PhD Thesis
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Item Magnetized irrigation water for enhancing production of brinjal (Solanum melongena L.)(Department of Agronomy, College of Agriculture, Vellayani, 2022-11-05) Vijayakumar, Pullagura; Sajitha Rani, TThe investigation entitled “Magnetized irrigation water for enhancing production of brinjal (Solanum melongena L.)” was carried out as two experiments at the Instructional Farm, College of Agriculture, Vellayani during 2018-2021, to study the effect of magnetization on quality of irrigation water, to assess the impact of magnetized water on growth, yield and quality of brinjal, to evaluate the effect of magnetized irrigation water on soil properties and to work out the economics. The present investigation revealed that employing magnetic strength of 2000G was effective for getting good quality irrigation water, and scheduling of irrigation with this water at IW/CPE ratio of 0.8 along with 75 per cent RDF could be recommended for obtaining higher growth, yield and monetary returns from both plant and ratoon crop of brinjal.Item Mechanisms of resistance in Brinjal Shoot and fruit broer, Leucinodes orbonalis (Guenee) (Lepidoptera:Crambidae) to diamide insecticides(Department of Agricultural Entomology, College of Agriculture ,Vellanikkara, 2024-10-18) Anu ThomasThe development of insecticide resistance among insect pests is a major concern in pest management. Generating data on the baseline susceptibility of field populations to insecticides facilitates to track the resistance development in insects. This helps in designing suitable insecticide resistance management (IRM) strategies; thereby, to delay the development of resistance and extend the useful life of an insecticide.Understanding the mechanisms of resistance, the possibilities of developing cross- and multiple-resistance, and the fitness costs involved in resistance are also crucial to maintain the sustainability of an insecticide. In this context, the present investigation entitled “Mechanisms of resistance in brinjal shoot and fruit borer, Leucinodes orbonalis (Guenee) (Lepidoptera: Crambidae) to diamide insecticides” was undertaken during 2019-2024 with the objectives to study the baseline susceptibility of brinjal shoot and fruit borer to diamide insecticides, to assess the possible mechanisms of resistance development, to investigate the potential of developing cross and multiple resistance in diamide-resistant populations and to analyze the fitness costs associated with resistance. Field populations of brinjal shoot and fruit borer were collected from brinjal fields of Kerala, Kullarayanpalayam (Palakkad) and Anchal (Kollam); Tamil Nadu, Devarayapuram (Coimbatore) and Trichy (Tiruchirappalli); and Karnataka, Heggadadevankote (Mysore) and Doddaballapur (Banglore Rural). A laboratory susceptible population, maintained without any insecticide exposure since 2012, was procured from NBAIR, Bangalore. The collected populations were assigned unique accession codes such as PKD, KLM, CMB, TRY, MYS, BAN, and Lo-S, respectively, and maintained separately in the laboratory. Information on insecticide usage pattern in brinjal cultivation obtained from farmers at collecting sites revealed the usage of insecticides of different modes of action and application above recommended dosages. An intensive application of various insecticdes including diamides was practiced in Bangalore Rural, Tiruchirappalli, Coimbatore, and Palakkad. In Kollam, on the other hand, a need-based application in recommended doses was followed. In Mysore, the farmers did not use any diamide insecticide; instead, they relied on organophosphates and neonicotinoids applied at frequent intervals. The laboratory bioassay of field populations of L. orbonalis was performed against flubendiamide (Fame 39.35% SC) and chlorantraniliprole (Coragen18.5% SC) to determine the median lethal concentration (LC50). The resistance ratio (RR) was assessed by comparing the LC50 values with that of the Lo-S population. All field populations of L. orbonalis except MYS displayed a significant shift in LC50 value compared to the Lo-S population and were considered resistant to flubendiamide and chlorantraniliprole based on the hypothesis of equality. Among the resistant populations, the BAN and TRY were resistant homozygotes according to the hypothesis of parallelism. The LC50 value of field populations ranged from 0.83 ppm in MYS to 544.07 ppm in TRY for flubendiamide compared to 0.50 ppm recorded with the Lo-S population. The TRY population showed the highest resistance ratio (RR) of 1079.5- fold to flubendiamide, followed by the BAN (845.85-fold), CMB (532.56-fold), and PKD (218.84-fold) populations. However, the KLM population