PhD Thesis
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Item Technological evaluation of kera ice cream(Department of Dairy Science, College of Veterinary and Animal Sciences, Mannuthy, 1996) Geevarghese, P I; Francis, U TAn experiment was conducted to assess the suitability of incorporating coconut fat in the form of coconut cream in preparing ice cream and ice cream mix powder replacing milk fat at 25, 50, 75 and 100 per cent levels (treatments) so as to reduce the cost of preparation of ice cream. The product developed was named as kera ice cream and the qualities were compared with normal ice cream (control). Kera ice cream was prepared with pineapple flavour and a combination of sodium alginate and glyceryl monosterate as stabilizer since it was found to be the most suitable. It was found that replacement of milk fat with coconut fat at any level does not influence the acidity, pH and specific gravity of kera ice cream mix. The relative viscosity of kera ice cream was increased as fat substitution level increased. Higher surface tension was observed for the control, and among treatments it showed a gradual increase as replacement level increased. It was observed that the overrun percentage increased as replacement with coconut fat increased. Contrary to this a decreasing trend in meltdown time was observed as percentage replacement with coconut fat increased. Whipping ability was lowest for the control during the first 5 min of freezing but it significantly increased during the second five min of freezing. Structural details of the ice cream revealed that as replacement level increased the air cell diameter and cell wall thickness increased. Organoleptic quality of kera ice cream were comparable to normal ice cream. The savings in cost of production for kera ice cream with 100 per cent replacement was calculated as 40.57 per cent compared to control. The properties of the reconstituted ice cream revealed more or less similar trend in characters like acidity, pH, specific gravity, overrun, meltdown time and organoleptic properties as that of the freshly prepared ice cream. The ultra structure of the kera ice cream mix powder particle were studied and it revealed that as replacement level increased the particle size also increased. Clumping of the particles and irregular surface were more evident at 75 and 100 per cent level whereas particles of the control and 25 per cent had smooth surface. Solubility index of the powder increased as percentage replacement increased. Significant difference could be noted with regard to bulk density and percent volume occupied by the powder particle. Storage studies were conducted with different packaging material and metallised polyester polyethylene was found to be the best. The moisture and titratable acidity of kera ice cream mix powder with and without antioxidant were significantly higher at any replacement level at 180 days of storage. The thiobarbituric acid value showed a significant difference for the powder without antioxidant at 120 days of storage and with antioxidant the difference could be noted at 180 days of storage. Peroxide value was recorded as zero at different periods of storage upto 180 days of storage. At 180 days of storage, powder without BHA at any replacement level showed significant difference whereas in antioxidant added powder difference could be noted at 75 and 100 per cent replacement levels. Nutritional qualities of kera ice cream was evaluated by rat feeding trials and was found that protein efficiency value and feed efficiency were comparable to ice cream diet. The cholesterol and triglyceride level in animals fed with kera ice cream and ice cream were also not different. Pathological examination of carcases and tissues of animals under treatment and control groups did not reveal significant changes indicating that incorporation of coconut fat cannot cause any untoward effect in organs and tissues of animals. It can be concluded that coconut fat can be incorporated in the prepartation of ice cream and mix powder with out any noticeable changes in the quality. Addition of antioxidant prolongs the keeping quality of the powder by two months. There is no health hazard in consuming the kera ice cream as revealed by the pathological examination of tissues from the experimental animals fed with kera ice cream.Item Potassium supplying capacity of Neyattinkara- Vellayani soil association and its relationship with potash nutrition of major crops on them(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1989) Valsaji, K; Subramonia Aiyer, RDetailed study on the potassium supplying capacity of Neyattinkara-Vellayani soil association and its relationship to potash nutrition of major crops on them namely coconut and cassava has been made. This soil association represents the red loam soil type and consists of Neyattinkara series tentatively classified under Typic Eutropepts and Vellayani series under Typic Tropudalfs. Soil samples were collected from selected fields under coconut and cassava for the dominant soil types namely sandy clay loam and sandy loam soils under Neyattinkara and Vellayani series. To find the most suitable depth and location of soil sampling for coconut samples were also drawn at two different depths of 0-30 and 30-60 cm from basins and interrows. Empirical methods, quantity intensity studies, electro