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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access Genetic studies in red gram (eafanui caiaixL)(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1988) Radhakrishnan, V V; KAU; Narayanan Namboodiri, K NThesisItem Open Access Deterioration of oil cake by fungi(Department of Plant Pathology, College of Agriculture, Vellayani, 1989) Naseema, A; KAU; Wilson, K IFungi causing deterioration of coconut, groundnut and sesamum oil cakes were studied. ficremonium implicatum, Asperdllus aculeatus, A. flavus, A. fumigatus, A. nlaer, A. terreus, A. versicolor, Bipolaris hawaiiensis, Curvularia clavata, Monascus ruber, Penicillium aurantioqriseum, P. Pinophilum, Pestalotiopsis palmarum, Rhizomucor £usillus and Ehizopus stolonifer were obtained from coconut oil cake. Aspergillus flavus, A. niaer, A. terreus, A. versicolor, Gliocladium sp. Penicillium pinophilum, RhizoEUS or^zae and Rhizopus stolonifer were noticed in groundnut and Aspergillus candidus, A. flavus, A. fumigatus, A. nlaer, A. tamarii, A. terreus, Curvularia clavata, Eurotium. chevalieri, F"sarium pallidoroseum, Monascus ruber, Fenicilliuiu pinophilum, Pestalotiopsls palmarum and Rhizopus or^zae in sesamum oil cake. Of these, Acremonium implicatum, Aspergillus aculeatus, A. caeslellus, A. .f"-igatus, Bipolaris hawaiiensis, Curvularia clavata, Monascus ru^, Penicillium anrantlogriseum, P. pinophilum, Pestalotiopsls palmarum and Rhizomucor pusillus from coconut oil cake, Aspergillus versicolor, Gliocladium sp., Penicillium pinophilum, Rhizopus oryzae and R. stolonifer from groundnut and Aspergillus candidus, A. fumigatus, A. tamarli, A. terreus, Curvularia clavata, Eurotium chevalieri, Fusarium pallidoroseum,Monascus ruber, Penicillium pinophilum, Pestalotiopsis palmarum and Rhizopus oryzae from sesamum oil cake have not been reported earlier. * Aspergillus flavus and A. niger were isolated from all the samples of groundnut and sesamum oil cakes. In coconut oil cake, these two fungi were present in 88.89 and 77.78 per cent of the samples. A. terreus was isolated from 66.67 per cent of groundnut and 55. 56 per cent of coconut and sesamum oil cake samples. Penicillium pinophilum was obtained from 66.67 per cent of groundnut, 44.44 per cent of sesamum and 27.78 per cent of coconut oil cake samples. Wide variation was noticed in the population of fungi present in the oil cakes collected from different regions during different periods of the year. Oil cakes collected during June-July had the highest population, of fungi. The central and the northern regions recorded higher population of fungi than the southern region. Positive and significant correlation could be obtained between weather parameters and population of fungi in different oil cakes. Maximum correlation was noticed in relation to total rainfall. Qood mycelial growth of fungi was obtained in all the oil cakes incubated at 27, 29 and 32°C. Maximum mycelial growth was noticed at 100 per cent relative humidity. This was followed by 96.1 per cent and 92.9 per cent in the descending order. The oil content of the oil cakes was considerably reduced due to the growth of all the fungi tested individually and in combination. Maximum reduction v/as noticed due to the growth of Pestalotiopsis palmarum in coconut oil cake, Rhizopus stolonifer in groundnut and Fusarium pallidorosem in sesamum oil cake. In the case of combinations, Aspergillus flavus, A. niger and Penicillium pinophilum together caused maximum reduction in oil content of coconut oil cake. In groundnut, combined growth of A. flavus, A. niger and A. terreus caused maximum reduction in oil whereas, A. niger and P. pinophilum together effected maximum reduction of oil in sesamum oil cake. Oil cakes inoculated with different fungi showed considerable reduction in total carbohydrates, crude protein, free amino nitrogen, crude fibre and ash to the extent of 6.11 to 76.95 , 4 . 28 to 68.03, 14.91 to 92.52, 1.25 to 92.55 and 0.17 to 65.16 per cent respectively. In the case of mineral nutrients like phosphorus, potassium, magnesium. calcium, copper and iron reduction ranging from 15.07 to 75.54, 23.13 to 94.41, 10.89 to 63.37, 28.78 to 90.20, 52.52 to 97.12 and 0.32 to 60.77 per cent respectively was noticed. Fourteen out of 2 0 isolates of Aspergillus flavus produced aflatoxins B^, and G2 in culture medium with maximum quantities being 1210, 1040 and 151 ppb respectively by the isolates from coconut oil cake. Eight out of 19 isolates of A. niger elaborated upto 222 ppb by the isolate from sesamum oil cake. When grown on the respective host material, A. flavus isolates from coconut oil cake produced maximum quantity of B^^, B^ and being 1517, 1092 and 272 ppb