Browsing by Author "Kamalam, N"

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Combining ability for shade tolerence and yield in greengram grown under coconuts
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2001) Preeta Liz Korah; Kamalam, N
The current research programme on "Combining ability for shade tolerance and yield in greengram (Vigna radiata (L.) Wilczek) grown under coconuts" was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 1998-2000. The objectives were estimation of gene action, combining ability effects of parents and hybrids and heterosis. The experimental material consisted of five lines, three testers and their fifteen hybrids. Analysis of variance revealed significant differences among the genotypes for all the eleven characters subjected to statistical analysis except height of plants and shade intensity. The genotypes L3 (MGG. 314), Ls (LGG. 460) and T3 (CO.2» were superior in mean performance for yield and most of the yield attributes. The hybrids Ls x T 2 (LGG. 460 x Pusa baisakhii and L1 x T3 (IIPRM.3 x CO.2) were superior in mean performance for yield, pod characters, photosynthetic efficiency and tolerance to pod bug infestation. Non-additive gene action predominated for all the nine characters showing significant differences among the treatments. Ls (LGG. 460) and T 2 (Pusa baisakhi) were the best general combiners for yield and 2 length of pod while L) (IIPRM.3) was the best combiner for crop duration, pods per plant and photosynthetic efficiency. The hybrid L) x T 3 (IIPRM. 3 x CO.2) was the best specific combiner for yield. Significant heterosis was observed for all the characters studied. Ls x T 2 (LGG. 460 x Pusa baisakhi) showed maximum relative heterosis and heterobeltiosis for yield and pod length whereas L) x T 3 (IIPRM.3 x CO.2) showed maximum heterosis over mid parent and better parent for days to 50 per cent flowering, days to final harvest, pods per plant and photosynthetic efficiency. Combining the mean performance, sca effects and heterosis, Ls x T 2 (LGG. 460 x Pusa baisakhi) and L) x T 3 (IIPRM.3 x CO.2) were identified as superior crosses in terms of yield and yield attributes. The hybrid L) x T 3 (IIPRM.3 x CO.2) was also superior for days to 50 per cent flowering, days to final harvest and photosynthetic efficiency.
Correlation and path coefficient analysis in guinea grass (Panicum maximum Jacq.)
(Department of Agricultural Botany, College of Agriculture, Vellayani, 1983) Sreenivasan, E; Kamalam, N
A study was undertaken at the Department of Agricultural Botany, College of Agriculture, Vellayani, to determine the character association for yield and quality of green fodder and their degree of association and relative influence on yield in guinea grass. Twenty four diverse varieties of guinea grass were selected for the study and laid out in randomised block design with three replications. Observations were made on nine morphological characters and four chemical attributes and the data collected were subjected to variability studies and correlation analysis. Five morphological characters which showed highly significant genotypic correlation with green fodder yield were considered for path coefficient analysis in order to separate the total correlation of these characters with green fodder yield into direct effects and indirect effects via. other characters.
Gene action and combining ability in grain cowpea (Vigna unguiculata (L.) Walp) in relation to aphid borne mosaic virus resistance
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Smitha, S; Kamalam, N
Two lines, five testers and ten hybrids of cowpea were evaluated in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 94-95, with the objective of estimating the combining ability of parents and gene action involved in the inheritance of different yield attributes and CAMV resistance. The lines and testers were selected based on their previous performances and crossed in line x tester manner to get ten hybrids. Observations were made on ten characters, of which nine characters showed significant difference among the 17 treatments. It was seen that nonadditive gene action was predominated for the inheritance of number of pods/plant, number of seeds/pod, 100 - seed weight and seed yield/plant and aphid borne mosaic resistance and additive gene action for days to flowering, days to maturity and number of branches/plant. The varieties Pournami, V - 317, V - 276 and Charodi were the best general combiners and the cross combinations V - 317 x CO4 and V-276 x Pournami were the best specific combinations for yield and CAMV resistance. Hence they can be utilized for further crop improvement programme.
Genetic analysis of greengram genotypes for shade tolerance
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1998) Rajeswari, A; Kamalam, N
An investigation was carried out to evaluate the shade tolerance potential of 25 genotypes of green gram under partially shaded coconut gardens in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. The genotypes were evaluated in a randomised block design with three replications and observations were recorded for nineteen quantitative characters. The genetic parameters, correlation and path coefficients were studied and a selection index was formulated to identify superior genotypes. The genotypes showed significant differences for all the characters except incidence of pod borer Measurement of periodical shade intensity did not show significant difference among the plots which indicated the prevalence of uniform shade. High genotypic coefficient of variation was observed for leaf area index (flowering) followed by number of abnormal, oblique, unfilled pods, LAI (pod formation), pod clusters per plant and pods per plant. High heritability coupled with high genetic advance was recorded for pods per plant, LAI at flowering and pod formation and pod clusters per plant indicating additive gene action. Correlation studies indicated that pods per plant followed by branches per plant, clusters per plant, photosynthetic efficiency (flowering) and LAI (flowering) showed strong positive correlation with grain yield whereas days to blooming, days to first harvest and grains per pod recorded negative correlation. The path coefficient analysis revealed high positive direct contribution of pods per plant to grain yield per plant. In addition, pod length and plant height also showed positive direct contribution to grain yield per plant. A selection index was constructed based on grain yield per plant and 9 yield contributing characters identified through correlation and path analysis. Five top ranking genotypes viz. IIPRM 3, MGG 314, RMG 353, Ganga 4 and LGG 460 were identified for cultivation under partially shaded condition of coconut garden and for further breeding programme.
