Cultivation Of The Oyster Mushroom (Pleurotus sp.) On Wood Substrates In Hawaii

Abstract

Agriculture remains one of the top industries in Hawaii. To strengthen both this industry and Hawaii's overall economic situation, there has been a committed effort to diversify Hawaii's agriculture. As plantation agriculture (sugarcane and pineapple) have declined tremendously, there is a great opportunity for small, diversified agriculture in the state. The U. S. mushroom industry is of substantial value, producing over $889 million dollars of fresh mushrooms in the 2002 - 2003 season (USDA 2003). However, there are very few producers of edible mushrooms in Hawaii. Substrate is a key component in mushroom cultivation. First, the substrate must be suitable for the growth and fruiting of the fungus. Second, the substrate should be available locally in sustainable quantities and at low cost. Climate is another factor in successful mushroom cultivation. The majority of mushroom operations in the United States are indoor operations, which allow for precise climate control. Such operations are generally extremely expensive to establish and operate (Shen et al. 2004). High investment costs can be prohibitive to many farmers, especially small farmers or those interested in producing mushrooms as an additional crop. Outdoor cultivation methods, used primarily in China and many other countries, are far less costly but produce relatively lower yields (Shen et al. 2004). In the end, production must be economically feasible for farmers in Hawaii. Significance: With agriculture as one of Hawaii's major industries, the availability of substrate for mushroom cultivation is promising. Many of the common edible mushrooms can be grown on plant derived materials such as wood, straw and various agricultural wastes. On the Island of Hawaii, a great deal of former sugarcane land has been shifted to timber forests. Approximately 11,740 hectares of land on the Big Island have or will be planted using Eucalyptus grandis for short rotation forests and Acacia koa for long rotation (Martin et al. 2001). There is a definite potential for thinned trees to serve as a local and sustainable source of substrate for mushroom cultivation in Hawaii. There are also a number of fast growing tree species that have been introduced to the islands for various reasons. Whether they are growing wild or intentionally farmed, wood from rapidly growing trees is a potential substrate. The tropical climate of Hawaii, the east coast of the Big Island in particular, provides a wet, humid environment with an average precipitation rate of 3,404 mm annually (NOAA 2004). It also offers a long growing season, uninterrupted by a harsh winter season. With natural environmental conditions conducive to mushrooms, outdoor cultivation may be a feasible option in Hawaii.