Browsing by Author "Bhavani Devi, S"

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Biology of termitomyces species and standardisation of its cultivation techniques
(Department of Plant Pathology, College of Agriculture, Vellayani, 1989) Sreelatha Nair; Bhavani Devi, S
State wide survey was conducted during the South West and North East monsoon periods in 1984-85 and nine species of Termitomyces were collected and identified from thirty two localities of the State. Among the nine specices, T. heimii, T. clypeatus and T. microcarpus var. Santalensis were the first record for Kerala. Detailed description of the morphological and microscopical characters of the nine species collected were recorded in the data sheet along with the ethiono mycological and gastronomic details. All termitomyces species were commonly consumed by the local people during the seasons and were known by different vernacular names. Observations on the periodicity frequency and intensity of occurrence of the nine species showed that T. microcarpus, T. microcarpus var. santalensis and T. robustus were the most commonly occurring species abundantly distributed throughout the State, irrespective of soil type. Their habit of occurrence also revealed that T. robustus and T. striatus were always seen solitary while all the other species occur gregariously consisting of ten to hundred sporocarps. The results relating to the periodicity of occurrence of different species of Termitomyces indicated a post monsoon maxima for the seven species belonging to subgenus Eutermitomyces and a monsoon maxima for the two species viz. T. microcarpus and T. microcarpus var. santalensis of the subgenus pratermitomyces. Studies conducted to observe the developmental morphology of T. robustus from mycelial stage till maturity revealed that different stages of development can be divided into eight stages viz. spherule, clove bud, primordial elongation, pseudorhizal stage, epigeal button, epigeal egg, epigeal elongation and mature stage. The first four stages of development were hypogeal and took 192 h to attain the 4th stage while the next four epigeal stages took only 96 h to reach the mature stage. Critical observations of the different stages of growth and development of the sporocarp revealed the significance of pseudorhiza and perforatorium in the hypogeal development of the sporocarp. The data relating to the temperature and humidity of the comb of T. clobulus and surrounding the environment showed insignificant variations. A comparative study of the chemical composition of the comb of T. robustus and T. heimii showed little difference in the total moisture content, cellulose, carbon, nitrogen and pH. Isolation of other fungi from the termitaria obtained from different localities revealed the occurrence of 19 species of fungi belonging to 12 genera indicating their possible role in cellulose decomposition in the environment. Among the nineteen species isolated, species of Aspergillus and xylaria were found to be the predominant fungi in the combs. Species belonging to Odontotermis was found to be the most common termite associated with different species of Termitomyces in Kerala. O. obesus was always found to be associated with its fungus mutualist Termitomyces microcarpus. The beetle Amblyopus cincetipinnis was found to be the common pest of Termitomyces. The beetle was found to interest and feed the emerging as well as mature sporocarps and turn them unfit for consumption. Field trials on the effect of soil moisture for the production of sporocarps revealed that the number of sporocarps emerged from the daily irrigated plots were more when compared to the non irrigated plots. Among the eight media tested Rebeeca’s selective medium was found to be the only medium to support scanty mycelial growth of T. robustus. Maximum mycelial growth was observed at 300C. Experiments on the effect of light in mycelial growth of T. robustus showed no significant differences in growth. In vitro studies indicated that cellulose was the best source of carbon followed by maltose and lactose. Maximum protein content was observed in T. heimii when compared to other species. Trials on the suitability of different substrates for spawn production failed to support any mycelial growth of the fungus. Dehydrated sporocarps preserved in sealed polythene covers showed maximum shelf life when compared to other ‘methods of preservation. Though fresh sporocarps could be stored in polythene bags for only 48 h it was possible to extend their shelf life when preserved in brine solution. Blanching and pickling and were the other method of preservation of the sporocarps of Termitomyces tried.
