Browsing by Author "Chandra Mohanan, R."
Now showing 1 - 20 of 92
Results Per Page
Sort Options
Item Antagonistic activity of coconut rhizospheric and endophytic Bacillus spp. against Ganoderma applanatum and Thielaviopsis paradoxa(2011) Priya George; Alka Gupta; Murali Gopal; Chandra Mohanan, R.; Litty Thomas; George V. ThomasA screening study was carried out to detect the antagonistic potential of Bacillus spp. against Ganoderma applanatum and Thielaviopsis paradoxa, fungal pathogens of coconut. A total of 327 heat resistant, endospore producing bacilli were isolated from the rhizospheric soil and roots of coconut growing in Kerala, Tamil Nadu, Karnataka, Andhra Pradesh and Maharashtra. All the isolates were tested for antifungal activity against G. applanatum and T. paradoxa by dual cultural technique on nutrient agar medium. The zone of inhibition was measured and percentage of inhibition was calculated. More than 90 % of the rhizospheric and root endophytic isolates were found to effectively inhibit the mycelial growth of G. applanatum, with a maximum inhibition zone of 12 mm and percentage inhibition ranging from 44 to 91. About 86 % of the isolates inhibited the mycelial growth of T. paradoxa, with a maximum inhibition zone of 14 mm and percentage inhibition ranging from 42 to 93. Further tests of potent antagonists revealed that more than one mode of mechanisms like production of chitinase, siderophores, HCN, antibiotics, ammonia, β-1,3- glucanase and salicylic acid may be involved in the antagonistic activities. The results of this study revealed 13 Bacillus spp. having potential for use as biocontrol agents against G. applanatum and T. paradoxa, fungal pathogens of coconut.Item Arecanut bunch waste - A promising substrate for Pleurotus sajor-caju (Fr.) Singer cultivation(2007-02-08) Chandra Mohanan, R.; Madhusudhanan, K.PLEUROTUS SAJOR-CAJU (Fr.) Singer was cultivated on naturally dried arecanut (Areca catechu L.) bunch waste during rainy and summer seasons. The mushroom yield, number of flushes and biological efficiency (BE) varied between the two seasons. The average substrate was 717.7 g (BE 77%) and 524g (BE 56%) during rainy and summer seasons respectively. The time taken to produce first flush as wellas the total cultivation period did not vary much with the seasons.Item Arecanut yellow leaf disease : Varietal reaction(2007-02-08) Ravindran, P.S.; Nampoothiri, K.U.K.; Pillai, R.S.N.; Chandra Mohanan, R.; Mohammed Sayed, A.A.Item Biochemical Variability in Lasiodiplodia theobromae, the Incitant of Fruit rot in Eriophyid Mite Infested Coconut(2009) Venugopal, S.; Chandra Mohanan, R.Item Cacao canker caused by Phytophthora palmivora(2007-02-08) Chandra Mohanan, R.A severe canker on the trunk and branches of Criollo and Forestero cacao varieties, and subsequent dieback of affected plants or branches, were observed in India. Phytophthora palmivora was consistently isolated from the cankered portion. Pathogenicity experiments proved that this fungus is the causal organism of the disease. Symptoms of the disease are described. This is the first report of canker of cacao in i India.Item The Castor capsule borer Dichocrocis punctiferaus Guen. as a pest of cacao in India(2007-02-08) Chandra Mohanan, R.; Harishu Kumar, P.Item Chemical sterilization of areca leaf sheath substrate for the cultivation of Pleurotus sajor-caju (Fr.) Singer(2007-02-08) Chandra Mohanan, R.Chemical sterilization of areca leaf sheath in a solution of formalin + carbendazim for 18 h. was found to be better than steam pasteurization for the cultivation oiPleurotus sajor-caju. The average yield of fresh mushroom was the highest (418 g/bag containing 3.5 kg wet weight of leaf sheath) in the treatment formalin 500 ppm + carbendazim 25 ppm,with a biological efficiency of 49.8 per cent. The average time taken for first flush from the day of spawning was 19 days. The results of the study indicate the possbility of adopting chemical sterilization of areca leaf sheath instead of steam pasteurization of the substrate.Item Cocoa diseases and current strategies for their control(2007-02-08) Chandra