Browsing by Author "Rajamony, L"

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Characterization of vegetable cowpea
(Department of Olericulture, College of Agriculture, Vellayani, 2006) Manju, P R; Rajamony, L
The research project “Characterization of vegetable cowpea (Vigna unguiculata (L.) Walp.)” was conducted at the Department of Olericulture and Department of Plant Biotechnology, College of Agriculture, Vellayani, during 2002 to 2005. The objective of the study was to genetically catalogue the accessions based on IPGRI descriptor for cowpea, to estimate the genetic parameters for different traits in the germplasm as well as to characterize them based on morphological, anatomical, biochemical and molecular parameters. Sixty six accessions of vegetable cowpea collected from various sources upon cataloguing pointed out wide variation for several morphological characters. Analysis of variance revealed significant differences among the accessions for all the characters studied coming under growth, flowering, pod, yield and quality. Among the accessions evaluated, VS 8 (CHCP-1) had the highest yield (1136.89 g) and pods per plant (102.59), while VS 19 (Aryanad, Thiruvananthapuram) and VS 4 (Kanjikuzhi Payar) were noted for their high pod length, pod weight, pod girth, seeds per pod, 100-seed weight and vine length. Root : shoot ratio had the highest phenotypic and genotypic coefficients of variation, followed by pod weight and yield per plant. High heritability coupled with high genetic advance was observed for yield per plant, pods per plant, pod length and pod weight. Correlation studies revealed that characters like vine length, collar girth, pod length, pod girth, pod weight, pods per plant, seeds per pod, 100-seed weight, seed length, seed width, number of harvests, keeping quality and pod protein observed high positive correlation with yield, whereas root : shoot ratio and peduncle length were negatively correlated with yield. Path coefficient analysis indicated that pods per plant exerted the highest positive direct effect on yield, while seed length, pod weight and vine length had high indirect effects on pod yield. In discriminant function analysis, the accession VS 27 (Pattom, Thiruvananthapuram) ranked first, followed by VS 8 (CHCP-1) and VS 19 (Aryanad, Thiruvananthapuram). Based on Mahalanobi’s D2 statistic, the 66 accessions were grouped into ten clusters. Cluster I was the largest containing 18 accessions, while cluster X was the smallest with two accessions. Cluster X performed better most of the biometric characters, with the highest intercluster distance observed between clusters VI and X. On screening the accessions for legume pod borer resistance, VS 19 (Aryanad, Thiruvananthapuram) was found to be the most tolerant, while VS 42 (Pilicode, Kasargode) was the most susceptible. Pod trichome density as well as phenol content were negatively correlated with plant susceptibility index. On the basis of the present study, VS 27, VS 8 and VS 19 were found to be promising based on their superiority in yield, quality and tolerance to legume pod borer and hence they may be utilized for further crop improvement programmes. The organoleptic quality and overall acceptability of all the accessions was also assessed based on appearance / colour, doneness, taste, flavour and texture. The overall acceptability ranged from 2.00 to 3.60 and 2.40 to 3.60 in vegetable and dual purpose / grain types respectively. Characterization of vegetable cowpea based on seed protein banding pattern as well as RAPD revealed the presence of wide variability among the accessions. Similarity coefficient values ranged from 0.20 to 0.97. At 66 per cent similarity, the selected 50 accessions were grouped into eleven clusters. It may be concluded that molecular characterization may be used as a tool for DNA fingerprinting as well as parental selection for further crop improvement in vegetable cowpea. The study also highlighted the probable development of yard long beans from grain type cowpeas with the dual purpose and bush types as intermediate forms.
