Browsing by Author "Nisha, M S"

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Bioefficacy of Quisqualis indica L. and Samadera indica gaetrn against tobacco caterpillar, Spodoptera litura fabricius (LEPIDOPTERA: NOCTUIDAE) in poly house condition
(Depatment of Agricultural Entomology, College of Agriculture, Vellayani, 2016) Anusree, S S; Nisha, M S
Biomanagement of root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood - wilt fungus, Fusarium oxysporum disease complex in vegetable cowpea
(Department of Nematology, College of Agriculture, Vellayani, 2021-12-07) Katakam Rupini Krishna; Nisha, M S
The study entitled „Biomanagement of root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood - wilt fungus, Fusarium oxysporum disease complex in vegetable cowpea‟ was conducted at Department of Nematology, College of Agriculture, Vellayani, Thiruvananthapuram during 2019-2021. The objectives were to study the interaction between M. incognita and F. oxysporum and to evaluate the efficacy of biofumigation, biocontrol agents and organic amendments in the management of nematode - fungus disease complex in vegetable cowpea. An pot culture experiment was laid out in completely randomized design to study the interaction between M. incognita and F. oxysporum and their effect on nematode multiplication, disease incidence and growth parameters in vegetable cowpea. In Interaction study, the treatments were M. incognita alone, F. oxysporum alone, simultaneous inoculation of M. incognita and F. oxysporum, M. incognita + F. oxysporum one week after nematode inoculation, F. oxysporum + M. incognita one week after fungus inoculation and uninoculated control. M. incognita was inoculated @ one J2 g soil-1 and F. oxysporum mass multiplied in sand maize medium (20×107 cfu g-1 ) was mixed in soil @ 500 g in different intervals. The results unveiled that highest cohabitation of both the pathogens was observed when M. incognita was inoculated seven days prior to F. oxysporum inoculation with lowest shoot length (11.15 cm) and root length (9.26 cm). Meanwhile, lowest number of nodules 5 g root-1 (14.00) was recorded in plants treated with M. incognita alone. Highest reproduction factor of 1.67 was observed in M. incognita alone followed by M. incognita + F. oxysporum one week after nematode inoculation (1.14). Similar trend was observed in number of galls, egg masses and eggs per egg mass. Highest (100.00%) and early (23 days) disease incidence was recorded in plants inoculated with M. incognita + F. oxysporum one week after nematode inoculation 120 Field study was conducted to evaluate the efficacy of biofumigation using crop residues of cauliflower, bioagents (Pseudomonas fluorescens, Trichoderma viride, Purpureocillium lilacinun) and organic amendment (neem cake) in comparison to chemical (Fluopyram 400 SC). The experiment was laid out in CRD with eight treatments and three replications. Variety used was Vellayani Jyothika. All treatments showed statistically significant reduction in nematode population in comparison with control. Among the non chemical methods, P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 showed maximum reduction in nematode population in soil (88.68 per cent over control) and root (83.68 per cent over control). Lowest reproduction factor was recorded in chemical (0.14) followed by P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 (0.30), T. viride enriched FYM @ 20 g m -2 (0.69) and P. lilacinum enriched FYM @ 20 g m -2 (0.70). Similar trend was observed in the case of number of galls also. Effect of P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 found to be equally effective to P. lilacinum enriched FYM @ 20 g m -2 in reducing number of egg masses and eggs per egg mass giving 52.51 to 76.74 per cent reduction over control. Lowest disease incidence (27.76 %) was recorded in fluopyram 400 SC @ 250 g a.i. ha-1 , P.fluorescens@ 10 g kg seed-1 + neem cake @ 100 g m-2 and T. viride enriched FYM @ 20 g m-2 . Regarding biometric characters (shoot length, fresh and dry shoot weight, root length, fresh and dry root weight) and yield, effect of P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 was statistically on par with chemical fluopyram giving 56.81 to 76.90 per cent increase over control. Highest number of nodules (87.00 5 g root-1 ) was observed in P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 and it was significantly superior to all other treatments. From this study, it was concluded that highest interactive effect between nematode and fungus was recorded when M. incognita inoculated seven days prior to F. oxysporum inoculation.Application of P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 can be recommended for 121 management of M. incognita and F. oxysporum disease complex in organic cultivation of cowpea.