respectively. A. niger isolate from coconut oil cake produced B^^ upto 419 ppb. oil cakes treated with calcium propionate (0.6 per cent, w/w) were free from fungus growth throughout the period (180 days) of observation and showed minimum number of fungal propagules whereas, those kept as control had higher population of fungi than the treated ones, at all period.of observation. Oil cakes stored in polythene lined gunny bags had the least population of fungi, whereas those stored in ordinary gunny bag had very high population of fungi. These results revealed that fungal deterioration and spoilage of oil cakes could be prevented or reduced to the minimum by treatment with 0.6 per cent calcium propionate- and by using polythene lined gunny bags for storage arid transport.ThesisItem Open Access Homeostatic analysis of components of genetic variance and inheritance of fruit colour, fruit shape and bitterness in bitter gourd (Momordica charantia L.)(Department of Olericulture, College of Horticulture, Vellanikkara, 1989) Abdul Vahab, M; KAU; Gopalakrishnan, P KThesisItem Open Access In vitro studies on the propagation of cardamom (Elettaria cardamomum maton)(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1989) Reghunath, B R; KAU; Gopalakrishnan, P KThesisItem Open Access Qualitative changes of yoghurt prepared from milk preserved by different methods(Department of Dairy Science, College of Veterinary and Animal Sciences,Mannuthy, 1990) Prasad, V; KAU; Sukumaran, M VAn experiment was conducted to study the qualitative changes of yoghurt prepared from milk preserved by different methods. An attempt was also made to study the efficiency of LP system in controlling psychrotrops in refrigerated milk thereby extending the keeping quality of such stored milk. The efficacy of the system was compared with pasteurized milk and raw milk stored under similar conditions. An exhaustive review of literature has been presented on the use of various preservation methods employed in milk, quality of yoghurt and other related aspects. The methods of analyses of some important components of milk and yoghurt has been detailed. The milk after collection were divided into three portions and used for various treatments A (raw milk as such), B (laboratory pasteurized) and C )LP activated). Samples in each treatment were again divided into four parts and stored under refrigeration for 0, 24, 48 and 72 hours for further analysis and yoghurt preparation. When raw milk was stored under refrigeration, acidity developed to a significantly high level (P < 0.05) at the end of 72 hours of storage whereas no significant increase in activity was noticed in treatments B and C. This result was corroborated by a decrease in both psychrotrophic and total bacterial counts in milk under treatments B and C. So it was concluded that the development of acidity in treatment A could be due to bultiplication of microbes particularly psychrotrophs. In B and C its growth was arrested by the treatments. Hydrogen peroxide and thiocyanate were detected in all raw milk samples at a level of 3.78 and 7.33 ppm respectively. The level of H2 O2 and SCN – used for the activation of LP system for the study were found to be adequate, since the psychrotrophic count in milk at the end of 72 hours in treatment C was less than that found in treatment B. The residual H2 O2 and SCN – contents at the end of 72 hours were found to be within the normal level found in milk thus having no health hazards, by this method of preservation. When yoghurt samples were prepared from stored milk no significant differences between treatments were noticed in the values of fermentation period, acidity, pH, total proteins and total solids. A significant increase in NPN and tyrosine values were noticed in yoghurt prepared from milk under treatment A indicating extensive proteolysis in milk during storage under this treatment. However, no difference was noticed between treatments B and C. Diacetyl and acetaldehyde were produced at a desirable level in yoghurt samples under all the three treatments. A proper ratio of Str. Thermophiles – 6 and L. bulgaricus – 4 was found to be maintained in all yoghurt samples. On organoleptic evaluation the yoghurt prepared from milk under treatment C could not be distinguished from other two treatments. In fact, yoghurt under C got a higher total score on organoleptic evaluation than A and B. Low score for body and texture, and falvour was observed under treatment A. This may be attributed to the effect of growth of psychrotrophs in raw milk during refrigeration. From the results, it was concluded that good quality yoghurt can be prepared from milk stored under refrigeration following pasteurization or LP activation. Yoghurt samples prepared