Browsing by Author "Govindankutty, M.P."
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Item Annotated Bibliography of coconut in India 1977-1990(1991) Kamalavijayan, D.; Radhakrishnan Nair, C.P.; Chempakam, B.; Govindankutty, M.P.; Das, P.K.Item Detection of Mycoplasma-like organisms in root (wilt) disease affected coconut and its putative insect vector(2007-02-08) Solomon, J.J.; Govindankutty, M.P.; Mathen, K.Item Etiology - Phytoplasma(2007-02) Solomon, J.J.; Nair, C.P.R.; Rajan, P.; Srinivasan, N.; Govindankutty, M.P.; Mathen, K.; Pillai, N.G.Item Etiology e. Mycoplasma-like organisms(2007-02) Solomon, J.J.; Govindankutty, M.P.Item Evidences for transmission of yellow leaf disease of areca palm, Areca catechu L. by Proutista moesta (Westwood) (Homoptera : Derbidae)(2007-02) Ponnamma, K.N.; Solomon, J.J.; Rajeev, G.; Govindankutty, M.P.; Karnavar, G.K.Item Evidences towards a mycoplasmal etiology for the root (wilt) disease of coconut in India(2007-02) Solomon, J.J.; Govindankutty, M.P.; Mathen, K.; Nair, C.P.R.; Sasikala, M.; Pillai, N.G.Item Histopathological studies(2007-02) Govindankutty, M.P.Item Histopathology of roots of coconut palm affected with root (wilt) disease(2007-02) Govindankutty, M.P.; Vellaichamy, K.Anatomy of loots from healthy and diseased coconut palms was studied using aerial microtome and free-hand sections. Some externally healthy roots from apparently healthy, and obviously diseased trees (naturally infected) from an area of active disease spread showed poorly staining mechanical and vascular tissues. Walls of tracheal elements were thinner and disorganized. Tyloses occurred occasionally in metaxylem vessels. Several roots revealed degenerate phloem. Necrotic effects were shown by abnormally and deeply staining phloem with dense contents. Tissue degeneration was less pronounced in metaphtoem. Many healthy-looking roots from apparently healthy and diseased palms had fungal hyphae (?) in metaxylem. Sections of roots with external lesions of the burrowing nematode Radopholus similis revealed the presence of nematodes and their eggs in cortical burrows. Such burrows contained deeply staining cells encircled by abnormal sclerenchyma. Degenerative changes in conducting elements could derange the flow of nutrients and thereby contribute to root death due to starvation.Item Identification and critical study of eilte palms to evolve an ideal plant type in coconut(Central Plantation Crops Research Institute Regional station Kayangulam, 1982) Iyer, R.D.; Rao, E.V.V.B.; Sukumaran, C.K.; Jacob, P.M.; Viveknath, B.C.; Govindankutty, M.P.Item Investigations on Vascular Browning in the Roots of Root (Wilt) Diseased Coconut (Cocos Nucifera Linn.)(2007-02) Snehi Dwivedi, R.; Solomon, J.J.; Govindankutty, M.P.; Sumathy Kutty Amma, B.; Potti, V.P.Item Nature and Extent of Damage to Coconut as a Result of Feeding by Stephanitis Typicus (Distant) (Heteroptera : Tingidae)(2007-02) Mathen, K.; Govindankutty, M.P.; Chacko MathewThe lacebug Stephanitis typicus (Distant), a minor pest of coconut foliage, assumes importance because of its reported role as vector of Coconut Root (wilt) disease. Inoculation of palms in the field and of seedlings under insect proof green house conditions had brought < bout transmission of the disease. The nature and extent of damage to coconut pinnae are discussed here on the basis of feeding marks, histology and chlorophyll content analysis. Both adults and larvae of all stages feed from the lower surface of coconut pinnae, leaving permanent chlorotic spots on the adaxial surface. These yellow scars vary from small pinpricks to large coalesced patches with an average area of 0.112 mm2 under laboratory conditions. The mean number of feeding marks produced by one adult in 24 h was 80. An average area of 8.96 mm3 is therefore dechlorophylled by a single insect per day. With an average count of 490 adults on the crown of a palm, the total area rendered unsuitable for photosynthesis is 4390 mm2/day. The removal of chlorophyll per adult per day is to the tune of 0.24 ug. per gram fresh weight or 0.078 pg./cm2 of leaf. Not only the chlorophyll, but the entire cell contents are drained while feeding; the palisade cells appear to be depleted. A stylet sheath is not made out and evidence of a prominent role of saliva during feeding is little.Item Nematodes Associated with the Coconut Palm (Cocos Nucifera L.)