Development of formulations from Samadera indica Gaetrn. for the management of leaf feeding pests in snake gourd(Trichosanthes anguina L.)
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2022) Remya, S; Nisha, M S
The study entitled ‘Development of formulations from Samadera indica Gaetrn. for the management of leaf feeding pests in snake gourd (Trichosanthes anguina L.)’ was carried out in the Department of Agricultural Entomology, College of Agriculture, Vellayani and at Council of Scientific and Industrial Research – National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram during 2018 to 2021. Objectives of the study were exploration of anti-insect properties of bark and seeds of S. indica, identification of bioactive compounds in the effective extract, development of suitable formulations and field evaluation of the same against pumpkin caterpillar, Diaphania indica Saund and epilachna beetle, Henosepilachna septima (Dieke). Estimation of lethal doses viz., LD50 and LD90 of bark and seed extracts by probit dose analysis showed that LD50 of bark extract in hexane, acetone, ethanol extract and aqueous extract were 1.66, 1.03, 1.51 and 2.38% respectively against D. indica and 2.17, 1.95, 1.68 and 2.49% respectively against H. septima. Meanwhile, LD90 values were 6.49, 7.05, 5.24 and 7.90% respectively against D. indica and 6.82, 6.60, 6.17 and 7.85% against H. septima. In the case of seed extract, LD50 values were 1.79, 0.59, 1.03 and 1.54% respectively against D. indica and 1.63, 0.83, 1.60 and 2.43% against H. septima. LD90 values were 6.99, 5.17, 7.05 and 9.17% against D. indica and 9.53, 5.27, 7.94 and 9.02% against H. septima. Results of in vitro studies on antifeedant effect of S. indica bark extracts against D. indica showed that ethanol extract @ 5.24% exhibited the highest leaf protection of 62.79 per cent at 72 Hours After Treatment (HAT). In the case of H. septima, ethanol extract @ 6.17% resulted in 65.00 per cent leaf protection. Regarding insecticidal effect, ethanol extract @ 5.24% resulted in 93.33 per cent mortality of second instar larvae of D. indica. Meanwhile, in grubs of H. septima, ethanol extract @ 6.17% inflicted 91.67 per cent mortality. Insecticidal effect of both the extracts was found to be statistically on par with chemical check (Malathion 50 EC 0.1%). With regard to insect biology, there was increase in larval duration (15.00 days), pupal duration (5.33 days), reduction in pupal weight (0.19 g) and reduction in adult longevity (4.33 days) in D. indica, whereas in control, larval and pupal period were 9.67 and 2.67 days each, pupal weight was 0.31 g and longevity of adults was 7.67 days. Similar trend was observed in H. septima. Among various extracts from S. indica seeds, acetone extract @ 5.17% resulted in the highest leaf protection of 74.41 per cent in D. indica and acetone extract @ 5.27% exhibited 71.79 per cent leaf protection in H. septima. With respect to insecticidal effect, acetone extract @ 5.17 and 5.27% each caused 86.67 per cent mortality in D. indica and H. septima respectively. Considering biology of the insects, there was prolongation in larval period to 17.00 days, pupal period to 8.67 days, reduction in pupal weight to 0.25 g and reduction in adult longevity to 6.33 days in D. indica as against larval period of 12.67 days, pupal period of 5.33 days, pupal weight of 0.35 g and adult longevity of 7.67 days in control. Similar was the trend with H. septima also. A comparison between LD50 and LD90 of bark and seed extracts pointed out that seed extract contained more potent compounds with insecticidal properties. Hence, seed extract was taken for further studies. Chromatographic fractions from acetone extract of seeds @ 5% exhibited mean leaf protection of 91.83 per cent in D. indica and 85.71 per cent in H. septima. Meanwhile, there was mortality of 73.33 per cent in both the pests. Analysis of chromatographic fractions revealed the presence of quassinoids viz., samaderin A, samaderin B, samaderin C and cedronin in the seed extract. Molecular structures were elucidated to confirm the identity of the compounds. Two formulations of S. indica seed extract were prepared by mixing seed extract, emulsifier and distilled water in different