Mushroom scientist Dan Royse is developing better ways for growers to produce exotic mushrooms such as shiitakes and maitakes.

The market for mushrooms seems to be on the rise. Per-capita consumption of fresh Agaricus mushrooms climbs every year and reached 2.17 pounds in 1997. Brown Agaricus varieties, marketed as portobellos and creminis, can be found on many supermarket shelves. Specialty mushrooms such as oyster and shiitake, once used only by adventurous chefs in big-city restaurants, now are found in salad bars, frozen dinners, and many other food products.

Specialty mushrooms account for less than 10 percent of the total amount of mushrooms consumed, but consumption of exotic mushrooms is slowly growing. According to the American Mushroom Institute, more than 46 million pounds of the 1997 mushroom harvest were portobellos and creminis -- about 6 percent of the total crop. Shiitake and oyster varieties tallied 6 million pounds and 2 million pounds respectively. A variety of other exotic mushrooms accounted for 1.3 million pounds.

"The mushroom industry has done a very good job of marketing different kinds of mushrooms, building a niche carefully, and expanding to fill the needs of consumers," says mushroom scientist Dan Royse, whose research into production methods for shiitake and oyster mushrooms helped Pennsylvania producers branch out into specialty markets. "I even see shiitakes used in airline meals."

Popularized by chefs on the West Coast, shiitake, oyster, enoki, and other gourmet mushrooms have found fans across the country. Concurrently, producers in Pennsylvania realized that brown strains of the white Agaricus mushroom offered different flavors for gourmets and, inspired by the emergence of Italian pastas, created the names portobello and cremini to market a previously underused mushroom.

Despite their unusual appearance, maitake mushrooms are marketed throughout Asia, both for their taste and their possible medicinal properties. Penn State scientists are looking for varieties that will grow well under commercial conditions in Pennsylvania.

Royse believes another underutilized mushroom, Grifola frondosa, can be aggressively marketed not only for its exotic taste, but also for medicinal qualities. Known as the maitake (pronounced my-tocky) mushroom, this fungus has proven effective as an antiviral and antitumor agent. The gray-colored mushroom, which is found wild in Europe, Asia, and North America, grows into a leafy mass that resembles a head of lettuce. Produced commercially in Japan since 1981, maitakes are tasty food mushrooms also marketed throughout Asia as medicines in powdered or tablet form. "Western medicine has not thoroughly tested the medicinal properties of maitakes, but their benefits are taken as fact in Asia," Royse says. "Among other properties, maitakes are credited with stimulating the immune system, reducing blood pressure and cholesterol, and aiding in cancer treatments."

Although Royse has found maitakes growing wild on the University Park campus, profitable production practices for growing the mushroom commercially are more elusive. Royse is trying to find a maitake variety that produces consistent crops of high quality mushrooms. To date, he has tested 49 maitake strains taken from across the world, and 23 have grown under production conditions. "Sometimes we just get chunks of tissue that look like something out of science fiction," Royse says. "The idea is to match the right strain of maitake with the right growing mixture to form a production system that can be replicated by commercial growers."

Royse says the financial incentives for producing maitakes, which sell for between $4 and $6 a pound, have Pennsylvania producers eagerly awaiting a viable production system. "Right now there's less labor in growing maitakes and the value is higher," Royse says. "As a production system is developed, quality will go up and the price will come down."