1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Plant growth promotion and stress mitigation mediated by the root endophytic fungus Piriformospora indica In Cassava (Manihot esculenta Crantz)(Department of Microbiology, College of Agriculture, Vellayani, 2025-12-12) Akhila P Subhash; Anith, K NThe study entitled “Plant growth promotion and stress mitigation mediated by the root endophytic fungus Piriformospora indica in cassava (Manihot esculenta Crantz)” was conducted in the Department of Microbiology, College of Agriculture, Vellayani, Thiruvananthapuram and in the ICAR–Central Tuber Crops Research Institute (CTCRI), Sreekariyam, Thiruvananthapuram during 2021-2024, with an objective to investigate the effects of the root endophytic fungus P. indica in cassava on productivity, nutrient acquisition and disease suppression against major pathogens. Other microbial agents used in the study were arbuscular mycorrhizal fungus Glomus mosseae, and the biocontrol bacterium Pseudomonas fluorescens PN026. Initially, the pathogens causing stem and root rot disease in cassava were isolated from the naturally infected plants. Three fungal isolates were obtained from the infected cassava samples, and these isolates were identified as Lasiodiplodia theobromae, Fusarium sp. and Cunninghamella elegans with morphological studies and by molecular identification using internal transcribed spacer region (ITS) sequence-based technique. Among them, L. theobromae and Fusarium sp. were identified as the major pathogens and C. elegans as a minor pathogen causing the disease. Pathogenicity of the isolates was verified by proving Koch’s postulates by inoculating the isolated pathogens separately, sequentially and in different combinations in freshly harvested healthy cassava tubers. Treatment with the combination of pathogens L. theobromae and Fusarium sp. was identified as the one showing highest infectivity with high percentage of weight loss and with least number of days taken for the symptom development. This inoculum combination was used for further studies. Direct and indirect antagonism of P. indica against the cassava stem and root rot fungal pathogens was evaluated on potato dextrose agar (PDA) plates. Direct antagonism was evaluated through dual culture plate assay and indirect antagonism through agar well diffusion method using the culture filtrate of P. indica. However, in both the tests P. indica did not inhibit these fungal pathogens in vitro. In vivo studies included cassava root colonization and root initiation, nutrient acquisition and plant growth promotion experiment as well as stem and root rot disease and cassava mosaic disease suppression. An experiment was conducted in protray to evaluate the root colonization abilities of P. indica in Sree Suvarna, Sree Jaya and Aswathy varieties of cassava in both sterile and unsterile planting medium. Fungal structures were detected by trypan blue staining, WGA-AF 488 (Wheat germ agglutinin- Alexa flour 488) staining and confocal imaging. Pear shaped chlamydospores were observed within the root cortical tissues at 14 days after inoculation. Further confirmation was done by molecular detection with the help PiTEF gene primer using a PCR reaction. This is the first report of successful colonization of P. indica in cassava. The root colonization ability of the AM fungus G. mosseae in all the three varieties of cassava in sterile planting medium was also evaluated using trypan blue staining method. The percentage of root colonization was 100 percent in all these varieties, where AM fungal vesicles as well as arbuscles were observed in the roots at 14 days after inoculation. Root initiation tests in minisetts were carried out in Sree Jaya and Aswathy cassava varieties by applying P. indica and Pseudomonas fluorescens in both sterile and unsterile planting medium. When P. indica and P. fluorescens colonized plants were compared to control plants, all root growth parameters were observed to be higher. However, most of parameters were found significant in unsterile planting medium when compared to the sterile planting medium which may be due to the insufficient root colonization of both the beneficial microbes in cassava minisetts in the sterile medium. A field experiment was conducted by applying P. indica and AM fungus G. mosseae, along with different doses of NPK fertilizers in cassava variety Sree Suvarna to evaluate the abilities of both beneficial fungi to promote growth and acquire nutrients. Different biometric, physiological, yield as well as quality parameters were analyzed. The application with a combination of 75 percent of the recommended dose of NPK along with P. indica was found to be the best treatment that improved growth and yield attributes, whereas the combination of 75 percent NPK along with G. mosseae recorded significant improvement in total dry matter contents as well as tuber quality parameters. The results showed that the chemical fertilizer dose could be reduced to a level of 75 percent of the recommended dose, without compromising the growth and yield, if the fertilizers are applied together with the bio-inoculants, either P. indica or G. mosseae. The same treatments also resulted in higher total nitrogen uptake while the combination of 100 percent NPK and G. mosseae resulted in better phosphorous and potassium uptake by the cassava plants. A grow bag experiment was conducted to examine the stem and root rot disease suppressing ability of P. indica in the local disease-prone cassava variety Aswathy. The treatment combination of pathogens, L. theobromae and Fusarium sp. was selected for the inoculation purpose. An increase in the growth and yield and decrease in disease incidence was noted in P. indica and G. mosseae inoculated plants, even when the plants were challenged with the stem and root rot pathogens. The pathogen inoculated control plants recorded the least number of days taken for the initial symptom development (6 months after planting), highest percentage of tubers affected per plant (53.33%) and extent of damage in each tuber (50%) followed by the chemical control plants. Simultaneously another grow bag experiment was also conducted, in the mosaic susceptible variety Sree Jaya to assess the cassava mosaic virus disease suppression by P. indica. Natural incidence of cassava mosaic virus in the cassava plants was monitored by visual scoring from 4 MAP till harvest (7 MAP). The plants from absolute control recorded highest visible symptoms of mosaic disease which was on par with G. mosseae treated plants, and least symptoms were recorded in the P. indica treated plants. Viral load in the cassava leaves estimated by quantitative polymerase chain reaction (qPCR) showed highest viral copy number in the G. mosseae treated plants and least in the P. indica treated plants. However, the G. mosseae treated plants showed maximum yield parameters compared to all other treatments. From the results of the present study, it can be inferred that the combined application of P. indica (vermiculite based inoculum one percent w/v @ 20 g/pit) or AM fungus G. mosseae (@ 5 g/pit) along with 75 percent recommended dosage of NPK fertilizers at the time of planting helps to reduce the amount of chemical fertilizers as well as enhance the growth and yield parameters of cassava plants. The study also suggests that P. indica as well as AM fungus G. mosseae can be utilized as biocontrol agents to combat stem and root rot disease of cassava. Effective colonization of P. indica also reduces the