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Professor Jayashankar Telangana State Agricultural University, Hyderabad (Telangana State)
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ThesisItem Open Access EVALUATION OF DUAL TOXIN TRANSGENIC Bt COTTON HYBRIDS AGAINST INSECT PESTS OF COTTON(PROFFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2014-05-06) B.DILEEP KUMAR; Dr. D.SRIDEVIThe performance of dual toxin transgenic Bt cotton hybrids viz., Bunny, Mallika, Neeraja, Brahma, Tulasi-9, RCH-2, RCH-530 and a non-Bt hybrid, Orugallu Krishna (WGHH-2) against insect pests of cotton in both field and laboratory were undertaken during Kharif, 2011-12 and 2012-13 at Regional Agricultural Research Station, Warangal. The population (pooled mean for both the years) of aphids and whiteflies showed no significant variation among the various BG-II/non-Bt hybrids under protected conditions. The population ranged between 3.87 and 5.32 and 1.50 to 2.04/top 3 leaves in aphids and whiteflies, respectively. However, leafhoppers and thrips varied significantly amongst the various BG-II/non-Bt hybrids. The population of leafhoppers was significantly lowest in non-Bt Orugallu Krishna (1.53 leafhoppers/top 3 leaves) and was on par with only Neeraja (1.60 leafhoppers/top 3 leaves). The population ranged between 1.80 and 3.29 leafhoppers/top 3 leaves in the remaining hybrids, the highest (3.29 leafhoppers/top 3 leaves) being in RCH-2. The population of thrips ranged between 9.77 and 17.80 thrips/top 3 leaves. A total of six need based sprayings were required for dual toxin Bt hybrids to manage the sucking pest complex in both kharif, 2011-12 and 2012-13. During both the years the cost-benefit ratio was found to be higher in RCH-530. Egg laying by bollworms in dual toxin Bt cotton hybrids was almost nil in BG II/non-Bt hybrids during kharif 2011-12, while in kharif 2012-13, non significant differences with respect to the number of eggs laid in different BG-II/non-Bt hybrid were observed. Larvae of Helicoverpa armigera (Hubner), Spodoptera litura (Fabricius) and Erias vitella (Fabricius) were observed in non-Bt Orugallu Krishna but below ETL while in dual toxin Bt hybrid none were recorded. The incidence of pink boll worm[Pectinophora gossypiella (Saunders)] during both the years was nil. There was significant difference in mortality of H. armigera and S. litura larvae between BG-II and non-Bt Orugallu Krishna. BG-II hybrids were highly effective against the first instar larvae of both H. armigera and S. litura compared to later instars. Irrespective of the age of leaves and squares, Neeraja and Mallika, respectively, were superior in suppressing all the three instars of H. armigera while in S.litura variable responses were observed. The studies on effect of age of different plant parts of BG-II cotton hybrids on the mortality of larvae of H.armigera have shown that irrespective of the age of leaves and squares, Neeraja and Mallika, respectively, were superior in suppressing all the three instars. However, with respect to bolls, 90 day old bolls of RCH-530 and 120 day old bolls of RCH-2 and Mallika were effective against all the three larval instars. The studies on the effect of age of different plant parts of BG-II cotton hybrids on the mortality of larvae of S.litura has shown variable responses to different plant parts. 60 and 90 days old leaves of RCH-530 were effective against all three instars, while 120 days of RCH-2 and Mallika were effective against first and second instars and first and third instars, respectively. With regards to squares, irrespective of age of squares, Tulasi-9 gave better control of third instar larvae. However, the performance of bolls varied i.e 90 days bolls of Tulasi-9 were effective against third instar while 120 days old bolls of RCH-530 were effective only at 5 DAR while at 10 DAR Bunny, Mallika and Neeraja were superior. Also, the mortalities of S. litura larvae were greater on leaves followed by squares and bolls. The effect of age of various plant parts (leaves, squares and bolls) on the pupation and adult emergence of third instar larvae of H. armigera and S.litura showed that the percentage pupation and adult emergence in non-Bt Orugallu Krishna was significantly high compared to Bt hybrids. The effect of age of leaves on the larval weights of different instar larvae of S. litura showed that there was significant reduction in the larval weights when fed with dual toxin Bt cotton leaves compared to non-Bt leaves. Cry 1Ac content was highest in leaves compared to squares and bolls, while Cry 2Ab recorded highest levels in squares compared to leaves and bolls. Cry1 Ac levels were higher in leaves at 90 DAS compared to 60 and 120 DAS. Significantly lowest trichomes were registered in RCH-2 (35.60 / 4 x microscopic area) indicating that this hybrid was highly susceptible to leafhoppers attack. The efficacy of different insecticides against leafhoppers in RCH-2 revealed that diafenthiuron 50% WP was the most effective.ThesisItem Open Access MOLECULAR CHARACTERIZATION OF BROWN PLANTHOPPER Nilaparvata lugens (Stål) POPULATIONS IN TELANGANA STATE AND IDENTIFICATION OF GENES FOR BPH RESISTANCE(PROFFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2022-01-03) SUBHASHREE PRIYADARSHINI; JHANSI LAKSHMI, V.The present studies were conducted at ICAR-Indian Institute of Rice Research, Rajendranagar and Central Instrumentation Cell, College of Agriculture, Rajendranagar to study the spectrum of virulence, morphometrics, molecular characterization and clustering of brown planthopper (BPH) Nilaparvata lugens (Stål) (Delphacidae: Hemiptera) populations collected from Telangana state. Resistance sources were identified and characterization of resistance gene (s) for BPH in germplasm accessions was carried out. Mechanisms of resistance were studied in the selected rice gene differentials and germplasm accessions. A total of thirty two rice gene differentials with known and unknown genetics were evaluated for their resistance to nine brown planthopper populations collected from different districts of Telangana i.e., Adilabad, Khammam, Karimnagar, Mahbubnagar, Medak, Nalgonda, Nizamabad, Rangareddy, Warangal along with IIRR glasshouse population by adopting internationally accepted Standard Seedbox Screening Test (SSST) and scored on 0-9 scale by following the IRRI method of Standard Evaluation System (SES) for rice. Among thirty two rice gene differentials tested, 3 gene differentials viz., PTB 33, RP 2068-18-3-5 and RPBio4918-230S were categorized as resistant (DS 1.0 to 3.0), 13 as moderately susceptible (DS 5.1 to 7.0), 15 as susceptible (DS 7.1 to 8.9) and 1 gene differential as highly susceptible (DS 9.0) to brown planthopper populations. Among all the BPH populations, Medak BPH population was found highly virulent (DS 7.46) and least