Even if the growing room climate is ideal, problems with evaporation still regularly occur. As evaporation is based on the difference in moisture between inlet air and exhaust air, not just the absolute humidity of the growing room air, but the absolute humidity of the inlet air and fan position are important.
The recently introduced Heat Humidity and CO2 (HHC) measuring system available from certain climate computer suppliers allow aspects such as evaporation to be readout. The graph in the example shows the evaporation rate (in litres per 100 kilo compost per day) in the final days before the first flush.
By stimulating or reducing evaporation based on this kind of measurement data growers will have more control over the number of pieces the timing and the quality of the mushrooms. Growers will also be able to more accurately decide on the right moment to spray and the amount given (eg based on the amount of evaporation between spraying actions). The first results from practical application show that quality problems in particular such as (brown) discolouration limited shelf life and internal moisture can be better controlled.
Jan Gielen, Specialist climate & energy, C point