Research Article
Open Access
Authors:
Aruna R1*, Srinivasan M R 1, Selvarajan R 2, Subramanian S3 and Thakur R K 4
Abstract:
Honey bees are affected by various diseases caused by viruses, bacteria, fungi and mites. Of these, the Thai Sac Brood virus (TSBV) disease attacking Indian honey bee has been posing threat to hives of Apis cerana indica F. in different parts of Southern India. The virus is caused by picorna-like virus characterized under Iflaviridae family. The symptoms of TSBV are perforated brood scattered among capped brood, the presence of prepupae with typical raised and pointed heads in the comb cells, the dead larvae turn into sac-like structure filled with milky white fluid which when lifted up ruptured easily. Infective broods are odourless and show no ropiness. These symptoms were clearly visible in the present study. Studies conducted on the seasonal incidence of the disease revealed the prevalence of the disease during winter (October to January) season which prolonged to spring (Late January to March) season and was influenced by brood rearing. The TSBV disease incidence decreased in the month of April (2 / 30 colonies infected, 80 cells infected / colony) when the mean maximum temperature (34.3oC) was high while the relative humidity (RH 65%) and rainfall (62.7 mm) were low. In the succeeding four months namely May, June, July and August, the disease incidence was nil. The disease incidence started again in the month of September and reached a peak in the month of November (9 / 30 colonies were infected, 342 cells infected / colony) at which time the mean maximum temperature was low (28.6oC) while the RH (82%) and rainfall (191.3mm) were high. Thus the high disease incidence was found to be significantly correlated with low temperature and non significantly correlated with high RH and rainfall. The disease incidence also coincided with the active brood rearing period (November to March). Electron microscopic study of purified virus particles revealed that the virus is 32.3 ± 0.7 nm in diameter and icosahedral in shape. The morphology was found to be similar to that of sacbrood virus attacking Italian honey bee, Apis mellifera.
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Research Article
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Authors:
SNCVL Pushpavalli, Jayashankar
Abstract:
Twenty five safflower genotypes were evaluated at Agricultural Research Station, Tandur during Rabi 2014-15 to determine the genetic divergence and relationship among yield and yield components. The genetic parameters like divergence, genotypic and phenotypic variability, genotypic and phenotypic coefficient of variation, heritability and genetic advance were studied along with correlation coefficient and path analysis for seed yield, oil content and the component traits of safflower. Broad sense heritability estimates and genetic advance as per cent of mean (5%) was the highest for 100-seed weight followed by seed yield/plant. Significant and positive correlation was observed between seed yield/plant and number of seeds/capsule and 100-ssed weight. Path coefficient analysis indicated that 100-seed weight followed by number of seeds/ capsule exhibited the maximum direct effect on seed yield/plant. The genotypes were grouped into four different clusters based on Mahalonobis D2 statistics. Seed yield/plant contributed to the maximum genetic divergence followed by 100-seed weight among the genotypes studied.
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Research Article
Open Access
Authors:
Ravichandran V1, Jayapriya S2, and Boominathan P2
Abstract:
An investigation was carried out during Kharif season of 2014-15 at Department of Rice, Tamil Nadu Agricultural University, Coimbatore-3 to study the influence of sowing dates on phenology and yield traits of some rice genotypes. Among the three sowing dates (9th June, 23rd June and 7th July) and twelve rice genotypes were used in this study revealed that, rice genotypes sown on 9th June and the long duration rice genotype (CB-05-022) consumed more number of days to reach different growth stages viz., active tillering, panicle initiation, 50 per cent flowering and physiological maturity stages 42, 87, 126, 141 days where it took longer vegetative growth duration to produce more productive tillers and provided higher grain yield. The GDD (Growing Degree Day) was accumulated more in rice genotypes sown on June 9th at active tillering, panicle initiation, 50 per cent flowering and physiological maturity stages where it can efficiently utilize the available natural resources for its growth and development. The maximum grain yield of 9764 kg ha-1 was registered by the genotype CB-05-022 sown on 9th June with an increase of 16.4 per cent over other sowing dates. To conclude, sowing date (9th June) favoured better growth and yield in rice genotypes and the long duration genotype, (CB-05-022) showed desired phenological characters which utilize heat units efficiently under favourable environment to provide better yield than other genotypes used.
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Research Article
Open Access
Authors:
Vallal Kannan S
Abstract:
Rice- Rice- Blackgram or Rice-Rice-Sesame is the existing cropping pattern followed in Cauvery New delta zone of Tamil Nadu. Alternate method of cultivation like Drum Seeded Rice and alternate short duration crops like Maize, Pulse during kharif season have been identified as an alternative to face the scarcity of water with higher profitability to the farming community. Among the different cropping systems, Drum Seeded Rice- Transplanted Rice-Maize + Black gram system has registered the highest economic efficiency of 319.41 Rs./ha/year and RiceRice- Brinjal recorded the economic efficiency of 303.94 Rs./ha/year over the existing system of Rice-Rice-Sesame sequence. Similarly both the sequence recorded the highest system productivity of 48.20 and 48.49 kg/ha/year respectively. The cropping sequence of Drum Seeded Rice – Transplanted Rice – Maize + Black gram and Rice-Rice-Brinjal as an alternate cropping system, instead of existing Rice- Rice – Pulse / Oilseed cropping systems in Cauvery New Delta Zone to achieve higher income, higher productivity and profitability.
