Browsing by Author "Beena, S"

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Agave Americana - a new host of Phytophthora palmivora (Butler) butler
(Kerala Agricultural University, 1987) Beena, S; Ravi, S; Wilson, K I; Estellitta, S
Characterization and management of ganoderma lucidum inciting basal stem rot of coconut
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2012) Yunus, C; Beena, S
The present study on “ Characterization and management of Ganoderma lucidum inciting basal stem rot of coconut ” was undertaken in the Department of Plant Pathology, College of Horticulture, Vellanikkara during 2010-2012 with an aim to isolate the pathogen associated with the disease and to study the cultural, morphological and pathogenic characters of different isolates of the pathogen, symptomatology of the disease, host range and effective management of the pathogen using bio-control agents, phytoextracts and selected fungicides. Purposive sampling surveys were conducted and the occurrence of basal stem rot disease of coconut was observed through out Kerala. The isolation of pathogen from basidiocarps yielded eight isolates of Ganoderma sp. which produced fruiting body in saw dust- rice bran substrate. The pathogenicity of these isolates was tested and observed yellowing, drying and drooping of leaves of coconut seedlings inoculated with all isolates except the isolate GT- from Trivandrum. Basidiocarp formation was noticed only in one seedling inoculated with the isolate GV from Vellayani and reisolation of pathogen was done from this basidiocarp. Symptomatology of the disease under natural and artificial conditions was studied. Under field condition the typical symptom of BSR disease viz., yellowing and drooping of leaves, stem bleeding and basidiocarp formaton were observed in all surveyed areas but all the typical symptoms of disease were not observed under artificial condition. The cultural characters of all the isolates of pathogen were studied on four media viz., Potato dextrose agar, Czapek’s (DOX) agar, Richard’s agar and Soil extract agar media. All isolates produced white mycelial growth on all media but variations in texture, mycelial type, and colour change of mycelium, exudates production and formation of aberrant fruiting body were observed. PDA was found to be the best medium for the growth of pathogen in which all isolates recorded highest growth rate. The pathogen preferred a temperature range of 30-350C and neutral to acid pH of 5-7 for the growth. Slight variation in growth rate was observed under light and darkness. Basidiocarps showed variations in the morphological characters and were stipitate in all isolates except GC from Chirakkacode and GVe from Vettikkal, semicircular to conical shaped, yellowish red to reddish brown with smooth to waved margin, creamy white to brown pore surface, 4.4 – 12.0 x 2.6- 17.0 cm size, 1-10 mm pore length, 139- 254 x 122 – 190 μm pore diameter and 2-10 mm flesh thickness. Basidiospores were brown, ovate to ellipsoidal, truncated apex, double walled with inter wall pillars separating two walls. The size of these basidiospores showed variation in the range of 4.8-13 x 4.5-7.0μm with a spore index of 1.15-1.7. It was trimitic, with generative hyphae hyaline, thin walled, branched, septate and clamped. Reddish brown pigmented skeletal hyphae and colourless binding hyphae were noticed. Based on these observations the eight isolates of the pathogen were identified as Ganoderma lucidum (Leys) Karst. Regarding the in vitro management of the pathogen, two isolates of T. virens and one isolate of T. viride were isolated from rhizophere soil and were proved equally effective with the reference culture, T. viride and T. harzianum in inhibiting the growth of pathogen. Mycoparasitism and production of non volatile metabolites were found to be the mechanisms exhibited by the selected Trichoderma spp. The bacterial antagonists obtained from rhizosphere soil and the reference culture P. fluorescens recorded less than 50 percent inhibition on the growth except in cases of few isolates of the pathogen. It was observed that the selected bacterial antagonists were not much effective in inhibiting the pathogen compared to fungal antagonists. Among the phytoextracts, Azadirachta indica at 20 per cent concentration was found the most effective and recorded more than 50 percent inhibition on the growth of pathogen over control. It was followed by Musa sp. at 10 per cent concentration. The in vitro evaluation of fungicides showed that flusilazole, hexaconazole and iprobenphos at 0.2 per cent concentration were the most effective and recorded cent per cent inhibition on the growth of all isolates of pathogen. The study on the host range of G. lucidium revealed that the seedlings of arecanut, breadfruit, acacia and jack fruit showed yellowing and drooping of leaves and finally wilting of all the seedlings were observed