proportions. Formulation A contained acetone extract of S. indica seed, tween 80 and distilled water in 15: 5: 80 ratio. Formulation B was prepared by mixing seed extract of S. indica in acetone, tween 80 and span 80 (1: 1) and distilled water in 15: 5: 80 ratio. Both the formulations A and B were equally effective against D. indica and H. septima under in vitro conditions, with 80.00 per cent mortality each at 72 HAT. Safety evaluation on beneficial insects indicated that formulation A @ 1% resulted in 30.00 per cent mortality in honey bee after 24 HAT, while in A. taragamae, it was 23.33 per cent. Furthermore, both the formulations were stable under normal room temperature for six months. Formulation A @ 1% recorded 71.67 to 80.00 per cent mortality in D. indica and H. septima from the day of preparation till sixth month of storage. Meanwhile, formulation B @ 1% resulted mean percentage mortality of 70.00 and 75.00 per cent in D. indica and H. septima. Considering the insecticidal effect under in vitro conditions and environmental feasibility, formulation A was chosen for in vivo studies. Field experiment was carried out to test the efficacy of the botanical in comparison with biopesticide and chemical at Instructional Farm, Vellayani in snake gourd (variety Kaumudi). Formulation A @ 2% was evaluated for its efficacy against D. indica and H. septima at vegetative stage and 50 per cent flowering stage. Observations were taken on pest population and percentage of damaged leaves. It can be deduced that formulation A @ 2% was as effective as neemazal @ 0.2% as evident with reduction in pest population at vegetative and 50 per cent flowering stage of the crop. With regard to reduction in leaf damage, formulation A @ 2% excelled equally as neemazal @ 0.2% at vegetative stage. The study revealed that both bark and seed extracts of S. indica exhibited feeding deterrence, insecticidal properties and caused adverse effects in the biology of D. indica and H. septima. Anti-insect properties are more prevalent in the seeds and they contained the bioactive compounds samaderins A, B, C and cedronin. Formulations containing acetone extract of S. indica seeds, tween 80 and distilled water (15: 5: 80) @ 1 and 2% each were effective against both the pests under in vitro and in vivo conditions respectively and were stable for a period of six months under room temperature. Hence, it can be concluded that formulations from S. indica can be considered as safer botanical insecticides in this era of organic farming.
Eco-friendly management of root-knot and burrowing nematodes associated with kacholam (Kaempferia galanga Linn.)
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2001) Nisha, M S; Sheela, M S
Entomopathogenic nematode for the management of cucumber moth, Diaphania indica (Saunders) (Lepidoptera: Crambidae) in bitter gourd
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2023-04-12) Gayathri, P S; Nisha, M S
The research work entitled “Entomopathogenic nematode for the management of cucumber moth, Diaphania indica (Saunders) (Lepidoptera: Crambidae) in bitter gourd” was carried out at Department of Entomology, College of Agriculture, Vellayani during 2020 to 2022. The objectives were to test the pathogenicity of entomopathogenic nematodes (EPNs) and to evaluate the effective EPN formulation against cucumber moth, D. indica in bitter gourd. The pathogenicity of two strains of entomopathogenic nematodes viz. Heterorhabditis indica Poinar and Steinernema carpocapsae Weiser were assessed against 3rd instar larvae of D. indica and Henosepilachna septima Dieke. Three different formulations viz. sponge, talc and alginate gel of the effective EPN strain were prepared and stored up to 11 weeks. Then, the survival percentage and virulence of infective juveniles (IJs) in each formulation was evaluated. A pot culture study was also conducted to evaluate the pathogenicity of effective EPN formulation against D. indica in bitter gourd. In the pathogenicity test, H. indica @ 100 IJs recorded highest mortality percentage of 42.50 for D. indica and 40.00 for H. septima at 24 Hours After Treatment (HAT). No mortality was observed for S. carpocapsae at all the concentration levels (10, 20, 50 and 100 IJs) for D. indica at 24 