Browsing by Author "Koshy, P.K."

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    Additional host records of root-knot nematode, Meloidogyne incognita
    (2007) Sundararaju, P.; Sosamma, V.K.; Koshy, P.K.
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    Additional host records of root-knot nematode, Meloidogyne incognita
    (2007-02-08) Sundararaju, P.; Sosamma, V.K.; Koshy, P.K.
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    Additional hosts of the burrowing nematode, Radopholus similis, infesting coconut palm in South India
    (2007-02-08) Sosamma, V.K.; Koshy, P.K.
    The hoel atatua of twenty-four specie from sixteen plant families -was teated gainst RadophoJua acnilla. Adenanthera pavqai. Taaoar indue tedica, Vicia faba. Careya arborea, Lagenaru vulgarta, Cucurbita ptoo. Trichoeaathca anguxoa, Fieus reltgtoaa, and Phoeni* dactyUfera were recorded aa hoeta for R. jrunhis. Except for Cucurbita pepo. all are new boat record* for R, aim ilia.
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    Appraisal of the distribution of coconut root wilt and heavy incidence of the disease in Cumbum Valley of Tamil Nadu
    (2007-02-08) Srinivasan, N.; Koshy, P.K.; Kamalakshi Amma, P.G.; Sasikala, M.; Gunasekaran, M.; Solomon, J.J.
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    Biological control of Meloidogyne incognita on black pepper by Pasteuria penetrans and Paecilomyces lilacinus
    (1997-06) Sosamma, V.K.; Koshy, P.K.
    Root-knot nematode, Meloidogyne incognita causes considerable damage to black pepper (Piper nigrum L.). Efficacy of two known bio-control agents namely Pasteuria penetrans, an endospore forming bacteria and Paecilomyces lilacinus, a parasitic fungus on eggs for the control of M. incognita on black pepper was studied in pots under greenhouse condition. P. Penetrans and P. lilacinus reduced nematode population, root-gall indices and improved the growth of the plants and root mass production significantly. Fifteen per cent reduction was noticed in the vine length of plants inoculated with nematode alone while it was only 8 to 15% in vines treated with either P. lilacinus or P. penetrans or both with nematodes. Number of leaves/nodes produced was maximum in control plants compared to a minimum in nematode inoculated vines. Fresh shoot and root weight were significantly greater in all treatments infested with M. incognita in the presence of one or both the bio-control organisms than M. incognita alone. Among the two biocontrol agents studied, /. lilacinus was more effective compared to /. penetrans, but combination of both the organisms (PI + PP) was found to be very effective in the management of root-knot nematode in black pepper. Both /*. lilacinus and P. penetrans did not cause any adverse effect on plant growth and they were found to survive and effective even after two years of innoculation under greenhouse conditions. The natural occurrence of P. penetrans on M. incognita on cardamom from Vandanmedu, Idukki district, Kerala is reported for the first time. Black pepper being a perennial crop is a very good host for the maintenance of P. penetrans on M. incognita.
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    Biological control of Meloidogyne incognita on black pepper by Pasteuria penetrans and Paecilomyces lilacinus
    (2007-02-08) Sosamma, V.K.; Koshy, P.K.
    Root-knot nematode, Meloidogyne incognita causes considerable damage to black pepper (Piper nigrum L.). Efficacy of two known bio-control agents namely Pasteuria penetrans, an endospore forming bacteria and Paecilomyces lilacinus, a parasitic fungus on eggs for the control of M. incognita on black pepper was studied in pots under greenhouse condition. P. Penetrans and P. lilacinus reduced nematode population, root-gall indices and improved the growth of the plants and root mass production significantly. Fifteen per cent reduction was noticed in the vine length of plants inoculated with nematode alone while it was only 8 to 15% in vines treated with either P. lilacinus or P. penetrans or both with nematodes. Number of leaves/nodes produced was maximum in control plants compared to a minimum in nematode inoculated vines. Fresh shoot and root weight were significantly greater in all treatments infested with M. incognita in the presence of one or both the bio-control organisms than M. incognita alone. Among the two biocontrol agents studied, /. lilacinus was more effective compared to /. penetrans, but combination of both the organisms (PI + PP) was found to be very effective in the management of root-knot nematode in black pepper. Both /*. lilacinus and P. penetrans did not cause any adverse effect on plant growth and they were found to survive and effective even after two years of innoculation under greenhouse conditions. The natural occurrence of P. penetrans on M. incognita on cardamom from Vandanmedu, Idukki district, Kerala is reported for the first time. Black pepper being a perennial crop is a very good host for the maintenance of P. penetrans on M. incognita.
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    Biometric clustering of coconut populations of three Indian Ocean Islands
    (2007-02-08) Kumaran, P.M.; Koshy, P.K.; Arunachalam, V.; Niral, V.; Parthasarathy, V.A.
