Browsing by Author "Ramesha, B"

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Biorational management of major pests in brinjal (Solanum Melongena L.)
(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2014) Gowrish, K R; Ramesha, B
Biorational management of major pests in brinjal (Solanum Melongena L.)
(2015) Gowrish, K.R; Ramesha, B; Ushakumari, R
Biorational management of major pests of Kerala, Abelmoschus esculentus(L.) moench
(Department of Entomology, College of Agriculture, Padannakkad, 2023-11-13) Gagan, B S.; Ramesha, B
The study entitled “Biorational management of major pests of okra, Abelmoschus esculentus (L.) Moench” was carried out in the Instructional Farm, Karuvachery during two seasons viz., summer (January to May) and kharif (June to September) in the year 2022 to study the efficacy of different microbial agents, neem based and biorational insecticides against major pests of okra viz., okra shoot and fruit borer, aphids, jassids and leaf roller. Bioassay studies were conducted in the laboratory of Department of Entomology, College of Agriculture, Padanakkad during 2022-23 to evaluate the efficacy of microbial agents, neem based and biorational insecticides against aphids, jassids and leaf roller. Treatments were applied on test insects as three replications and the percentage mortality at fixed intervals was worked out. The field experiment was laid out in randomized block design (RBD) with nine treatments and three replications. The okra variety ‘Salkeerthi’ released by KAU was selected for the study. Treatments included were; T1: Bt formulation 2× 109 cfu/ml @ 10 ml/l of water; T2: Neem based formulation (Azadirachtin 1%) @ 2 ml/l of water; T3: Raksha (Neem oil, garlic, soap based formulation- KAU product) @ 6 g/l of water; T4: Emamectin benzoate 5% SG @ 0.4 g/l of water; T5: Pyridalyl 10 EC @ 1.5 ml/l of water; T6: Flonicamid 50 WG @ 0.6 g/l of water; T7: Spinosad 45 SC @ 0.4 ml/l of water; T8: Malathion 50 EC @ 2ml/l of water- Standard check; T9: Absolute control. Treatments were imposed at 30th, 45th and 65th day after sowing and observations were recorded at weekly intervals corresponding to standard weeks. The data were subjected to square root transformation and analysed using ANOVA in GRAPES (General R-shiny based Analysis Platform Empowered by Statistics) software. Bioassay studies indicated that highest percentage mortality of aphids, jassids and leaf roller were recorded in treatment T6 (Flonicamid 50 WG), T4 (Emamectin benzoate 5% SG) and T7 (Spinosad 45 SC) respectively after 24 hours of treatment application. Analysis of field experimental results showed that there is significant difference between the treatments in reducing the pest status of the crop as well as yield parameters of the crop. After three sprays, treatment T7 (Spinosad 45 SC @ 0.4 ml/l of water) at fortnightly intervals completely reduced shoot and fruit borer larvae in both summer and kharif seasons and leaf roller larvae in kharif season. Therefore, it was found that Spinosad 45 SC was effective in reducing the population of shoot and fruit borer and leaf roller as well as the percentage of shoot and fruit infested. During summer season, treatment T6 (Flonicamid 50 WG @ 0.6 g/l of water) was found to be the most effective treatment in reducing the nymphs and adults of aphids and their percentage shoot infestation in the vegetative phase of the crop. Treatment T4 (Emamectin benzoate 5% SG @ 0.4 g/l of water) and T2 (Azhadirachtin 1% @ 2 ml/l of water) were found effective in controlling the nymphs and adults of jassids in both summer and kharif seasons. T6 (Flonicamid 50 WG @ 0.6 g/l of water) also provided effective control of jassid population in the crop. Among the different treatments, maximum fruit length was recorded in T7 followed by T4 during both summer (17.13 and 15.50 cm) and kharif season (17.32 and 16.10 cm) respectively. Total yield was highest in T7 followed by T4 showing per plant yield of 384.87 and 360.53 g respectively during summer season and 502.65 and 479.47 g respectively during kharif season. Also, the same treatments recorded highest marketable yield of 369.79 and 339.75 g/plant respectively during summer season and 482.91 and 458.83 g/plant respectively during kharif season. During both seasons viz., Summer and kharif, highest benefit-cost ratio was recorded in T4 (2.73 and 3.62) and T7 (2.70 and 3.54) respectively. The results of the investigation clearly indicated that, along with then recommended package of practice, spraying of Spinosad 45 SC @ 0.4 ml/l of water provides effective control of okra shoot and fruit borer and leaf roller without reducing the marketability of the fruits. Spraying of Flonicamid 50 WG @ 0.6 g/l of water can be used to effectively control the sucking insects like aphids and also jassids. Emamectin benzoate 5% SG @ 0.4 g/l of water and Azadirachtin 1% @ 2 ml/l of water can be used to control nymphs and adults of jassids on okra
Eco-friendly management of major pests of yard long bean, vigna unguiculata subsp. sesquipedalis (L.) Verdcourt.
