1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Conching cum tempering machine for chocolate production(Department of processing and food engineering, Kelappaji college of agricultural engineering and technology,Tavanur, 2023-07-24) Navale Abhishek Govind; Rajesh, G.KItem Optimum stratification for yield estimation in cocoa (Theobroma Cacao L.)(Department of Agricultural Statistics, College of Horticulture, Vellanikkara, 2000) Sunil Kumar, G; Gopinathan Unnithan, V KInvestigation on "Optimum stratification for yield estimation In cocoa (Theobroma cacao. L)" was carried out in the department of Agricultural Statistics, College of Horticulture, V ellanikkara during 1997-99 using data on 1025 'F orestro' variety cocoa trees from the Cadbury-KAU Co-operative Cocoa Research Project (CCRP), College of Horticulture, Kerala Agricultural University. Four different stratification rules, viz, cumulative root 'f rule, cumulative cube root 'f rule, Ekman's rule and an iterative procedure for function minimisation, were used to arrive at boundary points of strata. For each of these rules stratification was carried out on average yield of yester years, canopy spread, value of HxG2 where 'H' is height and 'G' is the girth of the trees, the first principal component derived from these variates and height and girth of the trees and regression estimate of the study character with the predictor variables mentioned above. Sampling variance of the estimator of the population mean under Neyman allocation for two to five strata situations was estimated in each case, assuming a uniform sample size of 200. Different stratification rules and stratification variables were compared using these estimates. No single rule was found to be appropriate for all the stratification variables and for different number of strata. But in most of the cases the cumulative root 'f rule was found to be good for smaller number of strata followed by the cumulative cube root 'f rule. For large number of strata, the iterative procedure performed consistently well compared to all the other methods. In the case of stratification based on the canopy spread, the Ekman' s method was found to be good for different numbers of strata. Regarding the stratification variables, the average yield of yester years was found to be best followed by the regression estimate in the sense of resulting in smaller sampling variance of the estimator of the population mean. Stratification based on value of HxG2 and the first principal component were found to be inferior. Average yield of yester years or regression estimate of yield could be used as covariate to perform the analysis of covariance for experiments in cocoa and also blocking of trees could be done based on these for the conduct of planned experiments on cocoa.Item Estimation of genetic parameters from specific crosses of cocoa (Theobroma Cacao L.)(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1999) Sridevi, R; Prasanna Kumari Amma, SThe research project entitled 'Estimation of genetic parameters from specific crosses of cocoa (Theobroma cacao L.)' was carried outean ongoing experiment of Cadbury-KAU Co-operative Cocoa Research Project (CCRP), College of Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur during 1998-99. The studies were conducted in four year old hybrids. The major objectives were to study the genetic variability, heritability, correlation of different traits with yield, extent of heterotic expression of various traits and to examine the association between seedling vigour and yield. Twenty five cocoa hybrids were maintained in randomised block design with three replications. The hybrids exhibited significant variability for most of the traits studied. The estimates of pev were higher than gcv for all the traits studied. The highest heritability was recorded for number of beans per pod and seedling vigour recorded as °HD2 (6 MAS) had a high genetic gain. Yield and number of pods per tree recorded moderate genetic gain. Yield was found to be significantly and positively correlated with number of pods per tree, height (2 YAP) and girth (2 YAP) of the tree. Absence of significant correlation between yield and seedling vigour was observed. Path analysis revealed the importance of pod number per tree and wet bean weight per pod in determining yield. Yield and number of pods per tree showed a very high heterotic expression in most of the hybrids. Among the 25 cross combinations H23 was identified as the superior cross combination followed by H16 and H; The parents of these cross combinations can be used for raising biclonal seed gardens, as they had a good specific combining ability. The floral traits did not vary markedly in the hybrids. However the qualitative traits exhibited wide variation in the different hybrids.Item Studies on the floral biology and fruit set in cocoa (Theobroma cacao L.)