Collar rot and wilt of clove seedlings incited by Cylindrocladium camelliae Venkitaramani and Venkata Ram - A aew record from India
(Kerala Agricultural University, 1994) Beena, S; Anita Cherian, K; Varma, A S; James Mathew
Collar rot of Murraya koenigh L. by corticium rolfsii curzi
(Kerala Agricultural University, 1994) Anita Cherian, K; Beena, S; Koshy Abraham
Cylindrocladium leaf blight of Acacia auriculjformis A. cunn
(Kerala Agricultural University, 1996) Koshy Abraham; Beena, S; Anitha Cherian, K; Sally K Mathew
Enhancement of systemic resistance to soil borne pathogens of ginger by enriched spent mushroom substrate of pleurotus sajor-caju
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2017) Remya, J S; Beena, S
Enhancing bio - efficacy of Trichoderma spp. for the management of soil borne fungal pathogens
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2017) Hima, V M; Beena, S
Etiology and management of die back disease of mango grafts in nursery
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2009) Sangeetha, C; Beena, S
Etiology of leaf spot diseases of ivy gourd (Coccinia grandis (L) Voigt) and their management
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2003) Deepa Davis, C; Beena, S
A study on various aspects of leaf spot disease of ivy gourd was conducted at College of Horticulture, Vellanikkara during 2002-2003. Etiological studies revealed that Cercospora cocciniae Munjal, Lall and Chona, Colletotrichum gloeosporioides (Penz.)Sacc, and Alternaria alternata Fr.Keissler were the main pathogens causing different leaf spot diseases of ivy" gourd. Colletotrichum gloeosporiotdes was found as the main pathogen causing spots on fruits of ivy gourd. Among the nineteen ivy gourd genotypes tested eight genotypes were found highly resistant to different leaf spot diseases. For Cercospora and Colletotrichum leaf spots, low temperature, high humidity and high rainfall were found to favour infection, so they were prevalent in rainy season. Alternaria infection was noticed during summer months favouring high temperature, moderate relative humidity and rainfall. From the in vitro evaluation conducted for testing the efficacy of fungicides and botanicals, 0.2 per cent copper oxychloride, copper hydroxide, captan and mancozeb, 10 per cent leaf extract of Lantana and Adathoda, bulb extract of garlic and 0.2 per cent neem oil were selected. The fungal antagonists Trichoderma viride, T. harzianum and the bacterial antagonist, Pseudomonas jluorescens were " also selected for pot culture studies. During the pot culture experiment, copper oxychloride, copper hydroxide(both at 0.2 per cent), garlic (l0 per cent) and neem oil (0.2 per cent) and the antagonists, Trichoderma viride (0.4 per cent) and P. jluorescens (0.2 per cent) were found effeotive against leaf spot diseases and selected for field evaluation. From disease management study conducted in the field, 0.2 per cent copper oxychloride, co~per hydroxide, 10 per cent garlic and 0.4 per cent Trichoderma viride were found equally effective in controlling both leaf and fruit infection in ivy gourd.
Hirsutella Thompson II var. Synnematosa Samson, Mccoy & O'donnell on coconut mite aceria (Eriophyes) guerreronis (Keifer) - a new report from India
(Kerala Agricultural University, 1999) Pathummal Beevi, S; Beena, S; Sukumara Varma, A; Lyla, K R; Maicykutty P Mathew; Nadarajan, L
Interaction between VA mycorrhiza and bradyrhizobium in cowpea
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 1999) Beena, S; Rajendran Pillai, M V
Necrotic streak - A symptom of kokkan disease of banana
(Kerala Agricultural University, 1992) Ravi, S; Vilasini, T N; Beena, S; Abi Cheeran
New bacterial wilt of Coleus Vettiveroides Jacob
(Kerala Agricultural University, 1992) Estelitta, S; Beena, S; Koshy Abraham; Ravi, S; Varadarajan Nair, P
New leaf spot disease of kodampuli (Garcinia cambogia) desr.