incidence of cassava mosaic virus. The combined application of these two beneficial endophytic fungi might have the potential to improve the growth and yield parameters of cassava with positive effects on disease control.Item Morpho- molecular characterisation and hybridisation in Oncidium and equitant oncidium orchids(Department of Genetics and Plant Breeding, College of Agriculture, Vellayani, 2025-07-30) Aswini, M S; Beena ThomasThe present research programme entitled “Morpho-molecular characterisation and hybridisation in Oncidium and equitant Oncidium orchids” was carried out in the Department of Genetics and Plant Breeding, College of Agriculture, Vellayani during 2022-24. This research programme aimed to develop novel hybrids in Oncidium orchids as it is a less focused commercially important orchid species for crop improvement programmes. A total of twenty parental genotypes were collected from different nurseries across South India viz., Oncidium Jairak Fragrance (P1), Oncidium Jairak Fragrance OngKnot (P2), Oncidium J.F. Ha-Nu-Man (P3), Oncidium J.F. Pra-Lak(P4), Oncidium J.F. Montho (P5), Oncidium Guan Shin Rouge Ruby (P6), Oncidium Spacerace coco (P7), Brassia arcuigera (P8), Oncidium Sharry Baby (P9), Oncidium Yuan Nan Gold (P10), Oncidium Winterwonder white fairy (P11), Oncidium Kampangsan White (P12), Oncidium Golden Shower (P13), Oncidium Hybrid Miltasssia Sheloib Tolkein (P14), Oncidium Narisara SS (P15), Miltasia Royal Robe (P16), Oncidium Gum Pagan (P17), Oncidium Wild Cat 'Golden Red Star', Tolumnia Jairak Firm Sweet Pink (P19) and Tolumnia William Thurston (P20) were chosen for the research. They were subjected to evaluation for various qualitative and quantitative traits. Evaluation of parents was done for twenty-four quantitative traits. In addition, sixteen quality traits were also estimated in all the parental genotypes. In this study, for most of the traits, genotypic variance was observed close to the phenotypic variance, indicating that genetic factors predominantly control the variation in these traits. The PCV and GCV values were high for petal width, indicating substantial variability. Heritability was high (>60%) for nearly all traits, such as plant height, number of flowers per inflorescence, flower length, flower width, petal length, petal width, lip length, lip width, vase life and longevity of flowers in the stalk. Meanwhile, all the floral traits had high genetic advance as a percentage of the mean, indicating significant potential for improvement through selection, making them prime candidates for targeted breeding efforts. Overall, this analysis highlighted the strong potential for genetic enhancement of these traits in future breeding programs. In the correlation analysis, longevity of flowers in stalk or inflorescence exhibited a strong significant and positive correlation with vase life and length of inflorescence both at genotypic and phenotypic level. In the path analysis study, petal length stood out with the highest positive direct effect, making it the primary trait associated with enhancing the longevity of flowers. In this research programme, twenty parents were subjected to the molecular polymorphism study with the aid of twenty-five different ISSR (Inter Simple Sequence Repeat) markers. The ratio of absorbance at 260 nm and 280 nm (A260/A280) of all twenty extracted DNA samples of parents ranged between 1.80 and 2.03, indicating nearly 100% purity for the samples. The concentration of samples ranged between 445 and 1553 µg/ml. In this polymorphism study, UBC 844, UBC 824, UBC 807, UBC 818 and UBC 810 have shown higher PIC value. The percentage of polymorphic loci was found more for the primers UBC 807, UBC 808 and UBC 899 followed by UBC 810 and UBC 824. Further, hybridisation was carried out with the best ten genotypes selected based on flower synchronisation, flowering nature and variability studies. A total of seventy- three cross combinations were attempted based on flower synchronisation and flowering nature. P3, P4, P5, P8, P9, P10, P12, P16, P18 and P19 were the parents involved in the hybridisation process. Incompatibility reactions were noticed at different stages ranging from flower abscission before the onset of any visible post-pollination change to instances during the development of the capsule (seed pod). All the five cross- combinations obtained (P3 x P9, P10 x P5, P12 x P19, P19 x P5 and P5 x P19) were germinated successfully, sub-cultured at respective periods and planted successfully after the evaluation of plantlets. Oncidium species exhibit both self-incompatibility and interspecific pollination barriers, critical for maintaining genetic diversity and hybrid vigour. Following successful pollination, the developing capsule underwent several changes before harvest. Initially, the ovary showed slight enlargement and turned green. The longest capsule was obtained for the cross P10 x P5 (O. Yuan Nan Gold x Oncidium Jairak Fragrance Montho) and the shortest capsule was obtained for the cross P19 x P5 (Tolumnia Jairak Firm Sweet Pink x Oncidium Jairak Fragrance Montho). The cross combination P10 x P5 (O. Yuan Nan Gold x O. Jairak Fragrance Montho) recorded the highest days in this process and the lowest by P19 x P5. The total days required for green capsule harvest in successful crosses was minimum in the cross-combination P19 x P5. Orchid seeds are difficult to germinate naturally since it is devoid of natural storage organs for food reserves and the embryo is naked. In vitro germination using media like MS supplemented with benzylaminopurine (BAP) and Indoleacetic acid (IAA) has shown promising results. Out of five cross combinations in different bottles, all the combinations exhibited greening thereby initiating protocorm formation. In vitro propagation study revealed that the shortest time for initial germination was observed in P19 x P5 (Tolumnia Jairak Firm Sweet Pink x O. Jairak Fragrance Montho) (less than 1 month), while the longest is in P12 x P19 (1 month and 3 weeks). The fastest time for deflasking is also seen in P19 x P5 (O. Kampangsan White x Tolumnia Jairak Firm Sweet Pink) (7 months and 1 week), whereas the longest is in P12 x P19 and P5 x P19 (8 months and 1 week). This variation highlighted the influence of genetic combinations on growth stages in Oncidium orchid cross-combinations. Wide variation in days for different stages was noticed among different cross-combinations. The total days for initial germination ranged from 4 weeks to 1 month and 3 weeks. Further, days to protocorm formation varied from 1 month 4 weeks to 3 months and 1 week. The first leaf initiation started in 3 months and 2 weeks and ended up to 3 months and 4 weeks. Shoot initiation occurred from 4 months, 2 weeks of culturing to 5 months and 3 weeks of culturing. The roots were finally produced in 6 months to 6 months and 3 weeks. The deflasking was done for each cross-combination from 7 months, 1 week to 8 months, 1 week. Deflasked plantlets were subjected to morphological evaluation. Among the five cross combinations, P5 x P19 (Oncidium Jairak Fragrance Montho x Tolumnia Jairak Firm Sweet Pink) was observed as the longest plantlet for leaf length, root length, a greater number of roots and a higher root diameter. This indicated robust growth in seedling height, potentially due to favourable genetic combinations. The longest leaf reflected that superior leaf development is beneficial for photosynthesis and vigour. The longest root aids for better root extension, nutrient and water uptake. In conclusion, this research on Oncidium and equitant Oncidium orchids successfully integrated morpho-molecular characterisation, hybridisation and in vitro propagation to develop novel hybrids with significant genetic potential. Molecular diversity analysis using ISSR markers facilitated parental variability analysis, while hybridisation efforts yielded five promising cross-combinations, with P5 x P19 (Oncidium Jairak Fragrance Montho x Tolumnia Jairak Firm Sweet Pink) emerging as the most robust in terms of seedling vigour, leaf and root development and overall growth performance making it a promising candidate for further development. The study also optimised in vitro propagation protocols, ensuring successful germination and plantlet establishment. These findings underscore the potential of Oncidium orchids for commercial breeding, paving the way for further genetic enhancement and large-scale propagation.Item Direct regeneration of banana(Musa spp.) cultivar njalipoovan through in vitro male bud culture.