Mohanan, R.; Chowdappa, P.Item Cocoa sweating, a promising culture medium for mass production of fungal bioagents(2011) Ambilikutty Amma, P.; Chandra Mohanan, R.Cocoa sweating collected on the first day of fermentation of beans was used for the preparation of culture media. When cocoa sweating as collected from the fermentary was used as liquid medium to grow Trichoderma harzianum and Metarhizium anisopliae, there was no growth. Therefore, growth and sporulation of both the fungi in different dilutions of cocoa sweating were compared with that in potato dextrose broth (PDB) and potato jaggery broth (PJB). Growth and sporulation of both the fungi were the highest in cocoa sweating (CS) diluted with tap water (TW) in the proportion CS: TW 1:4 (CS 1:4). Both the biocontrol agents did not exhibit any difference in growth and sporulation in CS 1:4 and in CS1:4 supplemented with 15 g dextrose and pH adjusted to 6.5. Growth and sporulation of both the fungi in CS1:4, PDB and PJB increased with number of days of incubation and was the highest on 20 th day after inoculation. When 800 ml CS 1:4 was used to grow the biocontrol agents and to prepare talc formulations using 2 kg talc powder, the moisture content was 8 % after 72 h of drying. Shelf life of talc formulations of both the biocontrol agents could be maintained for 5 months with very high colony forming units(CFUs). The CFUs /g of talc formulations of both the fungi stored for 6 months were less than that in the 5th month.Item Confirmation of occurrence of root (wilt) disease of coconut in Dakshina Kannada district of Karnataka state(2005-11) Sasikala, M.; Chandra Mohanan, R.; Prakash, V.R.; Ajith Kumar, R.; Sapna, V.P.; Rajeev, G.Item Cost of production of Pleurotus sajor-caju in Dakshina Kannada dist. of Karnataka State(2007-02-08) Varanasi Krishna Moorthy; Chandra Mohanan, R.Item Crop Diseases: Identification and Management - A Colour handbook: Arecanut(CPCRI Kasaragod, 2000) Gunasekaran, M.; Chandra Mohanan, R.Item Crop Diseases: Identification and Management - A Colour handbook: Coconut(CPCRI, Kasaragod, 2000) Gunasekaran, M.; Chandra Mohanan, R.Item Cultivation of Pleurotus sajor-caju (Fr.) Singer on areca wastes - Standardization of substrate preparation during summer and rainy seasons(2007-02-08) Madhusudhanan, K.; Chandra Mohanan, R.Fallen areca leaves, areca bunch waste and dried arecanut husk are the major byproducts of areca cultivation, which are available in large quantities in the areca growing areas of India. Studies were conducted to standardize the method of pasteurization of these substrates for Pleurotus sajor-caju cultivation during summer and rainy seasons. The average yield of fresh mushrooms obtained in 3 flushes on areca leaf sheath and areca bunch waste was the highest in the treatment formalin 500 ppm+carbendazim 25 ppm in both summer and rainy seasons. The average yield on leaf sheath was 325.7g (BE 40.46%) and 651g (BE 69.75%) and on areca bunch waste it was 524g (BE 56.17%) and 594g (BE 61.53%) during summer and rainy seasons respectively. The yield was highest in the treatment formalin 500ppm + carbendazim 12.5ppm when areca whole leaf (leaf along with sheath) was used as substrate. The cultivation period varied with the seasons. Thus, chemical sterilization technique has been found to be an ideal and suitable method of substrate preparation. The yield obtained on arecanut husk was very poor in all the treatments tried.Item Cushion galls of cocoa in India(2007-02-08) Chandra Mohanan, R.; Subramonian, N.; Balasimha, D.During a survey of cocoa gardens in South India, cushion galls were observed in Trichur District (Kerala State). Based on symptomatology they were identified as fan gall and knob gall. The etiology of these galls are yet to be established. Attempts to transmit these disorders were unsuccessful. In a pod collected from a normal cushion of a fan gall affected tree, only 50 per cent of the beans were normal and healthy. The abnormal beans failed to germinate. Anatomical peculiarities of knob gall and biochemical basis of hyperauxinity in gall tissue were investigated.Item Defoliation and dieback of