HAT. At 48 HAT, hundred per cent mortality was recorded only for H. indica at 100 IJs and it was on par with H. indica at 50 IJs. Both H. indica and S. carpocapsae at 50 and 100 IJs showed hundred per cent mortality at 60 HAT. All treatments showed hundred per cent mortality at 72 HAT. The number of IJs emerged from cadavers were slightly more for H. indica than S. carpocapsae for the same concentration of IJs. From the 1st experiment, H. indica was found to be more effective than S. carpocapsae against D. indica and H. septima. Therefore, survival percentage of IJs of H. indica were evaluated in different formulations. Highest survival percentage (100 per cent) was observed in alginate gel formulation in 1st week and it was on par with talc formulation up to 2 weeks. More than 50% survival of IJs was observed upto 8 weeks in alginate gel, 6 weeks in talc, 5 weeks in sponges and 3 weeks in water. 112 Results on virulence of IJs in different formulations revealed that IJs from alginate gel recorded mortality percentage ranging from 32.50 to 100.00 and 0.00 to 23.33 in 1st and 11th week of storage respectively against D. indica. It was statistically on par with freshly harvested juveniles at 72 HAT up to 5th week of storage. The next best formulation was found to be talc which was on par with freshly harvested juveniles at 72 HAT up to 4th week of storage. In the pot culture study, it was observed that the mortality of D. indica caused by IJs from alginate gel-based formulation of H. indica @ 4g L-1 (42.22 and 68.88) and talc- based formulation of H. indica @ 20g L-1 (40.00 and 68.88) was superior to talc-based formulation of Beauveria bassiana @ 2% (26.66 and 62.22) and neemazal 1% @ 0.2% + tween 80 (1%) (17.77 and 42.22) at 1 and 3 DAT respectively. The effect of H. indica was on par with talc-based formulation of B. bassiana @ 2% and neemazal 1% @ 0.2% + tween 80 (1%) at 5 and 7 DAT. At the same time, the highest mortality (100 per cent) was obtained for chlorantraniliprole 18.5SC@ 30g a.i. ha-1. The damage caused by D. indica ranged from 16.92 to 34.99 in alginate gel-based formulation of H. indica @ 4g L-1 and 19.97 to 41.74 in talc- based formulation of H. indica @ 20g L-1. Its effect on damage of leaves was on par with talc-based formulation of B. bassiana @ 2% of damage percentage 28.57, 40.21 and 41.00 at 3, 5, and 7 DAT respectively. Effect of H. indica formulations on the emergence of Bactrocera cucurbitae (Coquillett) from soil was studied under in vitro. Soil treated with alginate gel-based formulation of H. indica @ 4g L-1 and talc- based formulation of H. indica @ 20g L-1 recorded 16.66 per cent emergence of B. cucurbitae and its effect was on par with chlorantraniliprole 18.5SC@ 30g a.i. ha-1. Based on the present study, it can be concluded that H. indica can be stored in formulations viz. alginate gel and talc for better shelf life and it can be used as a biocontrol agent against D. indica, H. septima and B. cucurbitae in bitter gourd.
Exploitation of indigenous bacterial antagonists against root-knot nematode, meloidogyne incognita (kofoid and white ) chitwood
(Department of Nematology, College off Agriculture, Vellayani, 2018) Vishnu, J S; Nisha, M S
Integrated management of root- knot nematode, meloidogyn incognita(kofoid & white) chiywood in coleus, solenostemon rotundifolius (poir) morton
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2005) Nisha, M S; Sheela, M S
The root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood is a serious pest in coleus, Solenostemon rotundifolius Poir (Morton) causing damage to tubers both in field and storage. A detailed study was undertaken at College of Agriculture, Vellayani during 2002-2005 to evolve an integrated management strategy in coleus. Experiments were carried out to find out the extent of crop loss under micro plot and storage conditions, biochemical changes due to M. incognita infestation in tubers, to identify the varietal resistance and to select effective treatments in nursery (physical methods, bioagents and organic amendments) and main field (bioagents and organic amendments singly and in combination). Crop loss studies conducted under microplot condition indicated that there was significant reduction in biometric