virulent was Mahbubnagar population (DS 6.34). In the resistant gene differentials, PTB 33 and RP 2068-18-3-5 the feeding was less in terms of low honeydew excretion and more number of probing marks suggesting antixenosis mechanism of resistance for feeding. Brown planthopper adults probed more number of times and fed more and excreted more honeydew compared to nymphs. The resistant gene differentials viz., RP 2068-18-3-5, RP BIO 4918-230S showed less nymphal survival (%), low growth index, highest proportion of males (%) indicating antibiosis mechanism of resistance. The sex ratio in most of the BPH populations was in favour of females. The proportion of macropterous adults was more than brachypterous adults in the BPH populations. The macropterous females emerged in more numbers compared to brachypterous females, macropterous males and brachypterous males. In general, the brachypterous females weighed more compared to macropterous females, macropterous males and brachypterous males. The gene differential, RP BIO 4918-230S revealed longest nymphal duration and more number of days to wilt indicating the antibiosis and tolerance mechanisms of resistance. The damage score has a positive correlation with fecundity, honeydew excretion and adult body weights. The damage score is negatively correlated with probing marks, days to wilting, nymphal duration, percent males and macropterous adults. Growth index has positive and significant correlation with nymphal survival. The measurements such as total length of the body, width of the body, length of wings, width of the wing, interocular distance, antennal length and tibial spur length of adult Brachypterous and macropterous forms of females and males were recorded. On an average Nalgonda BPH population showed highest body length, wing length, antennal length, interocular distance, length of tibial spur and highest rostrum length. Other morphological parameters i.e., body length and width, wing length and width, antennal length, interocular distance and length of tibial spur differed among different brown planthopper populations. When both genotypic and phenotypic clusters were compared, Adilabad & Warangal populations, Nalgonda & Khammam populations and Mahbubnagar & Nizamabad populations were found to be similar, whereas, Ranga Reddy & Medak and Karimnagar & IIRR glasshouse populations differed phenotypically and genotypically. Out of thousand germplasm accessions screened, one germplasm accession IC 518805 was highly resistant (DS 0.9), eleven germplasm accessions were resistant to brown planthopper with a damage score of 1.1-3.0. The brown planthopper adults fed less and excreted less honeydew on the germplasm accession i.e., IC 515974 (22.66 mm2 ). Nymphal honeydew was low 21.33 mm2 to 49 mm2 ) on resistant and moderately resistant entries viz., PTB 33, IC 576798, IC 519101, IC 517008 and IC 518849 compared to susceptible check. Fecundity and nymphal duration were less on resistant germplasm accessions compared to susceptible ones. In general, the sex ratio was in favour of females (1.22Females:1.0Males). In the germplasm accessions, the winged females were maximum in proportion (24.57%) followed by winged males (28.50%), wingless females (26.29%) and wingless males (20.63%). In general, the macropterous females weighed more (2.95 mg) compared to brachypterous females (2.89 mg), macropterous males (1.09 mg) and brachypterous males (1.05 mg). The number of days to wilt were more in the entries IC 519101, PTB 33, IC 75778 and IC 540340(A). Molecular profiling by using 17 SSR markers for detecting 9 BPH genes revealed that the germplasm accessions viz., IC 75883, IC 75887, IC 75778, IC 75886, IC 515880, IC 517008 and IC 515974 were observed to have Bph2 gene. The germplasm accessions viz., IC 575211, IC 75778, IC 75886, IC 75883, IC 515159, IC 515880, IC 540340(A), IC 200940, IC 517008 and IC 444008 were observed to have Bph3 gene. The germplasm accessions viz., IC 519101, IC 75883, IC 575211, IC 75887, IC 75778, IC 75886, IC 515159, IC 540340(A), IC 200940, IC 517008 and IC 515974 were observed to have Bph6 gene. The germplasm accessions viz., IC 75885, IC 515159 and IC 540340(A) have Bph17 gene. IC 519101 and IC 540340(A) were found to be have Bph20 gene. Among the germplasm accessions with different genes/gene combinations, Bph6+Bph20 (IC 519101), Bph2+Bph6 (IC 515974, IC 517008 and IC 75883), Bph2+Bph6+Bph17 (RP 2068-18-3-5 and RP 4918-230-S) and Bph32+Bph17 (PTB33) showed resistant reaction. The genes/gene combinations viz., Bph3+Bph6 (200940), Bph3+Bph17 (IC 75885) and Bph2+Bph3+Bph6 (IC 75886) showed moderately resistant reaction. The identified gene differentials and germplasm accessions can be used in the breeding programmes to develop brown planthopper resistant varieties.ThesisItem Open Access STUDIES ON LIFE-FERTILITY AND INSECTICIDAL MANAGEMENT OF FALL ARMYWORM(PROFFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2022-11-04) Supriya, G. B.; Sridevi, G.Studies on life-fertility and insecticidal management of fall armyworm (FAW), Spodoptera frugiperda (J. E Smith) were carried out during 2019-20 and 2020-21. The life-fertility studies were conducted in the Department of Entomology, College of Agriculture, Rajendranagar, while the trial on bioefficacy of insecticides was carried out during rabi, 2019-20 and 2020-21 at the College farm. Studies on dissipation of selected insecticides were conducted at Pesticide Residues Laboratory, AINP on Pesticide Residues, PJTSAU, Rajendranagar, Hyderabad. The age specific survivorship of S. frugiperda on vegetative and reproductive parts of different host plants (7 no.) and artificial diet, revealed that the larval period of S. frugiperda on vegetative parts ranged between 11.97±0.015 days (tomato leaves) and 13.99±0.035 (paddy leaves) whereas on reproductive parts it ranged between 13.73±0.046 days (tomato fruits) and 14.92±0.072 (sorghum earheads) while on artificial diet, it was 14.84±0.139 days. The pupal period varied between 7.02±0.043 (paddy leaves) and 7.97±0.028 days (maize leaves) on foliage while it ranged between 7.05±0.052 days (sorghum earheads) and 9.87±0.122 days (maize kernels) on reproductive parts. The pupal period of S. frugiperda was recorded highest on artificial diet 8.86±0.170 days. The adult longevity ranged between 9.89±0.098 days (paddy leaves) to 13.84± 0.170 days (maize leaves) and 10.92±0.101 days (sugarcane setts) to 11.90±0.107 days (sorghum earheads) when S. frugiperda fed on vegetative and reproductive parts, respectively and on artificial diet it was 12.02±0.034 days. The total life cycle of S. frugiperda reared on vegetative (33.20±0.091 to 35.92±0.217 days) and reproductive parts (33.99±0.041 to 36.09±0.025 days) was significantly less than that on artificial diet (37.00±0.012 Name of the author : SUPRIYA G. B Title : “STUDIES ON