from milk stored under treatment A was found to be of inferior quality when compared to B and C. The result also confirmed that LP system can be recommended as a safe preservative for extending storage life of refrigerated milk. When such stored milk was used for yoghurt production, no significant difference in the quality was noticed when compared to yoghurt under treatment B. Suggesting that LP activated milk can be conveniently and economically used for the production of fermented milk products like yoghurt without any apparent harmful effect.ThesisItem Open Access Effect of phorate applied for the control of bunchy top vector of banana Pentalonia nigroneroosa Coq. on the plant and in the soil environment(Department of Agricultural Entomology, College of Agriculture, Vellayani, 1989) Sitarama Rao, D; KAU; Mohandas, NA series of experiments were carried out for ascertaining the basic problems related to the current recommendations for managing bunchytop disease of banana through the application of phorate. The absorption, translocation and metabolism of phorate applied in the soil was influenced more by the condition and age of the plant than by the dose of the insecticide. Since the application of 2.50 g ai/plant did not result in corresponding increase in the residue content or the bioefficacy in the early phases of crop growth, when compared to the 1.25 dose, the latter can be used without significant loss in efficacy. A definite dose-effect relationship existed between the phorate content of plant and the mortality of P.nigronervosa confined at feeding sites. The median lethal doses of the insecticide content of the plant tissue were higher during declining phase of absorption as compared to those obtained during the active absorption phase. The result indicated the lesser toxicity of some components in the total residue during the later phase of the crop. Application of phorate granules in leaf axils was less effective than the treatment done in the soil and hence the current recommendation to use less quantity of insecticide when applied in the leaf axils has to be altered. A simple technique for the separation, identification and quantification of phorate and its metabolites was developed. Phorate and phorate sulfoxide contents of the total residue showed inverse relationship with each other while the other metabolites did not exhibit a clear relationship among them. Phorate and phorate sulfoxide exhibited more positive direct influences on the morality of the vector than the other metabilites. The absorption and toxicity of the insecticide content in plants did not vary significantly up to 174 DAP, when applied @ 2.50 g ai/plant at different intervals after planting. Absorption was very low when the insecticide was applied at 180 and 210 DAP. For ensuring residues within tolerance limits (0.10ppm) in raw fruits, the insecticide treatment has to be limited to 150 DAP and for ripe fruits the limit can be extended up to 180 DAP. The absorption and persistence of phorate and metabolites was significantly higher in plants grown in summer season than in those grown in rainy season. The absorption of insecticide was high in sandy soils and it was lowest in black cotton soils during the active absorption phase. The insecticide persisted at effective levels for 75 days in sandy, 90 days in lateritic upland and 105 days in black cotton soil. Sulfoxidation of the thioether moiety was the dominent metabolic pathway in sandy soil while desulfuration pathway was predominent in the other three soils. Application of phorate at planting, @ 2.50 g ai/plant, did not adversely affect the soil microflora as observed at the time of harvest of the crop.ThesisItem Open Access Phosphorus management in a rice based cropping system(Department of Agronomy, College of Agriculture, Vellayani, 1989) Annamma, George; KAU; Sasidhar, V KIn order to standardize an appropriate phosphorus management practice in a rice based cropping system involving rice-rice-cowpea/sesamum, field experiments were carried out in the rice fields of the Instructional Farm, College of Agriculture, Vellayani from June 1984 to September 1986. The experiment was laid out in a randomized block design with three replications. There were eight treatments. The treatments comprised of (1) continuous phosphorus application to all the three crops in the system (2) phosphorus application to the first and second crops of rice (3) phosphorus application to the first crop of rice and third crop of cowpea/sesamum (4) phosphorus application to the first crop of rice only (5) phosphorus application to the second crop of rice and third crop of cowpea/sesamum (6) phosphorus application to the second crop of rice only (7) phosphorus application