ultrafiltration studies and foliar diagnostic techniques were employed to decide on the most suitable method for plant available K. The various intensity, quantity and capacity factors which relate the readily available, difficultly available and storage or buffer capacity were assessed for a proper appraisal of the K status and supplying capacity. The various soil K parameters such as total K, water soluble K, exchangeable K, available K, nonexchangeable K, HNO3 extractable K, H2SO4 extractable K, sodium tetraphenylboron extractable K and percentage K saturation were found to be low. The water soluable K formed higher proportion of available K than exchangeable K. Interrelations showed that water soluble K, exchangeable K and available K are in dynamic equilibrium. Nonexchangeable K did not show any relationship with available K indicating that it is a poor source of available K. Quantity-intensity studies showed that the shape of the Q/I curve was similar in all types of soil since they belong to a group of related soils. The Q/I parameters like Are.K, Ko, Kx. KL and potential buffering capacity values were low. The KL values were higher than NH4OAc.K. The free energy values were found to be high indicating easy release rates of K. For both coconut and cassava, the leaf K did not show any consistent relationship with the soil K parameters. Among the Q/I parameters, KL had significant relation with leaf K of coconut. EUF 10 and EUF 35 showed significant relationship with leaf K of both coconut and cassava. Electro-ultrafiltration studies showed that the easily desorbed K was more than the strongly desorbed K indicating easy supply rate. The EUF 30-35 values were related to HNO3.K showing that this fraction included some initially nonexchangeable K. EUF 10 had significant relation with exchangeable K and EUF 35 had significant relation with exchangeable and available K. The buffer parameters BK (EUF 10/EUF 30) and EUF.Q (EUF 30-35/EUF 30) values were low indicating low buffer capacity. The EUF desorption pattern showed that the first peak was within 10-20 minutes and prominent than the second peak. This indicated low reserve K but easy supply rates. The EUF desorption curve of soils with high NH4OAc.K was above that of soils with low NH4OAc.K. This indicated that with increase in NH4OAc.K the easily desorbed K also increased. The yield of coconut and cassava were related to the various K parameters to evaluate the suitability of different methods for available K. In most of the cases NH4OAc method was found to be suitable for both coconut and cassava. Leaf analysis was also found to be suitable. For cassava the result obtained after 41/2 months is meaningless for the current crop. For coconut collection of index leaf is laborious. It was also found that the Q/I and EUF were suitable for coconut. But these methods cannot be followed in routine soil testing because of the high input of laboratory work involved. Considering these aspects it was found that NH4OAc method is the most suitable one because it is simple, cheap and easy to adopt. Based on the NH4Ac.k content the fertility status was found to be low to medium. The various intensity, quantity and capacity factors of soil K, Q/I and EUF parameters revealed that this soil association has low K supplying capacity. Hence heavy dose of K fertilizers is required. Split application is preferable especially in sandy loam soils to reduce leaching losses. NH4OAc.K which was found as a suitable indicator of plant available K varied significantly in basin and inter-row samples of sandy clay loam soils. This K fraction did not vary with depth in both sites. In general, the K nutrient index indicated that the basin samples had a higher level than inter-row and surface samples. Thus basin sampling at 0-30 cm depth was found to be the ideal site of soil sampling for coconut tree.Item Production dynamics of ginger (zingiber officinale R.) under varying levels of shade, nutrients and triazole(Department of Horticulture, College of Agriculture, Vellayani, 1999) Ajith Kumar, K; Jayachandran, B KThe experiments were conducted at the Coconut Research Station, Balaramapuram, during 1996-97 and 1997-98 to study the production dynamics of ginger under varying levels of shade, nutrients and triazole. The specific objectives were to study the production potential of ginger under open and different shade levels, to standardise optimum dose of nutrients and mulch for ginger intercropped in coconut garden and to evaluate the efficacy of triazole in the improvement of yield and other desirable characters. The effect of shade on growth and yield contributing parameters viz., tiller number, leaf number, leaf area, leaf dry weight, root spread, root volume, rhizome spread, rhizome thickness, number of rhizomes, leaf thickness, stomatal frequency, DMP and LAI under 20 and 40 per cent shade levels exhibited significant superiority in pot culture study. In pot culture study: maximum fresh ginger yield of 450.0 and 396.3 g plant" were resulted from plants kept under 20 and 40 per cent shade levels respectively. This was 27.4 and 12.2 per cent higher compared to open- condition. The dry ginger yield of 94.5 and 89.2 g plant" were obtained from plants kept under 20 and 40 per cent shade levels respectively. This was 27.8 and 20.7 per cent higher compared to open condition. However, the dry