Genetic evaluation of F2 generation of intervarietal crosses in greengram (vigna radiata (L.) wilczek)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2001) Leenamol, M A; Kamalam, N
A research programme was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2000-2001 with the objective of assessing the potential of F2 progenies of greengram in terms of variability and correlation with respect to yield, yield attributes and shade tolerance. Fifteen F 2 progenies derived from intervarietal crosses were evaluated under the partial shade of coconut garden adopting a randomised block design with three replications. Data collected for seventeen characters were subjected to statistical analysis. Coefficient of variation, heritability, genetic advance, correlation and path coefficients were estimated. The 15 F 2 progenies revealed significant difference for all the characters. However, measurement of periodical shade intensity did not show significant difference among the plots indicating the prevalence of uniform shade. Phenotypic and genotypic coefficient of variation were high for grain yield, leaf area index, number of pods per plant, photosynthetic efficiency, harvest index and 100 seed weight. High heritability coupled with high genetic advance was observed for harvest index, grain yield, number of pods per plant, 100 seed weight and photosynthetic efficiency. Correlation studies indicated that the characters leaf area index, . photosynthetic efficiency, number of seeds per pod, 100 seed weight and harvest index exhibited significant positive correlation with grain yield whereas days to 50 per cent flowering and days to maturity recorded significant negative correlation. Among yield components, photosynthetic efficiency and harvest index exhibited significant positive correlation with number of seeds per pod and 100 seed weight. Photosynthetic efficiency exhibited the highest positive direct effect on grain yield followed by harvest index. Negative direct effect on grain yield was recorded for number of seeds per pod, days to maturity and days to 50 per cent flowering. It can be concluded from the present study that under partially shaded condition, photosynthetic efficiency and harvest index are the most important yield components which can serve as selection criteria for better yield in greengram. Accordingly the genotypes T 7 (Ganga 4 x Pusa Baisakhi), T 5 (LGG 460 x Philippines), T I (IIPRM 3 x Philippines), T 2 (Ganga 4 x Philippines) and TI4 (RMG 353 x CO-2) and Tlo (LGG 460 x Pusa Baisakhi) may be selected for further work.
Morphological effect of gamma rays and EMS on winged bean [Psophocarpus tetragonolobus (L.)]
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1993) Reeja Dharan, S; Kamalam, N
Path analysis in guinea grass (Panicum maximum jacq.)
(Kerala Agricultural University, 1986) Sreenivasan, E; Kamalam, N; Nayar, N K
Twenty four diverse genotypes of guinea grass were assessed to test the path coefficient relation to fix the characters having maximum influence on fodder yield. Path analysis revealed that the maximum direct contribution to fodder yield was through plant height followed by girth of internode. Number of days to 50 per cent flowering, girth of internode and length of panicle also showed indirect contributions towards higher yield. It was also clear from the present investigation that a positive selection can be achieved based on plant height and culm thickness »B tfas fodder crop.
Rate and time of application of nitrogen on dwarf indica rice under the agroclimate of Wynad
(Kerala Agricultural University, 1972) Muralidharan, A; Kamalam, N; Nair, S S
Relative biological effectiveness of gamma rays and ethyl methane sulphonate on cardamom varieties
(Department of Agricultural Botany, College of Agriculture, Vellayani, 1987) Benney Joseph; Kamalam, N
The direct effect of 60 Co-gamma rays and ethylmethane sulphonate (EMS) on three varieities of cardomom namely Malabar, Mysore and Vazhukka was studied during the course of present investigation. The experiment was carried out at the Department of Agricultural Botany, College of Agriculture , Vellayani during the year1985-1986. Dry seeds were exposed to gamma rays at dose levels ranging from 10-70 kR at 10 kR interval and the pre-soaked seeds for 16 hours were treated with EMS concentrations ranging from 0.25 % to 1.75% at an interval of 0.25%. Soaked seeds were also exposed to gamma rays with 10 and 20 kR. The experiment was laid out in RBD with two replications. Direct effect of the mutagens was assessed by analysing the effect of various growth metrices like number of days taken to start germination , number of days taken to complete germination from the date of sowing and also from the date of first sprout, rate of germination , germination percentage, survival percentage, growth rate based on plant height , leaf number, leaf area and tiller number , frequency of chlorophyll deficient plants and cytological effects. The data collected were analysed statistically . Since sufficient population was not available at higher doses of both the mutagens they were not considered for growth metric analysis.