Harvesting
Mushrooms are harvested over a 2–4-day period in a 7–10-day cycle called flushes or breaks. When mature mushrooms are picked, an inhibitor to mushroom development is removed and the next flush moves toward maturity. Timing of the breaks or flushes is managed by control of the watering, CO2, and temperatures. The first two flushes account for the majority of the total yield, with the subsequent flushes tapering off to relatively low levels of production. Mushrooms are harvested by hand and are picked at a time before the cap becomes soft, indicating the mushroom is past prime fresh-quality potential (Figure 18). Harvesting rates depend mainly on the amount of crop on the beds and size of the mushrooms. Rates vary from 30 to 80 lbs/hour.
Figure 18. Mushrooms for the fresh market are only harvested by hand.
The stem with some of the “root» attached is trimmed before
the mushroom is placed in a market container.
Some consumers seem to prefer closed, tight mushrooms, while others prefer stronger-flavored, more mature, open-cap mushrooms. Mushroom maturity is evaluated by how open the veil is, not by its size. Mature mushrooms are both large and small, although both farmers and consumers favor medium to large mushrooms. Growers harvest just three to four breaks per crop—a shorter harvesting time allows more crops to be produced in a year and helps to prevent disease and insect problems.
Diseased, malformed, and fly-damaged mushrooms are considered second-grade and are discarded. Diseased mushrooms should not be touched. Diseased tissue should be treated with registered chemicals, biopesticides, or common disinfectant materials such as salt or alcohol.
While mushroom yields vary, the average yield for the United States in 2001 was about 5.75 lbs/sq ft. With improving technology, such as airhandling systems, heavier compost dry weights, supplementation, and improved strains, growers have achieved yields higher than 8.0 lbs./sq.ft. However, these high yields are only achieved on farms that are properly equipped and have very experienced growers.
3110 view.