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Research Article
Open Access
Authors:
Vaiyapuri K*, and Manivannan V
Abstract:
Field experiments were conducted at millet breeding farm of Tamil Nadu Agricultural University,Coimbatore (11o29â€N latitude and 77o 08†E longitude at an altitude of 256 MSL), India during Kharif 2012, 2013 and 2014 in split plot design. The experiment comprised of twelve treatment combinations with four plant growth regulators (salicylic acid @ 100 mg/l, ethrel @ 200 mg/l, cycocel @ 500 mg/l and water spray) in main plots and three stages of application (at flower initiation, pod initiation and flower + pod initiation) in sub plot replicated thrice. Foliar spray of salicylic acid@ 100 mg/l was significantly higher Pods per plant than cycocel @ 500 mg/l, ethrel @ 200 mg/l and water spray. Salicylic acid 100 mg/l recorded significantly higher seed yield and but was found to statistically on par with cycocel @ 100 mg/l. Pods per plant with application of plant regulators at flower + pod initiation stages were significantly higher than application either at flower or pod initiation. Application of growth regulators at flower and pod initiation gave significantly higher seed yield than flower and pod alone. The pooled mean revealed that growth regulators at flower + pod initiation stages gave 16.07 % and 12.50 % higher yield than spraying growth regulators either at flower initiation or pod initiation stage alone.
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Research Article
Open Access
Authors:
Malarkodi N
Abstract:
Field experiments were conducted during 2013 and 2014, at Agricultural College and Research Institute, Madurai (Tamil Nadu Agricultural University) to study the effect of pre-emergence application of Calotropis gigantea leaf extract spray on weed control in cotton. The weed management practices consisted of Calotropis gigantea leaf extract spray at three concentrations (10, 20 and 30%) in combination with power weeder operation twice and manual weeding twice.The results revealed that pre-emergence application of Calotropis gigantea at 30 % concentration followed by hand weeding at 40 DAS recorded lower weed density and dry weight and increased the yield in irrigated cotton
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Research Article
Open Access
Authors:
Paramasivan M*, Arunkumar V and Senthilkumar N
Abstract:
A field experiment was conducted during 2012-13 and 2013-2014 at Agricultural College and Research Institute, Killikulam to study the effect of different levels of nutrient on productivity, nutrients uptake, economics and soil fertility of rice. The experiment was carried out in a randomized block design replicated thrice with 7 treatments involving three levels of N and two levels of P and K. Application of 200:75:75 kg NPK ha-1 produced the maximum plant height (95.7 cm), number of productive tillers / plant (18.3), panicle length (27.2), number of grains /panicle (212 ), 1000 grain weight (26.0 g), grain yield (7.04 t ha-1), straw yield (8.58 t ha-1), net return (52,576/ha), B:C ratio (1.65), N, P and K (171.9, 28.6 and 185.2 kg/ha, respectively) and uptake compared to control. Significant built up of organic carbon (1.24 %), available N (326.7 kg ha-1), P (21.4 kg ha-1) and K (362.7 kg ha-1) was registered with the application of 200:75:75 kg of NPK ha-1. The maximum balance of N, P and K (50.7, 5.6 and 74.0 kg ha-1, respectively) were also recorded under this treatment.
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Research Article
Open Access
Authors:
Nannapaneni Kiran kumar1, Krishnamoorthy A S *2 and Amirtham D 3
Abstract:
A total of 9 strains consisting of both V. volvacea (5 cultivated strains viz., CBE TNAU 1401 to 1405; 2 wild strains viz., CBE TNAU 1505 and 1516) and V. bombycina (one cultivated strain CBE TNAU 1406 and one wild strain CBE TNAU 1504) were evaluated to ascertain the variation in their morphological, cultural and molecular characters. Among strains tested, CBE TNAU 1505 was the best strain, which showed earliness in spawn run, more biomass production in unit time and more chlamydospores production with high density. In the trials conducted with partially decomposed paddy straw, the highest yield of 1041.2 g per 5 kg of substrate with an average biological efficiency of 20.8 per cent was recorded with CBE TNAU 1505. Molecular detection of Volvariella strains through 5.8S rDNA regions showed that ITS primers had amplified a product size between 700 and 740 bp. RAPD - PCR phylogenetic analyses revealed 2 major clusters. V. volvacea strains showed approximately 13 per cent genetic similarities with the strains of V. bombycina.
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Research Article
Open Access
Authors:
Punitha S, Senthil A*, Jeyakumar P, Sritharan N and Boominathan P
Abstract:
Strobilurins are new class of fungicide with an unique mode of action, effective in altering the physiological and biochemical traits of crop plants. An experiment was conducted to study the influence of strobilurin compounds on nitrate reductase, indole acetic acid oxidase enzymes and total phenolics of chilli. Combined application of strobilurin with triazole compound in the form of Nativo (trifloxystrobin + tebuconazole) @ 400 g ha-1 recorded significantly higher NRase activity and total phenolics content compared to control and other treatments. It is also observed that the combined application of pyraclostrobin with metiram as Cabriotop @ 1500 g ha-1 recorded the maximum IAA oxidase activity.