LIFE-FERTILITY AND INSECTICIDAL MANAGEMENT OF FALL ARMYWORM” Degree to which it is submitted : DOCTOR OF PHILOSOPHY IN AGRICULTURE Faculty : AGRICULTURE Department : ENTOMOLOGY Chairperson : Dr. G. SRIDEVI University : PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY Year of submission : 2022 days). S. frugiperda when reared on maize leaves, sorghum leaves and artificial diet showed type-I survivorship curve, while on paddy and tomato leaves it was stair step, type-I. However, on sugarcane leaves, castor leaves, paddy panicles and sugarcane setts, the survivorship curve was type-II, stair step, type-III and type-II, respectively. The age specific survivorship of female S. frugiperda and its fecundity on different hosts were studied. The potential fecundity was significantly highest in artificial diet (4077.14±567.52 eggs) followed by maize leaves (2859.38±169.40 eggs)>castor leaves (2778.86±69.95 eggs)> maize kernels (1627.91±69.82 eggs)> sorghum leaves (1016.98±14.51 eggs). The various life parameters of S. frugiperda on different hosts revealed the suitability of host. The net reproductive rate (R0) was highest (947.43±0.479) in artificial diet, followed by maize leaves (707.57±0.584), maize kernels (496.88 ±2.127) and castor leaves (324.46±0.150), whereas, the highest mean generation time (Tc) was recorded on maize kernels (32.75±0.015 days) followed by artificial diet (32.03±0.012 days). The highest intrinsic rate of increase (rm) value was recorded highest on maize leaves (0.2193±0.00), followed by artificial diet (0.2140±0.00). The highest finite rate of increase (λ) recorded on maize leaves as (1.64±0.003 female offsprings/ female/day) followed by artificial diet (1.62±0.003 female offsprings/ female/day day), whereas highest weekly multiplication rates (WMR) value was recorded on maize leaves (4.64±0.006) followed by artificial diet (4.48±0.006) and castor leaves (3.84±0.006). Doubling time (DT) was recorded highest on maize leaves (3.17±0.006 days) followed by artificial diet (3.24±0.006 days), castor leaves (3.61±0.006 days) and maize kernels (3.67±0.006 days). The stable age distribution of S. frugiperda on different host plants indicated that the larval stage contributed maximum (92.60 to 97.49 %) compared to other stages to the total population, while the life expectancy on different hosts revealed that early stages recorded higher life expectancies than adult stages on all the hosts. The life table study of S. frugiperda on cotton leaves and bolls revealed that the larval duration on cotton leaves was 12.45±0.327 days and on bolls it was 12.47±0.306 days. The survivorship curve on cotton was type-II on both leaves and bolls. The life parameters like R0, Tc, λ, WMR and F2 females, were lower on cotton leaves compared to bolls. The per cent contribution of larvae to stable age was more than 90 per cent on cotton leaves and bolls, similarly, the larval and adult expectancy were significantly lower. The bio-efficacy studies revealed that spinetoram was the most effective insecticide against S. frugiperda with 97.61 per cent reduction in population followed by indoxacarb (91.09 %), spinosad (71.43%), emamectin benzoate (60.21%) and chlorantraniliprole (55.56 %). Among the selected insecticides, the mean highest yield of 3.34 t ha-1 was recorded from spinetoram treated plots followed by indoxacarb (3.09 t ha-1 ) and spinosad (2.45 t ha-1 ) which were found to be on par. The studies on dissipation pattern of selected insecticides in immature maize cobs revealed that indoxacarb persisted for 1.05 days while spinetoram dissipated below the limit of quantification (10 ppb), 2hrs after spraying.ThesisItem Open Access RESISTANCE TO LEAFHOPPER, Amrasca biguttula biguttula (Ishida) IN SUNFLOWER: SCREENING AND IDENTIFICATION OF RESISTANCE MECHANISM(PROFFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2021-07-01) Fatima, T.; Sridevi, G.The present studies were conducted at ICAR-Indian Institute of Oilseeds Research, Rajendranagar and College of Agriculture, Rajendranagar, Hyderabad to screen sunflower germplasm accessions, identify the various biophysical and biochemical factors of resistance and to understand the mechanism of resistance in some of the identified germplasm sources. Fifty seven accessions along with commercial hybrid, Syngenta-SB-275 and a susceptible check, Morden were screened against A. biguttula biguttula in field under natural infestation.The population of leafhopper and leafhopper injury were recorded from all the germplasm accessions during Rabi, 2016-17 and 2017-18 and categorized based on MSI (0: highly resistant; 0.1-1.0: resistant; 1.1-2.5: moderately resistant; 2.6- 3.5: susceptible and 3.6-5.0: highly susceptible). During Rabi 2016-17, out of 57 germplasm accessions screened, twenty two accessions were found resistant with a MSI ranging from 0.6 to 1.0, while twenty five were found moderately resistant with a MSI ranging from1.1 to 2.2, ten accessions were found susceptible with a MSI ranging from 2.6 to 2.7. Syngenta-SB-275 and Morden were found susceptible to leafhoppers with a MSI of 2.6 and 3.2, respectively. During Rabi-2017-18, fifteen germplasm accessions were found as resistant with a MSI of 0.8 to 1.0; thirty accessions were found as moderately resistant with a MSI ranging from 1.2 to 2.4 and twelve accessions as susceptible with a MSI ranging from 2.6 to 3.5. Syngenta-SB-275 andMorden were found susceptible to leafhoppers with a MSI of 3.0 and 3.4, respectively. Thus, fifteen accessions were found resistant to leafhopper consistently for two years, i.e., 2016-17 and 2017-18. Twenty three accessions were recorded moderately resistant while ten accessions were found susceptible for two consecutive years.However, the remaining eight accessions were inconsistent in their reaction. Among the various biophysical and biochemical parameters studied, significant differences were observed in mean values of trichome density (midrib, lateral vein and leaf lamina), trichome length (midrib, lateral vein and leaf lamina), MDA, H2O2, SOD, CAT, POX, APX, total phenols, total free amino acid and total sugars between resistant and susceptible accessions. Correlation of leafhopper nymphal population with biophysical parameters revealed a significant negative correlation with trichome density on midrib (-0.813*), lateral veins (-0.727*), leaf lamina (-0.837*), trichome length on midrib (-0.706*), lateral veins (-0.755*) and leaf lamina (-0.692*)total phenols (-0.886*).Other biophysical factors like plant height, leaf area, petiole length, leaf thickness and midribthickness didn‟t show any significant effect on leafhopper nymphal population. Correlation of leafhopper nymphal population with biochemical factors showed significant positive correlation with malondialdehyde, hydrogen peroxide, total free amino acids and total sugars (r = 