Brown FB29

External appearance

FB29 produces a medium to large-sized, solid mushroom of 40 to 70 mm in diameter with a dark brown coloured round cap and thick white stem. This strain produces mushrooms for the fresh market of an extraordinary quality with a long shelf-life.

Growing characteristics

This brown strain prefers not wet, well fermented composts and needs incubation duration of at least 14 days or longer. It is important to have sufficient mycelium on the top of the casing-soil at the moment of fresh-air. The ambient temperature at pinning and cropping should be around 18 oC. Too early watering on pins can be negative but watering on fruit bodies during the flush is favourable. Can be grown well alongside hybrids like F599 in the same room.

Compost and peak heating

FB29 prefers well fermented composts with low moisture contents of between 62% and 65% at spawning. Under composted substrates and ammonia rests at the moment of spawning are negative for this strain.

Spawning and incubation

Spawn rate is 5 to 6 litres per tonne of fresh compost or 8 litres per tonne of pasteurized compost. The first 10 days after spawning the mycelium growth is not very strong but after 12 days it gets more white and strong. The optimal average substrate temperature is 26° C., but compost temperature temporary over 30 oC. has a negative effect with this strain. Incubation duration should be at least 14 days, favourably 17 days.


This strain responds favourable to a moderate delayed release supplementation applied before casing. It improves the quality and yield.


Brown strains are very susceptible for watering mistakes, therefore it is advisable to use a good water holding casing soil with a coarse structure. Too fine casing, results in over- pinning and small mushrooms.

Aeration and pin-setting

Pin-setting is easy with this variety. Because of the not fast mycelium growth of this strain it is necessary to start fresh air not early. Decrease the air temperature in four days to 17 °C. In the case of overlay it might be necessary to knock back the mycelium with halve a litre per m2 . Compost temperature decreases to about 19°C. Keep the Relative Humidity during the first 5 days at 92% or higher, CO2 content varies between 1000 and 2000 ppm depending on the outside climate conditions.


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Click here to download our growing proposal for FB29

Pin growing and cropping

After the first pins have formed, the relative humidity should be reduced to induce evaporation from the casing soil surface. Pins are susceptible for early watering at not drying circumstances. So watering should not commence until pins are large “pea-sized” and should then be continued several times even at picking days. Do start picking the first mushrooms early to make space for the coming fruit bodies because the growth is very fast. If the first flushes are coming too uniform than raise the air temperature at about 6 days after the start of fresh air like the growing proposal shows. Before the first flush the air-temperature is decreased to 16 °C to maintain quality. Do increase the air-temperature CO2 and R.H. at watering at the end of the flush for re- pinning. Heavy watering’s should be avoided on later flushes.

Lots of success with FB29

Feel free to contact us for more information.