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Research Article
Open Access
Authors:
Smitha K P*, Rajeswari E, Alice D and Latha P
Abstract:
The present investigation was carried out to study the variability among R. bataticola isolates causing root rot disease of pigeonpea in Tamil Nadu. Totally 10 isolates of the fungus wererecovered from different pigeonpea growing regions of Tamil Nadu. Morphological observation revealed the occurrence of variation with respect to colony type, growth pattern, and size and shape of microsclerotia. Based on morphology, the isolates were grouped into two morphological catagories viz., isolates with appressed type growth (I) and fluffy type growth (II). The size of microsclerotia varied from 87.6 x 79.2 µm to 146.3 x 133.9 µm. All the isolates were analyzed through RAPD-PCR for genetic diversity. The UPGMA cluster analysis identified four main groups. Similarity matrix and Jaccard’s similarity co-efficient between the isolates indicated the maximum genetic variation of 43 per cent among the isolates from Vellore and Thiruvannamalai districts. Maximum similarity of 92 per cent was recorded between the isolates from Erode and Salem. The results demonstrated existence of variability within R. bataticola isolates causing pigeonpea root rot and thereby can be used for developing management strategies.
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Research Article
Open Access
Authors:
Kanmani E, Sivakumar R, Ravichandran V, Senthil A, and Boominathan P
Abstract:
Soil salinity is the major problem in arid and semi-arid regions, where rainfall is insufficient to leach salt and excess of sodium ion and it is one of the major constraints to the sustainability and expansion of rice cultivation. The depressive effect of salinity on germination could be related to a decline in endogenous levels of hormones. Presoaking seeds with optimal concentration of plant growth regulators (PGRs) has been shown to be beneficial to growth and yield of some crop species under saline conditions. It is extremely important to standardize the concentrations of PGRs as the activities changes drastically with concentrations. Therefore, we have used eight different concentrations of four PGRs along with absolute control and salinity stress treatments known to alter the germination viz., gibberellic acid, kinetin, salicylic acid and brassinosteriods and measured various physiological traits associated with germination. In case of germination percentage, brassinosteriods at 0.005 ppm was found to be the best as it registered highest germination percentage followed by gibberellic acid. Higher dry matter production was found in seeds treated with gibberellic acid and kinetin that recorded 37.4 % higher dry matter production than control. The critical enzyme in germination, a-amylase activity was higher in seeds treated with 500 ppm of gibberellic acid. These results strongly suggest that PGRs at optimum concentrations could be effectively used for improving germination associated traits undersalinity condition in rice.
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Research Article
Open Access
Authors:
Nirmala N* and Irene Vethamoni P
Abstract:
An experiment was carried out at Department of vegetable crops, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore to evaluate 30 green fruited brinjal genotypes. The study revealed that highly significant differences were observed for all the traits. Among the 30 genotypes, ABSR-2 recorded the maximum number of fruits and fruit yield per plant whereas, EC 316201 was found to be best for number of branches, number of fruits, fruit yield per plant next to ABSR-2. The genotype Devachinnampatti local was found to be good for the earliest flowering and yield per plant and protein content. The three genotypes viz., ABSR-2, EC 316201, Devachinnampatti local were superior for yield and yield contributing characters. These three genotypes can be used as parents in hybridization programmes.
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Research Article
Open Access
Authors:
Sahu R K1, Agrawal A K*2 and Geetesh Sinha3
Abstract:
In the present study, various treatments viz dipping in 500 ppm bavistin solution, packaging in 150 gauge LDPE bags, packaging in 150 gauges LDPE with ethylene absorber and packaging of bavistin treated fruits in 150 gauge LDPE bags were applied on custard apple to enhance its shelf life. The treated custard apple fruits were kept at 25-30oC (ambient), 20 and 10oC to determine the effect of temperature and analyzed after every two days interval for various changes. During storage of custard apple, at all temperatures, physical loss in weight, titrable acidity and total soluble solids were found to increase, while the pH was found to decrease. The investigation at ambient conditions (temperature 25-30oC, RH 60-85%) showed that minimum loss in fruit weight was achieved, when fruits were treated with bavistin and packed in LDPE bags with ethylene absorber. This treatment was proved to be the best on account of slower increase in acidity total soluble solids.
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Research Article
Open Access
Authors:
Indu Rani C
Abstract:
The effects of pre-harvest treatments on long term storage of aggregatum onion (Allium cepa L. var. aggregatum) cv. CO(On)5 were studied. Thirteen pre-harvest treatments viz., cycocel, ethrel and kinetin were used individually and also in combination with ridomil, sprayed at different levels at 15 and 30 d before harvest for improving the quality and storage life of aggregatum onion. Harvested bulbs were pre-cured in the field for three days and in shade for two days. Onion bulbs retained with 2 cm neck length recorded ower reduction of physiological loss in weight and control of sprouting. Cured bulbs were stored under low cost, bottom ventilated storage structure for three months for assessing the quality and shelf life. Among the pre-treatments, application of cycocel @ 200 ppm + ridomil @ 0.2% spray at 30 d before harvest and stored with 2 cm neck length in low cost, bottom ventilated storage structure showed increased shelf life with aggregatum onion cv. CO(On)5.
