Browsing by Author "Vijayagopal, P D"
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ArticleItem Open Access Effect of levels of nitrogen and spacing on the yield of rice(Kerala Agricultural University, 1981) Droupathi Devi, G; Vijayagopal, P D; Sasidhar, V K; KAUThesisItem Open Access Genetic studies on induced viable mutants in rice [Oryza sativa L.)(Department of Plant Breeding, College of Agriculture, Vellayani, 1985) Vijayagopal, P D; Gopinathan, Nair VThesisItem Open Access Induced mutations in cowpea(Department of Agricultural Botany, College of Agriculture, Vellayani, 1989) Mini, V; KAU; Vijayagopal, P DSeeds of cowpea ( vigna unguiculata) cultivar kuruthola-payar were subjected to induced mutagenesis using four doses of gamma rays (10 to 40 krad) and four doses of EMS (0.5 to 2.0 per cent) and their effects in the M1 and M2 generations were studied. The germination percentage was observed to decrease prgogressively with the increase in dose of both mutagens although the reduction was more drastic with EMS. Reduction in survival percentage was observed with increase in the dose of gamma rays and EMS. The growth of shoot and root and plant height were reduced by both the mutagens, although gamma rays showed greater shoot inhibition and EMS showed greater root inhibition. The pollen fertility as well as seed fertility decreased linearly with increase in doses of both the mutagens. Chlorophyll chimeras were observed only in the 30 krad and 40 krad gamma ray treatments. Morphological variations noticed included plants with alterations in the number, size and shape of leaflets. The chlorophyll mutation frequency estimated on M2 progeny row basis showed an increase with increasing doses of gamma rays, except in the 40 krad treatment, which showed a slight decrease. In the case of EMS, maximum mutants were observed at the lowest dose. The chlorophyll mutation frequency estimated on M2 seedling basis showed dose-dependence. The frequencies of the different types of chrolophyll mutants did not show any dose-relationship. The segregation ratio of chlrophyll mutants was higher for EMS than gamma irradiation. The viable mutation frequencies did not show any definite relationship with the doses in both the mutagen treatments. The mutagenic effectiveness in inducing chlrophyll mutations was high at the lowest dose of both mutagens. On the basis of lethality, 20 krad of gamma rays was the most efficient, while on the basis of injury and sterility, 10 krad was the most efficient. With EMS, the 0.50 per cent treatment was the most effective as well as the most efficient treatment on the basis of lethality, injury and sterility. The mutagenic efficiency in inducing chlorophyll mutations was higher for gamma rays with respact to lethality and injury, while on the basis of sterility, EMS proved to be more effcient than gamma rays.ThesisItem Open Access Induction of genetic variability in guinea grass (Panicum maximum Jacq.) Var.Makuenii(Department of Agricultural Botany, College of Agriculture, Vellayani, 1989) Rani, N; KAU; Vijayagopal, P DGuinea grass (Panicum maximum J.) being a facultative apomicts under continuous vegetative propagation carry very little variability. The cross incompatibility also restricts attempts to produce variability through conventional methods of plant breeding. The main objective of the study is to induce variability through mutations in guinea grass variety Makuenii using gamma rays at four doses ranging from 15 Krad to 30 Krad and EMS at four concentrations ranging from 0.25 percent to 1.00 percent. The effect of the mutagens in M1 and M 1 V1 generations were studied. The observations in the M1 generation indicated that germination of seeds was progressively reduced with increase in the dose of mutagens. The survival and early growth of seedlings were adversely affected by the mutagen treatments. The seedlings appeared to suffer from the transplanting shock as indicated by high mortality of the plants in the field. Higher doses of mutagens induced height reduction. However the tillering ability of the plants did not seem to have been affected but higher doses of mutagens inhibited flowering initiation. Pollen sterility in M1 generation exihibited dose dependence. A few chlorophyll chimeras were observed in the M1 generation. Morphological abnormalities induced dwarf, tall, semi open and open types with leaf and inflorescence modifications. The means of M1 V1 clones exhibited both positive and negative shifts from the population means with respect to plant height. Treatments 20 Kard gamma rays and 0.25% EMS caused positive shifts in the means of girth at internode and leaf area index. Certain clones were identified to have higher green fodder yield than the control. These clones also had higher girth at internode and higher leaf area index. The study revealed that variability with respect to plant height, girth at internode, leaf area index and green fodder yield can be induced by mutations using appropriate doses of gamma rays and EMS. A medium dose of 20 Krad gamma rays and a relatively lower dose of 0.25 percent EMS were found to induce more useful variations.ArticleItem Open Access Nitrogen use efficiency and grain yield of rice(Kerala Agricultural University, 1980) Droupathi Devi, G; Vijayagopal, P D; Sasidhar, V K; KAUArticleItem Open Access Permanent manurial experiment in paddy(Kerala Agricultural University, 1979) Vijayagopal, P D; Droupathi Devi, G; KAUThe results of the P. M.E. consisting of treatments receiving organic nitrogen in the form of green leaf or inorganic nitrogen in the form of ammonium sulphate or both and treatments without N, for three successive seasons were reviewed. The results showed that the plots receiving P and K alone gave the lowest y'reld and that P and K failed to show any effect evenafter their discontinuance for 21 continuous seasons. In normal seasons inorganic and organic N were on par as far as grain production was concerned.ArticleItem Open Access Role of rain water in the pollination of pepper (Piper nigrum Linn.)(Kerala Agricultural University, 1977) Sreekumari Amma; Vijayagopal, P D; KAUArticleItem Open Access Sneha, an improved variety of groundnut for uplands(Kerala Agricultural University, 2000) Suma Bai, D I; Manju, P; Sverup John; Wilson, D; Gopimony, R; Vijayagopal, P D; KAUInitial evaluation trials (lETs) were conducted with 18 superior types and 18 extra early segregants from the Fs progenies during 1993. From the lETs, seven high yielding types and nine high yielding, extra early progeny bulks were selected and subjected to CYTs during kharif 1994 and 1995 at the College of Agriculture, Vellayani, Thiruvananthapuram along with check varieties. Two promising types, VGE-551 and 1SKO-8805 with high yield and two cultures, Culture 15 and Culture 18 with high yield and early maturity were advanced to farm trials along with TMV 2 and local check at nine locations in Thiruvananthapuram district during kharif 1996. Culture 15 with high yield and early maturity was recommended for release as Sneha suitable for cultivation in the uplands of Thiruvananthapuram district.ArticleItem Open Access Studies of the intervarietal hybrids of Solanum melongena, L.(Kerala Agricultural University, 1973) Vijayagopal, P D; Sethumadhavan, P; KAUArticleItem Open Access Studies on the fractional application of nitrogen on the yield of rice(Kerala Agricultural University, 1980) Droupathi Devi, G; Vijayagopal, P D; Sasidhar, A V K; KAUThe effect of fractional application of nitrogen on the grain yield of two high yielding rice varieties Jaya and Annapurna was studied for six consecutive seasons during 1972-73 to 1974-75 in the Rice Research Station, Mannuthy. Significant results were obtained in two first crop seasons and the treatments receiving 50 kg N as basal and another quantity of 50 kg N in two equal splits given either at booting and heading or at panicle initiation and booting gave maximum grain yield.