Many countries are feeling the effects of depressed prices after Easter. A logical result is that growers try to achieve the maximum yield per square metre. As well as various cultivation methods graze picking can also help. The mushrooms are harvested up to the maximum acceptable diameter and by picking several times a day the yield can be increased by up to 25 kilos per square metre.
But growers often forget that on the first day of harvesting smaller diameter caps must also be picked. The first picking day must be used to thin out mushrooms to give the remaining fruits space to develop into bigger and heavier mushrooms during the rest of the harvesting period.
Effective thinning is done by removing all mushrooms with a diameter of 25 to 35 millimetres from groups. Solitary mushrooms can be left alone. If thinning is not done and only larger mushrooms are picked from day one, the mushrooms will be too weak from about the third day onwards. They will be underweight with a reduced shelf life.
The kilos seen as wasted during the thinning process on the first picking day, will be compensated for after two days of picking – both in weight and in quality.
Henk van Gerwen, AdVisie ‘The mushroom cultivation advisors’