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Research Article
Open Access
Authors:
Deepa J*1, Rajkumar P 2 and Indu Rani C 3
Abstract:
Commercial handling of ‘Banganapalli’ mangoes is burdened by lack of uniformity in ripening of the fruits. A viable approach to overcome this problem could be application of ethylene. Mango (var. Banganapalli) fruits harvested at 75 per cent maturity were exposed to 50, 100 and 150 ppm for 15, 20 and 25 h and subsequently, ripened at 16 ± 2ºC, 23 ± 2ºC and 30 ± 2ºC. Ripening was enhanced in all the treated fruits at all concentrations used. The ripening rate progressively increased with increase in ethylene concentration. Depending on the concentration, ripening was achieved in 4-6 d earlier, when compared to untreated fruits. Untreated control mango fruits remained shriveled, green and failed to ripen uniformly, even after 8 d of storage. Fruits treated with 150 ppm of ethylene for 25 h at 23 ± 2ºC induced uniform ripening without impairing the taste and flavour of mango. The effect on fruit ripening was assessed by change in peel colour, increase in total soluble solids and decrease in flesh firmness and acidity.
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Research Article
Open Access
Authors:
Sivakumar R*, Nandhitha G K and Boominathan P
Abstract:
Drought is a major problem in arid and semi-arid regions and is the primary cause of crop loss worldwide, reducing average yields for most of the crop plants by more than 0%. Tomato cultivation is concentrated in semi-arid zones, where water stress is frequent. It is important to ascertain its response, while selecting cultivars that are tolerant and productive. Therefore, eighteen tomato genotypes were used to assess the impact of drought on various growth traits such as plant height, number of leaves, leaf area, TDMP and yield by adopting 100 and 50% field capacity. The results indicated 53% yield reduction under drought compared to 100% field capacity. As the stress increased from 100 to 50% field capacity, significant reduction in growth traits associated with yield were noticed. However, slight increment of root length and root volume were observed at 50% field capacity. The genotypes LE 114, LE 57, LE118 and LE 27, which showed significantly less reduction in plant height, leaf area, TDMP and yield during drought were considered as drought tolerant. Genotypes LE 1, LE 3, LE 20 and COTH 2, which recorded the highest reduction in plant height, leaf area, TDMP and ultimately poor yield were considered as drought susceptible.
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Research Article
Open Access
Authors:
Irene Vethamoni P* and Praneetha S
Abstract:
An experiment was carried out with twenty lines and three testers to develop green fruited brinjal F1 hybrids with cluster bearing habit, striped fruit, shoot and fruit borer resistance and high yield. The lines and testers were raised in the crossing block and crossing was carried out in L x T mating design and hybrid seeds were obtained. Among the sixty hybrids developed, six hybrids with high yield and shoot and fruit borer resistance were identified and raised in the field and their growth, yield, shoot and fruit borer resistance were studied. Based on mean performance, the parent L15 was found to be the best for plant height, no. of fruits, fruit yield and marketable yield with less borer infestation. Among the hybrids, the maximum number of fruits (54.8) was recorded in the hybrid L15 x T2 followed by L2 x T2 (43.4) and L16 x T2 (42.2) respectively. The maximum per plant yield of 4.2 kg/plant was recorded by the hybrid L15 x T2. The hybrid L2 x T2 stood in the second place by recording 3.6 kg and L16 x T2 was in third position with a yield of 3.4 kg. The minimum borer infestation of shoot (12.0 %) was recorded in the hybrid L15 x T2 followed by L2 x T2 (12.4 %) and L12 x T2 (12.9 %). The
minimum borer infestation of fruit (13.0 %) was recorded in the hybrid L15 x T2 followed by the hybrid L12 x T2 (13.8 %). Among the F1 hybrids, the performance of L15 x T2 was superior for growth and yield characters. The shoot and fruit borer damages were also recorded at lower level in the same hybrid.
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Research Article
Open Access
Authors:
Gayathri Devi N*, Narayanamoorthy A* and Madhusudan Bhattarai**
Abstract:
It is increasingly argued that the Mahatma Gandhi National Rural Employment Guarantee Scheme (MGNREGS) introduced during 2006 has escalated the wage rate of agricultural labourers in different states. But, not many studies are available as to what happened to the wage rate of male and female agricultural labourers after its introduction covering the districts of Tamil Nadu. An attempt is made in this study to answer this by using data during 2001-02 to 2012-13. The growth analysis reveals that the pace of increase in real wage rate for male and female labourers is substantially higher during post-MGNREGS period as compared to pre-MGNREGS period across the districts. The results of simple regression suggests that the irrigation development and employment days per household provided by MGNREGS appeared to have positively fuelled
the growth rate of wage for male labourers, while foodgrains productivity, cropped area per farm labourer, rainfall and employment days provided by MGNREGS appeared to have fuelled the growth of female wage rate.
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Research Article
Open Access
Authors:
Chandrasekar V* Ganapathy S and Thirupathi V
Abstract:
Solid state fermentation was employed to isolate the starch from finger millet to improve its functional properties. This process was optimized by Box-Behnken response surface
methodology by varying pH (4-7), innoculum concentration (10 -30), temperature (25-35oC) and time (2-6 d). Aspergillus oryzae (MTCC 3107) was obtained from National hemical Laboratory, Pune and used for this study. Growth medium of 0.2% of KH2PO4, MgSO47H2O and soluble starch each along with traces of FeSO4.7H2O in 100 ml distilled water was used. Higher starch (0.64 mg/g) was isolated at pH 5.65, innoculum concentration of 28.57 per cent and temperature 35oC, time 3.8 days. A quadratic equation was fitted to develop a relationship between independent and dependant variables. The fitted model has high regression coefficient (R2 - 0.99), adjusted regression coefficient (Adj.R2 -0.99) with less standard deviation (SD- 0.005). This study concluded that SSF could be an effective method for isolation of starch from finger millet.