(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2017) Vineetha, V; KAU; Ramesha, B
The study entitled ′′Eco-friendly management of major pests of yard long bean, Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt′′ was carried out in the Instructional farm of College of Agriculture, Padannakkad, Kasaragod during two seasons viz., kharif (May to August) and rabi (September to December) in the year 2016. The vegetable cowpea variety ‘Lola’ released by KAU was selected for the study. The study was undertaken with an intention to find out the efficacy of different microbial agents, neem based and biorational insecticides. The experimental design was RBD with 9 treatments and three replications. The treatments included; T1- Beauveria bassiana (liquid formulation @ 107 spores/ml of water), T2- Metarhizium anisopliae (liquid formulation @ 107 spores/ml of water), T3- Lecanicillium lecanii (liquid formulation @ 107 spores/ml of water), T4- Bt formulation 2× 108 cfu/ml @ 1 ml/l of water, T5- Neem based insecticide (Azadirachtin 1 per cent @ 5 ml/l of water), T6- Neem oil emulsion 5 per cent (50 ml/l of water), T7- Spinosad 45 SC @ 0.4 ml/l of water, T8- Malathion 50 EC @ 2ml/l of water (standard check), T9- Absolute control. All the treatments were imposed at fortnightly intervals just after the initial attack of pest was seen and observations were recorded at weekly intervals corresponding to standard weeks. The data were subjected to square root transformation and analyzed using ANOVA. After three consecutive sprays of Spinosad 45 SC @ 0.4 ml/l of water at fortnightly intervals there was complete reduction of pod borer larvae during kharif and rabi season. The percentage of flowers and pods infested by pod borer larvae were also reduced completely and no infestation was noticed after three consecutive sprays of Spinosad during both seasons. Thus it was found that Spinosad 45 SC was effective in reducing the number of pod borers, percentage of flowers infested and percentage of pods infested. During kharif season, Beauveria bassiana was found to be the most effective treatment in reducing the nymphs and adults of pod bugs with minimum number of 0.56 bugs per plant followed by 0.63 bugs in T5 compared to T9 with 7.46 bugs per plant after three consecutive sprays. During rabi season, Azadirachtin 1 per cent showed no incidence of pod bugs after three sprays and Neem oil 5 per cent consistently reduced number of bugs to zero on 15 days after third spray whereas T9 exhibited maximum number of 4.26 bugs/plant. The effect of Beauveria bassiana was lowered during rabi season. It might be due to the inability of Beauveria spores to germinate and cause infection during that season because of inadequate humidity. Azadirachtin 1 per cent incessantly lowered the per cent of pods infested by pod bugs to zero even after two sprays during both seasons and leaf miner attacked leaves was also found minimum in plot treated with Azadirachtin 1 per cent (0.63 leaves/plant) compared to T9 (7.12 leaves/plant). The aphid population on shoots and per cent of aphid infestation on shoots were found to be zero after three consecutive sprays of Lecanicillium lecanii at fortnightly intervals during kharif season. Lecanicillium lecanii also lowered the aphid population on pods and caused exorbitant reduction in the percentage of infested pods during both seasons after three sprays. Though pod length is an inheriting character, maximum length of 42.30cm and 48.40cm was shown by T7 during kharif and rabi seasons respectively. During both seasons viz., kharif and rabi, the total and marketable yield was high in T7 with highest benefit – cost ratio of 1.50 and 2.26 respectively.
