Discussions upon quality issues during a few recent farm visits have prompted the following article. Some growers, over the course of time, have drifted away from their optimum casing to such an extent that it has become impossible to achieve satisfactory quality at the required yields. Having witnessed these changes, although they may have been gradual, I have wondered why I have not commented upon this drift earlier. With fewer growers in the industry, am I becoming too careful not to upset anyone? Has diplomacy prevented me from earlier comment? Whatever, I eventually end up saying “Hang on, we are miles out here!” Coincidentally, a couple of growers have recently made changes to their application equipment. Unfortunately, these changes have further aggravated this casing issue in the extreme.
For what it’s worth, in my opinion, some thoughts:
What do we want from a casing material? It should be capable of holding a lot of water (say be “a quart pot” rather than be a lesser size) and hold on to that water. It will typically be dense and restrict the volume of casing growth and promote strong individual separate stranding. Although dense, it will not be anaerobic, as growth requires oxygen to develop.
If the water is not freely available to the mushroom it will have to work harder and thus be a stronger fruitbody.
If the water is freely available, it is also free to readily evaporate.
I regard casing to act both as a reservoir and a funnel. Expect the majority of water applied to casing to be taken up by the compost below. A “quart pot” that holds on tight to its moisture is a large funnel with a small release hole. Don’t worry about the compost’s ability to suck out the required moisture. It probably takes less than 1 minute in total to apply say 6 Lt. to a sq.m. (via separate waterings during 24 hours). There are however, 1440 minutes available in the day for the compost to absorb any moisture required.
A “lower grade” of casing may be chosen for manageability i.e. for ease of application. This is a compromise. Overworking a low-grade material makes things worse.
If we order a “pint pot” material, it will only be able to hold a maximum of - one pint! If we fluff up this material at application, it will hold even less. It the material has a larger content of brown young peat it will tend to be less dense and provide freely available water. Our funnel is now small with a large exit hole. Try to input significant volumes of water and most will end up on the floor. The proportion absorbed will not be retained for long. We may ask the supplier for a denser material but we might simply receive the same material with water added. This would be more dense as would be the case, if alternatively, we “puddened up” the material during application. Unfortunately, the material would remain, intrinsically, only a pint pot.
On one farm the grower has been modifying ruffler tines and numbers of passes to create better casing growth and subsequent quality. Improvements have been limited because the material received is only a pint pot. He throws water at the casing but to no avail. The casing has dried out halfway through the first flush. Does yours?
Another farm has recently installed a ruffler machine to improve cac mix and enable them to use a heavier casing mix. The material here is applied to the beds by hand. Unfortunately the casing mix was not changed from a very “low grade” material. The extra ruffling then fluffed up and lightened the material further. This resulted in minimal water holding capacity, excess growth, dry casing, excess pins, more mushrooms on the bed than one could wave a stick and premature opening. Coincidentally, another farm did exactly the same (new ruffler, similar material). This resulted in so dry a casing after the first flush that the second flush failed to show up.
Looking at other farms, some obviously have a quality limit caused by their choice of casing grade (and/or by how they manage it).
A few points to consider:
Am I totally satisfied with my quality?
Does casing moisture carry through the first flush? If not, is this due to excess evaporation or more due to the fact there was little there in the first place?
Is my casing reluctant to release its moisture?
Am I using a pint pot or quart pot?
Do I choose a casing grade for ease of application rather than performance?
Am I overworking the material?
Am I using the heaviest material (with the right characteristics) that I can handle? Would it be useful to look at other growers and make comparison?
Some of the above points may seem fairly basic. They may not seem to apply to your farm. Are you sure? I have recently been surprised to suddenly realise how far some growers have drifted downscale with casing. Others have simply accepted their existing finished material as being the ideal whereas it is in fact imposing a quality limit? Perhaps it’s time for a reassessment.
A word of caution if you do make changes: in the current economic climate don’t go overboard, take gradual steps. After all, as one grower once said to me, “There’s a difference between scratching your **** and tearing it all to pieces”.