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Research Article
Open Access
Authors:
Aruna R1*, Srinivasan M R 1, Selvarajan R 2, Subramanian S3 and Thakur R K 4
Abstract:
Honey bees are affected by various diseases caused by viruses, bacteria, fungi and mites. Of these, the Thai Sac Brood virus (TSBV) disease attacking Indian honey bee has been posing threat to hives of Apis cerana indica F. in different parts of Southern India. The virus is caused by picorna-like virus characterized under Iflaviridae family. The symptoms of TSBV are perforated brood scattered among capped brood, the presence of prepupae with typical raised and pointed heads in the comb cells, the dead larvae turn into sac-like structure filled with milky white fluid which when lifted up ruptured easily. Infective broods are odourless and show no ropiness. These symptoms were clearly visible in the present study. Studies conducted on the seasonal incidence of the disease revealed the prevalence of the disease during winter (October to January) season which prolonged to spring (Late January to March) season and was influenced by brood rearing. The TSBV disease incidence decreased in the month of April (2 / 30 colonies infected, 80 cells infected / colony) when the mean maximum temperature (34.3oC) was high while the relative humidity (RH 65%) and rainfall (62.7 mm) were low. In the succeeding four months namely May, June, July and August, the disease incidence was nil. The disease incidence started again in the month of September and reached a peak in the month of November (9 / 30 colonies were infected, 342 cells infected / colony) at which time the mean maximum temperature was low (28.6oC) while the RH (82%) and rainfall (191.3mm) were high. Thus the high disease incidence was found to be significantly correlated with low temperature and non significantly correlated with high RH and rainfall. The disease incidence also coincided with the active brood rearing period (November to March). Electron microscopic study of purified virus particles revealed that the virus is 32.3 ± 0.7 nm in diameter and icosahedral in shape. The morphology was found to be similar to that of sacbrood virus attacking Italian honey bee, Apis mellifera.
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Research Article
Open Access
Authors:
SNCVL Pushpavalli, Jayashankar
Abstract:
Twenty five safflower genotypes were evaluated at Agricultural Research Station, Tandur during Rabi 2014-15 to determine the genetic divergence and relationship among yield and yield components. The genetic parameters like divergence, genotypic and phenotypic variability, genotypic and phenotypic coefficient of variation, heritability and genetic advance were studied along with correlation coefficient and path analysis for seed yield, oil content and the component traits of safflower. Broad sense heritability estimates and genetic advance as per cent of mean (5%) was the highest for 100-seed weight followed by seed yield/plant. Significant and positive correlation was observed between seed yield/plant and number of seeds/capsule and 100-ssed weight. Path coefficient analysis indicated that 100-seed weight followed by number of seeds/ capsule exhibited the maximum direct effect on seed yield/plant. The genotypes were grouped into four different clusters based on Mahalonobis D2 statistics. Seed yield/plant contributed to the maximum genetic divergence followed by 100-seed weight among the genotypes studied.
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Research Article
Open Access
Authors:
Ravichandran V1, Jayapriya S2, and Boominathan P2
Abstract:
An investigation was carried out during Kharif season of 2014-15 at Department of Rice, Tamil Nadu Agricultural University, Coimbatore-3 to study the influence of sowing dates on phenology and yield traits of some rice genotypes. Among the three sowing dates (9th June, 23rd June and 7th July) and twelve rice genotypes were used in this study revealed that, rice genotypes sown on 9th June and the long duration rice genotype (CB-05-022) consumed more number of days to reach different growth stages viz., active tillering, panicle initiation, 50 per cent flowering and physiological maturity stages 42, 87, 126, 141 days where it took longer vegetative growth duration to produce more productive tillers and provided higher grain yield. The GDD (Growing Degree Day) was accumulated more in rice genotypes sown on June 9th at active tillering, panicle initiation, 50 per cent flowering and physiological maturity stages where it can efficiently utilize the available natural resources for its growth and development. The maximum grain yield of 9764 kg ha-1 was registered by the genotype CB-05-022 sown on 9th June with an increase of 16.4 per cent over other sowing dates. To conclude, sowing date (9th June) favoured better growth and yield in rice genotypes and the long duration genotype, (CB-05-022) showed desired phenological characters which utilize heat units efficiently under favourable environment to provide better yield than other genotypes used.
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Research Article
Open Access
Authors:
Vallal Kannan S
Abstract:
Rice- Rice- Blackgram or Rice-Rice-Sesame is the existing cropping pattern followed in Cauvery New delta zone of Tamil Nadu. Alternate method of cultivation like Drum Seeded Rice and alternate short duration crops like Maize, Pulse during kharif season have been identified as an alternative to face the scarcity of water with higher profitability to the farming community. Among the different cropping systems, Drum Seeded Rice- Transplanted Rice-Maize + Black gram system has registered the highest economic efficiency of 319.41 Rs./ha/year and RiceRice- Brinjal recorded the economic efficiency of 303.94 Rs./ha/year over the existing system of Rice-Rice-Sesame sequence. Similarly both the sequence recorded the highest system productivity of 48.20 and 48.49 kg/ha/year respectively. The cropping sequence of Drum Seeded Rice – Transplanted Rice – Maize + Black gram and Rice-Rice-Brinjal as an alternate cropping system, instead of existing Rice- Rice – Pulse / Oilseed cropping systems in Cauvery New Delta Zone to achieve higher income, higher productivity and profitability.