characters at monthly intervals from lowest inoculum level of 100 J2 onwards. The yield attributing characters also showed significant reduction at 100 J2 level (15.77 to 19.13 per cent). In the case of nematode population, there was progressive increase in recovery as the initial inoculum level increased from 100 to 5000 J¬¬2. Crop loss studies under storage condition revealed that tubers obtained from 5000 and 1000 J2 inoculated plants started rotting and get deteriorated at 15 and 45 days after storage respectively. The stored tubers from 500 J¬2, 100 J2 and uninoculated plants exhibited a weight loss of 96.50, 86.50 and 12.50 per cent respectively at three months after storage. Germination percentage of tubers collected from 100 and 500 J2 inoculated plants showed 42.37 and 7.47 reduction respectively over the uninoculated at three months after storage. The vigour of the plants in terms of biometric characters also reduced significantly at the lowest inoculum level of 100 J2. The biochemical changes of tubers collected from plants inoculated with different levels of M. incognita revealed significant reduction in starch, sugar and crude fibre content. The percentage reduction being 6.32 to 33.33, 8.06 to 17.47 and 18.99 to 62.03 respectively as the population of nematodes increased from 100 to 5000 J2. However, there was slight increase in protein content from 12.94 to 14.42 per cent. Results on the resistance of coleus varieties/lines/accessions against M. incognita, established that variety Sree Dhara performed better in reducing the multiplication of nematodes in soil, root and tuber and production of root-knots, females, egg masses and eggs per egg mass. However in the case of total, marketable and edible portion weight of tubers, the performance of variety Sree Dhara and Nidhi was statistically on par. Based on the statistical superiority of the variety Sree Dhara to resist nematode infestation and numerically higher yield than Nidhi, Sree Dhara was selected as the resistant variety and included as a component in ensuing integrated nematode management study in coleus. The evaluation of various treatments in the nursery revealed that soil solarization using 150 guage LDPE film for 15 days or application of bioagent viz., Paecilomyces lilacinus or Bacillus macerans @ 30 g m-2 significantly reduced the number of larvae, root-knots and egg masses in root (65.74 to 90.75 per cent reduction over the untreated). The reduction in M. incognita population contributed significant improvement in biometric characters which in turn resulted healthy vigorous cuttings of S. rotundifolius for transplantation. Thus soil solarization and application of either P. lilacinus or B. macerans were selected as nursery treatments for further investigations. Among the main field treatments, application of P. lilacinus (15 g m-2) in combination with either neem cake (100 g m-2) or B. macerans (15 g m-2) significantly reduced M. incognita population and improved the biometric characters, yield and quality parameters of S. rotundifolius. The treatment combinations, P. lilacinus + neem cake and P. lilacinus + B. macerans showed 81.42 and 71.58 per cent increase respectively in total weight of tubers when compared to untreated. In integrated management, the selected treatments in the nursery and mainfield were evaluated using the resistant variety Sree Dhara. Based on the overall performance in reduction of nematode population (soil and root), the improvement of biometric characters and yield of coleus tubers, integration of soil solarization in nursery for 15 days with 150 guage LDPE film and main field application of P. lilacinus (15 g m-2) in combination with either neem cake (100 g m-2) or B. macerans (15 g m-2) were the best treatments for recommendation in the integrated nematode management strategy in S. rotundifolius. This strategy protected the crop against M. incognita and improved the per ha yield to a tune of 64.33 to 66.18 per cent. In addition to this, by reducing the nematode population in root (97.89 to 99.73 per cent), the quality parameters of tubers like starch, sugar and crude fibre content were also maintained.
Interaction between root-knot nematode and fungal pathogens in black pepper, Piper nigrum L.