0.842*, 0.807*, 0.886* and 0.863*, respectively). Whereas, significant negative correlation with total phenol content (r = -0.886*) was observed. The mechanismof resistance evaluated in terms of settling preference study also revealed less number of nymphs settling on resistant accessions (8.3 to 17.3 nymphs per plant) compared to susceptible check, Morden (47.1 nymphs per plant). The ovipositional preference by A. biguttula biguttula under choice and no-choice tests recorded significantly lowest number of nymphs (4.67 to 7.33 nymphs per plant under choice test and 4.0 to 6.2 nymphs per plant under no-choice test) on resistant accessions, compared to susceptible check, Morden (34.0 nymphs per plant under choice test and 12.8 nymphs per plant under no-choice test). Resistant accessions received less number of feeding punctures(24.33 to 37.50 numbers of punctures per leaf) and lower number of honeydew spots (11.83 to 15.83 number of honeydew spots/8 h/10 nymphs) compared to susceptible check, Morden (195.17 numbers of punctures per leaf and 62.83 number of honeydew spots/8 h/10 nymphs). Developmental studies revealed extended larval period (10.90 to 11.68 days), reduced nymphal survival (15.8% to 32.6%) and shortened adult longevity on resistant accessions (5.40 to 6.16 days) compared to susceptible check, Morden (9.3 days, 64.9% and 10.23 days, respectively). The resistant accessions took more number of days for the development of symptoms compared to susceptible check, Morden. GMU-339, GMU-696 and TSG-401 showed antixenosis and antibiosis mechanism of resistance and in future it can be used in the resistance breeding programme against A.biguttula biguttula.ThesisItem Open Access IDENTIFICATION OF SOURCES, MECHANISMS OF RESISTANCE AND MANAGEMENT OF MAJOR INSECT PESTS ON SESAME (Sesamum indicum L.)(PROFFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2021-07-01) Omprakassh, S.; Narendra Reddy, C.The study entitled “Identification of sources, mechanisms of resistance and management of major insect pests on sesame (Sesamum indicum L.)” was carried out during late kharif 2018, summer 2019, late kharif 2019 and summer 2020. The field experiment was carried out at Regional Agricultural Research Station, Polasa, Jagtial, physical parameters viz., trichome density at Central Instrumentation Cell and biochemical analysis of samples were carried out at Quality Control Laboratory and Department of Crop Physiology, College of Agriculture, Rajendranagar, PJTSAU, Hyderabad. As per seasonal incidence data of major insect pests during late kharif 2018 and 2019, the peak incidence of Antigastra catalaunalis larval population (1.03 larvae/ plant) and per cent flower infestation of Asphondylia sesami (10.87) was observed during 3rd week of October (42nd standard week) which coincided with flowering stage of the crop. The correlation between larval population of A. catalaunalis indicated that, incidence was strongly dependent on morning relative humidity, which was positive and significant. Multiple regression analysis revealed that, all weather parameters collectively influenced the A. catalaunalis larval population and A. sesami flower infestation to the extent of 70 and 51 per cent, respectively during late kharif seasons. During summer 2019 and 2020, seasonal incidence of A. catalaunalis larval population peak was observed (0.82 larvae/plant) during 2nd week of April (13th standard week) where as the peak infestation of A. sesami (5.7%) was observed in 3rd week of March (11th standard week). During summer seasons, a strong significant negative correlation between morning relative humidity and A. sesami flower infestation was recorded. Multiple regression analysis revealed that, all weather parameters collectively influenced the A. catalaunalis larval population and A. sesami flower infestation to the extent of 59 and 75 per cent, respectively. Field screening of sixty sesame genotypes along with one resistant check, SI 250 and susceptible check, TC 25 against A. catalaunalis and A. sesami was carried out during late kharif 2018 and 2019. Based on screening data, none of the genotypes were highly resistant, seven sesame genotypes viz., JCS 3894, JCS 3594, JCS 3593, JCS 3265, SI 9050, JCS 3910 and JCS 3605 were resistant, twenty two genotypes were moderately resistant and thirty one sesame genotypes were categorized as susceptible. Based on screening data of sesame genotypes against A. sesami, twenty sesame genotypes viz., JCS 3894, JCS 3739, DT 112, JCS 3992, JCS 3893, JCS 3884, JCS 3578, JCS 3605, JCS 3599, JCS 3594, JCS 3593, JCS 2611, JCS 3265, GT 50, SI 1125, ES-5, NIC 16226, ES 7, SI 9050, JCS 4013 were resistant, twenty five genotypes were moderately resistant, eleven sesame genotypes were moderately susceptible, four genotypes were categorized as susceptible and none of the sesame genotype showed highly susceptible reaction. Physical and biochemical basis of resistance of selected sesame genotypes to A. catalaunlis were assessed. The physical characters like trichome density and capsule wall thickness showed significant negative correlation with per cent leaf and capsule damage, respectively. The biochemical constituents like chlorophyll, total sugars, reducing sugars and phenols effect the damage caused by A. catalaunalis in sesame. The multiple step down regression studies showed that, physical and biochemical factors together influenced the leaf and capsule damage to an extent of 94 and 99 per cent, respectively. Regarding A. sesami flower infestation, total sugars, total free amino acids and phenols influenced the infestation. The multiple regression studies showed that, biochemical parameters together influenced the flower infestation to an extent of 95 per cent. Chlorantraniliprole 18.5% SC @ 0.3 ml l-1 (90.28%) was found to be the most effective in reduction of A. catalaunalis larval population followed by spinosad 45% SC @ 0.3 ml l-1 with 80.23 per cent larval reduction. The next best treatments were profenophos 50% EC @ 2.0 ml l-1 , acephate 75% SP @ 1.0 g l-1 , ethofenprox 10% EC @ 2.0 ml l-1 and imidacloprid 17.8% SL @ 0.4 ml l-1 recorded 73.48, 62.91, 58.77 and 53.45 per cent mean reduction of A. catalaunalis larval population, respectively. The azadirachtin 1500 ppm @ 5.0 ml l-1 (29.88%) recorded lowest per cent reduction of A. catalaunalis larval population compared to untreated control. Regarding efficacy of insecticides against per cent flower infestation by A. sesami, spinosad 45% SC @ 0.3 ml l-1 (1.40%) was found to be most effective followed by profenophos 50% EC @ 2.0 ml l-1 , acephate 75% SP @ 1.0 g l-1 and chlorantraniliprole 18.5% SC @ 0.3 ml l-1 with 2.37, 2.57 and 2.60 per cent flower infestation, respectively. The next best treatments were imidacloprid 17.8% SL @ 0.4 ml l-1 and ethofenprox 10% EC @ 2.0 ml l-1 with 3.52 and 3.61 per cent