Browsing by Author "Kamala Nayar"

Now showing 1 - 8 of 8

Anthracnose of betelvine in Kerala
(Kerala Agricultural University, 1994) Wilson, K I; Balakrishnan, S; Nair, S K; Kamala Nayar
Effect of certain plant protection chemicals on the incidence of VA mycorrhiza in black gram
(Kerala Agricultural University, 1991) Nair, S K; Girija, V K; Kamala Nayar
Evaluation of fluorescent pseudomonads for the management of sheath blight and bacterial blight of rice
(Department of Plant Pathology, College of Agriculture, Vellayani, 2002) Heera, G; Kamala Nayar
Biological control of major foliar diseases of rice in Kerala viz., sheath blight and bacterial blight using fluorescent pseudomonads was studied. Isolates obtained from the phylloplane were observed to be effective In inhibiting the growth of foliar pathogens. Isolate P 11 was most effective In inhibiting the growth of Rhizoctonia solani inciting sheath blight disease whereas growth of bacterial blight pathogen Xanthomonas oryzae pv oryzae . was suppressed by the isolate P33, under in vitro conditions. P 11 and P33 survived well in the inert material talc used as carrier material in the formulation developed, using these isolates. Seed treatment with talc based formulation of each isolate (P 11 and P33) increased the dry weight of root and shoot of rice seedlings of cultivar Jyothi and TN-l 14 days after sowing. The isolates produced almost equal and detectable amounts of IAA in culture supernatant. Greenhouse studies conducted at the College of Agriculture, Vellayani, indicated that a combination of seed treatment (10g kg" seed), seedling root dipping (1 per cent solution), and foliar spray (1 per cent) with the formulation of PI 1 and P33 effectively suppressed sheath blight and bacterial blight disease respectively and also appreciably increased the biomass yield of treated rice plants. Three foliar sprays starting two days prior to inoculation with the pathogen, during the tillering stage of the crop enhanced the efficacy of seedling root dipping with the biocontrol formulation. Isolates P 11 and P33 were tentatively identified as Pseudomonas aeruginosa and Pseudomonas fluorescens biovar 1 respectively.
Integrated management of anthracnose of snake gourd (Trichosanthes cucumerina L.)
(Department of Plant Pathology,College of Agriculture, Vellayani, 2016) Aswani Devi; Kamala Nayar
Integrated management of foliar fungal disease of culinary melon (Cucumis meloL. var. acidulus Naudin)
(Department of Plant Pathology, College of Agriculture, Vellayani, 2016) Narmadhavathy, S; Kamala Nayar
Integrated management of sigatoka leaf spot disease of banana (Musa spp.) using newer fungicides
(Department of plant pathology, College of agriculture, Vellayani, 2013) Dattatray L Shinde; Kamala Nayar
The present study was conducted on “Integrated management of Sigatoka leaf spot disease of banana (Musa spp.) using newer fungicides”. The objectives were to conduct survey for assessing the incidence and intensity of Sigatoka leaf spot disease of banana and to evaluate the efficacy of newer fungicides for management of the disease. Survey was conducted in four locations viz. Uzhamalakal in Nedumangad Taluk (Location I), Pallichal in Neyyatinkara Taluk (Location II) and Vellayani in Thiruvananthapuram Taluk (Locations III and IV; Block D and Block F in Instructional farm, Vellayani) indicated that black Sigatoka was prevalent from 2011 to 2012 in the cultivar Nendran. Disease Incidence was 100 per cent and Disease Severity Index (DSI) were 27.30, 29.86, 29.32 and 26.00 in locations I, II, III and IV respectively. Disease Incidence and Disease Severity Index were mainly influenced by maximum temperature ranging from 260C to 320C and high relative humidity of 90-96 per cent. Symptoms of yellow Sigatoka were more severe during the month of May 2013 when the average maximum temperature and relative humidity recorded 32.40C and 95 per cent respectively. Conidia and conidiophore typical to those of Mycosphaerella fijiensis were observed in the microscopic examination of leaf samples and in the culture. Results of the experiment conducted in farmer’s field (Thiruvananthapuram district) on the integrated management of Sigatoka disease, indicated that Azoxystrobin (0.15 per cent) and Tebuconazole (0.1 per cent) were effective in reducing black Sigatoka with concomitant increase in yield. Effect of Tebuconazole was more persistent than that of Azoxystrobin. Integrating fungicides with soil application of biocontrol agent, Trichoderma, was not beneficial in controlling the severity of black Sigatoka except for Tebuconazole (0.1 per cent). Mean per cent increases in yield for the two effective fungicides Azoxystrobin and Tebuconazole were 18.05 per cent and 24.83 per cent respectively over control.
Management of foliar blight of amaranthus (Amaranthus tricolor L.) caused by rhizoctonia solani kuhn using microbial antagonists
(Department of Plant Pathology, College of Agriculture, Vellayani, 2000) Smitha, K P; Kamala Nayar
The possibility of biological control of foliar blight pathogen of amaranthus Rhizoctonia solani with microbial antagonists was studied. Trichoderma longibrachiatum and a fluorescent Pseudomonas sp., Pl were found to be most effective in inhibiting R. solani in vitro. After mass multiplication the selected antagonists were formulated in an insert carrier material, viz., talc and were tested separately by different methods of application under greenhouse conditions. Soil application followed by foliar spray with one per cent suspension of the formulated product of the microbial antagonists was selected as the best method of delivering the biocontrol agent in checking the disease in vivo. Green house studies conducted indicated that soil application followed by foliar spray with T. longibrachiatum was more effective in suppressing the disease than by either combining the fungal and bacterial antagonists or by applying the bacterial antagonist Pl alone. Further, it was revealed that the abiotic elicitor salicylic acid had no synergistic influence on biocontrol properties of the antagonists. Application of T.longibrachiatum in the soil followed by foliar spray at 15 days interval starting from 25 days after sowing was very effective in controlling the disease in field conditions. There was no appreciable difference in the yield of plants. There was an earlier induction of the enzymes PAL and PO in plants treated with Trichoderma longibrachiatum compared to plants sprayed with mancozeb. Level activity of PO was high in R. solani inoculated plants in the presence of trichoderma longibrachiatum. The content of total phenols in plants treated with T. longibrachiatum was found to be low.
New leaf and flower blight of Anthurium Andreanum Lind
(Kerala Agricultural University, 1997) Naseema, A; Kamala Nayar; Gokulapalan, C