Browsing by Author "Sunny K Oommen"

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Breeding for yield and resistance to chilli thrips(Scirtothrips dorsalis Hood) and yellow mite( Polyphagotarsonemus latus Banks) in chilli(Capsicum annuum L.)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2009) Jayaramegowda, R; Sunny K Oommen
The present study aimed to estimate the combining ability and gene action for yield and resistance to chilli thrips and yellow mite by line x tester analysis and to identify high yielding hybrids resistant to these pests. The research work was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2008-09. Five susceptible high yielding chilli genotypes (lines) and three chilli thrips and mite tolerant chilli genotypes (testers) were crossed in a line x tester fashion to obtain 15 hybrid combinations. The lines, testers and their hybrids were evaluated in replicated field trials for yield and resistance to chilli thrips and yellow mite. The yield trial observations were recorded for 13 characters viz., days to 50 per cent flowering, plant height, number of primary branches, number of secondary branches, plant canopy width, fruit bearing period, number of fruits per plant, fruit length, fruit girth, fruit weight, green fruit yield, crop duration and capsaicin content. ANOVA revealed that the genotypes were significantly different for all the characters. Combining ability analysis indicated that the characters number of secondary branches, fruit length, fruit girth, fruit weight and green fruit yield were governed by both additive and non additive gene action. Among them fruit girth and fruit weight showing preponderance to additive gene action while others showing preponderance to non additive gene action. The remaining characters viz., days to 50 per cent flowering, plant height, primary branches, plant canopy width, fruit bearing period, number of fruits per plant, crop duration and capsaicin content are mainly governed by non additive gene action. Based on mean performance and gca effects, Vellayani Athulya was identified as the best general combiner among the lines and Bhaskar among the testers for yield and several yield contributing characters. The crosses, L1 x T3 and L5 x T2 were found to be promising chilli hybrids for yield and its component traits based on mean performance, sca effects and heterosis. The resistance was based on population count and damage intensity to chilli thrips and yellow mite. Combining ability analysis revealed that number of thrips per leaf, number of yellow mites per leaf and damage intensity due to mite were governed by non additive gene action whereas thrips damage intensity was governed by both additive and non additive gene action with preponderance to additive gene action. Among lines, Anugraha and Ujwala were tolerant to both the pests whereas, Bhaskar and Kiran were highly tolerant among testers. Anugraha, Jwalasakhi and Bhaskar were found to be best general combiner for both thrips and mite resistance among the parents. Considering both yield and resistance simultaneously, the hybrids L3 x T1 and L5 x T2 are high yielding and relatively resistant to chilli thrips and yellow mite respectively. These hybrids would hopefully yield desirable genotypes with high yield and resistance to chilli thrips or yellow mite in segregating generations. The hybrid L3 x T2 identified as relatively resistant to both chilli thrips and yellow mite was not remarkable with respect to yield.
Effect of desiccants on ripening of rice
(Kerala Agricultural University, 1984) Sasidharan, N K; Sunny K Oommen; Thomas, M J
Efficient mutagenesis in cowpea
(Kerala Agricultural University, 1984) Sunny K Oommen; Gopimony, R
Studies were undertaken to obtain precise information on the effects of six doses of gamma rays (5 to 30 krad) and seven concentrations of ethyl methanesulphonate {0.1 to 0.7 per cent) on cowpea. Gamma ray and ethyl methanesulphonate treatments resulted in physiological damages in M, generation as evidenced by the reduction in survival of plants, plant growth and fertility. Mutation frequency estimated on M, plant basis increased with increasing doses of gamma rays and ethyl methanesulphonate. Effectiveness of gamma rays increased with increasing doses upto 15 krad and there was a reduction at still higher doses. Most efficient gamma ray dose was found to be 10 krad when efficiency was estimated on the basis of lethality or sterility, while on injury basis 30 krad was the most efficient dose. Among the different doses of ethyl methanesulphonate tried, 0.4 per cent was the most effective as well as efficient, irrespective of the criterion adopted for the estimation of efficiency.