flower infestation of A. sesami. The treatment azadirachtin 1500 ppm @ 5.0 ml l-1 (5.43%) was least effective in controlling per cent flower infestation. The highest seed yield of 801 kg ha-1 was recorded in chlorantraniliprole 18.5% SC @ 0.3 ml l-1 treatment followed by spinosad 45% SC @ 0.3 ml l-1 (783 kg ha-1 ) and the least seed yield was obtained in azadirachtin 1500 ppm @ 5.0 ml l-1 (550 kg ha-1 ). The highest incremental cost benefit ratio was recorded in profenophos treatment (1:3.22) followed by chlorantraniliprole treatment (1:3.12) and spinosad (1:2.96) treatment. The highest per cent avoidable yield losses by major insect pests was recorded in Hima variety followed by Swetha, Sharada, GT 10, Madhavi, Gouri, VRI 1 and Rajeswari with 35.45, 34.27, 33.17, 32.48, 31.05, 30.53, 30.01 and 29.75 per cent, respectively. Regarding incremental cost benefit ratio, highest was recorded in Hima variety (1:2.23) followed by Swetha (1:2.05) and Sharada (1:1.75) varieties.ThesisItem Open Access SURVEY, MAPPING OF BROWN PLANTHOPPER, Nilaparvata lugens (Stal) INCIDENCE IN SOUTHERN TELANGANA ZONE AND PHENOTYPIC, GENOTYPIC EVALUATION OF ELITE RICE GENOTYPES FOR BPH RESISTANCE(PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2022-03-01) RAGHAVENDER, B; RAJANIKANTH, PRice is cultivated in an area of 4.19 million hectares in Telangana of which 35 per cent is cultivated in the agro climatic zone of Southern Telangana comprising erstwhile districts of Mahabubnagar, Ranga Reddy and Nalgonda with paddy area of 1.45 million hectares. Among the different pests that cause severe damage to rice crop, brown planthopper, Nilaparvata lugens (Stal) was found to be most destructive in the zone causing yield losses upto 25-30 per cent annually. Different factors such as changes in weather conditions, adoption of different rice varieties and development of resistance by BPH for different insecticides has made it difficult to manage this pest. Increase in irrigation facilities followed by mono-cropping of rice further aggravated the incidence of BPH year after year. Therefore, a comprehensive study was conducted during 2019 and 2020 to identify BPH endemic areas in the zone and analyze the gaps between IPM practices and farmer’s adoptions, and existing varieties being cultivated and the requirement of new varieties to combat BPH menace. Further, rice genotypes were screened to identify new sources offering BPH resistance along with studies on mechanisms of resistance. Farmers were also assessed for their ability to manage BPH through KAP (knowledge, attitude and practice) analysis. Extensive surveys were conducted during kharif, 2019 and 2020 to determine BPH endemic areas in Southern Telangana Zone following GIS/GPS. The surveys revealed Nalgonda district as the hotspot for BPH incidence in the zone. The other two districts viz., Mahabubnagar and Ranga Reddy recorded no severe incidence of BPH either in dough stage or heading stage. However, the incidence was relatively more in heading stage compared to dough stage in all the three districts. The major hotspots for BPH incidence were mapped in Gurrompode, Haliya, Nagarjunasagar, Tirumalgiri, Pedda Adiserlapally, Chandampet, Neredugommu, Nidamanur, Thripuraram, Damarcherla, Palakeedu, Chintapally, Mellacheruvu, Chinthalapalem, Mattampally and Miryalguda mandals of Nalgonda district. The pest weather regression models revealed weather parameters viz.,Tmax,Tmin. RH2 and rainfall significantly influenced BPH field counts with coefficient of determination (R2 ) as 0.57 and 0.53 during kharif, 2019 and kharif, 2020 respectively. However, the influence of RH1 on BPH population was found to be non-significant [P value = 0.19 (2019) & 0.27 (2020)] in both the years. Fifty six rice genotypes possessing desirable quality traits were screened following standard seedbox screening test (SSST) with two resistant checks viz., PTB 33, BM 71 and one susceptible check TN1 for their reaction to BPH to identify resistance sources. Among 56 genotypes that were screened, only two genotypes were found to show resistant (R) response (Magic 289 and RNR 28370) and five genotypes (Magic 88, IRUE 45, RNR 29325, IRUE 52, and Magic 179) were found to be moderately resistant (MR) while the remaining 49 genotypes were found to be either moderately susceptible or susceptible to BPH. The studies on mechanisms of resistance being offered by these seven genotypes (R& MR) against BPH revealed that the genotypes Magic 289 and RNR 28370 offered resistance by compelling BPH nymphs for higher probing frequency coupled with low honey dew excretion and resulted in longer adult developmental period. These, genotypes were also found to sustain BPH infestation for a longer period and took longer duration to wilt. The genotypes Magic 289 also impacted adversely the fecundity of BPH, resulting in lower number of hatched eggs per female, percent hatchability, nymphal survival percentage and growth index. Similar pattern of resistance was also exhibited by the genotype RNR 29325. The studies on antibiosis mechanism of resistance based on biochemical analysis revealed that the total phenolic content increased, while the quantity of proteins and total sugars decreased in infested genotypes compared to uninfested genotypes. The genotype Magic 289 and RNR 28370 produced high phenols and low proteins, low total sugars before and after infestation and exhibited high rate of antibiosis mechanism. Further, studies on molecular characterization of these seven genotypes using 21 SSR markers showed that only five markers viz., RM588, RM1305, RM8213, RM589 and RM190 were linked to resistance genes Bph3, bph4, BPH12, bph17(t) that were existed in the resistance checks PTB33 and BM71. Out of seven genotypes characterized only one genotype Magic 289 recorded presence of three resistance genes viz., Bph3, bph4, bph17(t) while the other three genotypes IRUE 52, RNR 28370 and RNR-29325 recorded the presence of only two resistance genes viz., Bph3, bph4. Mapping of farmers based on Knowledge Attitude and Practice (KAP) towards managing BPH was conducted following extension studies in all the three districts of the zone. Majority of farmers possessed low level of knowledge on BPH management in Mahabubnagar and Ranga Reddy and medium level of knowledge in Nalgonda district. The farmers of Mahabubnagar and Ranga Reddy exhibited neutral attitude while the farmers of Nalgonda exhibited positive attitude towards BPH management. However, low level of practice was recorded in all the three districts viz., Mahabubnagar, Rangareddy and Nalgonda. The study identified the following sources of contact by farmers in decreasing order for making BPH management decisions which includes Pesticide dealer >Neighbour farmers > Agriculture officer / Field extension worker > Own > University scientists > Kisan call center. It