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Research Article
Open Access
Authors:
Vaiyapuri K*, and Manivannan V
Abstract:
Field experiments were conducted at millet breeding farm of Tamil Nadu Agricultural University,Coimbatore (11o29â€N latitude and 77o 08†E longitude at an altitude of 256 MSL), India during Kharif 2012, 2013 and 2014 in split plot design. The experiment comprised of twelve treatment combinations with four plant growth regulators (salicylic acid @ 100 mg/l, ethrel @ 200 mg/l, cycocel @ 500 mg/l and water spray) in main plots and three stages of application (at flower initiation, pod initiation and flower + pod initiation) in sub plot replicated thrice. Foliar spray of salicylic acid@ 100 mg/l was significantly higher Pods per plant than cycocel @ 500 mg/l, ethrel @ 200 mg/l and water spray. Salicylic acid 100 mg/l recorded significantly higher seed yield and but was found to statistically on par with cycocel @ 100 mg/l. Pods per plant with application of plant regulators at flower + pod initiation stages were significantly higher than application either at flower or pod initiation. Application of growth regulators at flower and pod initiation gave significantly higher seed yield than flower and pod alone. The pooled mean revealed that growth regulators at flower + pod initiation stages gave 16.07 % and 12.50 % higher yield than spraying growth regulators either at flower initiation or pod initiation stage alone.
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Research Article
Open Access
Authors:
Malarkodi N
Abstract:
Field experiments were conducted during 2013 and 2014, at Agricultural College and Research Institute, Madurai (Tamil Nadu Agricultural University) to study the effect of pre-emergence application of Calotropis gigantea leaf extract spray on weed control in cotton. The weed management practices consisted of Calotropis gigantea leaf extract spray at three concentrations (10, 20 and 30%) in combination with power weeder operation twice and manual weeding twice.The results revealed that pre-emergence application of Calotropis gigantea at 30 % concentration followed by hand weeding at 40 DAS recorded lower weed density and dry weight and increased the yield in irrigated cotton
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Research Article
Open Access
Authors:
Paramasivan M*, Arunkumar V and Senthilkumar N
Abstract:
A field experiment was conducted during 2012-13 and 2013-2014 at Agricultural College and Research Institute, Killikulam to study the effect of different levels of nutrient on productivity, nutrients uptake, economics and soil fertility of rice. The experiment was carried out in a randomized block design replicated thrice with 7 treatments involving three levels of N and two levels of P and K. Application of 200:75:75 kg NPK ha-1 produced the maximum plant height (95.7 cm), number of productive tillers / plant (18.3), panicle length (27.2), number of grains /panicle (212 ), 1000 grain weight (26.0 g), grain yield (7.04 t ha-1), straw yield (8.58 t ha-1), net return (52,576/ha), B:C ratio (1.65), N, P and K (171.9, 28.6 and 185.2 kg/ha, respectively) and uptake compared to control. Significant built up of organic carbon (1.24 %), available N (326.7 kg ha-1), P (21.4 kg ha-1) and K (362.7 kg ha-1) was registered with the application of 200:75:75 kg of NPK ha-1. The maximum balance of N, P and K (50.7, 5.6 and 74.0 kg ha-1, respectively) were also recorded under this treatment.
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Research Article
Open Access
Authors:
Nannapaneni Kiran kumar1, Krishnamoorthy A S *2 and Amirtham D 3
Abstract:
A total of 9 strains consisting of both V. volvacea (5 cultivated strains viz., CBE TNAU 1401 to 1405; 2 wild strains viz., CBE TNAU 1505 and 1516) and V. bombycina (one cultivated strain CBE TNAU 1406 and one wild strain CBE TNAU 1504) were evaluated to ascertain the variation in their morphological, cultural and molecular characters. Among strains tested, CBE TNAU 1505 was the best strain, which showed earliness in spawn run, more biomass production in unit time and more chlamydospores production with high density. In the trials conducted with partially decomposed paddy straw, the highest yield of 1041.2 g per 5 kg of substrate with an average biological efficiency of 20.8 per cent was recorded with CBE TNAU 1505. Molecular detection of Volvariella strains through 5.8S rDNA regions showed that ITS primers had amplified a product size between 700 and 740 bp. RAPD - PCR phylogenetic analyses revealed 2 major clusters. V. volvacea strains showed approximately 13 per cent genetic similarities with the strains of V. bombycina.
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Research Article
Open Access
Authors:
Punitha S, Senthil A*, Jeyakumar P, Sritharan N and Boominathan P
Abstract:
Strobilurins are new class of fungicide with an unique mode of action, effective in altering the physiological and biochemical traits of crop plants. An experiment was conducted to study the influence of strobilurin compounds on nitrate reductase, indole acetic acid oxidase enzymes and total phenolics of chilli. Combined application of strobilurin with triazole compound in the form of Nativo (trifloxystrobin + tebuconazole) @ 400 g ha-1 recorded significantly higher NRase activity and total phenolics content compared to control and other treatments. It is also observed that the combined application of pyraclostrobin with metiram as Cabriotop @ 1500 g ha-1 recorded the maximum IAA oxidase activity.