(Kerala Agricultural University, 1996) Anita Cherian, K; Beena, S; Koshy Abraham
Parasitism of Hirsutella thompsonii Fischer var. synnematosa Samson, McCoy & O`Donnell on coconut eriophtid mite Aceria guerreronis (Keifer)
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2002) Shabnaz Padiyath; Beena, S
Performance and potential of gramasabhas in crop production in Athiyanoor block of Thiruvananthapuram district
(Department of Agricultural Extension, College of Agriculture, Vellayani, 2002) Beena, S; Sherief, A K
The study entitled 'Performance and potential of gramasabhas in crop production. in Athiyanoor block of Thiruvananthapuram district was undertaken to study the effectiveness, attitude and perception and to identify the constraints as perceived by the farmers, officials and people's representatives regarding the functioning of gramasabhas. The study was conducted in Venganoor, Vizhinjam, Athiyanoor and Kottukal panchayats of Athiyanoor block. A sample of 200 respondents were selected using multistage random sampling technique. Data were collected through well structured and pre-tested interview schedule. Sixty per cent of the farmers, fifty five per cent of the officials and sixty per cent of the people's representatives perceive the gramasabhas as effective in planning and implanting agricultural development programmes. Regarding the attitude towards gramasabhas, 58.43 per cent of the farmers and 87.50 per cent of the people's representatives possessed a very favourable attitude. Among the officials, 65 per cent were favourable towards gramasabhas. Eighty per cent of the people's representatives had very good perception about the functioning of gramasabhas. The study revealed that 57.50 per cent of the officials and 61.67 per cent of the farmers belonged to high group with respect to perception. Majority of the farmers had education upto high school level with farming as the main occupation. Most of the farmers expressed a high level of political orientation, cosmopoliteness, social participation and extension participation. Information source utilisation and orientation of the farmers towards incentives were also found to be high for majority of the respondents. Personal, socio-psychological variables viz., education, political orientation, cosmopoliteness, social participation, information source utilisation, leadership propensity, attitude towards people's plan and orientation towards incentives had shown a positive and significant relationship with effectiveness. Annual income had negatively significant relationship with effectiveness. Education, main occupation, political orientation, social participation, attitude towards people's plan, economic motivation and orientation towards incentives had shown a positive and significant relation with attitude of the farmers towards gramasabhas. Annual income was found to be negatively correlated with attitude. Education, main occupation, political orientation, social participation, attitude towards people's plan, economic motivation and orientation towards incentives had shown a 'positively significant relationship with perception of the farmers about. the functioning of gramasabhas. Annual income had negatively significant relation with perception. Venganoor and Kottukal panchayats differed significantly with respect to leadership propensity. The respondents of Venganoor panchayat had high level of leadership propensity as compared to those in Kottukal panchayat. Venganoor and Kottukal panchayats differed significantly with respect to perceived effectiveness. The respondents in Venganoor panchayat perceived the gramasabhas as highly effective in planning and implementing agricultural development progarammes. There was no significant difference among Venganoor, Vizhinjam, Athiyanoor and Kottukal panchayats with respect to attitude and perception about the gramasabhas. The officials and the people's representatives exhibited non- significant relationship regarding the perceived effectiveness of gramasabhas in planning and implementing agricultural development programmes. . As far as attitude towards gramasabhas is concerned, the officials and the people's representatives differed significantly. It was observed that the people's representatives had a more favourable attitude towards gramasabhas than the officials. Significant difference was observed between the officials and the people's representatives regarding the perception about the functioning of gramasabhas. As compared to officials, people's representatives possessed a better perception about the functioning of gramasabhas. Lack of active group discussions was perceived as the most important constraint by the farmers, officials and people's representatives.