Evaluvation of new insecticides against major pests of okra, Abelmoschus esculentus
(Department of Agriculural Entomology,Padanakkad, 2019) Reshma Chandran; Ramesha, B
An experiment was conducted on ‘Evaluation of new insecticides against major pests of okra, Abelmoschus esculentus L.’ at College of Agriculture, Padannakkad and RARS Pilicode sub centre, Karuvachery in two seasons viz., rabi season (September to December 2018) and summer season (January to April 2019).The objective of the study was ‘to study the efficacy of different new insecticides against major pests of okra, viz., shoot and fruit borer, gram pod borer, leaf roller and leafhopper’. The variety selected for the study was Varsha Uphar released by Haryana Agricultural University, Hisar. The experiment was laid out in Randomized Block Design with 8 treatments and 3 replications. The different treatments were; T1: Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC (Voliam flexi®) @ 0.7ml/l; T2: Lambda cyhalothrin 4.6 per cent + Chlorantraniliprole 9.3 per cent ZC (Ampligo®) @ 0.4 ml/l; T3: Thiamethoxam 12.6 per cent + Lambda cyhalothrin 9.5 per cent ZC (Alika®) @ 0.5 ml/l; T4: Flubendiamide 19.92 per cent w/w + Thiacloprid 19.92 per cent w/w (Belt-expert®) @ 0.4ml/l; T5: Novaluron 10 EC @ 2ml/l; T6: Chlorantraniliprole 18.5 SC @ 0.3 ml/l (check); T7: Thiamethoxam 25 WG @ 0.3g/l (check); T8: Absolute control. Treatments were applied one at vegetative and one at reproductive stage after the incidence of pest. The observations like damage symptoms were recorded at seven and fourteen days after treatment and population of jassids were recorded at one, three, five, seven and fourteen days after treatment. Biometric observations and yield parameters were recorded during each harvest. The data recorded from field experiment was tabulated and statistical analysis was performed using analysis of variance (ANOVA). Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC (T1 -Voliam flexi) @ 0.7 ml/l of water significantly reduced the percentage of shoot and fruit damage during both rabi and summer season. No infestation was recorded at seven and fourteen days after treatment. It was on par with the standard check Chlorantraniliprole 18.5 SC. The damage caused by leaf roller was significantly reduced by Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC @ 0.7 ml/l of water. There was no incidence of leaf roller after seven and fourteen days after first spray until the end of the crop period during both rabi and summer season. Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC @ 0.7 ml/l of water was very effective against the population of leafhopper. The population of adults and nymphs of leafhopper was drastically reduced by Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC and three days after spray no hoppers were found on plots treated with Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC. It showed non-significant difference with standard check Thiamethoxam 25 WG @ 0.3 g/l of water. Alika (Thiamethoxam 12.6 per cent + Lamda cyhalothrin 9.5 per cent ZC) @ 0.5ml/l of water significantly reduced the population of leaf hopper after Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC. Hopper population was negligible at fifth and seventh day after treatment while it was increased by fourteenth day. Length of the fruit was inversely proportional to the percentage of damage caused by Earias vitella. Maximum fruit length of 14.85 cm and 15.99 cm was recorded from Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC treated plots during both rabi and summer season respectively. This indicates higher efficacy of Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC against E. vitella. The highest total yield was recorded from Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC treated plots during rabi and summer season with yield of 469.86 and 594.31 g/plant respectively. Chlorantraniliprole 8.8 per cent + Thiamethoxam 17.5 per cent SC also showed high benefit-cost ratio of 2.42 and 3.12during rabi and summer season respectively.