Microflora of cassava chips
(Kerala Agricultural University, 1974) Balagopal, C; Bhavani Devi, S; Balakrishna Pillai, K
Monographic studies on agaricus species of Kerala
(Department of Plant Pathology, College of Agriculture, Vellayani, 2001) Susha S Thara; Bhavani Devi, S
The warm humid climatic conditions and wide diversity in soil types and pattern favoured a luxuriant growth of a wide variety of fungal flora in Kerala. In the present study collections were made during south-west and north-east monsoon periods of 1998-2000 in twenty agro climatic zones of Kerala and forty two species of Agaricus were collected. Among the 42 species collected A. abruptibulbus, A. actinorachis, A. altipes, A. annae, A. arenicolus, A. benesi, A. bernardii, A. bulbosus, A. caroli, A. chloroconius, A. ingrata, A. lividonitidus, A. mediojuscus, A. microflavus, A. micromegethus, A. microrubescens, A. moelleri, A. nivescens, A. ochraceous, A. ochroflavus, A. phaeolepidotus, A. pseudopratensis, A. purpurellus, A. rubicolus, A. rusiophyllus, A. semotus, A. silvicola, A. simulans, A. spissarujosa, A. squamuliferus, A. stadii, A. subperonatus, A. trisulphuratus and A. xantholepis are new reports from Kerala. Among these A. abruptibulbus, A. annae, A. arenicolus, A. benesi, A. bernardii, A. bulbosus, A. caroli, A. chloroconius, A. ingrata, A. lividonitidus, A. mediojuscus, A. microflavus, A. microrubescens, A. moelleri, A. nivescens, A. ochraceous, A. ochroflavus, A. phaeolepidotus, A. purpurel!us, A. rubicolus, A. rusiophyllus, A. simulans, A. spissarujosa, A. stadii and A. subperonatus are first reports from India. A. bulbosus, A. ochraceous, A. ochroflavus, A. microflavus, A. microrubescens, A. rubicolus and A. spissarujosa are the new reports during the study. 'f. Most of the collections were obtained during May-June and September- October months coinciding with the early south-west and north-east monsoon periods. The species of the Genus Agaricus preferred laterite soils. Growth of Agaricus species was maximum on complete medium and they preferred a temperature range between 25 and 30DC and pH 6. The results of the studies revealed that light did not play any significant role on growth of the fungi. Among the different carbon sources tried Agaricus spp. preferred glucose, sucrose and fructose. Agaricus spp. exhibited best growth in organic nitrogen compared to inorganic sources of nitrogen. From the study it was observed that wheat gram IS best for the production of spawn of A. bitorquis and maximum growth was obtained when incubated at 25 and 30DC. Spawn run of A. bitorquis was observed in traditional compost and pinheads started appearing within 30-35 days after spawning. The buttons can be harvested on fourth or fifth day after pinhead emergence. 400 g of buttons were obtained from 10 kg compost and this preliminary study showed the possibilities of commercial cultivation of this excellent mushroom species under Kerala condition.
Rhizosphere and non-rhizosphere mycoflora of certain fruit plants in Wynad
(Kerala Agricultural University, 1974) Bhavani Devi, S; Balagopal, C; Indrasenan, G; Varadarajan Nair, P
Studies on the seasonal and diurnal periodicity of Pyricularia oryzae cav. Codidia in the air over rice crop
(Kerala Agricultural University, 1975) Bhavani Devi, S; Balagopal, C; Samraj, J
Air spore over rice crop was studied during three seasons using Hirst's spore trap, A definite pattern of seasonal and diurnal periodicity of occurrence was noted in the case of Pyricularia oryzae. The conidia load of Pyricularia oryzae was highest during November and December while it was comparatively lower during other months. Conidia of Pyricularia orysae showed a night maxima throughout the period of study, the highest load occurring arround 01.00 to 05.00 hours.
Varietal reactions of ginger (Zingiber Officinale R.) towards soft rot caused by Pythium aphanidermatum (edson) fetz
(Kerala Agricultural University, 1974) Balagopal, C; Bhavani Devi, S; Indrasenan, G; Wilson, K I
Artificial inoculation of 22 varieties of ginger in the field with P. aphanidermatum showed that none of the varieties tested was resistant to infection. Only two varieties namely, Nadiya and Narasapattam were moderately resistant. Six varieties were moderately susceptible and twelve varieties were susceptible. The varieties Bajpai and Seirra-leone were highly susceptible to the disease.
Wilt of Vanilla planifolia A
(Kerala Agricultural University, 1974) Balagopal, C; Indrasenan, G; Bhavani Devi, S; Sukumara Varma, A