showed comparatively less RR with 47.59-fold resistance, while the MYS population was considered susceptible to flubendiamide. The LC50 value for chlorantraniliprole ranged from 0.169 ppm in MYS to 116.80 ppm in BAN in contrast to 0.119 ppm recorded with the Lo-S population. Concerning chlorantraniliprole, the highest RR of 979.22-fold was recorded with the BAN population followed by 788.18-fold in TRY, 480.30-fold in the CMB, 244.75-fold in PKD, and 18.22-fold in KLM populations. The lowest RR of 1.41-fold was observed with MYS population and was considered susceptible to chlorantraniliprole based on the hypothesis of equality. The activity of detoxifying enzymes in the field populations of L. orbonalis was quantified and compared with the Lo-S population to examine the role of detoxifying enzymes in diamide resistance. The field populations, BAN, PKD, CMB, TRY, MYS, and KLM showed 1.66-, 1.47-, 1.24-, 1.21-, 1.21-, and 1.17-fold increase in carboxylesterase (CarE) activity, respectively. Significantly higher titers of cytochrome P450 (Cyt P450) activity were displayed by all the field populations with a 5.54- fold increase in the TRY population, followed by BAN (5.38-fold), CMB (5.26- fold), PKD (5.13-fold), MYS (4.56-fold), and KLM (3.12-fold). The relative activity of glutathione S-transferase (GST) was >4-fold in PKD, CMB, TRY, and BAN populations displaying 4.31, 4.33, 4.34, and 4.44-fold variations, respectively, compared to the Lo-S population. Meanwhile, KLM and MYS populations exhibited only 1.5-fold and 1.25-fold increases, respectively. To assess the potential for developing cross-resistance, a laboratory bioassay was carried out against cyantraniliprole, a less commonly used diamide insecticide. The field populations displaying resistance to flubendiamide and chlorantraniliprole also exhibited resistance to cyantraniliprole, even though the population had no previous exposure to the chemical. However, the populations that were not previously exposed to emamectin benzoate and spinosad did not show resistance to these insecticides, and thereby the possibility of developing multiple resistance in diamide-resistant populations was rejected. Fitness costs associated with diamide resistance were ascertained by comparing the life table parameters of different field populations of L. orbonalis with the Lo-S population. In the study, diamide-resistant populations, TRY, BAN, PKD, and CMB displayed significantly longer larval and pupal duration, and less oviposition period and female adult longevity than the Lo-S population. Male adult longevity in the TRY and BAN populations was also notably shortened compared to the Lo-S population. The survival of egg, larva, and pupa as well as fecundity of the diamide-resistant populations except KLM were significantly less compared to the Lo-S population. The BAN and TRY populations exhibited a relative fitness of 0.62, suggesting a higher fitness cost associated with diamide resistance. The CMB population displayed a relative fitness of 0.68 followed by PKD (0.74) and the lowest was in KLM (0.82). These results indicated a survival disadvantage with the resistant populations compared to the Lo-S population. In investigating the molecular basis of resistance in L. orbonalis, a partial sequence of the ryanodine receptor (RyR) gene involved in diamide resistance was analyzed. Thymine (T) was found to be substituted with cytosine (C) in the sequences of the BAN and TRY samples that were tested, but the Lo-S sample did not exhibit this substitution, which is consistent with the reference sequence (Acc. No. PQWD01009585.1) of L. orbonalis. Alignment of the protein sequences revealed a non-synonymous amino acid alteration from isoleucine to methionine (I to M) in the RyR of BAN and TRY, which was not observed in the Lo-S gene sequence, indicating the crucial role of point mutation for higher diamide resistance in TRY and BAN populations. The study revealed a shift in susceptibility status and the development of higher folds of resistance to diamide insecticides among the field populations of L. orbonalis. The possible role of detoxifying enzymes and target site mutations in the development of diamide resistance was also established. The study on cross- and multiple-resistance provided valuable information for the selection of insecticides in IRM programs. The involvement of fitness costs in the diamide-resistant populations indicated a negative impact of resistance on pest fitness and the chance of resistance reversion in the absence of insecticides.Item Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs(Department of Agricultural Entomology, College of Agriculture ,Vellayani, 2022) Mithra Mohan; Anitha, NThe study on “Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs” was conducted at College of Agriculture, Vellayani during 2017 to 2020 with the objectives to identify mealybugs and their natural enemy fauna in solanaceous and cucurbitaceous vegetables, to carry out the molecular characterization of mealy bugs in solanaceous and cucurbitaceous vegetables and to find out the tritrophic interactions of mealybugs infesting brinjal. An investigation on mealybug diversity in solanaceous and cucurbitaceous crops of Kerala revealed a total of six mealybug species viz., Coccidohystrix insolita, Ferrisia virgata, Paracoccus marginatus, Phenacoccus solenopsis, Planococcus citri and Pseudococcus jackbeardsleyi. Besides, four mealybugs viz., Crisicoccus hirsutus, Maconellicoccus hirsutus, Planococcus lilacinus and Rastrococcus iceryoides infesting other vegetable crops were also recorded from Kerala. The study also revealed that the population of mealybug, C. insolita collected from different regions of Kerala exhibited significant morphological variation. The molecular characterization studies proved that the population belongs to C. insolita and the variations may be environmental induced. An exploration of the host range of mealybugs infesting solanaceous and cucurbitaceous vegetables in Kerala revealed a total of 113 plants under 73 genera belonging to 31 families, out of which 14 plants were recorded as new host reports. A rich natural enemy fauna on mealybugs belongs to five orders viz., Coleoptera, Lepidoptera, Diptera, Neuroptera and Hymenoptera were documented from Kerala. Twenty species of mealybug predators from five different families were recorded, among which the predominant family was Coccinellidae with 16 species under six genera. Among the various predators collected, Cacoxenus sp. was recorded for the first time as a predator of P. jackbeardsleyi. Eleven hymenopteran parasitoids belonging to five families were documented from mealybugs, of which the majority belongs to the family Encyrtidae. Four new host-parasitoid associations were also recorded for the first 288 time. The study also identified six hyperparasitoids under the family Encyrtidae, of which two species were recorded as new report which includes Cheiloneurus sp. and Prochilonerus sp. associated with the mealybug P. solenopsis. The ants associated with mealybugs in different agroecosystems were also investigated and a total of 14 species of ants belonging to nine genera under three subfamilies were recorded, of which the most dominant subfamily was Formicinae followed by Myrmicinae and Dolichoderinae. The present study also revealed 15 new ant-mealybug associations for the first time. The molecular characterization of eight mealybug species was carried out that complemented the morphological identification of species. A total of eight nucleotide sequences were submitted to NCBI GenBank and accession numbers were generated. The sequences were also submitted to BOLD and illustrative barcodes were generated. The barcodes of C. insolita, C. hirsutus and P. jackbeardsleyi were generated for the first time. The diversity of endosymbionts of the mealybug C. insolita was carried out for the first time. The study revealed a total of 15 phyla of endosymbionts on C. insolita, of which Proteobacteria was the predominant one. An experiment was conducted at Instructional Farm, Vellayani to identify the tritrophic interaction in brinjal, C. insolita and its natural enemies. The study revealed that out of the ten brinjal cultivars evaluated, the lowest mean population of mealybugs was observed in Pusa Uttam whereas the hybrid cultivar, Udit recorded the highest number of mealybugs. The lowest mean per cent leaf infestation was recorded in Pusa Purple Long which was statistically on par with Pusa Uttam whereas the hybrid cultivar, Udit was severely damaged by the mealybugs. Among the tested cultivars, Pusa Purple Long was recorded under the group resistant whereas Udit and Haritha were included under the highly susceptible group based on the mean per cent leaf infestation caused by C. insolita. The cultivar Haritha attracted the highest number of predators whereas the maximum mean population of spiders were observed in Pusa Purple Long. 289 The correlation analysis on the mean population of mealy bugs with biophysical parameters revealed that trichome density, length width ratio of leaf and number of branches exhibited a significant positive correlation with mean population of mealybugs. Correlation studies on the mean population of natural enemies with biophysical parameters revealed that plant height exhibited a significant negative correlation whereas leaf thickness and number of branches revealed a non-significant negative correlation with the mean population