ginger yield obtained from 60 and 80 per cent shade levels were significantly lower compared to open. The shade levels 20 and 40 per cent gave the highest shoot dry weight of 48.9 and 53.6 g plant" respectively. Volatile oil content showed an increasing trend with increasing levels of shade in pot culture study. Maximum NVEE was recorded under 20 and 40 per cent shade levels. Highest starch content was obtained from 20 per cent shade level. Crude fibre gradually reduced with increase in shade levels. The field trial on nutrient requirement of ginger as intercrop in coconut garden revealed that, NPK application at higher levels increased plant height, tillering, leaf number, leaf area, DMP and chlorophyll content. Physiological parameters like, NAR, CGR and RGR were promoted by higher rates of nitrogen application. The results revealed that, N: P, N : K and P : K ratios of l.5 : 1, l.5 : 1 and 1 : 1 respectively, were ideal to get maximum fresh ginger yield. Application of 150 kg N, 100 kg P20S and 100 kg K20 ha-l gave maximum net profit ofRs. 96605/- and Rs. 99227/- during first and second year respectively. The net profit when the existing recommendation of 75 kg N, 50 kg P20S and 50 kg K20 ha-l was Rs. 54960/- and Rs. 54730/- during first and second year respectively. Hence the study suggests that the existing recommendation (75 kg N, 50 kg P20S and 50 kg K20 ha") has to be doubled (150 kg N, 100 kg P20S and 100 kg K20 ha-l) for increasing the productivity of ginger intercropped in coconut garden. Increased rate of fertilizer application did not influence the quality of the produce. Plant uptake of NPK increased with higher levels of fertilizer application. The field experiment on mulch requirement of ginger intercropped in coconut garden showed that the rhizome yield from plots mulched with 30.0, 22.5 and 1 =r. 0 t ha' were on par. Therefore the mulch requirement of ginger intercropped in coconut garden can be reduced from 30 t ha-l to 15.0 t ha-I Application of triazole did not exhibit any beneficial effect on yield and quality of ginger.Item Distribution of species of phytophthora affecting coconut and pepper in Kerala(Department of Plant Pathology, College of Agriculture, Vellayani, 1996) Veena, S S; Peethambaran, C KThe present investigation was undertaken to correctly identify the species of Phytophthora causing bud rot of coconut and foot rot of pepper in Kerala and to find out their comparative role in causing diseases on coconut and pepper. The study also aimed at isolation of viable antagonistic agents against the pathogen, so as to utilize them in future for biological control. The study was conducted during 1992-96 at College of Agriculture, Vellayani and Indian Institute of Spices Research, Kozhikode. Detailed symptomatology of both the diseases at different locations were studied. Periodic collections were made from diseased coconut and pepper from seven districts of Kerala. The morphological characters of the isolates were studied in detail. The length, breadth, L/B ratio, pedicel length and caducity of sporangia of coconut isolates were smaller than pepper isolates. The sporangial shapes differed considerably between and among the isolates. All the isolates except those collected from Kannur and Kasaragod districts (C7 - C16), produced abundant number of sporangia on carrot agar. Phytophthora are either heterothallic or homothallic. Generally P. palmivora and P. capsici are heterothallic. But ten coconut isolates obtained from Kannur and Kasaragodu districts produced abundant number of sexual structures on carrot agar, indicating their homothallic nature and this is the first report of homothallic Phytophthora causing bud rot of coconut in Kerala. All other 52 isolates were mated with known A1 and A2 mating type and all the coconut isolates produced oospores with A1 and all the pepper isolates produced oospores when mated with A2. Zoospore production was induced from sporangia using cold treatment. The number of zoospores in sporangia ranged from 6-15 in number. Chlamydlospore production was a rare phenomenon in pepper isolates while all the coconut isolates and five pepper isolates produced chlamydospores. All the isolates were inoculated into pepper seedlings, coconut leaves, tender coconut and coconut seedlings and the time required for infection, variation in symptom expression by different isolates etc. were studied. All the sixteen coconut isolates produced foot rot in pepper. Fourty six isolates of pepper produced lesions on coconut leaves and nut rot in tender coconut, while, only six isolates of pepper produced bud rot in coconut plants. The cross infectivity of pepper isolates needed further confirmation to prove the point beyond doubt. Eight cultivated plants, 9 ornamental plants and 12 weed plants were tested for the host range of coconut and pepper isolates. Many plants belonged to the above three groups took infection successfully. The microorganisms found associated with healthy and diseased pepper and coconut plantations and microorganisms from soils of pepper and coconut gardens of different parts of Kerala were isolated. Out of more than 200 microorganisms, only 28 fungi inhibited the growth of Phytophthora in vitro. On pepper plant, 12 isolates had inhibitory action. Three organisms, viz., Verticillium chlamydosporium, Aspergillus terreus and Chaetomium sp checked the pathogen completely even after seven days of spraying with the organisms.Item Biology, Bionomics and control of coconut cockchafer Leucopholis coneophora Burm.