Evaluation of cowpea varieties for fodder and grain yield
(Kerala Agricultural University, 1982) Gopimony, R; Sunny K Oommen; Gopinathan Nair, V
Evaluation of okra [Abelmoschus esculentus(L)Monench] genotypes for yield resistance to shoot and fruit borer,Earias vittella(Fab)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2012) Shrishail B Duggi; Sunny K Oommen
Evaluation of vegetable cowpea (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt) for legume pod borer, maruca vitrata (fab) resistance and yield
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2000) Pournami R Panicker; Sunny K Oommen
The present study aimed at screening vegetable cowpea germplasm for legume pod borer resistance and evaluation of partially resistant cultivars thus identified for yield was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. Data for the investigation were collected from two field experiments conducted during the period 1997-1999. In the field screening programme for legume pod borer resistance, 51 diverse cultivars were evaluated on the basis of overall plant resistance index (Ipr) computed using a combination of flower, pod and seed damage measurements. The damage parameters employed in the computation of lpr were number of larvae in 25 flowers, percentage pod infestation and seed damage index (Jackai, 1982). Significant differences between cultivars were observed for these damage parameters as well as the resistance index computed based on them. Differences among cultivars in the severity of pod damage assessed as number of entry / exit holes on pod samples were also significant. The cultivar suffering least flower damage was Vs 27. The cultivars Vs 2 and 28 recorded the lowest percentage pod infestation as well as pod damage severity. Cultivar with the lowest seed damage was Vs 13. Lower Ipr values indicate higher levels of plant resistance. Consequently Vs 27 with the lowest Ipr value was identified as the most resistant among the 51 cultivars. Other cultivars on par with Vs 27 were Vs 2, Vs 7, Vs 8, Vs 10, Vs 19, Vs 28, ys 31 andVs35. Correlation analysis of different damage parameters did not suggest any relationship between flower and seed damages. Percentage pod infestation and pod damage severity showed highly significant positive correlation between . them but were uncorrelated with larval count in flowers. Seed damage was found to be positively correlated with pod damage. Despite differences in total leaf chlorophyll content among the cultivars, the correlation between total leaf chlorophyll content and plant resistance index was non-significant indicating the absence of any relationship between them. Similarly peduncle length did not show any relationship with Ipr as well as the different damage parameters. However, pod width was found to be positively correlated with Ipr, pod damage severity and percentage pod infestation. Non-glandular trichome density on pods recorded significant negative correlation with Ipr and pod damage indicating that plant resistance increases with increase in non-glandular trichome density on pods. Fifteen top ranking cultivars with respect to legume pod borer resistance were chosen and evaluated for yield and its components in a field experiment in RBD with three replications. Analysis of variances revealed significant difference among the varieties for eleven out of the fourteen characters studied. The cultivar Vs 14 was the top yielder of vegetable pods with Vs 24 on par with it. Highest pod length was recorded by Vs 28 and highest pod weight by Vs 2. High heritability and genetic advance were recorded for number of pods per plant, yield of vegetable pods per plant and pod weight. Number of pods per plant had high direct effect on vegetable pod yield. Its correlation with yield was significant and positive. This suggested that number of pods per plant is a character important in selection programmes for yield in vegetable cowpea. The cultivars Vs 14 and Vs 24 which were high yielders among the partially resistant accessions were identified as varieties suitable for cultivation in legume pod borer endemic areas.
Genetic analysis of legume pod borer a (Maruca vitrata(fab.) resistance and yield in cowpea
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2004) Anu Mary C Philip; Sunny K Oommen
Genetic divergence in cluster bean (Cyamopsis tetragonoloba (L.) Taub.)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2006) Anandhi, K; Sunny K Oommen
The present study aimed at evaluating a collection of clusterbean (Cyamopsis tetragonoloba (L.) Taub.) genotypes for yield and related characters and grouping of genotypes was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during the period 2003-2004. Twenty nine genotypes of clusterbean were evaluated for yield and yield related characters in randomized block design with three replications. The analysis of variance revealed significant differences among the varieties for all the characters studied which include days to 50 per cent flowering, plant height, number of primary branches, number of pod clusters per plant, number of pods per cluster, pod weight, pod length, number of seeds per pod, number of pods per plant and yield per plant. High values of PCV with correspondingly high values of GCV were observed in the present study for number of pod clusters per plant, number of pods per plant, number of pods per cluster and yield, which indicated the existence of high degree of genetic variation and ample scope for improvement of these characters through selection. High values of heritability coupled with high genetic advance was observed for number of pod clusters per plant, pods per plant, pod yield and number of pods per cluster suggesting additive gene action for these traits. There is immense scope for improvement of number of pod clusters per plant and number of pods per plant through selection on account of their high magnitude of heritability and exceptionally high genetic advance. Vegetable pod yield showed high positive genotypic correlation with the characters number of pods per plant, number of seeds per pod, pod weight and number of pod clusters per plant. Path coefficient analysis revealed number of pods per plant and pod weight are the characters with high direct effect. These two characters had got high indirect effect on yield through number of pod clusters per plant and number of seeds per plant respectively. Hence these characters can be identified as the major characters contributing towards pod yield and selection based on these characters would be effective for developing high yielding varieties of clusterbean genotypes. Based on Mahalanobis statistic, the 29 genotypes of clusterbean were grouped into four clusters. Cluster II was the largest with 10 genotypes. Intercluster distance was observed maximum between clusters I and IV while the close proximity was noticed between the clusters II and III. Cluster IV having the single variety Ct 11 exhibited the maximum mean value for yield per plant, number of pods per plant and number of clusters per plant indicating that this cluster is superior to the others with respect to these characters. Cluster II having Ct 7 was superior for pods per cluster, pod weight and days to 50 per cent flowering. On the basis of selection index the genotypes IC 10350 (Ct 11) and IC 8423 (Ct 7) recorded highest index value. Hybridization of the superior genotype Ct 11 of cluster IV with Ct 7 of cluster II having high pod weight would be beneficial for evolving high yielding genotypes.