to the third crop of cowpea/sesamum only (8) control plot with no addition of phosphorus to any of the crops in the system. The salient findings of the experiment are as follows: Phosphorus application had no significant influence on grain and straw yield of first crop of rice. But available nitrogen, available and total phosphorus and available potassium of the soil were increased with phosphorus application. Direct, residual and cumulative effects of phosphorus had no significant influence on grain and straw yield of second crop of rice. Phosphorus uptake could not show any variation due to the different treatments. Available and total phosphorus content of the soil were highest under cumulative phosphorus treatment. All the growth and yield attributes of third crop of cowpea and sesamum were increased by the direct and cumulative effects of phosphorus. Grain yield of cowpea was significantly increased by the direct application of phosphorus. Eventhough not significant the highest sesamum yield was accorded by the direct and cumulative application of phosphorus. Phosphorus uptake in all the growth stages of the crop was highest in direct phosphorus plots. Available and total phosphorus content of the soil was highest in continuous phosphorus applied plots. There was no significant influence on grain and straw yield of first crop of rice after cowpea and sesamum in the direct, residual and cumulative effects of phosphorus. Residual phosphorus was sufficient to maintain the available nitrogen status of the soil. Available phosphorus of the soil was increased by the direct, cumulative and continuous application of phosphorus and total phosphorus by continuous application of phosphorus. Balance sheet of available phosphorus revealed that the soil phosphorus level almost maintained, where phosphorus was applied only to the third crop of cowpea or sesamum. The highest net return and benefit-cost ratio for the rice-rice-cowpea and rice-rice-sesamum system was obtained when phosphorus was applied only to the third crop in the rice fallow and the residual effect being utilized by the succeeding rice crops.ThesisItem Open Access Nitrogen losses from the rice soils of Kerala with special reference to ammonia volatilization(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1989) Anila Kumar, K; KAU; Rajaram, K PIn order to get a deeper insight in to the N dynamics of selected submerged rice soils, an investigation entitled “Nitrogen losses from the rice soils of Kerala with special reference to ammonia volatilization” was carried at the Regional Agricultural Research Station, Pattambi during 1985 – 87 with the following objectives. 1. To estimate the magnitude of ammonia volatilization losses from submerged rice soils, representing major rice growing tracts of Kerala. 2. To study the factors which are responsible for accelerating the rate of ammonia volatilization under flooded soil conditions. 3. To evaluate the effect of submergence, organic matter application, complementary effect of P and K on ammonia volatilization from the rice soil ecosystem. 4. To identity suitable N carriers capable of reducing the loss of N due to ammonia volatilization from submerged paddy soils. 5. To find out the effect of continuous application of organic and inorganic manures in lateritic submerged paddy soils on the quantum of N loss through ammonia volatilization. 6. To find out the transformations and extent of mineralization of applied urea. With these objectives, in view, a serious of laboratory incubation studies, followed by pot culture trials were carried out and the results were finally verified under field experiment also. Besides these, the plots of permanent manorial trial (dwarf indica) were utilized for estimating the N loss through ammonia volatilization on long term application of organic manures and inorganic fertilizers. In the incubation study for estimating the magnitude of N loss though ammonia volatilization, eight rice soils of kerala viz., sandy, karapadam, kayal, kari, pokkali, kole, poonthalpadam and laterite soils representing the major rice growing tracts of Kerala were incubated with no N and 27 g N m-2 as urea. Air train and acid trapping device was utilized to collect the volatilized ammonia. The results showed that sandy soil collected from Onattukara region registered an increased N loss through ammonia volatilization, whereas in the kole soil of kattukampal, the process was retarded to the lowest level. More than 75 per cent of the volatilization loss was observed within 9 days after urea application. Significant negative correlation was observed between ammonia volatilization and organic matter content, clay fraction and cation exchange capacity of the soil, whereas the