can be concluded from these studies that approximately 16 mandals of Nalgonda district serve as hot spot areas for BPH in the Southern Telangana Zone and a strategic planning may be designed for management of BPH in these areas. The study suggests that new sources of resistance may be used for breeding new BPH resistance varieties and promotes two genotypes viz., Magic 289 and RNR 28370 which exhibits good host plant resistance. Further, the molecular characterization study also signifies the probability of presence of more number of BPH resistance genes in these two genotypes, which assures less scope for breakdown of resistance over a short period of time. Extension studies proved beyond doubt that majority of farmers have knowledge on chemical methods of pest management and there is a larger scope for training as well as promotion of integrated pest management practices in the zoneThesisItem Open Access SURVEY, IDENTIFICATION AND DOCUMENTATION OF IMPORTANT SPIDER FAUNA IN MAJOR CROPS OF TELANGANA AND DEVELOPMENT OF SPIDER BIODIVERSITY INDICES(PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2022-03-01) RAJU, A; RAHMAN, S.JA study was undertaken in several parts of Telangana during 2018-19 to identify and document key predatory spider fauna in major crops of the state viz., rice, maize and cotton. For each crop surveys were performed during kharif and rabi in six districts, two from the Northern, two from the Central and two from the Southern Zones of Telangana. Similarly, a field experiment was undertaken to explore the diversity and quantification of spider fauna in rice, maize and cotton crops. The survey pertaining to identification and documentation of spiders in the rice ecosystem were carried out in Telangana vast rice-growing regions viz., Northern Telangana Zone (NTZ)-Jagtial and Nizamabad districts, Central Telangana Zone (CTZ)- Warangal and Khammam districts and the Southern Telangana Zone (STZ)- Nagarkurnool and Nalgonda districts. A total of 3532 spider samples were collected from Northern (N=1224), Central (N=1066) and Southern (N=1242) Telangana Zones in state. In diverse parts of Telangana, the present study documented 23 species belonging to 17 genera, 13 families and eight guilds. Highest species richness of 21 was recorded from Nalgonda followed by 19 from Khammam, 16 each from Jagtial, Nizamabad and Nagarkurnool and 15 from Warangal. Among 23 species documented, eight species were designated as dominant species occurring regularly in the filed viz., Araneus sp., Tetragnatha mandibulata, Tetragnatha elongata, Tetragnatha montana, Pardosa sp., Pardosa pseudoannulata, Lycosa pseudoannulata, Oxyopes sp., 13 species as sub-dominant seen frequently viz., Zygiella indica, Zygiella sp., Araneus mitificus, Hogna sp., Arctosa maculata, Dolomedes aquaticus, Dolomedes tenebrosus, Runcinia sp., Heteropoda venatoria, Agelenopsis sp., Zoropsis spinimana, Evarcha sp., Chrysso sp., two satellite or rare species viz., Callitrichia sp. and Cheiracanthium sp. The abundance and density of spiders were significantly high during the kharif than rabi seasons. During both seasons, Lycosidae, Tetragnathidae, Araneidae, Pisauridae and Oxyopidae were abundant families. The most predominant families recorded were Lycosidae and Tetragnathidae, which had a relatively high population throughout the crop period. Among the several crop growth stages, the reproductive stage of the crop had a significantly higher abundance and density than the vegetative stage. Telangana’s rice fields have a moderate diversity of spiders with high dominance and eveness across all districts. In terms of diversity, eveness and richness of spiders after Nalgonda, Jagtial, Nizamabad, Khammam, Warangal and Nagarkurnool were in the order of priority. A total of 2321 spider samples were collected from maize growing districts. The zone wise amount of spiders as follows, NTZ (N=756), CTZ (N=755) and STZ (N=810).The study showed the existence of 16 species belonging to 13 genera, seven families and five guilds from maize ecosystem of different regions in Telangana. Among them 14 species each were recorded from Warangal and Khammam, 13 species each from Karimnagar, Nizamabad, Nagarkurnool and Nalgonda. Out of 16 species documented nine species were designated as dominant species viz., Neoscona theisi, Neoscona arabesca, Oxyopes sp., Rabidosa punctulata, Rabidosa rabida, Hogna radiata, Pardosa sp., Telamonia dimidiata, Tetragnatha mandibulata, seven species as sub-dominant viz., Argiope anasuja, Araneus angular, Oxyopes javanus, Bianor aurocinctus, Plexippus paykulli, Anelosimus studiosus and Cheiracanthium furculatum. Kharif recorded a significantly higher abundance and density of spiders than rabi. Families such as Lycosidae, Araneidae, Oxyopidae and Salticidae were recorded as dominant families during both seasons. Among them Lycosidae and Araneidae were the most prevalent and maintained a high population throughout the crop period. Spiders occupied moderate diversity and high dominance with uniform distribution in maize ecosystem. Khammam district represented high diversity, evenness and richness followed by Nalgonda, Nagarkurnool, Nizamabad, Warangal and Karimnagar in order of abundance. Identification and documentation of spiders was done through extensive roving surveys in cotton growing districts of Telangana viz., Jagtial and Adilabad of NTZ, Warangal and Khammam of CTZ, and Vikarabad and Nalgonda of STZ. A total of 3218 spiders were collected from NTZ (N=1042), CTZ (N=1141) and STZ (N=1035) in Telangana. The study resulted into the documentation of 16 species belonging to 11 genera, six families and four guilds in cotton ecosystem. Out of 16 species documented in cotton ecosystem higher species richness of 14 each was recorded from Jagtial, Adilabad, Warangal, Khammam, Nalgonda and Vikarabad. Among 16 species, 10 species were categorized as dominant species occurring regularly in the field viz., Araneus sp., Araneus diadematus, Zygiella indica, Zygiella sp., Tetragnatha elongata, Tetragnatha montana, Oxyopes sp., Thomisus sp., Pardosa sp., Arctosa maculata, six species as sub-dominant viz., Runcinia sp., Hogna sp., Evarchala falcata, Neoscona mukharji, Oxyopes birmanicus and Evarchala jucunda. Families such as Araneidae, Tetragnathidae and Lycosidae were recorded as dominant families during both seasons. Among the different crop growth stages, flowering to boll development stage harboured high abundance and density of spiders with high diversity. In cotton ecosystems of Telangana, spider fauna occupied moderate diversity and high dominance with even distribution across all districts. Vikarabad possessed high diversity, eveness and richness followed by Khammam, Nalgonda, Warangal, Adilabad and Jagtial. Studies pertaining to impact of weather parameters on spider fauna in rice ecosystem