• HOME
  • Search & Results
  • Full Text
  • Thesis Details
 
Page: 193
 
 Full Screen

  • TITLE
  • CERTIFICATE
  • DECLARATION
  • ACKNOWLEDGEMENT
  • DEDICATION
  • CONTENTS
  • 1 INTRODUCTION
  • 2 REVIEW OF LITERATURE
  • 2.1. Effect of location on VAM distribution
  • 2.2. Effect of season on VAM colonisation and sporepepalation
  • 2.3. Comparison of forest and rubber growing soils
  • 2.4. Effect of soil factors on the distribution of VAM fungi
  • 2.4.1. Soil temperature
  • 2.4.2. Soil moisture
  • 2.4.3. Soil organic matter
  • 2.4.4. Soil pH
  • 2.5. Effect of cultural operations on VAM colonisationand spore population
  • 2.5.1. Fertilizer application
  • 2.5.2. Fungicide application
  • 2.5.3. Pesticide application
  • 2.5.4. Weedicide application
  • 2.6. Soil solarisation
  • 2.7. Dissemination of VAM spores
  • 2.7.1. Active dissemination
  • 2.7.2. Passive dissemination
  • 2.7.2.1. Biotic agents
  • 2.7.2.2. Abiotic agents
  • 3 MATERIALS AND METHODS
  • 3.1. Collection of soil and root samples
  • 3.1.1. Enumeration of VAM spore population
  • 3.1.2. Identifxation of spores
  • 3.1.3. Assessment of root colonisation (Phillips and Hayman, 1970)
  • 3.1.4. Seasonal variability on VAM spore count in rubbergrowbg soils and colonisation in Hevea roots
  • 3.2. Determination of organic carbon in soil
  • 3.3. Determination of soil pH
  • 3.4. VAM spore population and root colonisation in Heveaplantations under different period of cultivation
  • 3.5. VAM spore population and root colonisation inrubber soils under 3 different cycles of cultivation
  • 3.6. VAM spore population at different soil depths
  • 3.7. Comparison of forest soil and rubber plantation soilfor VAM spore distribution
  • 3.8. Effect of soil factors on VAM spore count and rootcolonisation
  • 3.8.1. Effect of temperature
  • 3.8.2. Effect of soil moisture on VAM spore count and rootcolonisation
  • 3.8.3. Effect of different sources of organic matter in soil onVAM spore count and root colonisation
  • 3.9. Effect of cultural operations on VAM spore countand root colonisation
  • 3.9.1. Effect of fertilizers
  • 3.9.2. Effect of plant protection chemicals
  • 3.9.2.1. Fungicides
  • 3.9.2.2. Insecticides
  • 3.9.2.3. Weedicides
  • 3.9.3. Effect of soil solarisation on VAM
  • 3.10. Studies on the dissemination of.VAM fungi
  • 3.10.1. Biotic agents
  • 3.10.2. Abiotic agents
  • Plate 1. Earthworm castings in soil
  • Plate 2. Termitary on a rubber tree
  • Plate 3. Termitary in soil
  • Plate 4. Ant mound.
  • Plate 5. Wasp nest
  • Plate 6. Rainwater flowing through a rubber field.
  • Plate 7. spore trap (Insight - side view from right)
  • Plate 8. Spore trap erected in a rubber plantation.
  • 4 EXPERIMENTALRESULTS
  • 4.1. Influence of location and season on VAM sporepopulation in rubber growing soils of Kerala
  • Fig. 1. Sites of soil sample collection.
  • 4.2. Effect of location and season on Hevea rootcolonisation by VAM
  • Fig.2 Effect of season on the occurence of different generaof VAM spores in H e w plantations
  • 4.3. Effect of soil pH and organic carbon on VAM sporecount in soil and root colonisation in Hevea
  • Plates 9-12 Spores of different species of Glomus sp (x 160)
  • Plate 13. Spore of Acmlospora sp. (x 160)
  • Plate 14. Spore of Sclerocystis sp. (x 160)
  • Plate 15. Spore of Gigaspora sp. (xl60)
  • Plate 16. Enlarged view of Giga.~porasp.spore (x340) showing bulbousSubtending hypha
  • Plate 17. Fungal hyphae showing: appresorium (a) on Hevea root (x 160)
  • Plate 18. Root colonisation in Ht~vea showing vesicles (x 160)
  • Plate 19. Root colonisation in sorghum showing arbuscules (x 160)