Collection and characterization of landraces of brinjal (Solanum melongena L.) in Kerala
(Department of Olericulture, College of Agriculture, Vellayani, 2000) Sheena Sebastian; Rajamony, L
A study was carried out to characterize the landraces of brinjal Solanum melongena L. in Kerala at the Department of Olericulture, College of Agriculture, Vellayani. The collections were evaluated for morphology, yield, yield attributes and reactions to various biotic stresses viz, fruit and shoot- borer (Leucinodes orbonalis Guen.), bacterial wilt (Ralstonia solanacearum Yabuuchi), phomopsis blight (Phomopsis vexans (Sacc. & Syd.) Hartat) and -little leaf (Mycoplasma). The genetic parameters, correlation and path coefficients were studied and a selection index was formulated to identify superior genotypes. landraces showed significant difference for all the characters except stomatal distribution and branch and node of flowering. S 33 collected from Adoor (Pathanamthitta) was the top yielder. S. macranthum Dun., S. melongena var. insanum and S. xanthocarpum were highly resistant against shoot and fruit borer. Landraces, viz., S 1 (Neyyattinkara, Thiruvananthapuram), S 13 (Athichanallore, Kollam), S 28 (Thamarakulam, Alappuzha, S 35 (Poonjar, Kottayam), S 36 (Eara, Kottayam) and (S 37 (Manarkadu, Kottayam) were found with high resistance. Collections, viz., S 15 from Kundara (Kollam), S 22 from Thiruvakkal (Alappuzha), S 23 from Cherthala (Alappuzha), S 32 and S 33 from Adoor (Pathanamthitta), S 47 from Irinjalakuda (Thrissur) and S 55 from Ozhur (Malappuram) were resistant to bacterial wilt coupled with high yield and yield attributes. Resistance to phomopsis blight was noted in wild/semi-wild species, viz., S. macranthum, S. melongena var. insanum and S. xanthocarpum and in cultivated types, viz., S 1 (Neyyattinkara, Thiruvananthapuram), S 13 (Kundara, Kollam), S 15 (Athichanallore, Kollam), S 17 (Odanavattom, Kollam), S 23 (Cherthala, Alappuzha), S 32 and S 33 (Adoor, Pathanamthitta), S 34 and S 35 (Poonjar, Kottayam) S 36 (Eara, Kottayam), S 45 (Muvattupuzha, Ernakulam), S 46 (lrinjalakkuda, Thrissur), S 53 (Walayar, Palakkad), S 55 (Ozhur, Malappuram) and S 60 (Ambalawayal, Wynad). Incidence of little leaf disease was seen only in S 10, a landrace from N edumangad (Thiruvananthapuram). Multiple resistance to all the major biotic stresses was noted in S. melongena var. insanum and S. xanthocarpum and in landraces, viz., S 1 (Neyyattinkara, Thiruvananthapuram), S 13 (Athichanallore, Kollam) and S 36 (Eara, Kottayam). The landraces were described using the simplified descriptor for eggplant provided by the IBPGR, Rome. GCV and PCV were highest for fruits per plant followed by fruit length, petiole length, seed weight, fruit breadth and yield. High heritability coupled with high genetic advance was noted for fruits per plant, fruit length, petiole length, fruit breadth, seed weight, yield, leaf area index, branches per plant, dry weight and fruit weight indicating scope for the improvement through selection. Plant height, stem girth, branches per plant, canopy spread, dry weight, leaf area index, leaf thickness, vascular bundles, fruits per plant, fruit length, fruit weight, harvest index and organoleptic quality had high positive correlations with yield whereas days to flower and fruit breadth had a negative correlation. Path analysis revealed plant height, fruits per plant, stem girth and harvest index as primary contributors to yield. Fruit borer incidence showed a positive correlation with fruit breadth and a negative correlation with fruits per plant whereas, phomopsis blight incidence showed a significant negative association with plant height. A selection index was constructed based on the yield per plant and nine yield contributing characters. The landraces S 33 from Adoor (Pathanamthitta), S 22 from Thiruvakkal (Alappuzha), S 23 from Cherthala (Alappuzha), S 47 from Irinjalakkuda (Thrissur), S 25 from Thathampally (Alappuzha), S 55 from Ozhur (Malappuram), S 15 from Kundara (Kollam), S 42 from Thodupuzha (Idukki), S 32 from Adoor (Pathanamthitta) and S 52 from Nilambur (Malappuram) were identified as elite in terms of yield and field resistance against various biotic stresses.