(1978-09) Govindankutty, M.P.; Koshy, P.K.Item Nematodes. Fungi, Insects and Mites Associated with the Coconut Palm(2007-02) Govindankutty, M.P.Item Stylet course of lace bug Stephanitis typica (Distant) in coconut leaf(1988-11) Mathen, K.; Radhakrishnan Nair, C.P.; Gunasekharan, M.; Govindankutty, M.P.; Solomon, J.J.The lace bug Stephanitis typica feeds on coconut leaflet from its abaxial side. It inserts its stylet through stomata and sucks the contents of the coconut foliage. Besides this intracellular feeding, the stylet also ruptures the walls of the cells traversed in its course to reach the vascular bundles. The stylet tip in such cases terminates in phloem, thereby suggesting the ability of the bug to acquire the phloem-bound mycoplasma-like organisms, constantly associated with coconut root (wilt) disease in India.Item Stylet course of lace bug Stephanitis typica (Distant) in coconut leaf(1988) Mathen, K.; Radhakrishnan Nair, C.P.; Gunasekharan, M.; Govindankutty, M.P.; Solomon, J.J.The lace bug Stephanitis typica feeds on coconut leaflet from its abaxial side. It inserts its stylet through stomata and sucks the contents of the coconut foliage. Besides this intracellular feeding, the stylet also ruptures the walls of the cells traversed in its course to reach the vascular bundles. The stylet tip in such cases terminates in phloem, thereby suggesting the ability of the bug to acquire the phloem-bound mycoplasma-like organisms, constantly associated with coconut root (wilt) disease in India.Item Super Yielders In Coconut(1979) Iyer, R.D.; Govindankutty, M.P.; Bhaskara Rao, E.V.V.Item Super Yielders in Coconut(1979) Iyer, R.D.; Bhaskara Rao, E.V.V.; Govindankutty, M.P.Item Techniques to hold lace-bug for feeding, examining and photographing(1987) Mathen, K.; Govindankutty, M.P.Item Transmission of a mycoplasma-like organism from Cocos nucifera with root (wilt) disease to Catharanthus roseus by Cassytha filiformis(1988) Sasikala, M.; Mathen, K.; Govindankutty, M.P.; Solomon, J.J.; Geetha, L.A mycoplasma-like organism (MLO) was successfully transmitted through dodder laurel (Cassytha filiformis) from root (wilt) diseased coconut to periwinkle (Catharanthus roseus) plants. Symptoms caused by the organism in periwinkle were chlofotic spots in the interveinal areas and at vein endings of fully opened leaves, later coalescing into yellow patches, and premature leaf abscission. Light and electron-microscopic examination revealed the presence of MLOs in diseased coconut palms, dodder laurels and periwinkles.Item Transmission of root (wilt) disease to coconut seedlings through Stephanitis typica (Distant) (Heteroptera:Tingidae)(1990) Mathen, K.; Solomon, J.J.; Govindankutty, M.P.; Gunasekharan, M.; Sasikala, M.; Radhakrishnan Nair, C.P.; Rajan, P.Two-year-old West Coast Tall coconut seedlings obtained from a disease-free area were planted in methyl bromide-fumigated loamy sand collected from paddy field, held in field tanks and protected inside netted field cages. The seedlings were regularly inoculated with infective lace bugs, Stephanitis typica. Spear-loaf tissues of three of the four experimental seedlings gave strong positive serological reactions, indicating infection, nine months after the first inoculation. Root tissues treated with Dieness stain, DAPI and Hoechst 33258 fluorochromes indicated mycoplasma-like organisms (MLO) infection in the phloem. Serological and stain reactions in the fourth seedling were feeble at that time. Electron microscope examination of ultra thin sections of root apexes of all the seedlings revealed the presence of mycoplasma-like organisms in the sieve tubes. Of the four seedlings to which MLOs were transmitted by the tingids, two developed flaccidity of leaflets, the diagnostic and decisive symptom of the disease, eight months after infection was indicated by serodiagnosis. By the time the seedlings were visually identified as manifesting (he symptom of the disease, each seedling had received more than 1000 lace bugs with five days acquisition feeding on diseased palms known to harbour MLOs and about 1130 lace bugs with five days acquisition and thirteen days incubation. Control plants remained free of the organism and the symptoms of the disease.