cacao in India(2007-02-08) Chandra Mohanan, R.Severe defoliation and dieback of cacao were observed in many cacao gardens in India. The symptoms of this disease are described. Calonectria rigidiuscula (Berkeley & Broome) Saccardo was consistently isolated from the leaves and stem. Pathogenicity experiments proved that this fungus is the causal organisms. This is the first report of Jhe occurrence of defoliation and dieback of cacao caused by C. rigidiuscula in India.Item Development of Technology and Popularization of Biological Control Agents for Integrated Management of Coconut Leaf Rot Disease(2011) Srinivasan, N.; Chandra Mohanan, R.; Bharathi, R.; Radhika, N.S.; Shanty IssakCoconut is an important social crop of livelihood concern for millions of small- medium farmers.Leaf rot disease (due to a fungal complex-Colletotrichum gloeosoprioides, Exserohilum rostratum and Fusarium solani as major pathogens), in association with root(wilt),is a major problem of coconut in southern districts of Kerala besides certain districts in Tamil Nadu etc. Central Plantation Crops Research Institute(CPCRI) has evolved biological control teclmology for integrated management of leaf rot to improve the health of disease affected palms.Application of biocontrol agents in the disease affected areas was aimed for creation of widespread awareness on eco-friendly disease management,crop sustenance and in realizing human resource potential. Effective strains of biocontrol agents Bacillus subtilis,Pseudomonas jluorescens and Trichoderma viride-were evolved, their multiplications in media including coconut water standardized and the antagonists processed into bioformulations (totally 2000 Kg. talc formulations evolved distributed/utilized).Coconut gardens and rural groups in various districts of southern Kerala(Thiruvananthapuram, Kollam, Alappuzha,Pathanamthitta,Kottayam,Idukki, Ernakulam and Thrissur), various blocks in Theni district besides specified blocks in Dindigul district of Tamil Nadu could be selected.Through effective contacts with extension developmental agencies, coconut Research & Development (R&D) meetings etc. reached out to rural people and implemented the technology of mass production-use of biological control agents,and knowledge imparted to rural people. Conducted trainings and allied programmes by on-campus trainings (396 beneficiaries), off-campus trainings (1854 beneficiaries), household/field contacts of rural people (689 beneficiaries) and other awareness programmes encompassing lectures, interfaces etc.(661 beneficiaries) and enlightened women, rural people, youths etc. representing various locations (totally 3600 beneficiaries in three years).Field demonstrations of disease management with biological control agents in coconut gardens (55 units) besides clusters-compact gardens(1850 coconut palms) were also done. Also,promotional materials were made available to various stakeholders. An innovative participatory programme implementation approach for technology transfer was the outcome of the work.Creation of widespread awareness, percolation of knowledge on biocontrol agents to women and other rural people could be visualized that would go a long way.Item Diseases of arecanut in India - A review and further considerations(2007-02-08) Koti Reddy, M.; Saraswathy, N.; Chandra Mohanan, R.The major diseases affecting arecanut in India are: koleroga or mahali, anabe, yellow leaf disease, inflorescence die-back, and button shedding. Among the less serious diseases, the bud-rot, bacterial leaf stripe, stem breaking, seedling diseases, and infection of processed arecanuts, occurls at times in serious proportions in some places and cause considerable damage. Over 40 pathogenic and non-pathogenic forms have been recorded in India. The work done on them except the storage infections is reviewed here with suggestions for future lines of work.Item Diseases of cocoa(2007-02-08) Chandra Mohanan, R.Item Effect of Botanicals in Inhibiting Growth and Infection of Lasiodiplodia theobromae, the Causal Organism of Rotting and Immature Nut Fall of Coconut(2010) Venugopal, S.; Chandra Mohanan, R.