Poster Boy! - David Seaby in conversation about the posters at the 2001 conference!

The All Ireland Mushroom Conference 16/10/2003 at the Hillgrove Hotel in Monaghan has already received good photographic coverage and a broad outline of events has been presented. I’m going to try and be more specific in this and one or two other articles in the next few months.

The fluid attractions at the Trade Show meant that some of the growers who attended missed the technical papers and I saw virtually none of them venture round the poster display.

One of the reasons I never got to sample the joys of the Trade Show is that I spent literally hours trying to absorb what new mushroom growing information was on offer in the posters and in the four papers presented.

The fact that the posters took far too long to get round was one of the reasons why I missed all the refreshments! This could be part of the reason why I’m going to give the posters some stick? However I wish to be ‘cruel to be kind’ and I shall summarise their messages as best I can.

The posters

These actually contain much more information than is available in the formal papers. However, even as a retired DARD scientist I found the going very tough. I only saw one poster that really pleased me. It was by Stephen Jess and Jack Bingham. It was beautifully illustrated with colour photographs and the message was clear and simple, i.e. mushroom flies may one day be controlled by predatory mites as well as by tiny eel worms that attack these flies’ larval stages. A fly ‘maggot’ can be seen being attacked by a ferocious looking mite and another ‘maggot’ can be seen with several tiny eel worms penetrating its breathing pores.

When a series of often complicated experiments have been painstakingly performed, it is often difficult to illustrate the processes involved and the results in a simple manner. However, a poster by definition should give an easily followed summary of achievement. I have four complaints.

1. Initial letters (acronyms) are used to save space in tables but their meanings are seldom fully explained. Most would know that pH is a measure of acidity or alkalinity but what about %M (percentage moisture) or EC/ Ec (electrical conductivity of the water in which a sample of compost or casing has been placed), NIR (near infra red, part of the spectrum between light and heat. A range of different wavelengths of NIR are used to irradiate a sample of compost in a ‘short-cut’ method to help to rapidly determine the proportions of its constituents). I won’t bore you with a long list of mysterious acronyms that I came across, but to illustrate the gap between scientist and grower I found several of the latter thought NIR stood for Northern Ireland Railways! Maybe they were being mischievous.

**I suggest it is only polite to have all acronyms simply explained in a small table at the bottom of a poster. A few posters did this and I was grateful.

2. Some posters had two different but related stories with one set of conclusions. I found this confusing. I suggest it would be better to have a half poster for one story and a half for the other.

3. Some posters had titles that were difficult to understand due to the inclusion of ‘scientific’ jargon.

4. Most posters contained at least several highly technical terms (jargon) and/or far too many of words. One extreme example contained over 3000 words.

Posters were briefly manned (or womanned!) and there was an abstract to help explain the poster in the free booklet that was handed out at registration. However, it was not made crystal clear that each poster had an abstract that would help explain it. A label stuck to the poster saying see page 61 (or whatever) of the booklet would have been helpful.

A more serious complaint is several abstracts contained technical terms that could not be looked up in an ordinary household dictionary. Some abstracts also contained errors and some were not easily understood due to less than concise writing. I have two suggestions.

I think a small prize for the best poster each year should be awarded by a non technical member of the mushroom industry. This would demonstrate industry interest and would hopefully concentrate the minds of the poster creators. I also think a non technical person should be employed to read all the abstracts and weed out technical jargon and point out sentences that are less than clear to the layman.

I was told I would not be popular if I was critical! However last year I was equally critical and it does not seem to have had much effect.

A couple of days work looking at the posters and then reading the abstracts has yielded the following snippets of information that I personally find interesting, I have put these snippets in italics. My comments are not in italics and I may also ramble into other territory.

Compost

It has been discovered by painstaking experiments that the raw materials used to make compost vary in quality and the quality of these ingredients affects the quality of the resultant compost.

The word quality is all embracing, but what does it mean? From the growers’ point of view the main interest is that they are supplied with compost that consistently yields highly, does not get out of control in terms of overheating, does not have weed moulds in it, and most important of all, produces a clean firm white mushroom, one that will be in demand!

However, the growing method used by the grower and the casing chosen are probably equally important in obtaining clean firm white mushrooms.

Beware high bag temperatures and/or high air temperatures or humidity if you want good quality mushrooms. Casing flattened by very slightly compressing it will aid cleanness quality.

In my opinion straw is the major ingredient by far in compost, the poultry litter probably helps provide the organisms that start the breakdown of the straw, the high level of nitrogen (N) in litter is also important in the breakdown process, but there are also bag sources of N available. The wood shavings in poultry litter are probably not easily attacked by mushroom mycelium.

So good straw quality means it has higher amounts of easily available nutrients, even after composting, and these will be available for the mushroom mycelium to digest.

No matter how good straw is on arrival it will tend to break down during the months after harvest, thus the method of storage used is extremely important. Unfortunately, because composters have main suppliers who source their raw materials for them, they have minimal levels of control, geographical location yes but choice between individual crops no. What they do have is some control over storage when straw is on their premises.

The above poster is in a series of three from a team working in laboratories at Newforge Lane in Belfast. The next poster in the series flags the point that a section of DARD has been cooperating with a compost maker of bunker compost to help fine tune this relatively new process of making compost.

The third in the series makes the point that; five years of highly technical painstaking work has shown that compost yields vary widely and part of that yield variation can be related to compost. High and low yielding compost can now be recognised by the manner in which it absorbs or reflects certain wavelengths of near infra red radiation (NIR) and this provides a rapid method of testing. Furthermore NIR can also be used to rapidly predict a compost’s chemical constituents.

So, NIR does not stand for Northern Ireland Railways!

If this method is accepted by the industry it will probably be very useful. At the moment compost quality is kept on track by using four well tried and tested measurements.

Firstly the moisture must be in a certain narrow range, followed in importance by the percentage of nitrogen and then the structure. Results for all three can be obtained within 24 hours.

Despite making a structure measuring device many years ago I have to admit that structure measurement is still somewhat subjective and it appears to have least correlation with yield. However if the compost straw particles are allowed to become too strong there are usually overheating and disease problems.

If on the other hand the straw has gone almost to ‘dust’ the compost will lack activity and yield will probably be low. Furthermore the compost maker will not make an economic amount of compost from a bale of straw. Finally, the ash content is occasionally measured to make sure that there isn’t too much inorganic material in the compost such as minerals, sand or gypsum.

If one NIR analysis can replace all these 4 measures and even give extra information as well, it must be a winner. Results will of course have to be interpreted and then presented in such a way that the composter can immediately, beneficially, start to alter the compost mix and/or the timing.

The next series of four posters were work presented by researchers based at Loughgall. The first dealt with the differences between Bunker and Windrow compost. These two types of compost can be detected as different by various chemical tests. The bunker compost tends to be lower in dry matter, nitrogen and ash also with lower pH and electrical conductivity. The rumour that it has a faster spawn run was not substantiated. Yields and mushroom quality were similar or slightly better with bunker compost.

My comment would be, less ash would mean more useful dry matter. Furthermore because N is less able to ‘escape’ in a bunker (less N floats off as ammonia) it is possible to make compost with less poultry litter. Less litter means a higher proportion of straw hence better ‘quality compost. Bunker compost can be made with high dry matter and N, but commercial experience is that it is so active it causes growing problems such as uncontrollable heat surges and/or over-pinning.

The next four posters dealing with casing, I found particularly interesting, however, I have now run out of time and space, so will give my interpretation of them in my next instalment.