Browsing by Author "Ramanujam, B."

Now showing 1 - 15 of 15
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    Chemical control of stem bleeding disease of coconut
    (1993) Ramanujam, B.; Nambiar, K.K.N.; Anil Kumar
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    Comparison of techniques for organic manure production from plantation wastes
    (2007-02-08) Biddappa, C.C.; Palaniswami, C.; Upadhyay, A.K.; Ramanujam, B.
    The studies on organic manure preparation from plantation wastes viz. coir pith, areca wastes and coffee husk revealed that recovery per cent was highest in case of coffee husk followed by areca waste and coir pith. Highest recovery was recorded using chemical technique followed by anaerobic, aerobic and lastly microbial (Pleurotus sajor caju) technique. The C/N ratio was found to be the least in areca waste (7.82) and amongst the methods of composting, it was aerobic method (8.73). The nutritive value (N, P, K, Ca and Mg) of final compost was found to be more than the base material used. The pith - fibre ratio decreased to as low as 3.3 from initial value of 7.3 after composting of coir pith. The microbial load was higher for areca and coffee husk compost over their base materials. The cost of preparation of organic manure was found to be the least in chemical followed by anaerobic technique.
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    Current studies on etiology and management of stem bleeding disease of coconut
    (2007-02-08) Nambiar, K.K.N.; Ramanujam, B.
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    Effect of Gliocladium virens, Trichoderma sp. and organic amendments on the inoculum potential of Thielaviopsis paradoxa in soil.
    (2007-02-08) Ramanujam, B.; Nambiar, K.K.N.; Rohini Iyer
    The efficacy of four antagonistic fungi and two organic amendments in inhibiting the pathogen of coconut stem bleeding disease (T.paradoxa) in soil was studied using pot experiments. Among the nine treatments tested, Gliocladlum virens inoculum @ 10.0g/pot + neem cake (50g/pot) + FYM (500g/pot) showed maximum reduction in T.paradoxa population (50.6%). Trichoderma harzlanum, T. viride and T. hamatum, showed comparatively lesser reductions in T. paradoxa population. (31.3,25.3 and 21.9% respectively). Neem cake + FYM alone (@ 50g & 500g/pot respectively) showed the feast reduction In T. paradoxa population (6.1%). Among the four antagonistic fungi tested, maximum post-treatment populations were observed with T. harzlanum (334.67 and 406.67x104 cfu/g for the doses of 5 and 10g/pot respectively), followed by the populations of G.virens (66.06 and 82.6 x 104cfu/g for the doses of 5 and 10g/pot respectively). Soils amended with neem cake + FYM showed Increased levels of native populations of G. virens (0.0262 x 104 cfu/g) and 7: harzlanum (3.8187 x 104 cfu/g) compared to their populations in the un-amended soils (0.0029 and 0.0921 x 104 cfu/g respectively).
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    Identification of potential antagonistic fungi for the biocontrol of thielaviopsisparadoxa causing stem bleeding disease of coconut
    (2007-02) Ramanujam, B.; Nambiar, K.K.N.; Rohini Iyer
    Thirty two isolates of fungi belonging to 13 species were evaluated for their antagonistic effect on Thielaviopsis paradoxa by dual culture and antibiosis tests. Based on the percentage of inhibition, Gliocladium virens, Trichoderma harzianum, T. viride and T. hamatum were identified as potential antagonists of T. paradoxa. G. virens (Uduma), T. harzianum (Kallangai), T. viride (Calicut) and T. hamatum (Delhi) showed maximum inhibition of T. paradoxa in dual culture and in antibiosis tests. These four antagonists were tested on two other isolates of T. paradoxa (T.p-2 and T.p-3) as well. T. paradoxa lesion development on coconut petioles was inhibited by G. virens, T. harzianum, T. viride and T. hamatum by 69.9,66.9,63.4 and 57.7 per cent, respectively.
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    Investigations on black pod and canker disease of cocoa (Theobroma cacao L.)
    (C.P.C.R.I (RS) Vittal, 1995-12) Chandra Mohanan, R.; Ramanujam, B.; Chowdappa, P.
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    Investigations on leaf spot of arecanut prevalent in north kanara district.
    (Central Plantation Crops Research Institute ,Regional Station ,Vittal, 1987) Ramanujam, B.
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    Management of Stem Bleeding Disease of Coconut with Fungicides and a Biocontrol Agent
    (2007-02) Ramanujam, B.; Nambiar, K.K.N.; Rohini Iyer
    A field trial was conducted in the stem bleeding (a soil borne disease caused by Thielaviopsis paradoxa) affected gardens using either of two systemic fungicides, carbendazim and tridemorph; one biocontroL agent, Gliocladium virens, one sealant viz., coal tar and two organic amendments, necm cake and farm yeard manure in various combinations. Observations after four years of treatment showed the lowest disease index (2.62) and the highest nut yield (59.4 nuts/palm/year) in the palms treated with tridemorph 4% (root feeding and wound dressing) along with coal tar sealing and soil application of G. virens + necm cake + FYM.