(Division of Agricultural Entomology, College of Agriculture, Vellayani, 1983) Abraham, V A; Mohan Das, MThe biology of the coconut cockchafer Leucopholic coneophora Burm. was studied in detail for the first time. Techniques for rearing the pests from egg to adult in potted palnts kept in field were standardized. The egg laying behaviour of adults was observed. The morphological changes off eggs, different instars of grubs and pupae during development were studied in detail. The changes in immature stages of male and female insects were traced separately. The general morphology of different instars of the grubs was studied in full with a view to finding distinct identifying characters for each.Item Production potential of cassava (Manlhot esculent a Grants) intercropped in coconut gardens(Department of Agronomy, College of Agriculture, Vellayani, 1986) Ramakrishnan Nayar, T V; Sadanandan, NField experiments were conducted at the coconut Research Station. Balaramapuram during 1983-84 and 1984-85 to study the production potential of cassava varieties Sreevisakham and Malayan-4, intercropped in coconut gardens, as influenced by planting density, growth regulators and different levels of NPK fertilisers. The cassava hybrid Sreevisakham was superior to the popular cultlvar Maiayan-4 in nuirber of nodes plant 1, number of functional leaves plant™1, leaf area index, net assimilation rate, crop growth rates, dry matter production, utilisation index, tuber bulking rate and in fresh tuber yield. For intercropping one hectare of coconut garden in which coconuts are spaced at 7.5 x 7.5 m, cassava plant population of 8000 (spacing 90 x 90 cm) was found to be optimum to produce maximum fresh tuber yield* Cassava plants at higher planting density, were stunted in growth and produced poor quality tubers. The growth regulators cycocel and ethrel though decreased the plant height, could not Influence either the yield attributes or yield and quality of cassava tubers.Item Fertilizer Management of minor tuber crops in Coconut based cropping system(Department of Agronomy, College of Agriculture, Vellayani, 1989) Pushpakumari, R; Sasidhar, V KAn investigation was carried out to evolve the fertilizer management practices of minor tuber crops in coconut based cropping systems during the years 1985-86 and 1986-87. This investigation was carried out as two experiments. In experiment I, screening of minor tuber crops under varying intensities of shade was done adopting a split plot design with 4 replications. In experiment II the fertilizer management of minor tuber crops in coconut based cropping system was studied. The experiment II was conducted in randomised block design with 3 replications. While experiment I was taken up at the Instructional Farm, College of Agriculture, Vellayani, experiment II was conducted at Coconut Research Station, Balaramapuram. Shade had significant influence on the length of vine/height of plant, LAI, NAR, CGR, dry matter production chlorophyll content of leaves, starch and protein content of tubers and yield of tuber of greater yam, lesser yam, tannia and elephant footyam. With increase in shade intensity, the yield declined proportionately in greater yam and elephant footyam reocrding highest yield under open condition. The tuber yield of lesser yam under open and 25 per cent shade levels were statistically on par, beyond which a drastic reduction in yield was observed with increase in shade intensity. Tannia recorded highest yields under 25 per cent shade, with an almost equal yield under 50 per cent shade. Fertilizer levels did not significantly influence the growth and yield characters of lesser yam, elephant footyam and tannia. But for greater yam there was significant increase in plant height in the first year and tuber yield in the second year with increase in fertilizer level. Greater yam responded linearly to fertilizer levels recording maximum yield with full recommended dose of fertilizer, although the variation was significant only in the second year. Lesser yam had maximum yield at medium fertilizer level and elephant footyam at lowest level, though not significant. The general performance of tannia was very poor. The economics worked out for the fertilizer management practices of greater yam, lesser yam, tannia and elephant footyam revealed that among the four crops tried, elephant footyam gave the maximum net profit followed by greater yam and lesser yam. However, tannia resulted in a loss.Item Sequential analysis of constraints in increasing production of rice and coconut in Kerala(Department of Agricultural Extension, College of Agriculture, Vellayani, 1989) Prakash, R; Thyagarajan Nair, GThe study aimed at identifying the production constraints of rice and coconut and measuring the validity of identified constraints in selected production centres. The solutions to the identified constraints were also collected and their feasibility rated in order to formulate appropriate development strategies for increasing production of rice and coconut in Kerala. The study was conducted in all the NARP regions of the State, namely, Southern, Central, Northern, High Range and Problem Regions. The respondents of the study comprised of 