(Department of Fruit Science, College of Agriculture, Vellayani, 2025) Jovita Joju; Manju, P RThe present research work entitled “Varietal evaluation of guava (Psidium guajava L.) for urban horticulture” was conducted at the Department of Fruit Science, College of Agriculture, Vellayani, from 2023 November to 2024 October. The study was under taken to evaluate the growth and yield response of planting materials of guava to different type and size of containers and to evaluate the growth response of different varieties of guava in containers. The experiment 1 entitled “Performance evaluation of guava (Psidium guajava L.) in containers” was laid out in Completely Randomized Design (CRD) with 18 treatments and 3 replications using the guava variety Arka Kiran. The treatments included two container types (C1 - Plastic container and C2 - Air-pot), three container sizes (V1 – 40 L, V2 – 60 L and V3 – 80 L) and three different planting materials (P1 - Air layers, P2 - Rooted cuttings and P3 - Grafts). The medium of planting consisted of soil, coir pith and farm yard manure in 1 : 1 : 1 ratio across all treatment. Twelve- month-old potted plants were subjected to the study. Plants in plastic containers (C1), registered significantly taller growth with greater plant spread, primary stem girth, number of leaves per plant (at 15, 18, and 21 MAP), stem girth (at 15 and 18 MAP), root dry weight, shoot dry weight, and leaf area (at 21 MAP) compared to those in airpots. Meanwhile, plants in airpots exhibited earlier flowering, shorter duration from flowering to harvest and longer flowering duration. They also produced greater number of fruits and higher fruit weight, length, diameter and fruit yield. Among different container volumes, 80 L (V3) had the tallest plants with the highest plant spread, stem girth and primary stem girth and the highest number of leaves per plant (15 MAP, 18 MAP and 21 MAP). In addition, they exhibited earliness in flowering and harvest, highest flowering duration, fruit weight, length, diameter, number of fruits and fruit yield. Root dry weight, shoot dry weight (21 MAP) and leaf area were also the highest in V3. 168 Among the different planting materials, air layers produced taller plants with greater plant spread (at 15, 18, and 21 MAP), number of leaves per plant, leaf area and root-to-shoot ratio (at 21 MAP). In addition, they exhibited early flowering, longest flowering duration and the shortest number of days from flowering to harvest. The number of fruits, fruit weight, fruit length, diameter and fruit yield were also observed to be the highest in air layers. Grafts (P3) recorded the highest values for stem girth, primary branch girth, root dry weight and shoot dry weight. The fruits were analysed for quality parameters, including TSS, total sugar, reducing sugar, ascorbic acid, total antioxidant activity and total carotenoids. Container size, type, and planting material showed a significant difference in ascorbic acid and carotenoid content, whereas all other parameters were non-significant. Ascorbic acid and carotenoid content were higher in airpots. In terms of container volume, the 80 L containers showed higher ascorbic acid(227.67 mg 100g-1) and carotenoid levels (0.67 mg 100g-1) , while, among planting materials, air-layered plants had the highest values. Leaf tissue was analysed for physiological and biochemical parameters viz., chlorophyll content, total carotenoids, total reducing sugars and total soluble proteins at 18 MAP. Container type and planting material did not show any significant effect on these parameters, while 80 L container volume showed significantly higher total soluble proteins compared to 40 and 60 litres. The two factor interaction between container type and size (C x V), showed that 80 L plastic containers (C1V3) recorded significantly higher plant spread (E-W and N-S), stem girth, leaves per plant, leaf area and root dry weight. The shoot dry weight was higher in both plastic container and air-pots with 80 L (C1V3 and C2V3). Air-pots with 80 L (C2V3), exhibited early flowering with more fruits per plant, enhanced flowering duration, earlier flowering to harvest and the highest fruit weight, length, diameter and fruit yield. Interaction between container type and planting material (C x P) also confirms similar results in air-pots with air layers (C2P1). Root : shoot ratio was the highest in air-pots with grafted plants (C2P3). The two factor interaction between container size and planting material (V x P) showed that air layers grown in 80 L containers (V3P1) outperformed other combinations with respect to plant height, plant 169 spread, leaves per plant, leaf area, number of fruits, flowering duration, days to flowering, days from flowering to harvest, fruit weight, length, diameter and fruit yield. Shoot dry weight, stem girth and primary stem girth were the highest in 80 L with graft (V3P3). In three factor interaction, 80 L plastic containers with graft (C1V3P3) showed higher root dry weight and shoot dry weight while plant height and leaf area were the highest for air layers in 80 L plastic container (C1V3P1). The least number of days to flowering and days from flowering to harvest were observed in 80 L airpots with air layers (C2V3P1) they also produced the highest number of leaves and fruits, as well as the greatest fruit weight, length, diameter and fruit yield. Another notable feature observed in the study is the presence of root coiling in plastic containers of all sizes (40, 60, and 80 L), regardless of the type of planting material. In contrast, root coiling was absent in airpots of all container sizes. This study underscores the importance of selecting appropriate container types, sizes, and planting materials for successful guava cultivation in containers. Airpots outperformed plastic containers by enhancing reproductive traits like early flowering, extended flowering duration, and superior fruit yield and quality. Larger containers (80 L) showed the best results across growth, fruit yield and biochemical parameters, including ascorbic acid and carotenoids. Among planting materials, air layers excelled in vegetative growth, earliness in flowering, and fruit quality, establishing 80 L airpots with air layers as the optimal choice for container-based guava cultivation. The experiment 2 entitled “Varietal evaluation of guava (Psidium guajava L.) for urban horticulture” was laid out in Completely Randomized Design (CRD) with 5 treatments and 3 replications. The treatments