Phenotypic and pathogenic variability of sclerotium rolfsii sacc. infecting fruit crops and ornamentals
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2011) Hajara, P H; Beena, S
Potentiality of endophytic micro organisms in the management of leaf blight disease of amaranth
(Department of Plant Pathology, College of Horticulture,Vellanikkara, 2007) Sai Sree Uppala; Beena, S
A study on “Potentiality of endophytic micro-organisms in the management of leaf blight disease of amaranth” was carried out in the Department of Plant Pathology, College of Horticulture, Vellanikkara, during the year 2006-2007. The pathogen causing the leaf blight of amaranth was isolated from both red and green amaranth types from different locations and all the isolates were found to be same and identified as Rhizoctonia solani Kuhn based on the cultural and morphological characters. Endophytic micro-organisms were isolated from red, green and wild amaranth types, which yielded more of endophytic bacteria than fungi. Based on the nature of growth, 46 bacterial and 17 fungal endophytes were selected for further work. These selected endophytes were tested for their antagonistic effect on the growth of R.solani by dual culture studies under in vitro condition. For comparing the efficiency of endophytes, two standard cultures each of fungal bioagents viz. Trichoderma harzianum (IISR) and T.viride (KAU) and bacterial bioagents viz. P.fluorescens (KAU) and P.fluorescens (TNAU) were also used.Among the 46 endophytic bacteria, six viz. EB-4, EB-20, EB-22, EB-38, EB-43 and EB-45 showed antagonism towards R.solani with per cent inhibition ranging from 44.55 to 57.73. Out of the 17 endophytic fungi tested, only one fungus EF-2 recorded cent per cent inhibition of R.solani. The standard bioagents T. harzianum (IISR), T.viride (KAU), P.fluorescens (TNAU) and P.fluorescens (KAU) also showed antagonism towards R.solani with per cent inhibition of 91.1, 84.4, 57.27 and 57.73 respectively. Thus from the in vitro evaluation, six endophytic bacteria and one endophytic fungus were selected.The cultural, morphological and biochemical characters of selected endophytic bacteria were studied. All isolates were observed as short rods and among them four isolates viz. EB-4, EB-20, EB-38 and EB-43 were found as Gram positive and endospore forming and were identified as Bacillus spp. The other two endophytes viz. EB-22 and EB-45 responded negatively to Gram staining and identified as Pseudomonas spp. Based on the cultural and morphological characters the endophytic fungus EF-2 was identified as Trichoderma harzianum Rifai.A pot culture experiment was conducted to evaluate the efficiency of selected endophytes in managing leaf blight disease, promoting plant growth characters and inducing systemic resistance in amaranth. Their effects were compared with standard cultures of fungal and bacterial bioagents and fungicide, mancozeb. The results revealed that the endophytic bacteria isolated from red amaranth EB-22 and EB-43 were found to be efficient in reducing leaf blight disease severity in amaranth whereas EB-20 , EB-22 and EB-43 showed the ability to promote plant growth characters .The isolates EB-20 and EB-22 recorded maximum peroxidase and polyphenol oxidase activity where as the standard cultures of bioagents viz. T. harzianum (IISR), P.fluorescens (KAU) and P.fluorescens (TNAU) showed high phenylalanine ammonia lyase activity. The uninoculated healthy plants recorded higher peroxidase activity but lower PPO and PAL activity than control.
Standardisation of top working in nutmeg (Myristica fragrans Houtt.)
(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1994) Beena, S; Alice Kurian
The present investigations on “Standardisation of top working in nutmeg (Myristica fragrans Houtt.)” were conducted at the Department of plantation Crops and spices, College of Horticulture, Vellanikkara, Thrissur during 1991-1993. For the purpose of the study nutmeg trees available at state seed Farm, Mannuthy and farmers’ field at Mannuthy and Ettumuna in Thrissur district as well as Neduvannur in Ernakulam district were utilized. The presence of two type of buds on the bud stick could be distinguished by the bud scare at the inner side of the bark for the viable buds and absence of scar and browning in the non- viable buds. Among the difference methods tried, in situ budding on hard trunk proved to be most successful. Forkert method with bud selected from brown bud wood with fallen leaves and the buds inserted by leaving space on all the four sides gave maximum success. In order to achieve a quicker bud burst stumping the plants two months after budding was most effective. Budding on hard trunk could be done with maximum success in three year old plants and July was found to be the best season. Trials on topping of male trees indicated that heading back the tree above the first tier during August was found to be the best with regard to sprout production and reducing the time for sprouting. Forkert budding on new sprouts gave only initial success which failed to sprout even with physical and chemical treatments. Grafting on new sprouts showed least response among the method tried. Successful graft union was obtained during March with scion shoots having mature leaf and full green stem and stock having two months growth. The anatomical studies revealed low callus development and sparse differentiation of vascular tissues in the bud shield, presence of necrotic tissues hindering the formation of callus and the lack of union between old and new callus as the probable reasons for bud failure.