Genetic variability for yield and resistance to chilli thrips (Scirtothrips dorsalis H) and yellow mite(Polyphagotarsonemus latus banks) in chilli(Capsicum annuum L)
(Department of Plant Breeding and Genetics, College of Agriculture ,Vellayani, 2008) Narsi Reddy, A; Sunny K Oommen
Induction of mutations in cowpea (Vigna unguiculata (L.) Walp.)
(Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Sunny K Oommen; Gopimony, R
Studies were undertaken to obtain precise information on the effects of six doses of gamma rays (5-30 krads) and seven concentrations of ethyl methanesulphonate (0.1-0.7 per cent) in cowpea, using the variety ' New Era'. The effectiveness and efficiency of different doses of the two mutagens in inducing chlorophyll mutations were estimated. (1) The germination of cowpea seeds was not affected by green rays even at the highest dose employed , whereas ethyl methanesulphonate inhibited germination and the reduction in percentage was progressive with increasing doses. (2) The survival of plants based on the number of seeds sown was reduced by both mutagens. Post germination mortality occured to a certain degree with gamma irrediation, whereas it did not occur to any considerable extent with ethyl methanesulphonate treatment. (3) A differential effect on the growth of shoot and that of root was observed with both mutagens in the present study. The growth inhibition was more for the shoot with gamma rays ,while ethyl methanesulphonate produced a higher degree of inhibition for the growth of root than for shoot.
Inheritance of resistance to leaf hopper [Amrasca biguttula biguttula (Ishida)] in okra, Abelmoschus esculentus (L.) Moench
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2003) Deepthi Sivanandan; Sunny K Oommen
Kanjangad - a sweet potato variety for uplands
(Kerala Agricultural University, 1995) Manju, P; Sunny K Oommen
In an investigation to identify superior clones of sweet potato (Ipomoea batatas [L.\ Lam) suitable for uplands, 36 clones were evaluated in a preliminary yield trials and 14 superior ones were clonally selected and subjected to comparative yield trial for three years. The types SPC-13, SPC-18, SPC-20 and Kanjangad gave higher tuber yield in comparison to others. SPC-13 had the highest total acceptability score followed by Kanjangad which show their superior cooking quality. The results of the farm trial conducted at 12 locations revealed the superiority of SPC-18 and Kanjangad with respect to tuber yield and low weevil incidence. However, the farmers' preference and consumer acceptability were more towards Kanjangad due to its attractive spindle shape and purple colour. Kanjangad was hence released as variety for cultivation in the uplands of Kerala.
Legume pod borer resistance and genetic divergence in domestic germplasm of yard-long bean (Vigna unguiculata ssp. sesquipedalis(L.) Verdc.)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2000) Vidya, C; Sunny K Oommen
Malika, an improved variety of vegetable cowpea
(Kerala Agricultural University, 1995) Manju, P; Sunny K Oommen
In an investigation to identify a high yielding vegetable cowpea type with good quality green pods, 13 genotypes were collected from different agroclimatic regions of Kerala and 20 single plant selections made. Based on yield and yield attributes, nine promising selections were subjected to comparative yield trial for three seasons. Even though Selection 16 and 7 ranked first and second respectively for yield of vegetable pods in the comparative yield trials, pod length and number of seeds per potl were maximum for Selection 7 which is a single plant selection from Trivandrum Local. The results of the farm trials conducted at 10 locations in Trivamlrum district revealed the superiority of Selection 7 over the others with respect to the yield of vegetable pods. Hence, Selection 7 was released as "Malika" having a duration of 100 days. It is suitable for cultivation in the homestead during kharif and in the rice fallow during summer in Trivandrum district of Kerala.
Variability and path analysis in bush type vegetable cowpea
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2001) Ajith, P M; Sunny K Oommen
The present investigation aimed at evaluation of variability for yield and its association with yield related characters along with their direct and indirect influence on yield was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. Data for the study was generated from a field experiment conducted during the period 2000-2001. Twenty genotypes of bush type vegetable cowpea which included six improved varieties and 14 local cultivars were evaluated for yield and related characters in a field experiment in randomised block design with three replications. Analysis of variance revealed high variability among the genotypes for all the characters studied viz., days to 50 per cent flowering, number of days to first harvest, length of harvest period, duration, length of main stem, number of primary branches, number of pod clusters per plant, number of pods per cluster, number of pods per plant, pod length, pod girth, pod weight, number of seeds per pod and yield of green pods per plant. High phenotypic arid genotypic coefficients of variation were observed for length of main stem, number of primary branches and pod weight. The variety Vu 6 (Arka Garima) recorded the highest vegetable pod yield and pod weight. Vu 1 (Arka Suman) recorded the highest number of pods per plant. High heritability along with high genetic advance was seen for all the characters considered. Pod yield per plant showed high positive genotypic correlation with number of pods per plant, pod weight, number of pods per cluster, number of pod clusters per plant and pod girth. Path analysis revealed that number of pods per plant and pod weight were the main yield contributing characters due to their high direct effect on pod yield.