Taxonomic studies on indian belonnotus (coleoptera: curculionidae: ceutorhynchinae)
(Department of agricultural entomology, College of agriculture, Padannakkad, 2015) Shruthi, C; Ramesha, B
The study entitled “Taxonomic studies on Indian Belonnotus (Coleoptera: Curculionidae: Ceutorhynchinae)” was undertaken in the Department of Entomology, College of Agriculture, Padannakkad during 2013-2015. The members of the tribe Mecysmoderini of the subfamily Ceutorhynchinae are one of the very large, diversely represented group of weevils in India, compared to other geographical regions of the world. Amongst the diverse genera representing of this tribe in India, genera Belonnotus and Mecysmoderes are important as it is distributed in Oriental region. A total of eighteen species are reported worldwide, out of which ten species are known from India in genus Belonnotus, whereas 26 species are known to be reported from worldwide in genus Mecysmoderes, of which five are known from India. Some of these species are major pests on economically important crops such as cucurbitaceous and cruciferous vegetables, as they cause pitting on the leaves and fruits. Some ceutorhynchine species feed on weeds and therefore are considered as biological control agents. The only substantial work on these weevil groups had come from Pajni and Kohli (1982). The available information is limited and lacking in essential diagnostics especially genitalia and morphometric observations. Hence, the present study was undertaken with objectives of survey and collection, study of morphological characters, redescription of species and formulation of taxonomic keys for the identification of the species. The present study was based on the collections from Malabar Insect Repository, College of Agriculture, Kerala Agricultural University, Padannakkad, Kerala and the specimens loaned from National Pusa Collection, Indian Agricultural Research Institute, New Delhi. Collections were also made through surveys from different parts of Kerala and Karnataka. The study constitutes five species belonging to two genera. All the species known so far under genera Belonnotus and Mecysmoderes have been taxonomically described. The descriptions of all the species studied are supplemented with taxonomic characters of genitalia and morphometric observations. An annotated checklist of the world Ceutorhynchinae had been prepared and these covered a total of 1316 species in worldwide distributed under 90 genera while the number of species reported from India is 45 distributed under 5 tribe and 13 genera. The geographic distribution of these species had been documented by taking up to date literature. The discrepancies in the description of the genera and species had been corrected and descriptions standardized to a uniform format loaded with morphometric ratios. Taxonomic keys to the species of all these two genera have been formulated and augmented with valid characters. Thus the present study fulfills to bridge a glaring lacuna of knowledge on these weevils and to keep its taxonomy on International standards.
Taxonomy of rhynchophorinae (COLEOPTERA: DRYOPHTHORIDAE) of Kerala
(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2016) Arun Kumar Singh; Ramesha, B
Trapping of red palm weevil in coconut gardens
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1999) Ramesha, B; Jim Thomas
Experiments were undertaken in the Department of Agricultural Entomology, College of Horticulture, Vellanik:kara during 1997-1998 to evaluate the efficacy of the male aggregation pheromone Ferrolure (4-Methyl-5 nonanol) in mass trapping the redpalm weevil of coconut Rhynchophorus ferrugineus F (Oliv.) in the coconut plantations of Thrissur district. A survey was conducted in Thrissur district in three regions representing three geographical zones viz., coconut plantations in coastal zones, midland regions and upland conditions with the respective red palm weevil damage incidence of 5.33 per cent, 7.66 per cent and five per cent with an average incidence of six per cent. A convenient and suitable bucket trap was designed and fabricated for the mass trapping of the adult weevils from the field and for further laboratory experiments. Out of the different food attractants tried pineapple waste and toddy gave increased trapping efficiency of the weevils with the pheromone sachet. The food attractants was necessarily to be renewed afresh once in three to four days interval so as to keep the trap effective. At this rate of change of the food attractant a single pheromone sachet was found to be actively performing to trap the weevils for a period of 10-12 weeks. The Ferrolure tried was found to be predominently a male aggregation pheromone but with reasonable attraction to female weevils as well. The best exposure height of the pheromone trap was at a height range of one to two meters from the ground level within the coconut plantations to offer maximum trapping efficiency.' An DV light source at night was found to supplement the weevil trapping along with the pheromone trap giving 2.85 times more catch. In conclusion the experimental observation proves the overall efficacy of the ferrolure with pineapple as a food attractant coupled with the bucket trapping device. If the traps are installed at one to two meter above the ground level in the plantation, this gives good performance in trapping the male and female adult weevils for an effective period of nine to 10 weeks. A large number of weevils could be trapped which will probably reduce the damage of this weevil below the existing six per cent of damage. Food substance should be changed periodically at an interval offour days to retain the efficiency.