Variability of Alternaria isolates causing leaf blight diseases in cucurbits
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2005) Resmi, A R; Beena, S
Alternaria leaf blight is one of the serious diseases of cucurbits in Kerala. A study on “Variability of Alternaria isolates causing leaf blight diseases in cucurbits” were conducted at College of Horticulture, Vellanikkara during 2004 - 2005 and they include symptomatology, cultural, morphological, physiological and nutritional characters, host range and effect of toxin on disease development and also on the variability if any existing among the different isolates of Alternaria. Isolation of Alternaria from diseased samples of ash gourd, snake gourd, ridge gourd, bottle gourd, bitter gourd, ivy gourd and pumpkin collected from Vellanikkara and Elanad areas of Thrissur district was done in Potato dextrose agar medium and isolation of diseased specimens yielded fungal growth similar to Alternaria sp. and obtained seven isolates from Vellanikkara and six isolates from Elanad. Symptom or infection usually started from leaf margins as small, irregular brown lesions. Later brown lesions enlarged in size with characteristic yellow halo. Variation in symptom expression was noticed only with respect to the presence or absence of concentric zonations. Ash gourd, bitter gourd and ivy gourd produced symptoms with concentric zonations on the infected area. Variation in cultural and morphological characters of different isolates of Alternaria was studied. Alternaria spp. produced thick and velvety colony with brownish grey to dark brown aerial mycelium and the isolates showed variation in colony character only with respect to the presence of concentric zonations in the culture. All isolates sporulated well on Potato dextrose agar medium and spore count ranged from 2.5 to 4.9 x 105 spores ml-1. Ridge gourd isolate from Vellanikkara produced maximum spores and minimum spores were produced by the isolate of ivy gourd from Elanad. Variation in growth rate was observed among different isolates of Alternaria grown on different media. Among the different media tested Potato dextrose agar supported maximum growth of different isolates. All the isolates were found to produce conidiophores and conidia in pure culture. Variations in the size and branching of conidial chain were also noticed and size of conidial chain varies from 2-12. Cultural and morphological characters revealed that Alternaria alternata (Fr.) Keissler and Alternaria tenuissima (Kunze ex Pers.) Wiltshire was the two main species of Alternaria causing leaf blight diseases in various cucurbitaceous vegetables. There was no earlier reports of these species of Alternaria on ash gourd, snake gourd, bottle gourd and pumpkin and hence it is the first report of Alternaria alternata (Fr.) Keissler on ash gourd, snake gourd, bottle gourd and pumpkin and also Alternaria tenuissima (Kunze ex Pers.) Wiltshire on snake gourd as the pathogen of leaf blight diseases from India. Cluster analysis of morphological characteristics revealed a degree of variability among the isolates. The lowest dissimilarity index was noticed between A. alternata isolates of ash gourd and snake gourd of Vellanikkara. A. tenuissima of bitter gourd and ivy gourd from Vellanikkara found more similar in their morphological characters. A. tenuissima of snake gourd and bitter gourd of Elanad area stands separate and the latter showed maximum dissimilarity with other isolates. An in vitro study on the effect of physiological and nutritional characters such as temperature, pH, light, carbon and nitrogen sources on different isolates of Alternaria were carried out and observed that, among the different temperatures tested, 25 to 30oC was found to be the most favourable temperature range for the growth of different Alternaria isolates and the pH levels 6 and 7 supported the growth of most of the isolates. Among the light treatments full light and alternate light and dark were found to be better for the growth, medium containing starch as the carbon source and KNO3 and MgNO3 as nitrogen source supported maximum growth of different isolates of Alternaria. Study on conidial germination revealed that all isolates took three hours for starting germination and 10 h for cent per cent germination. All cells of conidium germinated by producing germ tube which elongated to form hyphae. All isolates of Alternaria species obtained from different cucurbitaceous vegetables from both the locations were found to be compatible with each other when grown together. Histopathological changes brought about by all the isolates of Alternaria were almost similar. Due to infection epidermal cells get destructed and hyphae and conidiophores of the fungus seen emerging through the broken epidermis. Destruction of chloroplast and necrosis and death of complete cells occurred in the final stages. Host range study proved that all the isolates of Alternaria from both the locations produced symptoms on all the cross inoculated cucurbits. They were also found producing symptoms on solanaceous vegetables and other vegetables viz., amaranthus, cowpea and bhindi. From the toxin study, it was found that both the exotoxin and endotoxin were effective in producing symptoms on all cucurbitaceous, solanaceous and other vegetables tested. The exotoxin produced the symptoms first.