Collection and characterization of landraces of culinary melon (Cucumis melo L.) in Kerala
(Department of Olericulture, College of Agriculture, Vellayani, 2001) Rakhi, R; Rajamony, L
A study was carried out to characterize the landraces of culinary melons Cucumis melo L. in Kerala at the Department of Olericulture, College of Agriculture, Vellayani. Forty two collections were evaluated for morphology, yield, yield attributes and reaction to the incidence of virus disease. The genetic parameters, correlation and path coefficients were studied and a selection index was formulated to identify superior genotypes. Landraces showed significant difference for all the characters except number of primary branches, branch of first male and female flower production. CM~, collected from Kattakada, (Thiruvananthapuram) was the top yielder. Landraces viz., CM 5 (Kattakada, Thiruvananthapuram), CM 17 (Kalavoor, Kottayam), CM 3 (Nemom, Thiruvananthapuram), CM 36 (Kattapana, Idukki) were superior in mosaic virus resistance and yield. CM 18 (Manimala, Pathanamthitta) and CM 33 (Velloor, Kottayam) were found resistant with medium yield. GCV and PCV were highest for yield per plant followed by fruit weight, fruit per plant, keeping quality of fruits and 1000 seed weight. High heritability coupled with high genetic advance was noted for fruit length, 1000 seed weight, average fruit weight and keeping quality of fruit indicating scope for the improvement through selection. Vine length, leaf area index, fruits per plant, average fruit weight, fruit length and fruit girth had high positive correlation with yield whereas days to produce first male flower, days to produce first female flower, days to first harvest and node of appearance of first female flower had a negative correlation with yield. Path analysis revealed fruits per plant, length of fruit and girth of fruit as primary contributions to yield. A selection index was constructed based on the yield per plant and eight yield contributing characters. The landraces CM 5 (Kattakkada, Thiruvananthapurarn), CM 48 (Periya, Wayanad), CM 6 (Aryanad, Thiruvananthapuram), CM 3 (Nemom, Thiruvananthapuram), CM 36 (Kattapana, Idukki), CM 46 (Perinthalmanna, Malappuram), CM 17 (Kalavoor, Kottayam), CM 35 (Thrikkodithanam, Kottayam), CM 50 (Kanhangad, Kasaragod), CM 7 (Aryanad, Thiruvananthapuram) were identified as elite in terms of yield, field attributes and resistance against mosaic virus disease incidence.
Device for bagging cocoa flowers
(Kerala Agricultural University, 1987) Rajamony, L; Mohanakumaran, N
Embryo rescue in the interspecific crosses of abelmoschus
(Department of Horticulture, College of Agriculture, Vellayani, 1996) Manju Chandran; Rajamony, L
Evaluation of desert type of muskmelon (Cucumis melo L.) for southern region of Kerala
(Department of Horticulture, College of Agriculture, Vellayani, 1992) Elizabeth Chacko; Rajamony, L
The present investigation was carried out with fifteen muskmelon varieties during December – May (1989 – 90) at the College of Agriculture, Vellayani. The evalution was done in a randomised block design with three replications and in three sowing months of December 1989, January 1990 and February 1990, to assess the variability available in desert muskmelon with respect to growth, production and quality parameters, to study the interrelationships among yield components and to assess the suitability of the available dessert types of muskmelon for cultivation in the southern zone of Kerala during December – February season. Significant differences were observed among the varieties in the three sowing months for the percentage of germination, number of days to first male/female/bisexual flower production, their node of production, days to first harvest and first fruiting node, yield per vine and volume of fruit, length of vine, number of branches, fresh weight of shoot, reaction towards pest and organoleptic test. Pooled analysis revealed significant influence of environment on the characters viz., days to first harvest, first fruiting node, yield per vine, volume of fruit, length of vine and number of branches. It was observed that December sown crop possessed the majority of the desirable characters and the varieties suitable were Pusa Sharbathi and PMR – 6. The percentage of germination, total weight of fruits/vine, volume of fruit, F/C ratio, percentage of reducing and reducing sugars, acidity, fresh weight of shoot and number of branches exhibited moderate or high values of GCV. High heritability in conjunction with high genetic advance was observed for percentage of germination, yield/vine, volume of fruit vine length. Therefore these characters form reliable index for selection. Significant positive correlations were observed between percentage of germination and yield per vine and number of fruits per vine. The association between number of days for first female/bisexual flower production and first harvest revealed that early flowering variety will be early in coming to harvest also. Yield per vine displayed significant positive association with volume of fruit which in turn was strongly associated with number of tertiary branches and the number of branches with the length of vine. TSS exhibited significant positive association with acidity.