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Research Article
Open Access
Authors:
Smitha K P*, Rajeswari E, Alice D and Latha P
Abstract:
The present investigation was carried out to study the variability among R. bataticola isolates causing root rot disease of pigeonpea in Tamil Nadu. Totally 10 isolates of the fungus wererecovered from different pigeonpea growing regions of Tamil Nadu. Morphological observation revealed the occurrence of variation with respect to colony type, growth pattern, and size and shape of microsclerotia. Based on morphology, the isolates were grouped into two morphological catagories viz., isolates with appressed type growth (I) and fluffy type growth (II). The size of microsclerotia varied from 87.6 x 79.2 µm to 146.3 x 133.9 µm. All the isolates were analyzed through RAPD-PCR for genetic diversity. The UPGMA cluster analysis identified four main groups. Similarity matrix and Jaccard’s similarity co-efficient between the isolates indicated the maximum genetic variation of 43 per cent among the isolates from Vellore and Thiruvannamalai districts. Maximum similarity of 92 per cent was recorded between the isolates from Erode and Salem. The results demonstrated existence of variability within R. bataticola isolates causing pigeonpea root rot and thereby can be used for developing management strategies.
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Research Article
Open Access
Authors:
Kanmani E, Sivakumar R, Ravichandran V, Senthil A, and Boominathan P
Abstract:
Soil salinity is the major problem in arid and semi-arid regions, where rainfall is insufficient to leach salt and excess of sodium ion and it is one of the major constraints to the sustainability and expansion of rice cultivation. The depressive effect of salinity on germination could be related to a decline in endogenous levels of hormones. Presoaking seeds with optimal concentration of plant growth regulators (PGRs) has been shown to be beneficial to growth and yield of some crop species under saline conditions. It is extremely important to standardize the concentrations of PGRs as the activities changes drastically with concentrations. Therefore, we have used eight different concentrations of four PGRs along with absolute control and salinity stress treatments known to alter the germination viz., gibberellic acid, kinetin, salicylic acid and brassinosteriods and measured various physiological traits associated with germination. In case of germination percentage, brassinosteriods at 0.005 ppm was found to be the best as it registered highest germination percentage followed by gibberellic acid. Higher dry matter production was found in seeds treated with gibberellic acid and kinetin that recorded 37.4 % higher dry matter production than control. The critical enzyme in germination, a-amylase activity was higher in seeds treated with 500 ppm of gibberellic acid. These results strongly suggest that PGRs at optimum concentrations could be effectively used for improving germination associated traits undersalinity condition in rice.
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Research Article
Open Access
Authors:
Nirmala N* and Irene Vethamoni P
Abstract:
An experiment was carried out at Department of vegetable crops, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore to evaluate 30 green fruited brinjal genotypes. The study revealed that highly significant differences were observed for all the traits. Among the 30 genotypes, ABSR-2 recorded the maximum number of fruits and fruit yield per plant whereas, EC 316201 was found to be best for number of branches, number of fruits, fruit yield per plant next to ABSR-2. The genotype Devachinnampatti local was found to be good for the earliest flowering and yield per plant and protein content. The three genotypes viz., ABSR-2, EC 316201, Devachinnampatti local were superior for yield and yield contributing characters. These three genotypes can be used as parents in hybridization programmes.
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Research Article
Open Access
Authors:
Sahu R K1, Agrawal A K*2 and Geetesh Sinha3
Abstract:
In the present study, various treatments viz dipping in 500 ppm bavistin solution, packaging in 150 gauge LDPE bags, packaging in 150 gauges LDPE with ethylene absorber and packaging of bavistin treated fruits in 150 gauge LDPE bags were applied on custard apple to enhance its shelf life. The treated custard apple fruits were kept at 25-30oC (ambient), 20 and 10oC to determine the effect of temperature and analyzed after every two days interval for various changes. During storage of custard apple, at all temperatures, physical loss in weight, titrable acidity and total soluble solids were found to increase, while the pH was found to decrease. The investigation at ambient conditions (temperature 25-30oC, RH 60-85%) showed that minimum loss in fruit weight was achieved, when fruits were treated with bavistin and packed in LDPE bags with ethylene absorber. This treatment was proved to be the best on account of slower increase in acidity total soluble solids.
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Research Article
Open Access
Authors:
Indu Rani C
Abstract:
The effects of pre-harvest treatments on long term storage of aggregatum onion (Allium cepa L. var. aggregatum) cv. CO(On)5 were studied. Thirteen pre-harvest treatments viz., cycocel, ethrel and kinetin were used individually and also in combination with ridomil, sprayed at different levels at 15 and 30 d before harvest for improving the quality and storage life of aggregatum onion. Harvested bulbs were pre-cured in the field for three days and in shade for two days. Onion bulbs retained with 2 cm neck length recorded ower reduction of physiological loss in weight and control of sprouting. Cured bulbs were stored under low cost, bottom ventilated storage structure for three months for assessing the quality and shelf life. Among the pre-treatments, application of cycocel @ 200 ppm + ridomil @ 0.2% spray at 30 d before harvest and stored with 2 cm neck length in low cost, bottom ventilated storage structure showed increased shelf life with aggregatum onion cv. CO(On)5.