included five varieties of air layered guava: T1-Allahabad Safeda, T2-Lucknow 49, T3-Arka Kiran, T4-Arka Rashmi and T5- Arka Mridula. (Note: The best container type, container size and planting material (Airpots 80 L air layers) was selected from the result of first year observations of the experiment entitled “Performance evaluation of guava (Psidium guajava L.) in container and used in this experiment). T5-Arka Mridula registered the highest plant 170 height, primary and the secondary stem girth, while early flowering with highest number of flowers was registered in T4-Arka Rashmi. Leaf tissue was analysed for physiological and biochemical parameters viz., chlorophyll content, total carotenoids, total reducing sugars and total soluble proteins at 6 MAP. Total chlorophyll (0.98 mg 100 g -1), reducing sugar (1.84%) and carotenoid content(0.70 mg 100 g -1) were the highest in T5-Arka Mridula and total soluble protein was the highest in T1-Allahabad Safeda. This study emphases the importance of the growth response of different varieties of guava in containers. Among vegetative parameters, plant height, primary and secondary stem girth were the highest in Arka Mridula which was reflected in physiological and biochemical parameters like chlorophyll, reducing sugar and carotenoid contents that gave the highest values. However, in plant spread and flowering parameters like days to flowering and number of flowers the highest values were in Arka Rashmi. Plants with a compact canopy and good reproductive parameters are ideal for container growing. Thus, the present study unveils the suitability of Arka Rashmi for container growing of guava.Item Strain improvement of Trichoderma spp.for management of foot rot of black pepper caused by phytophthora capsici(Department of plant pathology, College of Agriculture, Vellanikkara, 2025-09-22) Alby John; Susha S TharaThe research work entitled ‘Strain improvement of Trichoderma spp. for management of foot rot of black pepper caused by Phytophthora capsici’ was conducted at Department of Plant Pathology, College of Agriculture, Vellayani during 2022-2025 with an objective of enhancing the antagonistic potential and growth promotion of Trichoderma strains by protoplast fusion and mutagenesis; studying the biochemical and molecular mechanisms underlying antagonism and evaluation of its efficacy for managing P. capsici. Five promising isolates of Trichoderma spp.: TRMW-2, TRKR-2, TRPN-3, TRPN-11 and TRPN-17, previously collected from different agroclimatic zones of Kerala, along with Trichoderma asperellum, the reference culture from KAU were used as the parental isolates. Molecular characterization using species-specific primers (TEF1 and RPB2) and multi-gene phylogenetic analysis identified TRMW-2, TRKR-2, TRPN 3, TRPN-11 and TRPN-17 as Trichoderma brevicompactum [Tb], Trichoderma koningiopsis [Tk], Trichoderma pholiotae (PN3) [Tp (PN3)], T. pholiotae (PN11) [Tp(PN11)] and Trichoderma guizhouense [Tg], respectively. A total of 15 protoplast fusion combinations were performed using the six parental isolates and 30 fusants with a colony diameter exceeding 8.5 cm at 48 h were screened. Among these, the 10 most effective fusants, exhibiting a growth inhibition rate of 85.73% to 92.13% against P. capsici were selected based on their mycelial growth suppression. Simple sequence repeat (SSR) marker analysis was performed using 15 primers to determine whether the selected fusants were interspecific. Similar amplification patterns were observed between the fusants Ta × Tk-1, Tk × Tp (PN3)-1, Ta × Tp (PN3)-1 and Ta × Tp (PN3)-5 and their respective parental strains for the markers PRB ATC, TV1, KON 700, TA4, TA9 and TH5, confirming them as interspecific fusants. Strain improvement through UV irradiation (5, 10 and 15 min) exhibited an inverse correlation between exposure time and the number of regenerated colonies. Among 140 mutants screened, 30 with a colony diameter greater than 7.5 cm at 48 h were selected, which were further narrowed down to 10 with the highest inhibition rates of 80.87% - 84.47% against P. capsici. Similarly, gamma irradiation (150, 200, 250 and 300 Gy) showed a negative correlation between colony regeneration and radiation dose. Among 180 mutants screened, 10 superior mutants with a growth inhibition of 81.67% - 90.40% were selected. From the 30 improved Trichoderma spp. strains obtained through three distinct strain improvement techniques, the 10 most effective strains exhibiting significant pathogen inhibition (83.73% to 93.60%) were identified and subjected to genetic stability assessment via ten successive subculturing rounds, followed by dual culture assay against P. capsici. The five most promising Trichoderma strains: T. asperellum × T. koningiopsis-1 [Ta × Tk-1], T. koningiopsis ×T. pholiotae (PN3)-1 [Tk × Tp(PN3)-1], T. pholiotae (PN11) fifth UV mutant colony irradiated for 5 min [Tp(PN11).5m5], T. pholiotae sixth gamma mutant colony irradiated at 200 Gy [Tp(PN3).200m6] and T. asperellum first gamma mutant colony irradiated at 250 Gy [Ta.250m1] with superior mycelial growth suppression (83% to 91.27%) were selected. Culture filtrate assay at 50% concentration revealed maximum mycelial inhibition of P. capsici by Tk × Tp(PN3)-1 (98.33%) and Tp(PN11).5m5 (97.92%). Additionally, Ta × Tk-1 (76.13%) and Tp(PN3).200m6 (72.25%) exhibited significant volatile metabolite activity against P. capsici, outperforming T. asperellum (59.88%). The potential of the selected Trichoderma spp. strains to produce lytic enzymes, including β-1,3 glucanase, protease, chitinase and lipase was evaluated. Ta × Tk-1, Tk × Tp(PN3)-1, Tp(PN11).5m5 and Ta.250m1 exhibited higher enzymatic activity than T. asperellum, signifying enhanced antagonistic potential. Growth promoting attributes, including IAA (174.41 μg ml-1) and siderophore production (77.09%) were highest in the interspecific fusant Ta × Tk-1, while phosphate solubilization was most pronounced in the gamma mutant Ta.250m1(1326.90 μg ml-1). Cultural and morphological characterization of the improved strains revealed distinct variations in conidiation, pigmentation, hyphal width and conidial and phialide size compared to their parental isolates. Notably, Tp(PN3).200m6 exhibited deep yellow pigmentation, while Ta × Tk-1 and Ta.250m1 showed dense sporulation. Pot culture experiments were conducted to evaluate the biocontrol efficacy and plant growth promoting potential of five promising Trichoderma spp. along with T. asperellum in black pepper var. Panniyur - 1. Biometric characters (plant height, number of leaves, nodes and internodal length) were highest in plants treated with Ta × Tk-1, followed by Ta.250m1. Upon challenge inoculation with P. capsici, lesion size was smallest in plants treated with Tk × Tp(PN3)-1 and Tp(PN11).5m5, corresponding to a percent disease index of 20.19% and 35.44% respectively, compared to 83.57% in control plants. Elevated activity of defense related enzymes (peroxidase, polyphenol oxidase, phenylalanine ammonia-lyase, catalase and superoxide dismutase) was recorded in plants treated with Tk × Tp(PN3)-1, Tp(PN11).5m5 and Ta × Tk-1. The relative expression of antagonism associated genes from different functional groups; chitinase, β-1,3-endoglucanase, subtilisin-like protease and terpene synthase were analyzed in both improved Trichoderma strains and their respective parental isolates using semi-quantitative RT-PCR. Expression levels were significantly upregulated in Tk × Tp(PN3)-1 and Tp(PN11).5m5 across all four genes compared