160 farmers each for the identification and validation of constraints and 100 Research Workers, 100 Extension Workers and 57 Input Agencies for the indentification of constraints. To identify the production constraints of rice and coconut, Delphi technique – the methodology for elicitation of expert opinion – was used. Date from the farmers were collected using pre-tested structured interview schedules. Conversion of lands, drought and lack of irrigation were the major production constraints of rice ranked according to their importance in the Southern Region while nonavailability of FYM, low profitability and high cost of production were the constraints ranked high in the Central Region. High difficulty in cultivation, nonavailability of FYM and fragmentation were the production constraints of rice ranked high in the Northern Region. High wage rate of agricultural labour, indebtedness and high cost of production ranked high in the High Range Region. In the Problem Region, floods, low profitability and high cost of FYM were the high ranked production constraints of rice. In the case of coconut, lack of irrigation, drought and high wage rte of agricultural labour were the high ranking production constraints in the southern Region while low adoption of chemical fertilizers, high cost of fertilizers and lack of irrigation ranked high in the Central Region. In the Northern Region, the high ranking constraints were low adoption of plant protection chemicals, high cost of fertilizers and low labour productivity whereas high cost of seedings, high cost of fertilizers and pests and disease incidence ranked high in the High Range Region. Root (Wilt) diseases, high wage rate of agricultural labour and high cost of plant protection chemicals were the high ranking production constraints of coconut in the Problem Region. In the Southern Region, the production constraints of rice, namely, low adoption of chemical fertilizers, lack of knowledge about chemical fertilizers,, negative attitude towards plant protection chemicals, absentee landlordism, negative attitude towards HYV, low adoption of HYV and small farm size were found to be individually significant in predicting the yield of rice. Negative attitude towards HYV, low adoption of HYV, low labour productivity and lack of irrigation were individually found to be significant in predicting the yield of rife in the Central Region. In the Northern Region, the constraints namely, high cost of chemical fertilizers, low adoption of chemical fertilizers, indebtedness, lack of credit facilities and high incidence of pests and disease were found to be individually significant in predicting the yield of rice. Low adoption of HYV, incidence of pests and diseases, high cost of chemical fertilizers, low adoption of plant progection chemicals were found to be individually significant in prediction the yield of rice in the High Range Region. In the Problem Region, the constraints, namely, low adoption of plant protection chemicals, low adoption of chemical fertilizers, floods and incidence of pests and diseases were found to be significant in predicting the yield. The production constraints of coconut individually significant in predicting the yield in the Southern Region were low adoption of chemical fertilizers, drought and lack of irrigation. In the Central Region, lack of irrigation, lack of knowledge about plant protection chemicals, low adoption of chemical fertilizers and incidence of pests and diseases were found to be individually significant in predicting the yield of coconut. In the High Range Region the constraints namely nonavailability of quality seedings, small farm size, incidence of pests and diseases were individually significant in predicting the yield while low adoption of chemical fertilizers, incidence of pests and diseases and incidence of root (wilt) disease were significant production constraints in the Problem Region. Evolving varieties suited to different agro-climatic regions, promoting group farming, popularising cultivation of green manure seeds, providing fertilizer subsidy, providing crop insurance, fixing support price for paddy were found to be the most feasible steps to be taken for increasing production of rice in Kerala. Adoption of moisture conservation practices, decentralised nursery for coconut, supply of seedlings through Krishibhavans, large scale production of hybrid coconut, scientific replanting and underplanting programme and subsidising chemical fertilizers are the steps to be undertaken to increase the production of coconut in the State. Based on the results of the study, certain important implications have been spelt out.Item Agronomic evaluation of biofarming techniques for forage production in coconut gardens(Department of Agronomy, College of Agriculture, Vellayani, 1996) Sansamma George; Raghavan Pillai, GTwo field experiments were conducted at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala State to study the potential of biofarming techniques for forage production in coconut gardens. The study was carried out for a period of two years from September 1993 to August 1995. The influence of the different nutrient management techniques on uptake of nutrients, quality of produce and physico-chemical properties of soil was also investigated. In experiment no.1. the influence of two nitrogen fixing organisms., viz. Azospirillum