Floral biology anthesis and fruit development in drumstick (moringa oleifera lam.)
(Department of Olericulture, College of Agriculture, Vellayani, 2002) Sindhu K Mathew; Rajamony, L
A study was conducted at College of Agriculture, Vellayani during 2001-2002 to gather information on floral biology, anthesis and fruit development in drumstick (Moringa oleifera Lam.). Sixty bearing plants were utilized for the experiments carried out during June 2001 to May 2002. Flowering was observed throughout the year except in the month of November and December. Two flowering peaks viz., July - August and February - March were recorded. The fruit production peaked during July - August and March - April. Flower buds took an average of 29.8 days or 472.25 degree days for its complete development during rainy season and 24.8 days and 471.18 degree days during summer season. Anthesis continued throughout the day with two peaks at 14 hand 04 h. Anthers were of closed type at the time of anthesis and they dehisced later. Stigma was receptive a day prior to opening and continued up to the day of opening with maximum receptivity. The pollen grains w~re spherical with smooth ex me and had three germpores. The average diameter of fertile and sterile pollen grains was 43.5 urn and 33 urn respectively. The average pollen production per anther in rainy and summer seasons was 7250 and 7500 respectively. Pollen grains exhibited highest germination and tube growth in 15 per cent sucrose medium. Viability on acetocarmine staining and germination was 97 and 88 per cent respectively. The pollen grains stored under refrigerator lost their viability within seven days while under room temperature pollen lost viability within three days. The drumstick was found cross pollinated and entomophilous. Honeybees were the chief pollinators. Insect activity was maximum 60 between 10 and 14 h. Natural pollination per cent was maximum in March and minimum in September. An average of 5.55 and 5.00 days were taken for fruit set in rainy and summer seasons respectively. Flower shedding percentage was 92.73 and 88. 60 in rainy and summer seasons. The fruit maturity per cent was 2.7 and 3.7 during these periods. During rainy season, fruits took an average of 42 days or 635 degree days for horticul tural maturity whereas 70 days or 1112.15 degree days required for physiological maturity. In summer season, fruits attained horticultural maturity in 34 days and physiological maturity in 59 days. Degree days requirement for these was 634.65 and 1111.68 respectively.
Genetic analysis in f2 generation of irradiated interspecific hybrids in okra (abelmoschus spp.)
(Kerala Agricultural University, Vellanikara, 2001) Sophia, John; Manju, P; Rajamony, L
Genetic analysis in f2 generation of irradiated interspecific hybrids in okra (abelmoschus spp.)
(Kerala Agricultural University, Vellanikara, 2001) Sophia, John; Manju, P; Rajamony, L
Genetic analysis of shade tolerance in chilli (Capsicum spp.)
