Browsing by Author "Gopinathan Nair, V"

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Anthesis in Indian lemongrass Cymbopogon Flexuosus, stapf
(Kerala Agricultural University, 1979) Mercy, S T; Gopinathan Nair, V; Luckins C Babu
Studies were undertaken on the mechanism of anthesis in Indian lemongrass. An inflorescence takes 25 to 32 days for completion of anthosis. The peak period of anthesis is from the 6th day from commencement of anthesis to the 11th day. About 80% of spikes complete anthesis by the 15th day. Anthesis takes place in the morning between 7 and 8.30. !n the sessile spikelets anthesis appears earlier than its appearance in the pedicellate ones. There are four distinct stages in the anthesis of sessile spikelet which take plrce one after the other in quick succession. The most characteristic featrue of anthesis is the slight protogynous nature of the sessile spikelet. Though this is a basic adaptation for cross pollination, the large number of spikeleis opening in a short span of time indicate the possibility for self pollination under field conditions.
Association of yield and its components in bhindi
(Kerala Agricultural University, 1988) Sheela, M N; MAnikantan Nair, P; Gopinathan Nair, V
Bulbils in Penmsetum poltstachyon-short note
(Kerala Agricultural University, Vellanikara, 1968) Gopinathan Nair, V; Kumara Pillai, P
Cause-effect relationship of cane and sugar yield components in sugarcane
(Kerala Agricultural University, 1989) Gopinathan Nair, V; Sreekumar, S G
The cause and effect relationship of cane and sugar yield components studied in the plant crop performance of 48 hybrid varieties revealed that circumference of cane, number of millable canes per plot and length of cane had high direct contributions for cane yield. Pol percentage at 12th month had maximum direct effect on CCS percentage. Among the two components contributing to sugar yield, cane yield had maximum contribution rather than CCS percentage, thereby suggesting that increasing the cane yield through its components like circumference of cane, number of millable canes or length of cane, the sugar yield can also be increased, through correlated response.
Correlation and path analysis in groundnut in the summer rice fallows
(Kerala Agricultural University, 1988) Pushkaran, K; Gopinathan Nair, V
Pod yield and seventean other characters were studied in eighty groundnut varieties raised in summer rice fallows. Correlation coefficients at the genotypic and phenotypic levels were computed between these characters and path analysis for pod yield was carried out considering eight components. Dry pod yield was highly correlated positively with plant height on the 50th day, length of top, fresh weight of pods, number of mature pods and number of immature pods both at the genotypic and phenotyic levels. Pod yield was also correlated highly and positively with number of flowers and haulms yield phenotypically. Pod yield recorded highly significant negative correlation with duration upto flowering, number of branches and leaves on the 50th day and number of flowers while it was moderate with number of branches. Positive correlation of duration upto flowering and maturity and lack of significant correlation of the latter with pod yield suggest the possibility of recombining high yield with short duration. Fresh weight of pods had the highest positive direct effect on dry pod yield. Number of leaves, flowers and mature pods also had positive direct effects in that order. Number of mature pods exarted positive indirect effects via fresh weight of pods, number of basal primary branches, haulms yield and 100 pod weight. Length of top, numbar of basal primary branches, haulms yield and '00 pod weight had negative direct effects on pod yield, of which that by haulms yield was the highest.
Correlation studies in black gram under partially shaded conditions
(Kerala Agricultural University, 1992) Saji T Abraham; Sreekumar, S G; Saraswathy, P; Gopinathan Nair, V; Manikantan Nair, P
Correlation studies in groundnut
(Kerala Agricultural University, 1993) Pushkaran, K; Gopinathan Nair, V
For effecting dependable selection in breeding groundnut varieties suited to kharif uplands and summer rice fallows, genotypic correlation studies and path analysis were done based on 18 characters collected from 80 divergent groundnut varieties and the results compared and contrasted. There are differences in the direction, degree of relationship and relative effects for important characters on the economic trait on both the situations. Hence, in selecting ideal genotypes for the two situations, differential considerations had to be given for the component characters.
Cross compatibility between Sesamum indicum L. and S. malabaricum
(Department of Plant Breeding, College of Agriculture, Vellayani, 1987) Lali, K S; Gopinathan Nair, V
Sesame is most valued annual oilseed crop of Kerala. Lack of varietieswith resistance to drought and diseases is the main problem confronting sesame cultivation in the state. The wild species Sesamum malabaricum shows tolerance to drought and most of the diseases. But this wild species appears to be non compatible with the cultivated S. indicum. An investigation was therefore undertaken to study cross compatibility between these two species. Eleven adapted varieties of S. indicum were crossed reciprocally with S. malabaricum. Capsule set was normal in direct as well as reciprocal crosses. In general it was more in reciprocal crosses . In general it was more in reciprocal crosses than in direct crosses. In spite of normal capsule set , these crosses failed to produce any normal seed. The seeds were either medium shrivelled or highly shrivelled. Failure normal seed development in a wide range of crosses confirm that these two species are noncompatible.
Easy method of hybrid seed production in bhindi
(Kerala Agricultural University, 1982) Gopimony, R; Gopinathan Nair, V
Effect of combined mutagenic treatments on sensitivity and mutation frequency in rice
(Kerala Agricultural University, 1977) Gopinathan Nair, V
Puce seeds were subjected to two sets of combination treatments of radiations and NMH. The effects of mutagenic treatments in the MI and M2 generations were recorded and discussed. Mutation frequencies estimated as number of mutations per 100 M, ears were not higher than the values expected on the basis of additive effects. When estimated as number of mutants per ]00 M plants, the frequencies revealed more than additive effects. The synergistic effect on mutant frequencies was due to increase in the segregation ratio of mutants. This effect was more pronounced at the higher dose combinations of fast neutrons and NMH.