coarse sand fraction showed significant positive correlation. Soil sterilization had little influence on ammonia volatilization in any of the soil under study. Another incubation study to assess the impact of quantity of urea applied on the quantum of N loss through ammonia volatilization was carried out using four soil types (sandy, kayal, poonthlpadam and laterite soils) with four rates of N application (9, 18, 27 and 36 g N m-2 ). The results indicated that the N loss through ammonia volatilization had a positive relationship with increased rates of urea application, though not linear. The complementary effect of phosphorus and potassium on the extended loss of N through ammonia volatilization was estimated in another incubation study utilizing the same four soil types with treatment as N alone, N and P, N and K and N, P, K @ 27:13.5:13.5 g N, P, K m-2 respectively as urea, superphosphate and muriate of potash. The results revealed that combind application of urea and muriate of potash was found to be significantly better in reducing the volatilization loss to be significantly better in reducing the volatilization loss of ammonia compared to the treatments, N alone and N and P. The incubation study to find out the influence of depth of submergence on the rate of volatilization of ammonia was conducted using the same soil types and four treatments (soil saturation, 5,10 and 20 cm submergence). The results showed that the soil samples maintained at saturation point recorded double the values for ammonia volatilization, compared to samples kept under submergence of 20 cm depth. The effect of application of organic matter on N loss through ammonia volatilization was studied in the same four soil types with the treatments as no organic matter, 0.25, 0.50, 0.75 kg organic matter m-2 as farm yard manure. The results indicated that application of organic matter was found to reduce volatilization losses considerably in all the soils studied and the lowest value recorded was for the treatment receiving farm yard manure @ 0.75 kg m-2. The relationship between N sources and the extent of volatilization of ammonia was investigated in another incubation study employing the same four soil types and ten different N carriers to supply 27 g N m-2. The relative efficiency of different N carriers in reducing the ammonia volatilization loss was in the order sulphur coated urea > urea mudball > gypsum coated urea > rock phosphate coated urea = neem cake coated urea = ammonium sulphate = ammonium chloride > urea : coconut pith: soil = urea. The pot culture study to trace the pathway of transformation and extent of mineralisation of urea under flooded soil condition consisted of three soil types (laterite, kari and poonthalpadam soil) and two levels of N (no N and 90 kg N ha-1 as urea). The rate of mineralisation of applied urea followed the soil reaction and the mineralisation stopped at the stage of NH+4 formation and hence chances of N loss through denitrification is meagre, unless the soil is aerobic. The second pot culture experiment was conducted with a view to identify the different ways that result in minimum loss of N through ammonia volatilization in sandy and laterite soils. The study showed that the decreasing order of N loss through ammonia volatalization from different N carriers followed the order, urea basal = urea; coconut pith: soil = coaltar coated urea = gypsum coated urea = rock phosphate > coated urea > urea split > urea super granule > urea mudball > sulphur coated urea. The five treatments selected from this experiments viz., urea split, urea mudball, urea super granule, gypsum coated urea and rock phosphate coated urea on reduced ammonia volatilization and high grain yield were compared in another pot culture trial and finally it was verified under field experiments in trial and finally it was verified under field experiments in laterite soil. The results revealed that urea mudball placement in the anaerobic layer of soil was found to reduce the n loss through ammonia volatilization to negligible level. Treatments with surface application of rock phosphate coated urea and urea in split dose ranked second and third position respectively in reducing the volatilization losses. Treatment receiving split application (top dressing of urea at 20 and 40 DAT) reduced ammonia volatilization considerably. Significant positive correlation was found between the cumulative N loss through ammonia volatilization and flood water pH measured at 0800 hrs and 1400 hrs, flood water NH4 – N content and flood water bicarbonate content. The pH of flood water measured at 1400 hrs were significantly higher than the value recorded at 0800 hrs and highest diurnal variation was observed for treatment