of natural enemies. Among the biochemical parameters of brinjal cultivars, total phenol content exhibited a significant negative correlation with the mean population of mealybugs whereas total chlorophyll content showed a significant positive correlation. The correlation between biochemical parameters of brinjal cultivars with the mean population of natural enemies revealed that total phenol and carotenoid content exhibited a non-significant negative correlation whereas total protein content, reducing sugar and total chlorophyll content showed a nonsignificant positive correlation. The info-chemical mediated interactions in brinjal cultivars, mealybug and its natural enemies were studied using a multi-armed olfactometer and Y-shaped olfactometer assay. The results revealed that the cultivar Udit attracted the highest number of natural enemy Chrysoperla zastrowii sillemi while the cultivar Pusa Uttam attracted the lowest number. The variation in preference shown by the natural enemies may be related to the difference in volatile compounds emanating from the host cultivar. The GC-MS analysis of the synomonal compounds of the cultivar, Udit revealed a total of eleven compounds whereas the cultivar Pusa Uttam was recorded with a total of five compounds. The Y shaped olfactometer studies revealed that C. zastrowi sillemi adults showed more preference towards the synomonal compounds of mealybug infested plants than that of healthy plant synomonal extracts. On comparing the volatile profile of synomones of mealybug infested and healthy plants revealed that the synomonal extracts of the mealybug infested cultivar Udit comprised of 11 compounds whereas healthy plant synomonal extracts contained nine compounds. 290 The relative response of C. zastrowi sillemi towards the kairomonal compounds of C. insolita was evaluated in a Y tube olfactometer and the results revealed that the highest mean number of adult lacewings were attracted to the kairomonal compounds of mealybug compared to control. The kairomonal extracts of the mealybug comprised of seven compounds and the composition of these hydrocarbons may determine the selectivity of natural enemies towards the preferred host. The present study recorded a total of six mealybug species infesting solanaceous and cucurbitaceous vegetables and its host range, natural enemies and associated ants in different agro ecological regions of Kerala. The molecular characterization studies supported the morphological taxonomy and the sequences were submitted to NCBI Genbank and BOLD. The study also elucidated the interactions mediated by plant traits and info-chemicals in brinjal-mealybugnatural enemy tritrophic systems. The study recorded Pusa Purple Long as resistant cultivar and Udit and Haritha as highly susceptible cultivar to C. insolita. The plant traits viz., trichome density, length width ratio of leaf, number of branches, total phenol content and total chlorophyll content exhibited significant correlation with mean population of mealybugs whereas plant height exhibited significant correlation with mean population of natural enemies. The study on info-chemical mediated tritrophic interactions revealed that the concentration and composition of volatile compounds determine the differential selectivity of natural enemies. The volatile compounds identified in this study can also be used as a cue in moderating the behavior of natural enemies in the ecosystems. So a thorough knowledge on the tritrophic relations in the ecosystem will aid in manipulating these interactions to devise a better pest management strategy.Item Integrated nutrient management for long duration brinjal (Solanum melongena L.)(Department of Agronomy, College of Horticulture, Vellanikkara, 2003) Karmachandran, K M; Jose MathewAn investigation on integrated nutrient management for long duration brinjal was conducted at College of Horticulture, Kerala Agricultural University, Thrissur during 2000-2003. The preliminary evaluation revealed the extended duration and superiority of Haritha in respect of yield components, yield and storage qualities in comparison to other ruling varieties ofbrinjal. Among the seven organic sources tested, vermicompost, poultry manure and FYM recorded increased production of fruits at more than one stage of fruiting and were comparable even to inorganic sources and package of practices recommendations. Coir pith compost recorded the poorest performance regarding dry matter production, yield and fruit quality. Majority of the organic manures especially vermicompost, FYM and poultry manure recorded enhanced content of major nutrients in plant and enhanced dry matter production and fruit quality. Poultry manure was found to record increased uptake ofN, P, K and