Growers always want to have their flush planning under control. Cultivation is based on this plan; for example blow down takes place on a certain day of the week. After blow down the growing room is inspected several times daily for signs of pinheading.
You often see that after about a week a sudden spurt of relatively advanced mushrooms appears on the surface right from underneath. It's 100% sure that these mushrooms formed before blow down. They can cause a considerable hiccup in the planning because they obstruct the actual first flush and lack the required good quality. If this regularly occurs and in serious enough quantities to disrupt cultivation, it's essential to trace the cause. There are a number of possible culprits (all before the moment of blow down!):
- Sprinkling too late with cold water on mycelium already near the top of the beds.
- Too much fresh air.
- With a main duct: not closing the growing rooms exit doors properly.
- Casing soil too loose on the beds and with too many gaps.
John Peeters, C point