to the parental isolates. This study identified three improved Trichoderma strains; Ta × Tk-1, Tk × Tp(PN3)-1 and Tp(PN11).5m5 that exhibited enhanced antagonistic potential, biochemical characteristics, plant growth promoting traits and defense enzyme activities, surpassing the reference strain T. asperellum. Therefore, following multi-locational field trials across different crops and comprehensive toxicological studies, these strains could be released as efficient biocontrol agents in the future.Item Management practices for shelf life extension of fresh cut jackfruit and pomegranate(Department of Postharvest Management, College of Agriculture,Vellanikkara, 2024-11-21) Amrutha, R; Athulya S KumarThe study entitled “Management practices for shelf life extension of fresh-cut jackfruit and pomegranate” was conducted at the Department of Postharvest Management, College of Agriculture, Vellayani during the period of 2022-2024, with the objective of standardizing the pre-treatments, packaging and storage systems for shelf life extension of jackfruit bulbs and pomegranate arils. The study was conducted as two separate experiments for jackfruit and pomegranate. Fresh, good quality, optimum mature jackfruit (Varikka) with relatively uniform size and weight were harvested from the Instructional Farm, Vellayani, allowed to ripe and used for the study; whereas good quality ripe pomegranate relatively of uniform size, weight and colour were procured from VFPCK outlet, Thiruvananthapuram and used for the study. Both the fruits were subjected to ozonization (2 ppm). Experiments were carried out in two parts viz., evaluation of pre-treatments and development of packaging and storage system. Jackfruit bulbs with seeds intact and pomegranate arils (100% usable form) were extracted from the sanitized fruits, pre-treated with four different solutions viz., 0.5% ascorbic acid, 0.5% citric acid, 1% calcium chloride and 1% calcium ascorbate for 4 minutes, air-dried and were kept in areca sheath bowls wrapped with cling film along with the corresponding untreated bulbs and arils (control), under refrigeration (5±2oC), to analyze the efficacy of pre-treatments. Pre-treated fresh-cut jackfruit bulbs and pomegranate arils resulted in better physical, physiological and chemical parameters as compared to the untreated ones. Pre treatment of jackfruit bulbs with 1% calcium ascorbate resulted in maximum shelf life (5.00 days), vitamin C (24.53 mg 100g-1), carotenoid (0.83 mg 100g-1), lowest physiological loss in weight (1.39 %), percent leakage (85.40%), acidity (0.31%), phenol (35.64 mg 100g-1), total sugar (37.59 %), reducing sugar (18.87 %) and TSS (23.80oB) with best sensory scores after 5 days of storage. During the initial, 1st, 2nd and 3rd days also, the physiological parameters were superior for calcium ascorbate treated bulbs. 184 Pomegranate arils treated with 1% calcium ascorbate recorded the maximum shelf life (5.00 days), vitamin C (23.26 mg 100g-1), anthocyanin (3.19 mg 100g-1), lowest physiological loss in weight (1.70%), percent leakage (39.17%), acidity (0.38%), phenol (210.99 mg 100g-1), total sugar (33.05%), reducing sugar (15.01%) and TSS (15.89oB) with best sensory scores after 5 days of storage. Hence, 1% calcium ascorbate was selected as the best pre-treatment solution for both fresh-cut jackfruit bulbs and pomegranate arils. In second part of the study, fresh-cut jackfruit bulbs and pomegranate arils treated with 1% calcium ascorbate solution, were subjected to different packaging systems viz., shrink wrapping in 15µ polyolefin film, vacuum packaging in laminated pouches, MAP with N2 flushing in laminated pouches, aluminium tray wrapped with cling film and open storage in paper plate (control) and stored under refrigerated (5±2°C) and low temperature (10±5°C) conditions. Pre-treated jackfruit bulbs in MAP with N2 flushing in laminated pouches stored under refrigerated condition (5±20C) recorded the maximum shelf life (10.00 days), vitamin C (20.18 mg 100g-1), carotenoid (0.77 mg 100g-1), least physiological loss in weight (4.86%), percent leakage (78.05%), acidity (0.38%), total sugar (39.37 %), reducing sugar (16.81%), TSS (23.25oB) and phenol (35.42 mg 100g-1) with best sensory scores after 10 days of storage. Fresh-cut jackfruit bulbs without any package (control) had the least shelf life (2.00 days) with maximum physiological loss in weight (3.26%) when kept under low temperature condition. Pre-treated pomegranate arils in MAP with N2 flushing in laminated pouches stored under low temperature condition resulted in maximum shelf life (6.00 days), vitamin C (23.02 mg 100g1), anthocyanin (2.87 mg 100g-1), least physiological loss in weight (3.88%), percent leakage (68.15%), acidity (0.42%), total sugar (35.46%), reducing sugar (17.15%), TSS (16.00oB) and phenol (214.16 mg 100g-1) with best sensory scores after 6 days of storage. Unpackaged arils stored under refrigerated condition recorded the least shelf life (2.00 days) with highest physiological loss in weight (5.10%). The fresh-cut jackfruit bulbs and pomegranate arils, pre-treated with 1% calcium ascorbate solution for 4 minutes and kept in MAP with N2 flushing in laminated pouches were microbiologically safe with superior physical, physiological and chemical parameters upto 10 days under refrigerated (5±20C) and 6 days under low temperature (10±50C) conditions respectively.Item Growth and yield estimation of rice based on satelite data and land based observation using growing degree days(GDD)(Department of Agricultural Meterology, College of Agriculture, Vellanikkara, 2024-03-21) Fazil; Ajith, KRice, the primary staple food for approximately 3.5 billion people worldwide, is supporting food security in numerous countries through irrigated as well as rainfed rice ecosystems. Elevated temperatures may lead to a decline in productivity, impacting the ability to feed future generations. To address this challenge, the utilization of temperature-based agrometeorological indices, such as Growing Degree Days (GDD) supported by satellite data, emerges as a valuable tool for predicting crop growth and yield across large areas. Growth and yield estimation of rice based on satellite data and land-based observation using growing degree days (GDD) conducted in the Department of Agricultural Meteorology, College of Agriculture, Vellanikkara during the year 2022-23 with the objective of establishing a relationship between GDD and performance of rice crop and to examine the possibilities of remote sensing tools to evaluate plant and GDD interactions to a wider area. The field experiment was conducted in two medium-duration rice varieties, Uma and Pournami, at the Regional Agricultural Research Station, Kumarakom during mundakan season of 2022-23, and was laid out in Randomized Block Design. The treatments consist of five dates of planting, viz. D1-5th September, D2-20th September, D3-5th October, D4-20th October, D5-5th November, with four replications. Various biometric observations, heat unit accumulations, yield and yield attributes were recorded at definite intervals. The study on phenology revealed that crop duration decreased from early planting to late planting in both varieties. Grain yield was significantly affected by the planting dates in both varieties. D1 planting produced the highest grain yield in both Uma (4388.8 kg ha-1) and Pournami (3715 kg ha-1) varieties, while D5 planting produced the lowest yield in Uma (2118.8 kg ha-1) and Pournami (2313.8 kg ha-1). The yield attributes were