    Coconut populations of Indian Ocean Islands of Madagascar, Mauritius and Seychelles were clustered using principal component analysis. A total of 28 vegetative, reproductive and fruit characters were used for analysis. Floral, foliar and fruit characteristics analysis indicated the usefulness of 11 characters for clustering. Five clusters were obtained on the basis of these characters. Nut characters were also found to be good for cluster analysis. All the dwarfs were in one cluster when vegetative and nut characters were considered. While selected, characters of two tails, Comoros Tall and Coco Bleu Tall were also included along with dwarfs indicating die doubtfulness of the genetic nature of these materials. These may be in fact dwarfs erroneously recorded as tails. Cluster analysis did not show any geographical affinity within the region.
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    Breeding for resistance/tolerance to root (wilt) disease
    (2007-02-08) Nair, R.V.; Jacob, P.M.; Koshy, P.K.; Sasikala, M.; Nampoothiri, K.U.K.
    Root wilt is a serious disease of coconut in Kerala. The disease affects 16 million palms and cause an annual loss of 968 million nuts. Involvement of phytoplasma in the etiology of this disease has been established. Breeding for evolving root (wilt) resistant varieties - being the lasting solution for the disease is implemented since 1987. In the heavily diseased tracts, some high yielding west coast tall and chowgate green dwarf palms were found to be resistant and serologically negative under field conditions. Studies indicated that CGD palms were having higher level of resistance to the disease compared to that of other varieties. It has also been reported that CDO X WCT hybrids gave higher yield in spite of contracting the disease. Based on these,observations, the following crosses are made - WCT X WCT (inter-se), WCT (self), WCT X CGD, CGD X WCT, CGD (self/inter-se), CDO (self/inter-se). The present crossing programme includes 63 WCT, 97 CGD and 4 CDO palms in the farmers plots.The 2725 progenies were under planted among heavily infested palms for evaluating their resistance and use them as future mother palms. In the seventh year of planting, WCT (open pollinated) seedlings showed 60%disease incidence where as WCT (self) and WCT (inter-se) showed 45% disease incidence and only 31% in CGD X WCT. Four seed gardens have been established by planting 3371 artificially pollinated seedlings.
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    Burrowing nematode a potential threat to agriculture
    (2007-02-08) Koshy, P.K.; Sundararaju, P.; Sosamma, V.K.
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    Coconut root (wilt) disease
    (2007-02-08) Nampoothiri, K.U.K.; Koshy, P.K.
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    Control of Radopholus similis (Cobb, 1893) Thorne, 1949 in coconut nursery
    (2007-02-08) Koshy, P.K.; Radhakrishnan Nair, C.P.
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    Control of Radopholus similis on arecanut seedlings with aldicarb, aldicarb sulfone, carbofuran and fensulfothion
    (2007-02-08) Sundararaju, P.; Koshy, P.K.
    Efficacy of 4 systemic nematicides (aldicarb, aldicarb sulfone, carbofuran and fensulfothion @ 1 g a.i./ plant) applied 3 times in a year for 3 years, were tested against Radopholus similis on arecanut seedlings, All the chemicals were effective in reducing the numbers of R. similis significantly and increasing plant growth in comparison to control plants. Aldicarb and fensulfothion were most effective while aldicarb sulfone and carbofuran were less effective in controlling nematodes. None of the chemicals was phytotoxic on arecanut seedlings.
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    Culturing of burrowing nematode, Radopholus similis on carrot discs
    (2007-02-08) Koshy, P.K.; Sosamma, V.K.
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    Culturing of Radopholus similis within mesocarp of coconut
    (2007-02-08) Koshy, P.K.; Sosamma, V.K.
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    Distribution and symptoms of the coconut root wilt, Thatipaka and Thanjavur wilt diseases and their potential danger in genetic transfer
    (2007-02-08) Radha, K.; Koshy, P.K.
    For these diseases, curative or prophylactic control measures do not exist. As such the only precaution which can be adopted is to avoid collection of seednuts/ pollen from diseased localities within 200 km. International cooperation in funding the collection, maintenance and multiplication of indigenous and exotic germplasm is required as most of the coconut growing countries do not have enough available funds for this. Locating world germplasm collection of coconut at two centres and establishing regional germplasm centres for every region will be of immense value in view of the reported occurrence of an increasing number of seed borne and offer diseases of uncertain etiology.
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    Distribution of phytoparasitic nematodes on arecanut in South India
    (2007-02-08) Sundararaju, P.; Koshy, P.K.
    Extensive surveys of arecanut growing areas of Kerala, Karnataka and Tamil Nadu were conducted during 1976 to 1980. A total of 822 each of soil and root samples were collected from healthy and Yellow Leaf Disease affected arecanut gardens. Twenty eight genera of plant parasitic nematodes were isolated from the root zone of arecanut. The burrowing nematode, Radopholus similis was obtained from maximum number of root samples. Rotylenchulus reniformis, Helicotylenchus dihystera, Hemicriconemoides mangiferae, Caloosia longicaudata and Hoplolaimus seinhorsti were the most widely distributed ectoparasitic forms in the soil samples of arecanut growing areas in South India.