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    Mass multiplication of Trichoderma sp. on various agricultural and forest byproducts
    (2004-12) Ramanujam, B.; Nambiar, K.K.N.; Rohini Iyer; Biddappa, C.C.
    Nineteen agricultural and forest byproducts were tested as substrates (single substrates) for mass production of Trichoderma virens, T.harzianum, T.viride, and T. Hamatum, the promising antagonists of the pathogen of coconut stem bleeding disease viz. Thielaviopsis paradoxa. Among these, rice bran supported maximum growth of all antagonists followed by wheat bran and neem cake (703.33. 843.33, 753.67 and 660.0 x 10 cfu/g substrate respectively). Among the ten combination substrates (containing two promising substrates) tested, rice bran + neem cake (1: 1 w/w) showed maximum growths of all antagonists after 15 days of incubation (806.67,926.67,873.33 and 786.67 x 106 cfu/g substrate respectively). Among the six composts tested, coffee husk vermicompost showed maximum growths of all antagonists after 15 days of incubation (563.33,7 16.67,616.67 and 663.33 x 106cfu/g substrate respectively). Based on these studies rice bran + neem cake (1: 1 w/w) was selected as the best substrate for mass production of the four antagonists for soil application in the field trials for the management of stem bleeding disease of coconut.
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    Occurrence of Phytophthora capsici on cocoa in Kerala
    (2007-02) Chowdappa, P.; Chandra Mohanan, R.; Ramanujam, B.
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    Screening Of Coconut Cultivars/Hybrids Against Thielaviopsis Paradoxa (De Seynes) Hohnel,Using Petiole Inoculation Technique
    (1998) Ramanujam, B.; Nambiar, K.K.N.; Ratnambal, M.J.
    The reaction of 26 coconut cultivars comprising 16 talls, 6 dwarfs and 4 hybrids was tested against T. paradoxa, the pathogen of stem bleeding disease of coconut using detached petiole inoculation method. All the cultivars tested were susceptible to T. paradoxa in different degrees. Maximum lesion size was noticed in Malayan Green Dwarf (158.32 cm2) and minimum in Banawali Green Round (52.62 cm2).
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    Studies On Leaf Spot Disease Of Arecanut: Symptoms, Cause And Control
    (1993) Ramanujam, B.; Chandra Mohanan, R.; Nambiar, K.K.N.
    Leaf spot disease of arecanut was severe during S. W. monsoon in several gardens in Uttara Kannada, Dakshina Kannada and Kasaragod districts. Phyllosticta arecae Hohnel and Co lletotrichutn gloeosporioides (Fenz.) Sacc. were found to be the most common pathogens associated with this disease. Pathogenicity of these fungi individually and in combination was established on arecanut seedlings. The frequency of isolation of these two fungi varied from place to place. In vitro fungicidal evaluation against these two pathogenic fungi revealed that Carbendazim (Bavistin, 0.05%), Captafol (Foltaf, 0.2%) and Mancozeb (Dithane M-45, 0.3%) checked the growth of the two fungi completely, while Bordeaux mixture (1%) inhibited 85.7% growth of P. arecae and 81.6% growth of C. gloeosporioides. Field control trails involving these four fungicides were carried out at two locations, viz., Yellapur (Uttara Kannada dist.) and Puttur (Dakshina Kannada dist.) It was observed that monthly sprays of Mancozeb (Dithane M-45, 0.3%), Captafol (Foltaf, 0.2%) and Carbendazim (Bavistin, 0.05%) during June-August were effective in reducing the intensity of leaf spot disease during S.W. monsoon period.
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    Studies On The Virulence Of Different Isolates Of Thielaviopsis Paradoxa On Coconut
    (1996) Ramanujam, B.; Nambiar, K.K.N.
    The virulence of twelve isolates of Thielaviopsls paradoxa, the causal agent of stem bleeding disease of coconut collected from different locations in Kerala, Karnataka and West Bengal, were tested on detached petioles of West Coast Tall (WCT) palms using bore hole method of inoculation. The lesion size recorded after 15 days of incubation at 24 + 2°C varied from 26.8 - 55.55 cm2. Kudlu isolate (Kasargod-I) showed maximum lesion size and the minimum lesion size with Mohitnagar isolate (W. B). In a comparative study on virulence of six isolates on WCT stem, lesion size ranged from 9.72 - 31.4 cm2 after two months of inoculation. Kudlu isolate (Kasargod-I) produced maximum lesion size of 31.4 cm2 while Adoor isolate produced the smallest lesion of 9.72 cm2. The results indicated that Kudlu isolate (Kasargod-I) was the most virulent isolate of T. paradoxa
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    Yield performance of Arecanut (Areca catechu L.) varieties in maidan region of Karnataka
    (2002) Anuradha Sane; Ananda, K.S.; Sampath Kumar, S.N.; Sannamarappa, S.; Ramanujam, B.