also significantly affected by planting dates and showed similar trend. Heat units like GDD and Photothermal units (PTU) were found to reduce in delayed planting. D2 recorded the highest GDD in both Uma (2055°C days) and Pournami (2090°C days). The lowest GDD was recorded by D5 planting in Uma (1820°C days) and Pournami (1872°C days). A linear regression equation was developed to predict yield for both varieties using GDD as independent variables. The results indicated that the Uma variety performed better than Pournami variety in the field experiment with respect to plant characters and yield. Palakkad district and Kuttanad. MODIS LST product (MOD11A2) 8-day composite was used to retrieve day and night land surface temperature for the mundakan rice growing season of 2022-23. A linear relationship was developed with MODIS LST and air temperature data obtained from the ground station. The developed relationship was then validated to ensure its accuracy and reliability. Daily maximum and minimum air temperature was estimated from MODIS LST using the linear equation during the crop season for the study locations. GDD was calculated, and it was employed to estimate the number of days required to attain various phenological stages of the mundakan rice. Validation of the predicted number of days in comparison with the observed showed a good relationship with R2 values of 0.82, 0.82, 0.80, 0.87, 0.86, and 0.81, and RMSE 0.42, 0.65, 0.72, 0.74, 0.84, 1.33 respectively, for the six phenophases of the rice crop. Further studies were done to assess the potential of GDD as an agroclimatic indicator for climate change in selected 9 locations in Palakkad and Kuttanad. The study attempted to understand the spatial and temporal distribution of GDD of mundakan rice over the past 30 years (1993-2022). The 30-year period were divided into six pentads. Additionally, GDD during three warming scenarios (+1°, +2° and +3°C rise of daily temperature from last pentad) were also studied. The research finding indicates that accumulated GDD was found to be higher at Kuttanad compared to Palakkad ie., GDD decreases from lower latitude to higher latitude. Chittur of Palakkad district had the lowest accumulation of GDD, while the highest was reported at Moncompu in Kuttanad in the last pentad and as well as during the three warming scenarios. Analysis of the 30 year GDD data of Palakkad revealed that an alternate warming and cooling trend is observed during the first four pentads (i.e. the period from 1993 to 2012) and during the last two pentads (ie. period from 2013 to 2022) the cooling trend is not visible. In Kuttanad region the warming trend is more predominant and the GDD values showed a steady increase form the first pentad to the last pentad. The GDD values seems to decrease from west to east in both Palakkad and Kuttanad.Item Native ornamentals for water- wise landscaping(Department of Floriculture and Landscaping, College of Agriculture , Vellanikkara, 2024-03-05) Bhukya Mahesh; Shajma Nafeesa BasheerThe investigation entitled “Native ornamentals for water-wise landscaping” was conducted in the Department of Floriculture and Landscaping, College of Agriculture, Vellanikkara, with an objective to conduct the morphological evaluation of native ornamentals and to assess the suitability of selected native ornamentals for water wise landscaping. The study was conducted as two experiments i.e., morphological evaluation of native ornamental species and evaluation of native ornamental plants for drought stress tolerance. The native species selected for the first study were Murraya paniculata, Barleria mysorensis, Rauwolfia tetraphylla, Barleria strigosa, Clerodendrum inermi, Carmona retusa, Melastoma malabathricum, Ecbolium viride, Eranthemum capensis and Pogostemon quadrifolius. Significant variations were observed for vegetative and flower characters and air pollution tolerance index among the ten native species. Maximum plant height was observed in Murraya paniculata (65.00 cm), which was on par with Clerodendrum inermi (60.87cm). Plant spread was also maximum in Murraya paniculata (41.33 cm). The number of primary branches was the highest in Clerodendrum inermi (6.43), which was on par with Pogostemon quadrifolius (6.15). Clerodendrum inermi also recorded the highest number of secondary branches (11.33), which was on par with Eranthemum capensis (10.33). The highest number of leaves was observed in Clerodendrum inermi (95.33). The leaf length recorded the highest value in Ecbolium viride (9.01 cm), which was on par with Barleria strigosa (8.00 cm). The leaf breadth was recorded highest in Barleria strigosa (7.33 cm) followed by Eranthemum capensis (4.33 cm). The qualitative vegetative characters like leaf type (simple/ compound), shape of leaf lamina, type of leaf base, margin and tip, leaf surface texture (coarse or fine), pubescence (present or absent) and leaf colour (as per RHS colour chart) were also exhibited wide variability. Among the floral characters, the maximum flower diameter was recorded in Melastoma malabathricum (4.83 cm), maximum length of the flower stalk in Barleria strigosa (3.67 cm), maximum number of flowers in Barleria mysorensis (50.00), flowering duration in Melastoma malabathricum (7.33 months) and field life of flowers in Barleria strigosa (3.67 days). Qualitative characters of flowers like flower type (solitary / inflorescence), colour of flower (as per RHS colour chart), fragrance (presence/absence), season of flowering and field life of flowers (days) also recorded wide variation. Based on their APTI value Carmona retusa can thus be included under the moderate tolerant group and Pogostemon quadrifolius under the sensitive group. Melastoma malabathricum can be used as edge, hedge and flower borders. Murraya paniculata having the highest plant height and plant spread can be used as hedge. Barleria strigosa can be used for hedge planting. Clerodendrum inermi which recorded the highest number of leaves and plant height can be used as hedge and for topiary. In the second experiment the native ornamentals were evaluated for their drought stress tolerance. Morphological characters like plant height, shoot and root biomass, stem diameter, leaf fresh and dry weight and stem diameter decreased in drought condition when compared to control. Total root length and root-shoot ratio increased under drought condition compared to control. Physiological parameters like RWC and membrane stability reduced under 5-day and 10-day water stress. Biochemical parameters photosynthetic pigments and starch decreased under 5 day and 10-day stress. Anatomical characters like higher stomatal index and lowest cell size were observed in plants subjected to 10-day stress. Clerodendrum inermi recorded the highest root length (92 cm) under 10-day stress. Clerodendrum inermi recorded highest relative water content (86.98 %) under control. Rauwolfia tetraphylla recorded the highest root-shoot ratio (0.97), carotenoid (0.10 mg/g), proline (96.44 μmol g-1FW) and MDA (1.63 μmol g-1FW) under 10-day water stress. Barleria mysorensis showed the highest membrane stability index (100.46) and lowest MDA (0.14 μmol g-1FW) under control. Thus Rauwolfia tetraphylla, Clerodendrum inermi, Murraya paniculata, Melastoma malabathricum and Barleria mysorensis can be suitably used for water-wise landscapingItem Process optimization and utilization of resistant starch from banana.