of Telangana clearly indicated that except wind velocity all the other independent factors such as temperature (Maximum and minimum), relative humidity (7 am and 2 pm) rainfall and rainy days did not affect the abundance of spiders, whereas wind velocity was positively correlated with Zygiella sp., Tetragnatha montana, Hogna sp., Arctosa maculata, Pardosa pseudoannulata, Lycosa pseudoannulata, Dolomedes and Runcinia, but negatively correlated with other species in STZ. Studies pertaining to impact of weather parameters on spider fauna in maize ecosystem of Telangana showed that there is no impact of weather factors on spider fauna. Similar studies conducted in cotton ecosystem revealed that, maximum and minimum temperature and relative humidity at 2 pm (RH-II) were positively correlated with majority of spider species. Overall impact of weather parameters on spider fauna was found to be non-significant highlighting fact that the spider fauna in general, are tolerant to weather variations. Diversity studies on spiders in rice ecosystem at Rajendranagar resulted that, Lycosa pseudoannulata, Tetragnatha mandibulata and Chrysso sp. throughout the crop season from transplanting to harvesting i.e., July to November 2019, whereas Neoscona theisi, Zygiella sp., Zygiella indica and Mymarachne sp. were recorded during the reproductive stage only from September to October. Peak abundance of all species were observed during 38th and 40th standard meteorological weeks i.e., at reproductive stage of crop. Among the different crop stages reproductive phase recorded high diversity, density, eveness and richness than in the crop which is transplanted 15 days before. Diversity studies pertaining to spider fauna in maize ecosystem at Rajendranagar resulted that, the peak abundance of all species were observed during the flowering to cob formation stage i.e., 34th and 38th standard week (from the last week of August to the first week of September 2019), while the lowest abundance was recorded during the vegetative and crop maturity stages. Lycosa pseudoannulata, Tetragnatha mandibulata, Rabidosa punctulata, Rabidosa rabida, Neoscona arabesca and Neoscona theisi were recorded throughout crop season from July to October 2019. Argiope anasuja, Cheiracanthium furculatum and Binor aurocinctus were recorded during tasseling to cob formation stage only during September to October. The diversity, richness and evenness of spiders in maize ecosystem at the Rajendranagar were low during the vegetative stage, progressively increased up to the flowering and grain filling stages, thereafter gradually declined up to the end of the crop with moderate diversity throughout the crop period. Diversity studies on spider fauna in cotton ecosystem at Rajendranagar resulted that, Tetragnatha elongata, Araneus sp., Zygiella indica and Neoscona mukharji were recorded throughout crop season from vegetative stage to end of the crop i.e., July to November. Hogna sp., Araneus diadematus, Oxyopes sp. and Oxyopes birmanicus were recorded during flowering to boll development stages during September to October 2019. Most of the orb weavers occurred 15 days after sowing to till the crop end. The diversity of spiders in the cotton ecosystem at Rajendranagar was highest during October and September 2019, while lowest during July and November 2019. The highest levels of richness were seen in September and October, when pest prevalence was at its peak. Spiders obtained high evenness throughout the crop season and complete evenness at the middle of the crop growth period during flowering to boll formation. Moderate diversity of spiders in crop ecosystems might be due to intense use of pesticides, intervention by cultural practices and loss of natural habitat. Among the different crop ecosystems rice ecosystem showed high density, diversity and richness followed by maize and cotton ecosystems.ThesisItem Open Access SCREENING AND ECOLOGICAL STUDIES OF SOYBEAN INSECT PESTS(PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2021-01-07) RAJASHEKAR, K; SATYANARAYANA, JThe present investigation on “Screening and ecological studies of soybean insect pests” was carried out at Agriculture Research Station (ARS), Adilabad, Professor Jayashankar Telangana State Agricultural University during kharif, 2017 and 2018. The study was conducted to determine the seasonal abundance of insect pests of soybean and to estimate crop losses caused due to insect infestation. Screening of selected germplasms was also carried out to identify potential soybean genotypes that offer resistance against major insect pests. Apart from the above, studies were also conducted to determine the economic threshold level of stem girdler. The studies on seasonal incidence of insect pests of soybean showed infestation of five insect pests viz., tobacco caterpillar (Spodoptera litura), stem girdler (Obereopsis brevis), stem fly (Melanagromyza sojae), whitefly (Bemisia tabaci) and leafhopper (Empoasca kerri) during both kharif, 2017 and 2018. Based on the data obtained from the seasonal incidence of insect pests on soybean, the impact of insect incidence with respect to dates of sowing was analyzed. Five dates of sowing viz., 15th -18th of June (sowing I), 25th -28th of June (sowing II), 5th -7 th of July (sowing III), 15th -17th of July (sowing IV) and 25th -27th of July (sowing V) were tested for incidence of insect pests. Significant differences with respect to incidence of insect pests as well as yield were observed among the five dates of sowing that were undertaken both during kharif, 2017 and 2018. The incidence of insect pests was found to increase with increase in the delay of dates of sowing from second fortnight of June till first week of July. Similarly, yields of soybean reduced with delay in date of sowing with highest yield of 2112-2300 kg/ha in sowing I, 2012-2160 kg/ha in sowing II and least 1960-2080 kg/ha in sowing III. The insect pest load as well as yields were lowest in the sowings done after 7th of July and were found to be in the range of 1080-1404 kg/ha. First week of July was found to be the cut-off date for sowing of soybean in Adilabad district, Telangana. Among different weather factors rainfall was found to be significantly correlated with S.litura incidence at 69 DAS (r = 0.724*). Stem girdler showed significant positive correlation with maximum temperature at 83 DAS (r = 0.783*), morning relative humidity at 34 DAS, (r = 0.730*) and 48 DAS (r = 0.732*) and with evening relative humidity at 48 DAS (r = 0.670*). Morning relative humidity showed significant positive correlation with stem fly incidence at 20 DAS (r = 0.860*), 48 DAS (r = 0.693*) and 62 DAS (r = 0.650*). Rainfall also showed significant positive correlation with stem fly at 20 DAS along with morning relative humidity (r = 0.761*). Experiments were conducted to