Ca, whereas high content and uptake of-S in plants have been recorded by vermicompost. In respect of inorganic fertilizers, it was revealed that 100 per cent N (75 kg ha-I) had recorded the maximum uptake ofN, P and K and dry matter partitioning leading to increased yield in long duration brinjal. Increasing K levels in general did not enhance the content and uptake of major nutrients. But increasing K levels improved uptake at fruiting stage significantly improving fruit yield at early fruiting stage. It also marginally increased number of fruits and fruit yield at other stages of fruiting. The content and uptake of Ca, Mg and S were significantly increased at increased level ofK particularly 300 per cent (75 kg ha"). Regarding application timings of inorganic N and K, it was found that frequent application was required only during active growth stage of brinjal. Monthly application schedule significantly improved dry matter partitioning, yield and quality of fruits. Fortnightly application schedule was not advantageous in growth and yield attributes, yield, fruit quality, nutrient content, nutrient uptake and cost of cultivation. Among the three levels of substitution of nutrient doses with organic sources, 75 per cent organic substitution was superior in yield and quality of fruits which was facilitated by improved uptake of major and secondary nutrients, dry matter production and yield attributes. The increased proportion of organic manures generally decreased the content of Fe and Mn in plants. The status of available N in soil was significantly increased by the application of higher proportion of organic manures especially FYM, poultry manure and vermicompost.Item Bacterial wilt resistance and yield in brinjal (Solanum Melongena L.)(Department of Olericulture, College of Horticulture, Vellanikkara, 1996) Singh, P K; Gopalakrishnan, T RInvestigations on “Bacterial wilt resistance and yield in brinjal (Solanummelongena L.)” was undertaken in the Department of Olericulture, College of Horticulture, Vellanikkara during 1993 – ’96. Preliminary evaluation of seventy eight brinjal accessions during Kharif 1994 revealed considerable variation for most of the economic characters. Twenty four accessions/varieties selected based on productivity, resistance to bacterial wilt, crop duration, fruit and plant characters from the preliminary evaluation were subjected to detailed evaluation during March – November, 1995. In the long duration accessions, the non – prickly SM 141 has yielded as high as 6.4 kg/plant with maximum number of fruits (113.5) having maximum weight (128.27 g). Among short duration accessions maximum yield was recorded in white fruited Swetha (3.9 kg/plant). The study revealed the necessity for differential spacing depending on the duration and spread of the plant. In addition to the already available bacterial wilt (Pseudomonas solanacearum) resistant varieties viz., Surya, Swetha, ArkaKeshav, ArkaNidhi, BB 44 some more varieties/accessions viz., Annapurna, Composite 2, TGR, SM 71, SM 116 and SM 141 were found resistant under artificial inoculation. The contents of total phenol and O.D. Phenol was higher in the resistant varieties than the susceptible ones. The anatomical studies revealed well developed secondary xylem with small compact cortical cells in the resistant variety compared to the susceptible variety. The nine F1 hybrids differing in size, shape and colour of fruits were compared with their parents during summer 1996. Two F1 hybrids viz., the long stout and deep purple fruited ArkaKeshav x SM 71 and oval and deep purple fruited Surya x SM 116 had surpassed the standard parent by 337.62 per cent and 290.04 per cent respectively in productivity. Both the hybrids having bacterial wilt resistance, desired plant habit and attractive fruit characters can be progressed further. In general the F1 hybrids had more vigour and tolerated infestation of jassids better than the parents. In Kerala the cultivation of brinjal during summer is limited mainly due to heavy incidence of jassids. In the present study varietal variation was observed for resistance to jassids (Amrascabiguttulabiguttula). The long trichomes with high density contributing to a matting effect on the leaf surface may be responsible for the jassid tolerance in varieties like Pusa Kranti and BB 7. These jassid resistant but wilt susceptible varieties yielded 2417.2 per cent and 186.0 per cent respectively more over the intact plants after grafting onto Solanumtorvum. The present study revealed the scope of cultivating jassid resistant varieties viz., Pusa Kranti and BB 7, though highly susceptible to bacterial wilt during the summer months in the state.Item Effect of sub-lethal doses of decamethrin and carbaryl on the orientation, feeding reproductive rate and survival of key pests of brinjal, Solanum melongena L.