(Department of Community Science ,College of Agriculture,Vellanikkara, 2025-09-11) Sruthy,P M; Sharon, C LBanana (Musa spp.), often hailed as the common man’s fruit, holds a special place in the scenario of agriculture and nutrition, besides having immense economic significance in India and across the globe. Banana, known for its year round availability, affordability, and rich nutrient profile, has transitioned from a commonly consumed fruit to a functional ingredient of growing interest in modern health and food industry. Resistant starch (RS) found in unripe green banana is a promising bioactive compound with potential health benefits. India is leading the global banana production, hence there lies untapped potential in harnessing banana starch, especially its resistant form, for the development of value added food products. However, native banana starch faces limitations in its functional properties, which can be effectively addressed through modification techniques such as Heat Moisture Treatment (HMT). This approach not only enhances the nutritional and functional quality of banana starch but also paves the way for its incorporation into a wide range of health oriented food formulations. Hence, the current study “Process optimisation and utilisation of resistant starch from banana”, was carried out with the objective of optimising the conditions for resistant starch formation in banana and its quality evaluation. The study also aimed to develop value added products incorporating various proportions of banana resistant starch. The popular GI (Geographical indication) granted Kerala banana variety Chengalikodannendran banana and the worldwide popular Cavendish variety Grand Nainebanana were selected for this study. Starch extracted from their flours yielded 26.89% (Chengalikodan) and 27.40% (Grand Naine), with purity of 88.62% and 89.73%, respectively. Resistant starch content was 20.02% in Chengalikodan and 20.62% in Grand Naine. Starch samples of Chengalikodan and Grand Naine banana were modified by autoclaving at 110℃ and 121℃ with different moisture content (10, 20, and 30 %) at three different time periods (15, 30 and 60 minutes). Resistant starch (RS) content in Chengalikodan banana starch was significantly affected by autoclaving conditions. Maximum RS (25.84%) was observed at 121°C for 30 minutes with 10% moisture. In Grand Naine starch, autoclaving enhanced RS from a control value of 20.62% to a peak of 30.52% (at 121°C for 30 minutes with 10% moisture). Repeated autoclaving and cooling cycles further increased RS in Chengalikodan, which reached 54.56% after four cycles, while Grand Naine peaked to 59.63%. Repeated autoclaving and cooling cycles were applied to the isolated banana starch. As a result of this treatment, RS3 was formed. The presence of RS3 confirms that the modification process was effective. The samples with maximum RS content from Chengalikodan and Grand Naine were selected for further analysis and product development. Two treated banana starch (RS3) samples (Chengalikodan and Grand Naine), along with corresponding flour and isolated starch, were initially analysed for colour index and granular morphology. Morphological analysis showed that flour and isolated starch granules varied in shape, size, and surface texture based on processing. Chengalikodan and Grand Naine flours had irregular, oval, and elongated particles with smooth to rough surfaces, while isolated starch granules were smooth and more uniform. Autoclaving altered native starch structure, forming compact, aggregated granules due to retrogradation, with resistant starch showing larger, fused clusters and rougher surfaces. Chengalikodan flour had higher lightness and whiteness, which decreased isolated starch and treated starch. In contrast, Grand Naine showed consistently lower lightness across all forms, reflecting the impact of processing and variety on visual traits. The physicochemical properties of flour, isolated starch, and autoclaved starch samples from Chengalikodan and Grand Naine banana were evaluated over three months. Autoclaved starch samples of both Chengalikodan and Grand Naine showed higher pH (5.36 and 5.34), moisture (7.08 and 7.02%), water holding capacity (4.91 and 5.00%), and gelatinisation temperature (77.02 and 75.67℃), but lower bulk density (0.48 and 0.51g/ml), swelling power (8.86 and 8.88%), solubility (3.65 and 3.58%), syneresis (27.41 and 28.22%), dispersibility(75.14 and 76.31%), and peak viscosity (487cp and 571cp), which are important properties for the formulation of functional, shelf stable and healthy food products. This study assessed the nutritional, functional, and glycemic characteristics of flour, isolated starch, and treated starch (RS) samples of Chengalikodan and Grand Naine banana. Treated starch had the lowest total soluble solids (2.56 and 2.41ºBrix), with lower total and reducing sugars. Treated starch showed the highest carbohydrate content (87.72 g and 87.33 g/100 g), highest slowly digestible starch (18.88% and 18.59%) and lowest rapidly digestible starch (24.56% and 22.53%) for Chengalikodan and Grand Naine, respectively. It also contained high amylose of 35.42% (Chengalikodan) and 38.92% (Grand Naine) and lower amylopectin. Treated starch showed the lowest in vitro starch digestibility of 44.56% and 40.65% and the lowest glycemic index of 37.56 and 36.65, slightly increasing after three months, for Chengalikodan and Grand Naine, respectively. Instant custard mixes were developed using 10-35% banana resistant starch, 5-35% corn flour, and other ingredients. Both Chengalikodan (T4) and Grand Naine (T10) banana based custard mix with 20% RS had the highest overall acceptability of 8.55 and 8.22 respectively. Control custard mix (T0) had the highest brightness (L* = 83.93) and whiteness (WI = 79.66), while T4 and T10 showed reduced lightness (81.90 and 77.74) and whiteness (77.32 and 74.12). Banana resistant starch mixes had lower initial swelling power, solubility, water absorption capacity, and dispersibility, which declined further during storage. Bulk density and moisture were higher and increased over time. Carbohydrate, protein, and fat contents were initially lower and gradually decreased. Starch content was lower in T4 and T10 (56.21% and 54.95%) than in the control (62.91%). Rapidly and slowly digestible starch were also lower in T4 (57.62% and 10.23%) and T10 (58.23% and 10.25%), while resistant starch was higher (32.15% in T4 and 31.52% in T10) compared to the control. In vitro starch digestibility was lower in T4 and T10 (41.28% and 42.40%) than in the control (62.70%). Vermicelli was formulated using 25-45% resistant starch from Chengalikodan and Grand Naine banana, combined with banana flour and whole wheat flour (30-70%). Vermicelli with 100% refined wheat flour served as control. Sensory evaluation showed that T3 (35% Chengalikodan resistant starch + 15% banana flour + 50% whole wheat flour) scored highest overall acceptability (8.28). Correspondingly, uppuma made from T3 vermicelli also received superior sensory scores, with overall acceptability of 8.42. Products with Grand Naine resistant starch (35% Grand Naine resistant starch + 15% banana flour + 50% whole wheat flour) had slightly lower scores (8.24 for vermicelli and 8.15 for uppuma than Chengalikodan based products, though both were well accepted. The study compared physicochemical, nutritional, and starch digestibility properties of vermicelli made with RS from Chengalikodan and Grand Naine banana to a refined wheat flour control. Banana RS vermicelli had lower lightness and whiteness, with higher moisture content (6.89% in