Effect of recurrent and alternate mutagenic treatments in rice
(Kerala Agricultural University, 1978) Gopinathan Nair, V
The effects of repeated mutagenic treatment in the M2- and M3- gene. ation* in rice are reported. Recurrent irradiation with gamma rays and alternate treatment with gamma rays and NMH, neither increased the sensitivity of seeds r enhanced the frequency of induced chlorophyll mutations. This indicate that e inspite of its secondary polyploid nature behaves like a diploid in its reppo to the action of mutagens.
Embryonic differentiation in rice seeds as revealed in mutational analysis
(Kerala Agricultural University, 1976) Gopinathan Nair, V
Enhancement of the mutagenic effects of nitroso methyl urea in rice through alteration in the period of presoaking of seeds
(Kerala Agricultural University, 1978) Gopinathan Nair, V
The effect of presoaking seeds on sensitivity and mutation frequency in rjce was studied. Treatments were given in 3 series le. with 3 doses of M«/JLJ Each series consisted of 11 different periods of presoaking in range of 8 to 48 hours. Mutagenic effects were estimated in the M, and M. generations and interpreted. Sensitivity to NMH increased with the length of presoaking and reached a maximum at 32 hours. There was a decrease in sensitivity when presoaking was extended beyond this period. The time specificity of the sensitivity peak was independant of the dose of mutagen and the criteria adopted for its estimation. The peak period of sensitivity corresponds to the time of DMA synthesis in the initial cciis It appears that the first DMA synthesis in the initial cells is responsible for the peak sensitivity at 32 hours presoaking. The frequency of chlorophyll mutations increased with the length of presoaking reaching a maximum at 40 to 44 hours. Conspicuous increase were obtained during the periods 16 to 20 hours and 24 to 28 hours. The enhanced efficiency during the 16 to 28 hour period can be attributed to the synchronisation of treatment time with the 'S' phase of DMA synthesis. The spectrum of mutations indicated predominance of albino, viridis and chlorina. Xantha and tigrina were very rare and appeared only from 20 hours onwards. The increase in relative per cent of albino with the length of presoaking and the late appearance of Xantha and tigrina were the characteristic features of the mutation spectrum. The change in spectrum with different periods of presoaking indicate scope for further efforts towards attaining mutation specificity.
Estimation of the number of initial cells in panicle primordia of the rice embryo
(Kerala Agricultural University, 1983) Rajendran, T S; Gopinathan Nair, V
An attempt is made to estimate the size of the mutated sector in Mj panicles and number of initial cells constituting the various panicle primordia in the rice embryo. Normal plants from M,, progenies segregating with a deficit on recessive mutants were carried forward to the M^ generation of plant progeny basis. The data from segregating M3 progenies derived from the same M1 panicle were pooled and the mean Ma ratio for each progeny was calculated. The M3 ratios were generally higher than the corresponding M, ratios. The size of the mutated sector of the M1 panicle was estimated by dividing the Ma ratio in each progeny by the corresponding Mj ratio. The number of initial cells was obtained as the reciprocal of the sector size. Variation in the size of the mutated sector and number of initial cells was exhibited by panicles of the categories. For the apical ear the size of the sector was from 0.08 to 0.45 and number of initial cells from 2 to 12. The sector size in the primary ears ranged from 0.33 to 1 .00 and the number of initial cells from 1 to 3. The secondaries of primaries 2, 3 and 4 have originated from 1 to 2 initial cells. The primary and secondary ears of a primary group might have originated from the same set of initial cells in the embryo. Deficit of recessive mutant was found in the Ma generation of all categories of panicles. This deficit in a generation later than the M2 is attributed to genetic or zygotic eliminations. Since the apical panicle has more number of initial cells and consequently smaller mutated sector, it is necessary to grow a large progeny to recover a mutation induced in its primordium.
Evaluation of brinjal varieties for resistance to bacterial wilt
(Kerala Agricultural University, 1983) Narayanan, K K; Gopinathan Nair, V
Evaluation of cowpea varieties for fodder and grain yield
(Kerala Agricultural University, 1982) Gopimony, R; Sunny K Oommen; Gopinathan Nair, V
Evaluation of the productivity of certain sesamum genotypes
(Kerala Agricultural University, 1984) Abdul Khader; Gopinathan Nair, V
Fifteen genotypes of sesame were evaluated in replicated trials at two locations viz., upland during rabi at Veliayani and rice fallow during summer at Kayamkulam. Data collected on 13 characters were subjected to statistical scrutiny. Significant differences were observed for most of the characters at each location and also between locations. Length of pod and 1000 seed weight were not found to be influenced by seasons. The multiloculed varieties gave higher yield than the four loculed ones at both the locations. The variety No. 42-1 giving maximum seed yield per hectare at both the locations had larger number of pods (especially in upland), longer pods, larger number of seeds per pod and higher seed weight. Medium in duration and with the highest oil content and possessing multiloculed capsules, this variety holds promise for being enhanced as an improved strain for general cultivation, pending further trials on its stability in performance.
Floral biology of Indian lemongrass Cymbopogon flexuosus stapf
(Kerala Agricultural University, 1982) Luckins C Babu; Mercy, S T; Gopinathan Nair, V
Gamma ray induced economic mutations in groundnut
(Kerala Agricultural University, 1988) Gigi K John; Sreekumar, S G; Gopinathan Nair, V
Gamma ray induced viable mutations in sesamum
(Kerala Agricultural University, 1978) Ramachandran Nair, N; Gopinathan Nair, V