STUDIES ON DISEASES OF BAMBOOS AND NURSERY MANAGEMENT OF RHIZOCTONIA WEB BLIGI-IT IN KERALA THESIS Submitted in partial fulfilment ofthe requirement for the degree of DOCTOR OF PHILOSOPHY of the Cochin University of Science & Technology By MOHANAN CHORAN M.Sc. Division of Forest Pathology Kerala Forest Research Institute Peechi 680 653 Kerala, India MAY 1994 DECLARATION I hereby declare that this thesis entitled STUDIES ON DISEASES OF BAMBOOS AND NURSERY MANAGEMENT OF RHIZOCTONIA WEB BLIGHT IN KERALA has not previously formed the basis of the award of any degree, diploma, associateship, fellowship or other similar titles or recognition. _/A A///>’/79 Peechi 680 653 MOHANAN CHORAN May 1994 Dr. Jyoti K. Sllurma Division ofForest Pathology Scientist-in-Charge Kerala Forest Research Institute Peechi 680 653 Kerala, India CERTIFICATE This is to certify that the thesis entitled STUDIES ON DISEASES OF BAMBOOS AND NURSERY MANAGEMENT OF RHIZOCTONIA WEB BLIGHT IN KERALA embodies the results oforiginal research work carried out by Mr. Mohanan Choran, under my guidance and supervision. I further certify that no part of this thesis has previously formed the basis of the award of any degree, diploma, associateship, fellowship or other similar titles of this or other University or Society. Peechi 680 653 JYOTI K.4%/W SHARMA May I994 ACKNOWLEDGEMENTS I am gratefully indebted to Dr. J.K. Sliarma, Scientist-in-Charge, Division ofForest Pathology, Kerala Forest Research Institute, Peechi for suggesting this research topic and for his valuable guidance, constant encouragement and supervision throughout the course ofthis investigation. I express my deep felt gratitude to Dr. C.T.S. Nair, former Director, KFRI for permitting me to register as part-time scholar in Cochin University ofScience and Technology and Dr. K.S.S. Nair, fonner Director and presently Scientist-in-Charge, Division ofEntomology for his keen interest in the progress ofthis study and Dr. S. Chand Basha, IFS, present Director for his valuable suggestions and constant encouragement during the course of this study I gratefully acknowledge for the financial assistance extended by International Development Research Centre, Canada (IDRC) for a part of this investigation. My sincere thanks are also due to Dr. C.B. Sastry, Senior Programme Officer, IDRC for his keen interest in this study and support. Thanks are also due to Dr. R. Gnanaharan, Project Coordinator (Bamboo - lndia, Phase II), KFRI, for encouragement. lam grateful to Dr. K. Jayaranian, Scientist-in-Charge, Statistics Division, KFRI, for his valuable advice in statistical analyses, critically going through the relevant part ofthe drafi, and also for the valuable suggestions for improving the text. My sincere thanks are also due to Mr. V. Sreekumar, Statistics Division for the help rendered in statistical analyses ofthe data and also for preparing the HG diagrams. I am thankful to Prof.(Dr.) K.M. Leelavathy, Mycology and Pathology Research laboratory, Calicut University, Prof.(Dr.) W. Liese, Chairman, Wood Biology Laboratory, University of I-Iamburgh, Germany, Dr. E.R. Boa, Natural Resources Institute, Chatham, U.K., Prof. (Dr.) Zhu, X.Q., Nanjing Forestry University, China, for providing valuable literature on bamboos and their keen interest in the progress of the study. My sincere thanks are also due to Dr. Akira Ogoshi, Hokkaido University, Japan, for kindly providing the authentic tester isolates ofRI1iz0cl0nia solani, Prof. (Dr). Jeyarajan, Biocontrol Laboratory, Tamil Nadu Agricultural University, Coimbatore for kindly supplying the isolates of Trichodcrma spp. used in the screening trial, Dr. J.J. Solomon, Principal Scientist, Mycoplasma Research Laboratory, CPCRI, Kayamkulam, for the transmission electron microscopy of the little leaf diseased bamboo tissues and for identifying the etiology. I express my sincere thanks to Drs. B.C. Sutton, E. Punithalingam, A. Sivanesan, C. Booth, P.M. Kirk, J. David, M.A..l. Williams, D. Brayford, J.E.M. Mordue, P.F. Carillon, C. Hall, D.W. Minter, International Mycological Institute (IMI), Kew, England, for identification/confirmation ofvarious fungal cultures and herbarium specimens and also for their valuable explanations on specific queries. 