(Department of Olericulture, College of Agriculture, Vellayani, 2000) Sreelathakumary, I; Rajamony, L
Investigation on 'Genetic analysis of shade tolerance in chilli (Capsicum spp.)' was carried out in the Department ofOlericulture, College of Agriculture, Vellayani, during 1997 - 2000 with the objective of identifying superior genotype(s) of chilli to yield better under shade and to analyse the physiological, anatomical, biochemical and genetic basis of shade tolerance. Seventy genotypes of chilli belonging to C. annuum, C. Jrutescens and C. chinense collected from different parts of the country were initially evaluated under 25, 50 and 75 per cent shade in comparison with open condition for shade tolerance and yield. Plant height, internodal length, stem girth, leaf area, petiole length, days to first flower, node to first flower, height of node to first flower, fruits per plant, fruit length, fruit girth, fruit weight, yield and incidence of mite were found significantly different both among the genotypes and between different shade levels. High heritability combined with high GCV and expected genetic advance was observed for fruits per plant, fruit weight, fruit length, fruit girth, leaf area and yield under shade indicating the possibility of improvement of these characters through selection. A positive correlation was observed for fruits per plant, fruit length and fruit weight with yield at genotypic and phenotypic levels. CA 38 of C. annuum, CF 51 of c. Jrutescens and CC 63 of C. chinense were identified as shade tolerant and CA 39 of C. annuum, CF 46 of C. Jrutescens and CC 66 of C. chinense as shade susceptible genotypes. The shade tolerant genotypes were found to be superior in maintaining higher LAl, SLW, CGR, RGR and NAR under shade than shade susceptible ones. Genotypes grown under open had thicker leaves with more stomates per unit area. Anatomical attributes viz., upper and lower epidermal cells, palisade and spongy mesophyll cells and vascular bundle thickness were maximum in open. The increase in chlorophyll ~, h and total chlorophyll under shade was prominent in shade tolerant genotypes than that of susceptible ones. A decreasing trend was observed in chlorophyll ~ / h ratio in all the genotypes due to prominent increase of chlorophyll h fraction. The shade tolerant genotypes were found to maintain higher proline and total phenol content under shade compared to shade susceptible genotypes. Capsaicin, oleoresin and ascorbic acid content did not vary significantly due to shade. Under open condition the genotypes recorded higher carotenoid content. A polygenic system of inheritance with non-allelic interaction was revealed in shade tolerance. Duplicate type of epistasis with additive, additive x additive, dominance and dominance x dominance components of genetic variances could observe.
Relationships between seed and seedling characters in cocoa (Theobroma cacao L.)
(Kerala Agricultural University, 1982) Rajamony, L; Neelakantan Potty, N; Jayaprakash Nair, B; Kannan, K
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, N
Studies 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.
Variability studies in watermelon (Citrullus lanatus (Thunb) Mansf.)
(Department of Horticulture, College of Agriculture, Vellayani, 1995) Shibukumar, V N; Rajamony, L
Twenty watermelon genotypes were evaluated in RBD with three replication at College of Agriculture, Vellayani during 1994-95. The study was conducted to assess the variability in growth, production and quality parameters and to identify the superior types for further improvement programme. Data on nineteen characters were collected and subjected to analysis of variance and co-variance. Genetic parameters like heritability, genetic advance and correlation were estimated. The path analysis was done to assess the cause –effect relationship and discriminant function analysis to formulate selection index. The analysis of variance revealed significant difference with respect all the characters. High genotypic and phenotypic variances were observed for number of seeds/fruit and percentage of germination. Highest phenotypic and genotypic coefficients of variations were observed for 100 seed weight and weight of fruits/ plant indicating the presence of large amount of genetic variability. High heritability estimates were recorded for all the characters viz. days to germinate, percentage of germination, days to first male flower production, node at which first male flower was produced, days to first female flower production , node at which first female flower was produced, inter nodal length, length of vine node at which first fruit produced number of branches/plant, number of fruits/plant, weight of fruits /plants, weight of individual fruit, flesh thickness, rind thickness, TSS, number of seeds/fruit, 100 seed weight and days to first harvest. Number of seeds/fruit only recorded high heritability along with high genetic advance indicating additive gene action. High positive genotypic correlation and significant positive phenotypic correlation were obtained for yield with number of fruits per plant, weight of individual fruit, flesh thickness and number of branches / plant. TSS with number of branches/plant, percentage of germination and number of fruits/plants, earliness with days to first female flower production, node at which first female flower was produced, node at which first fruit was produced, length of vine and hundred seed weight. Path coefficient analysis revealed that number of fruits/plant had the maximum direct effect an yield followed by weight of individual fruits. Length of vine recorded negative direct effect on yield. Based on the result of variability, correlation and path analysis it is suggested that yield, TSS and earliness can not be improved simultaneously. Yield and TSS can be improved by selecting the characters viz. number of fruits/plant, weight of individual fruit number of branches /plant and percentage of germination. A selection index was constructed and by practicing twenty percent selection, genotypes viz. Sugar Baby, Asahi Yamato, HW 1 and Fuken were identified as the superior ones for the southern tracts of Kerala.