with urea super granule deep placement. The urea super granule deep placement treatment resulted in increased grain yield in both the pot culture trials and field experiment. However, in field experiment the effect of different N carriers on grain yield was found to be uniform. The periodical N uptake by plants as well as N accumulation in grain and straw at harvest were found to be higher in the case of treatments receiving USG deep placement and urea split application. The effect of long term application of organic and inorganic nitrogen sources in soil on the rate of n lose through ammonia volatilization was studied utilizing the permanent manorial experiments. Plots receiving combined application of cattle manure + green leaves + NPK @ 45:45:45 kg N, P2 o5, K2 o as ammonium sulphate, super phosphate and muriate of potash were recorded the lowest value of n loss via ammonia volatilization when compared to other treatment plots.ThesisItem Open Access Structural and functional linkages in the transfer of technology of improved rice varieties released by the Kerala agricultural university-a system analysis(Department Of Agricultural Extension, College Of Agriculture, Vellayani, 1989) Abdul rahiman Kunju, O; KAU; Tampi, A MThe study aimed at analyzing the extent of existing structural and functional linkages between and among the Research Sub- system (RSS), the Extension Sub-system (ESS), the Client Sub- system (CSS) and the Input Sub- system (ISS) in the transfer of technology (TOT) of improved rice varieties released by the Kerala Agricultural University (KAU). The study was conducted in the Alleppey, Ernakulam, Trichur and Palghat districts of Kerala. Respondents of the study consisted of 52 researchers, 134 extension personnel, 110 farmers and 32 representatives from the input agencies. To delineate the structural linkages between and among the four sub- systems involved in the TOT process, detailed analysis of the existing formal mechanics of linkage were analysed. Linkage activities that could be performed by each sub- system were identified and relevancy rated for measuring the extent of performance and perception of importance of these linkage activities by the respondents. A linkage index was developed to measure the perception of importance of linkage activities by the respondents. Data from the RSS, ESS, and ISS were collected using separate pre-tested structured questionnaires. Data from the CSS were collected using a pre- tested structured interview schedule. In structural linkage, it was found that there were appreciable linkage forums for the RSS and the ESS. But there was lack of organized linkage forums for the CSS and the ISS. Representation for the ESS in the linkage forums of the RSS was found to be restricted to higher officials. There was no representation for the ISS in the important linkage forums of the RSS. The regularity and periodicity of convening of the package of practices workshops, Extension Advisory Committee (EAC) and State Level Technical Committee (SLTC) were also found not being strictly adhered to. In functional linkages, the extent of linkage of the ESS with CSS and the ESS with the ISS were significantly better and reciprocal. Though the RSS viewed its linkage with the ESS and the CSS as good, the ESS and the CSS did not subscribe to this view. Similarly, the ISS viewed that its linkage with the RSS and the CSS was good but the RSS and the CSS did not corroborate this. Based on these results the hypotheses set for the study were either rejected or accepted. In order to segregate the factors associated with the functional linkages between and among the four sub- systems in the TOT of improved rice varieties, principal- factor analysis was done and the factors were extracted and labeled appropriately. The perception about the importance of linkage activities of the ESS with the CSS and the ISS was significantly better and reciprocal. But the perception about the importance of linkage activities of the RSS with the ISS, the ESS with the RSS and the CSS with the RSS and the ISS were significantly poor and hence the hypotheses set for the study were rejected. Lack of infra- structural facilities for research followed by insufficient staff strength and lack of facilities to multiply seeds were the most- important constraints in evolving and spreading the improved rice varieties as perceived by the RSS. Susceptibility to pests and diseases followed by the need for heavy dose of fertilizers and pesticides and poor cooking quality were the most important constraints in spreading and adopting the improved rice varieties as perceived by the ESS, the CSS and the ISS. Based on the results of the study, certain important implications have been spelt out.