(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1989) Sheila, M K; Abraham, C CThe effect of sub-lethal doses of decamethrin and carbaryl at their LD5, LD10, LD25 and LD50 levels on orientational stimuli, feeding, reproductive potential and survival of the three important pests of brinjal, namely, the epilachna beetle H.28 punctata, the aphidsA. gossypii and the leaf hopper A. b. bicuttula have been studied in the laboratory. In all the three test insects, positive orientational stimuli were not detected at all the tested sub-lethal levels of the two insecticides. A decrease feeding rate in H. 28 punctata was detected when the insects were exposed to the sub-lethal dose treatments. In A. crossypii and A. b. biguttula, the reduction in the feeding rate was more pronounced at the LD 50 level of both insecticides.Item Stability analysis and molecular characterization of F1 hybrids in brinjal (Solanum melongena L.)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2018) Kavishetti Vinay, Vishwanath; Lekha Rani, CStability analysis helps in assessing genotype × environment interaction in order to identify stable genotypes in large multi-environment trials. Therefore the present study entitled “Stability analysis and molecular characterization of F1 hybrids in brinjal (Solanum melongena L.)” was carried out to evaluate ten hybrids along with one check across four locations. The locations selected for trials were College of Agriculture, Vellayani and farmer’s fields at Thiruvalla, Sadanandapuram and Kayamkulam in Kerala. The trial seasons were kharif (2015- 16) and summer (2016-17). The objective was to study the performance of superior hybrids over different locations and seasons from heterotic crosses of brinjal and to confirm the hybridity using SSR markers. Randomized block design with four replications was employed. Stability and adaptability of yield and yield attributing characters of hybrids were analysed by Eberhart-Russell model (1966). Pooled analysis of variance revealed significant differences among the genotypes, environments and genotype × environment interaction for all the characters studied. The indication was that the hybrids responded differently to changes in the environment. Promising hybrids were identified on the basis of stability parameters viz., overall mean, regression coefficient (bi) and deviation from regression (S2di). In kharif season, the hybrid Wardha local × Palakurthi local was observed to be stable and widely adapted to all environments for days to first flowering, number of fruits plant-1, fruit weight, fruit length, fruit girth, calyx length, yield plant-1, yield plot-1 and plant height. The hybrid Wardha local × Swetha was identified as stable with regard to fruit weight, yield plant-1 and yield plot-1. The hybrid Wardha local × Vellayani local was identified as stable for favourable environments with regard to fruit length, yield plant-1 and yield plot-1. The hybrid Surya × Vellayani local was found stable for poor environments with regard to days to first flowering. Stability analysis for the summer season crop also revealed the hybrid Wardha local × Palakurthi local as stable across all environments with respect to days to first flowering, days to first harvest, number of fruits plant-1, fruit weight, fruit length and yield plant-1. Swetha × Vellayani local hybrid was stable across all environments with regard to days to first harvest, fruit weight, fruit length, calyx length, yield plant-1, yield plot-1 and plant height. The hybrid Surya × NBR-38 was found stable with respect to yield plant-1, yield plot-1 and plant height for favourable environments. Qualitative characters viz., total phenols, total sugars and vitamin C content and biotic stress traits viz., shoot and fruit borer infestation and bacterial wilt incidence were recorded for the eleven hybrids in kharif and summer season in all four locations. On the basis of overall mean performance of hybrids, results illustrated that the hybrid Swetha × Vellayani local recorded the highest values for total phenols and the hybrid NBR-38 × Vellayani local recorded the lowest values. Total sugar content was highest in Wardha local × Swetha and NBR-38 × Selection Pooja and lowest in Surya × NBR-38. The hybrid Neelima and Swetha × Vellayani local recorded higher quantity of vitamin C and NBR-38 × Vellayani local and NBR-38 × Selection Pooja recorded the lowest values. The hybrids Wardha local × Palakurthi local, Swetha × Vellayani local and Neelima recorded minimum infestation of shoot and fruit borer and was found resistant to bacterial wilt also. Hybrids and their parental lines