(Department of Nematology, College of Agriculture, Vellayani, 2024-04-09) Amruth Hari; Nisha, M S
The study entitled " Interaction between root-knot nematode and fungal pathogens in black pepper, Piper nigrum L." was conducted at the Department of Nematology, College of Agriculture, Vellayani, Thiruvananthapuram during 2021- 2023. The objectives were documentation of nematodes and fungal pathogens in the rhizosphere of black pepper, the interaction between root-knot nematode and fungal pathogens, histopathological and biochemical changes due to nematode-fungal disease complex in black pepper. A survey was conducted in the major black pepper growing areas of Kannur (AEU-15), Idukki (AEU-16) and Wayanad (AEU-21) districts to document the nematode fauna and fungal pathogens associated with black pepper. The plant parasitic nematodes identified were Meloidogyne incognita (Kofoid and White) Chitwood, Rotylenchulus reniformis Linford and Oliveira, Radopholus similis (Cobb), Helicotylenchus dihystera (Cobb) Sher and Macroposthonia sp. The highest population of M. incognita and R. reniformis was recorded in Padiyoor and Malapattam areas in Kannur district with prominence value (PV) of 14.99 and 12.29 respectively. In Idukki and Wayanad districts highest population of M. incognita was recorded in Marayoor and Panamaram with PV of 14.76 and 15.48 respectively. Fungal pathogens viz. Fusarium solani, F. oxysporum, Phytophthora sp. Rhizoctonia sp. and Pythium sp. were also isolated from soil and plant samples. Occurrence of F. solani and high population of M. incognita was recorded in Padiyoor and Irikkur areas in Kannur, Marayoor and Mattukatta areas of Idukki and Panamaram and Pulpally regions of Wayanad. Severe galling and yellowing were observed in plants infested with nematode and fungi. A pot culture study was conducted to investigate the interaction between M. incognita and F. solani, since F solani was observed to be the major fungal pathogen associated with nematode infested plants in surveyed locations. The interactive effect of nematode and fungus in plant growth parameters, nematode multiplication, and disease incidence in black pepper were observed. The experiment was laid out in a completely randomized design and the treatments were M. incognita alone, F. solani alone, simultaneous inoculation of M. incognita and F. solani, M. incognita + F. solani two weeks after nematode inoculation, F. solani + M. incognita two weeks after fungus inoculation, and uninoculated control. M. incognita was inoculated @one J2 g soil-1. F. solani was mass multiplied in sand maize medium and mixed with soil (0.5% w/w). After 45 days of inoculation, 55.00 to 70.21 per cent reduction in in plant growth parameters over uninoculated control was observed in plants inoculated with M. incognita fourteen days prior to fungus inoculation. Number of galls, females, egg 119 masses and nematode population were found significantly higher in plants inoculated with nematode alone followed by M. incognita + F. solani fourteen days after nematode inoculation. Reproduction factor of nematode was higher (4.12) in the treatment where, M. incognita was inoculated alone and in all other treatments it ranged from 2.72 to 3.39. Plants inoculated with M. incognita fourteen days prior to F.solani exhibited highest disease incidence (100 per cent) and early symptom development (24 days). The results point out that the nematode infestation can predispose plants to fungal infection and thereby can increase the disease severity in field conditions. After 45 days of inoculation, histopathological and biochemical changes due to M. incognita and F. solani was analysed. Largest (909.2 µm2) and highest number (5) number of giant cells in vascular bundles was observed in plants inoculated with M. incognita alone followed by M. incognita inoculated two weeks prior to fungus inoculation. Fungal mycelium plugging in xylem vessels were observed in all the treatments in which the M. incognita and F. solani were inoculated sequentially and simultaneously. The plugging in xylem vessels were comparatively less in the treatment where F. solani was given alone, showing that presence of nematode increases the activity of fungus. Regarding biochemical changes, the highest amount of phenol was observed in leaves (0.49 mg g tissue -1) and roots (1.75 mg g tissue-1) of plants inoculated with M. incognita + F. solani fourteen days after nematode inoculation. Defence enzymes viz., peroxidase (PO) (8.93 fresh weight), phenyl alanine ammonia lyase (PAL) (16.31 µg of cinnamic acid fresh weight) and polyphenol oxidase (PPO) (6.98 fresh weight) in leaves also increased in plants inoculated with M. incognita + F. solani fourteen days after nematode inoculation. Similar trend was observed in root samples also. Higher activity of phenol and defense related enzymes can be attributed to the defense induced in plants due to the increased infection by nematode and fungus. The protein content was found higher in leaves (3.22 µg of BSA g-1 fresh weight) and roots (3.46 µg of BSA g-1 fresh weight) of the uninoculated plants compared to plants inoculated with nematode and fungus. The decrease in protein content on inoculated plants can be due to the increased use of amino acids by galls or giant cells thereby reducing their availability for protein synthesis. Investigations of the present study highlighted that plant parasitic nematodes viz. M. incognita, R. reniformis, R. similis, H. dihystera and Macroposthonia sp and fungal pathogens viz. F.solani, F. oxysporum Phytophthora sp., Pythium sp. and Rhizoctonia sp. were found associated with black pepper grown in Kannur, Idukki and Wyanad districts of Kerala. Prior inoculation of M. incognita enhanced nematode multiplication and 120 disease incidence as evidenced by increased number of giant cells, distortion of vascular bundles and plugging of fungal mycelia in xylem vessels.
