Bamboos form the backbone of the rural economy of many Asian countries. The bamboo resource base in this region is dwindling at a fast pace because of various biotic and abiotic factors, including pests and diseases. Available information on diseases and disorders of bamboos from different countries in Asia is assembled in this manual. A large portion of the information is from China, India, Japan and Taiwan-China, and only a limited number of records are available from other countries.

About 170 species of bamboos belonging to 26 genera are found affected by various diseases and disorders. A total of 440 fungi, three bacteria, two viruses, one phytoplasma (mycoplasma-like organism) and one bacterium-like organism have been reported to be associated with these diseases and disorders. Only a few diseases are identified as serious ones, affecting culm production as well as stand productivity.

In bamboo nurseries, 13 diseases have been recorded from India, the Philippines and Thailand. Similar problems are likely to occur in other bamboo-growing countries in the region. Most of the diseases are common seedling diseases of other forestry species, with the exception of leaf striping and seedling stunting possibly caused by a virus. Among the nursery diseases, web blight caused by Rhizoctonia solani is a potentially serious disease that is widespread. Dasturella divina, which causes leaf rust, and Exserohilum spp. and Bipolaris spp., which cause foliage infection, are the other major diseases.

In the warm-humid tropical climate, an occasional

outbreak of any of these diseases is quite possible in bamboo nurseries. Most nursery diseases can usually be controlled by good nursery management practices or prophylactic fungicidal application.

Diseases that affect the rhizome, roots, culm, foliage, branches and minor branches, inflorescence, and seeds have been reported from bamboo stands. Decay and deterioration of culms in stands and storage, caused by an array of fungi, have also been noticed. Among the diseases that affect bamboos in stands, foliage diseases are most common, and about 220 fungi are known to be associated with such infections. Most of the disease records are earlier reports from China, India, Japan and Taiwan-China; and there is a lack of more recent data on foliage diseases from China and Japan. Most foliage diseases are of minor significance; nonetheless, under conducive microclimates, flare-up of certain foliage diseases -- such as leaf rust, leaf spot and leaf blight -- are often reported. Diseases which are recognized as potentially serious include: culm blight caused by Sarocladium oryzae in village groves in Bangladesh and in the coastal belts of Orissa state, India; rot of emerging and growing culms caused by Fusarium spp.; witches'-broom caused by Balansia spp. in China, India, Japan and Taiwan-China; little leaf disease caused by phytoplasma in the dry tracts of Southern India; culm mosaic caused by bamboo mosaic virus in Taiwan-China; and culm rust caused by Stereostratum corticioides and top blight of Phyllostachys spp. caused by Ceratosphaeria phyllostachydis in China.

Culm blight, culm rust, top blight and culm mosaic are spreading fast in bamboo stands in different countries, and new outbreaks are common, adversely affecting bamboo industries as well as the rural

economy as a whole. Disease management measures in practice in these countries have relied mainly on silvicultural measures and, to a lesser extent, on prophylactic treatment. However, etiology and epidemiology of these diseases are little investigated and control measures often prove inefficient. Hence, a concerted effort is required to develop appropriate measures to check further spread of the disease in stands, as well as to safeguard against the inadvertent introduction of the disease to new areas. Disease management strategies involving both short-term and long-term measures -- including broadening the genetic base of bamboos, and the development and introduction of disease-resistant species/provenances -- have to be made.

Decay and biodeterioration of culms in storage form an important problem. Natural durability of bamboo culms is very low. A large number of decay and staining fungi have been recorded on bamboos under storage in different countries. The severity of decay and deterioration depends on the duration of storage, the bamboo species, and environmental and storage conditions. Any appropriate storage technique devised to minimize the hazards must consider these aspects. Although effective preservative chemicals and treatment techniques for bamboos are available, more emphasis should be given to develop low-cost, easily available preservatives, and economically viable and environmentally friendly treatment methods.