were characterized using SSR markers. Among the four markers studied, three markers viz., emb01M15, eme08D09 and CSM31 were found to be polymorphic among the parental lines of respective hybrids viz., Surya × NBR-38, Surya × Vellayani local, NBR-38 × Selection Pooja, Swetha × Vellayani local, Wardha local × Swetha, Wardha local × Palakurthi local, Palakurthi local × Vellayani local and NBR-38 × Vellayani local which could be used for ensuring the genetic purity of respective parental lines and hybrids. F2 families viz., Wardha local × Palakurthi local, Wardha local × Swetha, Wardha local × Vellayani local and Swetha × Vellayani local were selected on the basis of yield performance from F1 for further evaluation. F2 populations revealed that family Wardha local × Palakurthi local and Wardha local × Vellayani local were superior in yield performance and yield attributing characters. The present investigation revealed that the hybrids Wardha local × Palakurthi local and Swetha × Vellayani local were stable and widely adapted over different locations and seasons and the hybridity was confirmed with the SSR markers, emb01M15 and eme08D09.Item Inheritance of yield and resistance to shoot and fruit borer (Leucinodes orbonalis GUEN.) in brinjal (Solanum melongena L.)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2017) Gangadhara, K; Mareen AbrahamItem Host resistance in brinjal varieties to the fruits and shoot borer Leucinodes orbonalis Guen ( Lepidoptera: pyralidae)(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1983) Madhavan Nair, G; Abraham, C CIn studies on the host plant resistance in brinjal (Solanum melongena L.) against the shoot and fruit borer, Leucinodes orbonalis Guen. (Lepidoptera : Pyralidae), germplasm materials were screened to identify sources of resistance and an attempt was made to investigate the mechanisms of resistance involved. Forty accessions of brinjal and related species were initially screened in a field trial conducted during the monsoon season of 1982 and these were classified into highly susceptible, moderately susceptible, moderately resistant and resistant classes. The accessions SM-6, SM-56, SM-72 and SM-74 from the highly susceptible group; SM-1, SM-45, SM-48 and SM-71 from in moderately susceptible group; SM-65, SM-68, SM-97 and SM-105 from the moderately resistant group and SM-67, SM-88, S.indicum and S.incanum from the resistant group were further field tested during the summer season, 1982-83 and were evaluated for the levels of resistance. Under artificial infestation of caged single plants of the accessions by the first instar larvae of L. orbonalis, the susceptibility spectrum was found to be similar to the trend noticed in the field trials. In the resistant types, the infestation by L. orbonalis occurred for a relatively shorter duration than in the susceptible ones. In studies on the antibiosis, it was found that the resistant accessions gave rise to larvae and pupae of reduced weights which took longer durations as compared to the highly susceptible accessions. The larval survival was lower in the resistant types. The highly susceptible accessions produced more females than did the resistant line. There was no significant variation in the fecundity of second generation females. In multiple-choice and no-choice tests, the females of L.orbonalis showed a clear preference for the highly susceptible and moderately susceptible accessions for oviposition. Correlation studies revealed that the density of trichomes on the shoot apex, lower leaf surface and lower surface of midribs exerted considerable influence on the ovipositional response of the female moth, the relationship between oviposition and trichome density being of a negative nature. Among the biophysical characters, the higher density of trichomes on shoot apex and lower midrid; lower pith area, lingnified selerenchymatous hypodermis and compact vascular bundles in shoot apex and tight or semi-tight calyx in fruit were found to impart resistance to borer infestation. Positive correlations were detected between the mean percentages of total sugars, crude protein, total ash, nitrogen, potassium and calcium in the fruit on the one hand and fruit infestation on the other. The contents of total ash, calcium, magnesium and iron in shoots on the one hand and shoot infestation on the other were also found to be positively correlated, while silica, zinc, copper and crude fibre contents were negatively correlated with shoot infestation.The implications of the findings have been discussed.Item Efficacy and biosafety of new generation insecticides for the management of fruit borers of cowpea, brinjal and okra(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2013) Vijayasree, V; Hebsy Bai