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Research Article
Open Access
Authors:
Deepa J*1, Rajkumar P 2 and Indu Rani C 3
Abstract:
Commercial handling of ‘Banganapalli’ mangoes is burdened by lack of uniformity in ripening of the fruits. A viable approach to overcome this problem could be application of ethylene. Mango (var. Banganapalli) fruits harvested at 75 per cent maturity were exposed to 50, 100 and 150 ppm for 15, 20 and 25 h and subsequently, ripened at 16 ± 2ºC, 23 ± 2ºC and 30 ± 2ºC. Ripening was enhanced in all the treated fruits at all concentrations used. The ripening rate progressively increased with increase in ethylene concentration. Depending on the concentration, ripening was achieved in 4-6 d earlier, when compared to untreated fruits. Untreated control mango fruits remained shriveled, green and failed to ripen uniformly, even after 8 d of storage. Fruits treated with 150 ppm of ethylene for 25 h at 23 ± 2ºC induced uniform ripening without impairing the taste and flavour of mango. The effect on fruit ripening was assessed by change in peel colour, increase in total soluble solids and decrease in flesh firmness and acidity.
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Research Article
Open Access
Authors:
Sivakumar R*, Nandhitha G K and Boominathan P
Abstract:
Drought is a major problem in arid and semi-arid regions and is the primary cause of crop loss worldwide, reducing average yields for most of the crop plants by more than 0%. Tomato cultivation is concentrated in semi-arid zones, where water stress is frequent. It is important to ascertain its response, while selecting cultivars that are tolerant and productive. Therefore, eighteen tomato genotypes were used to assess the impact of drought on various growth traits such as plant height, number of leaves, leaf area, TDMP and yield by adopting 100 and 50% field capacity. The results indicated 53% yield reduction under drought compared to 100% field capacity. As the stress increased from 100 to 50% field capacity, significant reduction in growth traits associated with yield were noticed. However, slight increment of root length and root volume were observed at 50% field capacity. The genotypes LE 114, LE 57, LE118 and LE 27, which showed significantly less reduction in plant height, leaf area, TDMP and yield during drought were considered as drought tolerant. Genotypes LE 1, LE 3, LE 20 and COTH 2, which recorded the highest reduction in plant height, leaf area, TDMP and ultimately poor yield were considered as drought susceptible.
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Research Article
Open Access
Authors:
Irene Vethamoni P* and Praneetha S
Abstract:
An experiment was carried out with twenty lines and three testers to develop green fruited brinjal F1 hybrids with cluster bearing habit, striped fruit, shoot and fruit borer resistance and high yield. The lines and testers were raised in the crossing block and crossing was carried out in L x T mating design and hybrid seeds were obtained. Among the sixty hybrids developed, six hybrids with high yield and shoot and fruit borer resistance were identified and raised in the field and their growth, yield, shoot and fruit borer resistance were studied. Based on mean performance, the parent L15 was found to be the best for plant height, no. of fruits, fruit yield and marketable yield with less borer infestation. Among the hybrids, the maximum number of fruits (54.8) was recorded in the hybrid L15 x T2 followed by L2 x T2 (43.4) and L16 x T2 (42.2) respectively. The maximum per plant yield of 4.2 kg/plant was recorded by the hybrid L15 x T2. The hybrid L2 x T2 stood in the second place by recording 3.6 kg and L16 x T2 was in third position with a yield of 3.4 kg. The minimum borer infestation of shoot (12.0 %) was recorded in the hybrid L15 x T2 followed by L2 x T2 (12.4 %) and L12 x T2 (12.9 %). The
minimum borer infestation of fruit (13.0 %) was recorded in the hybrid L15 x T2 followed by the hybrid L12 x T2 (13.8 %). Among the F1 hybrids, the performance of L15 x T2 was superior for growth and yield characters. The shoot and fruit borer damages were also recorded at lower level in the same hybrid.
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Research Article
Open Access
Authors:
Gayathri Devi N*, Narayanamoorthy A* and Madhusudan Bhattarai**
Abstract:
It is increasingly argued that the Mahatma Gandhi National Rural Employment Guarantee Scheme (MGNREGS) introduced during 2006 has escalated the wage rate of agricultural labourers in different states. But, not many studies are available as to what happened to the wage rate of male and female agricultural labourers after its introduction covering the districts of Tamil Nadu. An attempt is made in this study to answer this by using data during 2001-02 to 2012-13. The growth analysis reveals that the pace of increase in real wage rate for male and female labourers is substantially higher during post-MGNREGS period as compared to pre-MGNREGS period across the districts. The results of simple regression suggests that the irrigation development and employment days per household provided by MGNREGS appeared to have positively fuelled
the growth rate of wage for male labourers, while foodgrains productivity, cropped area per farm labourer, rainfall and employment days provided by MGNREGS appeared to have fuelled the growth of female wage rate.
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Research Article
Open Access
Authors:
Chandrasekar V* Ganapathy S and Thirupathi V
Abstract:
Solid state fermentation was employed to isolate the starch from finger millet to improve its functional properties. This process was optimized by Box-Behnken response surface
methodology by varying pH (4-7), innoculum concentration (10 -30), temperature (25-35oC) and time (2-6 d). Aspergillus oryzae (MTCC 3107) was obtained from National hemical Laboratory, Pune and used for this study. Growth medium of 0.2% of KH2PO4, MgSO47H2O and soluble starch each along with traces of FeSO4.7H2O in 100 ml distilled water was used. Higher starch (0.64 mg/g) was isolated at pH 5.65, innoculum concentration of 28.57 per cent and temperature 35oC, time 3.8 days. A quadratic equation was fitted to develop a relationship between independent and dependant variables. The fitted model has high regression coefficient (R2 - 0.99), adjusted regression coefficient (Adj.R2 -0.99) with less standard deviation (SD- 0.005). This study concluded that SSF could be an effective method for isolation of starch from finger millet.
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