and Azotobacter and the role of Vesicular Arbuscular Mycorrhiza (VAM) in improving the growth and production of guinea grass and congosignal was studied under inoculation alone and also in combination with chemical fertilizers. The nitrogen fixers were tested under varying levels of fertilizer nitrogen and for VAM the level of phosphorus varied between treatments. The prospects for vermicompost use for guinea grass production was examined under experiment no. 2. It was also envisaged to compare the impact of integrated use of manures and fertilizers with the continuous use of chemical fertilizers alone. Results of experiment no.1 revealed that Azospirillum inoculation alone and in combination with fertilizers had significant positive influence on guinea grass production. Azotobacter inoculation showed only limited effects on growth and yield of the forage grass during the first year but the effect was significant during the second year. The results indicated that 25 per cent of the recommended nitrogen could be saved through the use of either of the biofertilizers. VAM inoculation when combined with full dose of recommended fertilizer nitrogen and potassium, showed significant superiority over the POP treatment at 0, 25 and 50 per cent phosphorus doses while the 75 percent P dose gave comparable yields. The quality parameters of the forage recorded values on par or superior to that of the recommended fertilizer treatment. The use of biofertilizers improved the net income and benefit : cost ratio from guinea grass cultivation. The inoculation treatments were found to have a favourable influence on the physical and chemical properties of the soil. Integrated use of the nitrogen fixing organisms with chemical fertilizers was found effective for Congosignal cultivation. Pooled analysis studies indicated that when inoculated with either Azospirillum or Azotobacter, 50 per cent of the recommended fertilizer nitrogen was adequate for yields. VAM inoculation alone elicited significant yield increase over the absolute control. Combind doses of VAM with chemical fertilizers at all levels of applied phosphorus responded more or less similar to the recommended fertilizer treatment. This indicated the possibility of completely substituting the need for fertilizer phosphorus in VAM inoculated congosignal. The VAM effect in promoting growth and yield of the forage was found to decline in the presence of applied phosphorus. The data on economics also favoured the use of biofertilizers. Experiment no. 2 revealed that guinea grass responded well to integrated use of manures and fertilizers. As per pooled analysis vermicompost @ 5 t ha-1 or Farm yard manure @ 10 t ha-1 when combind with 75 per cent of the recommended NPK were comparable with the 100 per cent NPK treatment. Application of the organic manures improved the quality of the produce. The physic-chemical properties of the soil was also favourably influenced by the integrated use of manures and fertilizers. The economic analysis of the data emphasised the need for reducing the reliance on purchased inputs. Coconut yield was found favourably influenced by intercropping of the fodder grasses.Item Influence of high background radiation on coconut nutrition(Department of Agronomy, College of Horticulture, Vellenikkara, 1998) Rekha, C; Balachandran, P VAn investigation on the influence of high background radiation on coconut palms was conducted during 1994-97 at the College of Horticulture, Vellanikkara. This study was carried out in the high background radiation areas of the coastal Kollam district. A pot culture experiment was also conducted at the College of Horticulture, Vellanikkara. Soil collected from the high background radiation area (Chavara) was used for the study. The radiation exposure of coconut roots and its influence on the root activity of coconut palms, radiation profile of coconut rhizosphere, radionuclide accumulation by coconut palms and the influence of organic matter application on absorption of radionuclides by coconut palms were assessed. The main findings are given below. A wide variation in natural background radiation ranging from 200-8 200 nGy h-1 was observed in Chavara and adjoining areas. The radiation levels were generally higher in the coastal areas compared to the inland. 232 Th was the major radionuclide contributing to the high radiation and its content in soil ranged from 144 to 3580 ppm. The results from root exposure studies indicated that plant roots are continuously exposed to high radiation levels and a significant reduction in radiation exposure occurred only at a depth of 1 m. Correlation and regression analyses revealed a significant positive relation between surface radiation and the radiation exposure at different soil depths. The root activity studies employing 32P soil injection technique revealed that the root activity of coconut palms in the high radiation areas was comparable with that in the low radiation areas. The studies on 232Th uptake and its distribution within coconut palm pointed out that considerable accumulation of the absorbed 232Th occurs in roots and that only a small fraction of it is translocated up to the leaves and nuts. Application of organic matter, especially green leaf manure was found to be highly effective in reducing the 232Th uptake by coconut seedlings growing in monazite rich soil.