Management of reniform nematode rotylenchulus reniformis linford and oliveira in vegetable cowpea using bacterial antagonists
(Department of Nematology, College of Agriculture, Vellayani, 2020) Swathi Karthika, K S; Nisha, M S
Management of root knot nematode, meloidogyne incognita(Kofoid and white) chitwood in vegetable cowpea
(Department of Nematology, College of Agriculture, Vellayani, 2020) Divya, T S; Nisha, M S
Nematode association in cabbage, brassics oleracea L. var. capitata and its management using botanicals
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2015) Annie P Varghese; Nisha, M S
An investigation entitled „Nematode association in cabbage, Brassica oleracea L. var. capitata and its management using botanicals‟ was carried out at College of Agriculture, Vellayani during 2012-2014 with an objective to study the nematode fauna in rhizosphere of cabbage and to evolve an eco-friendly management strategy using plant products. A survey was conducted in major cabbage growing tracts of the state viz., Idukki, Kollam and Thiruvananthapuram districts. Result of the survey revealed the presence of Meloidogyne incognita (Kofoid & White) Chitwood., Rotylenchulus reniformis Linford and Oliveira, Helicotylenchus sp., Tylenchorhynchus sp., Radopholus similis (Cobb) Thorne and Xiphinema sp. The population of M. incognita ranged from 0-118, 0-247, 0-310 and 0-262 per 200 g soil in Vattavada (Idukki district), Kanthalloor (Idukki district), Kollam and Thiruvananthapuram respectively. The average and frequency of occurrence of M. incognita in these areas ranged from 29 to 104 and 38.5 to 61.5 respectively. The population of Helicotylenchus sp. ranged from 0-752 and was the dominant nematode in cabbage growing areas surveyed. The population of R. reniformis ranged from 0-374 with an average of 94 and frequency of occurrence of 67.3 in these areas. In the case of Tylenchorhynchus sp. the population ranged from 0-238 per 200 g soil with an average of 45 and frequency of occurrence of 48.73 in the above four areas. Xiphinema sp. and R. similis was observed in soil samples collected from Kollam and Thiruvananthapuram districts respectively. Community analysis of nematodes was also done. Aqueous leaf extracts of Tithonia diversifolia (Hemsl.) Gray, Lantana camara L., Eichhornia crassipes (Mart.) Solms and root extract of Chromolaena odorata L. were screened for ovicidal and larvicidal effect against M. incognita under in vitro condition. T. diversifolia 100 % recorded minimum egg hatching (1 to 1.5 %) three to eight days after treatment. The bio efficacy of fresh leaf extracts of T. diversifolia, L. camara, E. crassipes and C. odorata on mortality of M. incognita juveniles revealed that T.diversifolia 100, 50, 33.3 and 25 % were effective in increasing the mortality of M. incognita juveniles at 24, 48 and 72 hours after treatment (63 to 100 %). C. odorata 50 and 100% also showed significant superiority over other treatments giving a mortality of 56 to 98 % at 48 and 72 hours after treatment. Pot culture study was conducted to find out efficacy of different preparations of T. diversifolia and appropriate method of application. T. diversifolia dried powder @100 and 50 g(kg soil)-1 were effective in decreasing the nematode population in soil and root (98 to 99 %) and improving the plant growth (31 to 87 %). Results of field study revealed that highest reduction of nematode population in soil was observed in thiamethoxam followed by Paecilomyces lilacinus (Thom)Samson enriched neem cake and nematode population in these treatments was significantly lower than T. diversifolia dried powder.T. diversifolia dried powder @ 50 and 100 g plant-1 was statistically on par in reducing the nematode population (85 % reduction over untreated) in cabbage rhizosphere.
Population dynamics and management of nematodes in banana using non chemical methods
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2017) Nimisha, A M; Nisha, M S