(Department of Plantation Crops, College of Horticulture, Vellanikkara, 1981) Rajamony, L; Mohanakumaran, NStudies were conducted at the Regional Research Station, Pillicode during 1980-81 to gather information on the pattern of flowering and fruiting , aspects of floral biology, fruit set , fruit development etc. in cocoa. Though flowering was seen throughout the year, two peak seasons (may –June and November-December) could be identified . A double peaked pattern was also observed with regard to pod harvest, June –August being the major peak. Cherelle wilt occurred throughout the year , the maximum being in July. Cherelles did not wilt after the tenth week of development. Data on the commencement and completion of anthesis and anther dehiscence were collected . The stigma receptivity was found to be high between 12 noon to 2 pm . A medium for germinating pollen grains in vitro was identified . Keeping pollen grains in tissue paper packets under dry and comparatively cool conditions extended the viability up to five days . Seven Dipterous insects and five Formicid species were identified as floral visitors . The fifteen plants included in the studies were found to be cross-compatible ; but only four of them were self – compatible. Hand pollination increased the percentages of fruitset and pod harvest , indicating scope for assisted pollination in cocoa. Variation was observed between the main trunk and the fan shoots with regard to the percentage of fruit set, number of cherelles wilted and the percentage of cherelles carried to maturity . The cushions that supported developing pods up to the harvestable stage flowered less frequently than those which exhibited no set or complete wilting of cherelles. The development of cocoa pods was found to be a very gradual process. The pods took , on the average , about 140 days to reach the ripening stage.Item Somatic embryogenesis in cocoa (Theobroma cacao L.)(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1993) Jolly Antony; Achamma OommenInvestigation on somatic embryogenesis in cocoa (Theobroma cacao L.) were carried out at the college of Horticulture, Kerala Agricultural University, Vellanikkara during the period 1989-91, with the objective of studying the developmental potential of somatic embryos and its differentiation into plantlet by means of in vitro techniques. Stem and leaf segments, cotyledons and enbryonic axes of embryos collected from four typical genotypes of cocoa namely criollo, Amelonado, Amazon-forastero and Trinitario were used as explant. Cotyledons and embryonic axes of immature embryos (100 days pot anthesis) when incubated on MS basal semisolid medium supplemented with NAA 2 mg/1, thiamine 1 mg/1, casein hydrolysate 0.2 per cent (W/V) and coconut water 15 per cent (v/v) under dark for seven weeks resulted in high frequency and intensity of embryogenesis. Stem segements remined recalcitrant without embryoid regeneration, while leaf segments had a little potential. Auxins conditioned the culture for embryogenic competence while cytokinins had an inhibitory effect. The effect of NAA 2ppm was not replaceable by other auxins such as IAA, 2, 4-D. 2,4-D was a poor quantitative and qualitative stimulant of embryogenesis. Studies on auxincytokinin interaction revealed the counteracting effect of cytokinin on auxin. Fully mature embryoids germinated in hormone-free liquid medium consisting of half the salt concentration of MS and 5 per cent sucrose when incubated at 3000 lux (16 hours) for two weeks. De-cotyledonisation of embryoids and its rinsing with sterile distilled water and dessication, each for three minutes, enhanced the differentiation into plantlet. Shoot growth was stimulated by exogenous supply of NAA, GA3 and coconut water. In vitro rooting was promoted by reducing the salt concentration of MS medium to half strength and supplementing with IBA and activated charcoal. Germination and regeneration of embryoid into plantlet was dependent on its size. Sizes ranging from 0-4 mm were sub-optimal for germination and differentiation. Larger embroids (4-6 mm) had greater potential for differentiation. Quantitative and qualitative differnces were expressed by cocoa genotypes. Amelonado was found to be superior to Criollo and Amazon types for the induction of embryogenesis from cotyledons. Trinitario was the least efficient. Embryogenic potential of Amazon embryonic axes was superior to Criollo and Amelonado types. Trinitario embryonic axes remained recalcitrant. Plantlets were derived from embryoids within a time span of 13 weeks in Amelonado, Criollo and Amazon types.