research project revealed the effectiveness of Alcohol-Based Hand Sanitizers for the eradication of viable conidia of Lecanicillium fungicola (Teagasc/MDPI August 2021). The roll out onto farms provided an immediate impact by significantly reducing one of the principal sources of transferring infectious spores between staff, into new crops, contaminating packaging and around growing units. This has been a fundamental learning point which has been further reinforced and understood in the current climate
I want to avoid a re-examination of actual diseases, chemical types, dosage and timings. These aspects being comprehensively documented, adjusted, researched, readily available and with far greater levels of on farm knowledge. However, to truly understand what it is you are dealing with and implement an effective program of measures, it is essential to study all aspects of actual disease types, their characteristics and differences. Only then can the type and time of infection on a farm be systematically targeted and a more resolute level of control established. Understand who and what are the probable vectors, where the re-infection risk areas are, how accurate the monitoring is of the infection regarding its decline or advance. Then consider, what procedures and methodology needs reviewing. Challenge traditional thoughts, think outside the box and consider your specific situation. How often is it said that we have carried out all measures intended, followed external counselling, reviewed our processes. However, we still cannot contain or prevent these incidences as well as we would like.
Having managed an older block-built site myself which was unsuitable for cooking out, with an endemic hygiene breakdown which could not be solved in a traditional manner. There being other economic and cultural restrictions in conjunction with an urgent need to rebuild following major storm damage. The rooves and buildings being severely compromised. To preserve sales without interruption and a recently imposed chemical free growing regime in place. These unforeseen circumstances challenged me to rethink and explore a more cost effective and practical strategy. First and foremost by targeting the on-site spore load and associated re-infection routes physically.
This did require investing in site maintenance, waste disposal, drainage and the destruction of pest habitats alongside a serious staff retraining programme. Though success was not revealed initially and had to be planned in stages. Ultimately it was one of the best decisions I have taken and allowed the business to enter a new and more profitable era of achievement.
A significant part of this process was by changing to a disinfectant that offered three modes of action: sanitary, biological and physical. For this purpose, I chose the Nutrigain product Sporekill. The resultant barrier trapping infectious microorganisms and liberated spores as the drench dries on the treated surfaces. There was also an additional benefit of continuously creating a deterrent to flies. This was especially useful in managing damaged floors/concrete cracks once cleaned. The advantages of such changes were not limited to hygiene control alone but the staff became more comfortable with a user-friendly product. This helped to build a better overall approach and understanding within the working environment. There was a noticeable change to accept new methods, materials and more pleasant atmosphere to work within. Whilst promoting a more sympathetic mentality as to why and how cleaning routines had to be consistently executed. An often-commented point being that, as the disinfectant did not need to be rinsed off machinery, floors, or shelving before filling/casing saving valuable operational time. A significant reduction to the risk from infectious elements settling on clean equipment and raw materials became apparent. In practical terms doors being closed sooner, and the pre-crop stages commencing more hygienically on an increasing scale of impact.
In practice any site or set of circumstances has to be considered empirically in order to gain a realistic overview to reveal an honest start point. The understanding of theory regarding a chemical (where allowable), cleaning agents and the farms current hygiene protocol can be viewed in a dogmatic form. But to manage hygiene breakdowns systematically, that management must evolve with a high degree of pragmatism. I have endeavoured to indicate how altered criteria can be grasped and encourage others that additional practical advances are attainable in parallel as other allowable resources diminish for whatever reason. The essential element is an open mind, and the ability to keep learning whilst observing and understanding the inter-related cultural demands as crop phases advance.
During my 40 years in this fascinating industry I have worked as a grower/advisor on farms globally. No matter the set-up, scale, growing system, climate or resources, hygiene management has invariably been at the core of sustainable improvements. If you have concerns about infection incidence, general hygiene management, disease levels or indeed any other related issue on your mushroom farm or compost production site, please contact me at mwfirwin00@gmail.com if you would like to discuss your challenges further and how I may be able to help.
