Tanzanian farmers take up mushroom cultivation

In many parts of Africa, edible fungi are an important food source but in the Hai district of northeast Tanzania, many community members have traditionally perceived mushrooms as poisonous. Despite the successful introduction of oyster mushrooms in neighbouring countries, the crop, until a few years ago, was also considered an expensive luxury food for urban consumers, and not of use to resource poor households.

And yet, despite these initial challenges, a successful project initiated in May 2005, led by the Horticultural Research Institute Tengeru (Horti-Tengeru) and supported by FARM-Africa's Maendeleo Agricultural Technology Fund (MATF), has resulted in almost 300 Hai farmers adopting oyster mushroom production in their homes.

The Kilimanjaro highlands were once a thriving banana and coffee growing region. But with falling world market prices for coffee and unreliable rain in the lowlands, farmers have struggled to earn an income and produce enough food. Households have become poorer and malnutrition amongst children has increased.

However, Hai farmers became gradually convinced of the value of cultivating and consuming oyster mushrooms after attending training and a series of cooking demonstrations held by Horti-Tengeru during 2005. The farmers use crop residues, such as rice and millet straw, banana leaves and maize husks as substrate, which are pasteurised with steam before being mixed with mushroom spawn, the culture required to grow the fungi.

Oyster mushrooms, Pleurotus ostreatus, so called because of their resemblance to the scalloped mollusc, have virtually no stalk and grow in the wild in layers on dead deciduous wood in temperate regions. However, the mushrooms can also be cultivated relatively easily on a variety of substrates and, in recent years, have become increasingly popular as interest in their culinary, nutritional and health benefits have become more widely known.

Plastic bags are used to hold the inoculated substrate, which are suspended from ceilings or placed on racks in dark humid sheds made from local materials. The production cycle takes about 6-12 weeks, and the crop can be cultivated year-round.

The benefits of growing and selling mushrooms have enabled farmers to buy livestock (chickens and goats), pay school fees and household goods, and a number have invested in expanding their mushroom production. The benefits have included improved nutrition, as consumption of animal protein is low, even among those with livestock. Protein-rich oyster mushrooms provide an affordable alternative.

By mid 2006, one year after the introduction of the crop, growers were selling their mushrooms to local informal markets but also to hotels and supermarkets in Arusha and Moshi. By October 2006, Shoprite in Arusha had agreed to buy fresh and dried mushrooms for 3,000 Tanzanian shillings (US$ 2.5) per kg, and now buys 30 kg of fresh mushrooms a week.

Demand for oyster mushrooms in Hai and neighbouring districts currently exceeds supply, indicating potential for further growth. To maintain demand, mushroom quality, good packaging and consistent production will have to be sustained.

New Agriculturalist