  • 4.4. VAM spore ppttktion and root colonisation inHevea plantrations under different period ofcultivation
  • 4.5. Spore m a t i o n and root colonisation in the soilsof three BiPferent cycles of Hevea cultivation
  • Fig 3. VAM colonisation ofHevea roots under differentyears of cultivation
  • Fig 4. VAM spore count in rubber plantation soil underdifferent years of cultivation
  • Fig. 5. Per cent occurrence of different genera of VAMspores in Hmea plan tations under different years ofcultivation
  • Fig.6. VAM Spare count in soil of ru bber plantationunder different cultivation cycle
  • Fig 7. VAM colonisation in H m mots under differentcultivation cycle.
  • 4.6. Influence of soil depth on VAM spore population
  • 4.7. Comparative studies on VAM spore count in forestand rubber growing soils
  • Fig.8 Influence of soil depth on VAM spore count inrubber plantation
  • 4.8. Effect of soil factors on VAM
  • 4.8.1. Effect of soil temperature on VAM spore population androot colonisation in sorghum
  • Fig.9. Total VAM spore count in forest and rubber soil in.different locations
  • 4.8.2. Effect of soil moisture on VAM spore population and rootcolonisation in sorghum.
  • 4.8.3. Effect of soil organic matter on VAM colonisation insorghm and spore population in soil
  • Fig. 10 Effect of temperature on VAM spore count in soil
  • Fig. 11 Effect of temperature onVAM colonisation in roots of HM
  • Fig. 12. Effect of moisture on root colonisation by VAMfungi in sorghum
  • Fig. 13. Effect of moisture on VAM spore count in soil
  • 4.9. Effect of cultural operations on VAM
  • 4.9.1. Effect of fertilizers on per cent root infection and sporepopulation in Hevea
  • 4.9.2. Effect of pfPnt protection chemicals on VAM
  • 4.9.2.1. Effect of fungicides on V4M root colonisation in Hevea roots andspore population in soil
  • Fig. 14. Effect of fertilizer on VAM Spore count in soil
  • Fig. 15. ERect of fertilizer on VAM colonisation in HNea
  • 4.9.2.2. Effect of insecticides on root colonisation in Hevea roots and sporepopulation in soil
  • 4.9.2.3. Effect of weedicides on VAM colonisation in Hevea roots and sporepopulation in soil
  • Fig. 16. Effect of insecticides on root colonisation by VAMfungi in Hevea
  • Fig. 17. Effect of insecticides on VAM spore count in soil
  • 4.9.3. Effect of solaris&itm on VAM root colonisation and sporepopulation in sorghun~
  • 4.10. Influence of various agents on the dissemination ofVAM spores
  • 5 DISCUSSION
  • 5.1. Distribuaion of VAM in rubber growing soils
  • 5.2. Influence of location and season on VAM spore population
  • 5.3. Influence of location and season on root colonisation by VAM in Hevea
  • 5.4. Effect of soil pH and organic carbon on VAM spore population and root colonisation in Hevea
  • 5.5. VAM colonisation and spore population as influenced by duration and cycle of Hevea cultivation
  • 5.6. Vertical Distribution of VAM spores in soil
  • 5.7. Comparative study on VAM population in Hevea plantation and nearby forest
  • 5.8. Effect of environmental factors on VAM spore count and root colonisation
  • 5.8.1. Temperature
  • 5.8.2. Moisture
  • 5.8.3. Organic matter
  • 5.9. Cultural practices on VAM spore population and root colonisation
  • 5.9.1. Fertilizer
  • 5.9.2. Fungicides
  • 5.9.3. Insecticides
  • 5.9.4. Weedicides
  • 5.9.5. Effect of Solarisation
  • 5.10. Dissemination of VAM
  • 5.10.1. Dissemination by biotic agents
  • 5.10.1.1.Earthworms
  • 5.10.1.2. Termites
  • 5.10.1.3. Wasps
  • 5.10.1.4. Ants
  • 5.10.2. Abiotic factors in the dispersal of VAM fungi
  • 6 SUMMARY
  • REFERENCES