determine the yield enhancement if any, by use of insecticidal treatments during kharif, 2017 and 2018. The application of three insecticidal sprayings with thiomethaxam + lambdacyhalothrin @ 0.4 ml/l followed by betacyfluthrin + imidachloprid @ 1.25 ml/l and chlorantraniliprole @ 0.3 ml/l at 15 days interval recorded incidence of insect pests below economic threshold level compared to untreated soybean. Furthermore, the yield attributing characters viz., plant height, number of branches, pods/plant, grains/pod and 100 seed weight were significantly improved in treated plots. Significant higher yields of 2450 and 2550 kg/ha were recorded during kharif, 2017 and 2018 respectively in treated plots while low yields of 1450 and 1660 kg/ha were recorded during kharif, 2017 and 2018 respectively in untreated plots and avoidable yield loss recorded was 40.82 and 34.90 per cent in unprotected plots over protected plots during kharif, 2017 and 2018, respectively. Management of insect pests by use of host plant resistance was also worked out where in screening of 15 genotypes against insect pests of soybean was done. Among 15 promising genotypes that were screened, different genotypes showed different levels of resistance to insect pests. The genotype Basara and JS-335 were found to be highly resistant to stem girdler and stem fly while genotypes JS-335 was found moderately resistant to tobacco caterpillar. The genotypes Basara, RVS-29 and JS-20-34 were also found to show moderate resistance to whitefly while the genotypes DSB-2803 and JS-20- 34 were found to be moderately resistant to leafhoppers. The genotypes JS-20-69 and RSC-1046 were found to be susceptible to stem girdler and whitefly while genotypes RSC-1046, JS-20-69 and MACS-1460 were found to be highly susceptible to leafhoppers. Investigations on ETL for stem girdler in terms of damage for decision making on insecticidal sprayings revealed 10 per cent damage as the economic threshold level. Maximum of three insecticidal applications with triazophos @ 2 ml/l at ETL i.e. 10 per cent damage resulted in achieving good yields, thereby higher income and better incremental cost benefit ratioThesisItem Open Access SEASONAL INCIDENCE OF INSECT PESTS, BIO-EFFICACY AND DISSIPATION PATTERN OF SELECTED INSECTICIDES IN CAULIFLOWER(PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, 2021-01-07) JEMIMAH, N; SRIDEVI, GThe study entitled “Seasonal incidence of insect pests, bioefficacy and dissipation pattern of selected insecticides in cauliflower” was conducted during rabi, 2018-19 and 2019-20 at College Farm, College of Agriculture, Rajendranagar. During both these years, the population of aphids and leaf webber was high while the incidence of other pests viz., diamondback moth, painted bug and tobacco caterpillar was very low. The aphids infestation was recorded during 47th SMW during both these years. A single peak was noticed in the 1 st SMW (115/3leaves/plant) during 2018-19 while two peaks were recorded during 2019-20, the first in the 51st SMW (122.2/3leaves/plant) and the second in the 2 nd SMW (142.6/3leaves/plant). The leaf webber incidence was recorded in the 48th SMW during both the years. However, in 2018-19, a single peak was noticed in the 52nd SMW (4.8 larvae/plant) while in 2019-20, two peaks were observed, the first during 51st SMW (5.4 larvae/plant) and the second during 2nd SMW (6.4 larvae/plant), similar to aphids. The head borer damage was noticed in the 2 nd SMW during both the years recording 30 and 38 per cent damage during 2018-19 and 2019-20, respectively. The natural enemy population was also recorded simultaneously during both the years. In 2018-19, coccinellids were observed in the 50th SMW with the population reaching its peak in the 2 nd SMW (1.20/plant) while in 2019-20, it peaked during 1st SMW (1.40/plant). The incidence of syrphids initiated during 49th SMW and the population peaked in the 2 nd SMW (2.40 and 2.90/plant) during both the years. Aphids and leaf webber showed a negative correlation with temperature, windspeed and evaporation and positive correlation with morning RH and sunshine. The predators viz., coccinellids and syrphids exhibited a negative correlation with maximum and minimum temperatures and windspeed while showing positive correlation with morning RH and evaporation. The predators were found to be dependent on the density of aphids and showed positive correlation with aphid population. The bio-efficacy studies revealed that chlorantraniliprole was the most effective insecticide against leaf webber with 84.03 per cent reduction in population followed by spinosad (79.10%), emamectin benzoate (78.99%) and indoxacarb (73.25%). Chlorpyriphos, diafenthiuron and dimethoate were less effective with 52.97, 40.96 and 31.19 per cent reduction over control, respectively. In case of aphids, dimethoate was the most effective with highest overall reduction in population (77.70%) followed by chlorpyriphos (60.14%) while the remaining treatments recorded less than 50 per cent reduction of aphid population. The mean head borer per cent damage was lowest in chlorantraniliprole treated plots (10.36%) while it was highest in control (36.13%). Among the selected insecticides, the mean highest yield of 19.74 t ha-1 was recorded from chlorantraniliprole treated plots while emamectin benzoate (19.16 t ha-1 ), spinosad (18.79 t ha-1 ) and indoxacarb (18.36 t ha-1 ) were found to be on par. Highest incremental cost-benefit ratio of 1:18.63 was also obtained in chlorantraniliprole treatment. The studies on dissipation pattern of selected insecticides in cauliflower curd revealed that emamectin benzoate persisted for one day in cauliflower head while spinosad and dimethoate persisted for 5-7 days. Persistence of chlorantraniliprole, diafenthiuron and chlorpyriphos were observed for 10 days while the highest persistence was noticed for indoxacarb (15 days). Based on the designated MRL values (Codex/FSSAI), the calculated waiting periods were found to be lowest for dimethoate (1.79 days) followed by chlorpyriphos (6.71 days), spinosad (10.97 days) and indoxacarb. In case of chlorantraniliprole, the initial deposits were less than MRL values. The decontamination techniques help in bringing down the concentration of pesticides and the extent of reduction depends on the initial deposits at harvest and also on the substrate and the type of pesticide. The per cent reduction of residues of chlorantraniliprole, spinosad, emamectin benzoate, indoxacarb, diafenthiuron, chlorpyriphos and dimethoate by cooking in pressure cooker over treated control were 95.66, 91.36, 100, 70.89, 89.59, 50.60 and 73.75, respectively. Boiling in open vessel in case of chlorantraniliprole, spinosad, indoxacarb and diafenthiuron was the next best method for reduction of residues by 79.08, 77.13, 63.09 and 79.89, respectively.