1 gratefully acknowledge the cooperation and generous help received from the Field staff ofthe Kerala Forest Department in conducting field studies. My sincere thanks are also due to my friends and colleagues at KFRI, especially in the Forest Pathology and Entomology Divisions for their generous help throughout the study. I gratefully acknowledge Dr. K.V. Sankaran, Scientist, Division ofForest Pathology and Dr. V.V. Sudheendrakumar, Scientist, Division ofEntomology for going through the drafi text and for valuable suggestions for improving the text. I also express my sincere thanks to Dr. M.l. Mohamed Ali, Mrs. Maria Florence and Dr. M. Balasundaran, Scientists, Division of Forest Pathology, for their generous help during the course ofthis investigation. I also wish to thank Mr. M.C.K. Nair, for the help rendered in word processing the manuscript, Mr. M. Pradeepkumar for the cartography and Mr. Subhash Kuriakose for the photography. /(1 .J_f::"_z/ MOHANAN CHORAN CONTENTS Acknowledgements ipage I. INTRODUCTION 1 2. REVIEW OF LITERATURE 9 3. MATERIALS AND METHODS 33 ManagementDisease of Rhizoctonia Survey web blight 33 49 4.Disease RESULTS AND Survey DISCUSSION 67 67 DiseasesBamboo in bamboo nurseries nurseries 67 69 Bamboo plantations and natural stands 106 Disease recorded exclusively in plantations 108 Diseases recorded exclusively in natural stands 1 l2 Diseases recorded bothinplantations and natural stands 126 Management of Rhizoctonia web blight 190 AnastomosisLaboratory grouping of R.trials solani isolates 190 190 Cultural characters, growth and relative virulence 194 Utilization of carbon and nitrogen sources by R. solani isolates 199 Screening of antagonistic organisms against R. solani isolates 207 InNursery vilru evaluation of fungicides trials against R. solcmi 225 isolates 213 CulturalExperimental seedbedcontrol nursery ofweb and the microclimateblight 232 226 Biological control ofweb blight 245 Chemical control of web blight 249 6.5. GENERAL SUMMARY DISCUSSION 275 261 7. LITERATURE CITED 289 INTRODUCTION 1. INTRODUCTION Bamboos are fast growing versatile plants of nultiple end uses. For centuries, bamboos have been closely related to agriculture, cottage industries, arts, culture and day to day life of more than half of the world population. 'I‘heir plethora of essential uses have led to the use of the terns such as ‘poor man's timber‘, ‘green gold‘, ‘the cradle to coffin ti11ber', etc. Until recent past, bamboos were categorized as ‘minor forest produce‘ or treated even as weeds, because the other wood resources in the forest and their supply were plentiful. With the alarming shrinkage of forest resources, as well as restrictions on logging from natural stands the etphasis is being placed on raising fast growing nultipurpose trees incluiing banboos. Recently, bantnos have been classified as ‘non-timber vnody resources‘ and they have now gained international recognition and priority in contrast to their previous categorization as ‘minor forest produce. This elevated status attained is mainly due to their versatility, adaptability to different eco—climatic conditions and myriads of end U583. Banboos belonging to Banbusoideae of Gramineae consist of about 1250 species and 75 genera (Soderstrom and Ellis, 1988). Some are uoody giants of 20 to 30 m in height and 15 to 20 an dia whereas others are small senilignified plants; about 110 species belonging to 25 genera are herbaceous (Hsiung,1983,1991). Banboos, perennial woody grasses of extremely gregarious habits, have aerial stats called culms and underground stem Imown as rhizcme. Full sized culms are produced after 4 to 12 years depending on the species, and edaphic and microclimatic conditions . The duration of vegetative growth and the incidence of flowering in bamboos vary among species. Flowering in most bamboos, which is only once in lifetime, is either sporadic or gregarious. Most bamboo species have a more or less sharply defined flowering cycle of roughly 1,3,7,11,15,30,48,60 or 120 years at the end of which all the plants of the same seed origin flower gregariously. Gregarious flowering is followed by the death of clumps. Though, majority of bamboos flower at long intervals of 25 to 60 years, annual flowering takes place in species like Indocalarus wightianus (Nees) Nakai (= Arundinaria wightiana Nees), Bambusa atra Lindl., etc. (Tiwari, 1991) and the plant does not die after flowering. There are species like Dendrocalanus hamiltonii Nees, Gigantochloa spp., Oxytenanthera spp., etc. which flower at irregular intervals. QI. DISI‘RIBU'l'I(N It is estimated that about 21 million hectares of the earth is covered by bamboo forests. They are widely distributed through the tropical to tenperate zones and from sea level to alpine elevation (3000-4000 In) . Banboos are cormonly distributed at low elevations in the tropics and subtropics of Asia, America, Africa and Australia, where they grow either naturally in mixed forests or in plantations; Europe has no indigenous banboo. Geographically, banboo distribution can be divided into three major regions: Asia-Pacific, America and Africa (Fig.1). The Asia­ Pacific bamboo region is the largest which possesses more than 800 species and varieties of bamboos belonging to 45 genera and spread out in about 18 million hectares. In India, bamboos