Chengalikodan, 6.95% in Grand Naine) than the control (6.33%). It also had higher carbohydrate and energy content, while protein and fat decreased over storage. Rapidly digestible starch was lower in banana RS vermicelli (41.45% and 43.09%) than the control (84.42%), while slowly digestible starch and RS were higher. Glycemic index was also lower (46.23 in Chengalikodan, 45.55 in Grand Naine) compared to the control (76.23). Instant uppuma mixes were made using Chengalikodan and Grand Naine banana resistant starch vermicelli (35% RS + 15% banana flour + 50% whole wheat flour). Among treatments with varying water volumes, T3 (100g vermicelli with 300 ml water) received the highest sensory scores for both banana varieties. The mixes showed better stability over three months of storage. The production cost of banana flour was ₹ 33/100g (Chengalikodan) and ₹ 19/100g (Grand Naine), while isolated banana starch cost ₹ 34/100g and ₹ 20/100g, respectively. Treated starch production cost was ₹ 23/100g (Grand Naine) and ₹ 37/100g (Chengalikodan). Custard mixes made with banana RS cost ₹ 40/100g (Chengalikodan) and ₹ 36/100g (Grand Naine), while vermicelli and instant uppumamixes with Chengalikodan RS cost ₹ 42/100g and ₹ 54/100g, compared to ₹ 33/100g and ₹ 45/100g for Grand Naine. Banana starch is a promising functional ingredient that can contribute to the development of health enhancing food products. Heat moisture treatment enhances its functional and physicochemical properties, opening new opportunities for health focused applications. This research highlights banana starch as a sustainable, cost effective ingredient with transformative benefits, poised to meet the growing demand for nutritious, innovative food solutions and shape the future of the food industry.Item Pests of exotic fruit crops in Kerala(Department of Entomology, College of Agriculture, Vellayani, 2024-02-27) Akheela, P; Thanima Sara VargheseThe study entitled “Pests of exotic fruit crops in Kerala.” was conducted at the Department of Entomology, College of Agriculture, Vellayani from 2021 to 2023 with the objective of documenting the pests of exotic fruits, its natural enemies and pollinators in Kerala. The documentation was carried out at the orchard of Instructional Farm, Vellayani and in farmer’s field in Thiruvananthapuram, Kollam, Kottayam and Malappuram districts of Kerala through multiple field visits. A total of 60 different pests were documented from different exotic fruit crops. Among them, 32 pests were documented from rambutan Nephelium lappaceum (L.), 8 from dragon fruit Selenicereus undatus (Haw.) D. R. Hunt, 7 from mangosteen Garcinia mangostana (L.), 4 from passion fruit Passiflora edulis (Sim.), and 10 from other minor exotic fruit crops like miracle fruit Synsepalum dulcificum (Schumach. and Thonn.), pulasan Nephelium mutabile (Blume.), abiu Pouteria caimito (Radik.), soursop Annona muricata (L.), litchi Litchi chinensis (Sonn.), velvet apple Diospyros discolor (Willd.) and longan Dimocarpus longan (Lour.). Leaf and inflorescence caterpillars were predominant in rambutan followed by sucking pests and beetles. The sucking pests include, mealybug Planococcus lilacinus (Cockerel), Crisicoccus hirsutus (Newstead), Ferrisia virgata (Cockerell), scale Ceroplastis floridensis (Comstock), Icerya sp., bean bug Riptortus pedestris (Fabricius), cow bug Otinotus oneratulus (Walker), tree hopper Gargara sp., black plant hopper Ricania sp., flatid plant hopper Flatormenis sp. The lepidopterans recorded in rambutan were white looper moth Pingasa chlora (Stoll), slate flash Rapala manea (Hewitson), emerald moth Hemithea tritonaria (Walker), yellow-tail tussock moth Somena scintillans (Walker), tussock caterpillar Olene mendosa (Huebner), looper Comibaena cassidara (Guenee), pointed ciliate blue Anthene lycaenina (Felder), owl moth Avatha discolor (Fabricius) and a bark borer which is an unidentified micro lepidopteran. Scarab beetle Popillia sp., warty leaf beetle Exema salemensis (Bhasin), leaf beetle Monolepta sp. and flower beetle Oxycetonia versicolor (Fabricius) were the coleopteran pests documented on rambutan. Rambutan was identified as the host for the above-mentioned pests for the first time in India. In dragon fruit, the oriental fruit fly Bactrocera dorsalis (Hendel) was reported for the first time in India. The sucking pests like the brown stink bug Halyomorpha picus (Fabricius), plant hopper Eurybrachis sp., Ricania sp. and Flatormenis sp., striped mealybug Ferrisia virgata (Cockerell), and a destructive trailing ant Trichomyrmex destructor (Jerdon) were also reported for the first time as insect pests of dragon fruit from India. Pest infestation was comparatively lower in mangosteen and passion fruit. The brown soft scale Coccus hesperidum (Linnaeus), mealybug C. hirsutus, leaf eating caterpillar Agrotera flavobasalis (Inoue) and flower feeding caterpillar Homona sp. were reported for the first time in mangosteen from India. The rugose spiralling whitefly Aleurodicus rugioperculatus (Martin) and gold tail moth Sphrageidus xanthorrhoea (Kollar) were reported for the first time in passion fruit from India. Biology of B. dorsalis, H. picus and S. xanthorrhoea were studied under laboratory condition. The egg, larval, pupal and adult period of male, female B. dorsalis in dragon fruit were 1.6± 0.40, 8.0 ± 0.40, 8.0 ± 0.31, 6.4 ± 0.50 and 9.6 ± 0.5 days respectively. The egg, larval and pupal period of S. xanthorrhoea 5.2 + 0.20, 25.6 ± 1.20, 6.6 ± 0.37 days respectievely. Adult period of male and female were 4.4 ± 0.24 and 6 ± 0.44 days respectively. The egg and nymphal periods for H. picus were 5.2 ± 0.20 and 46.8 ± 2.53 days, respectively. Spiders were the dominant predators of the pests of exotic fruits. A total of 24 natural enemies were documented from exotic fruit crops, which include spiders (15), hymenopteran parasitoids (3) and insect predators (6) belonging to Coleoptera (1), Lepidoptera (1), Mantodea (3) and Hemiptera (1). The hymenopteran parasitoids documented were from the family Eupelmidae, Aphelinidae and Trichogrammatidae. For the documentation of pollinators, a study was conducted during the flowering season of rambutan and passion fruit at Instructional Farm Vellayani. For documentation of pollinators of rambutan, five inflorescences each were selected randomly from five different trees. Population of pollinators was recorded by visual observation once in a week from 0600 to 1800 h for a period of four weeks. For documentation of pollinators of passion fruit, the same methodology was adopted for plant selection and pollinators were recorded once in four weeks from 1200 to 1800 h for a period of four weeks. Ten pollinators were recorded from rambutan and four were from passion fruit. The pollinators documented belong to Hymenoptera (9) Diptera (3) and Lepidoptera (2). Stingless bee Tetragonula travancorica (Shanas and Faseeh) was the most abundant and frequent flower visitor of rambutan and carpenter bee (Xylocopa sp.) was the frequent visitor of passion fruit flowers. Seasonal incidence of pests infesting rambutan was carried out for one year from November 2022 to November 2023. The presence of pests in rambutan was noted specifically from March to July, encompassing the flowering to fruit-setting season. The peak pest infestation had a positive correlation with the temperature in rambutan. In the course of the current investigation, a comprehensive catalogue of 60 pests, 24 natural enemies, and 14 pollinators were documented from exotic fruits in Kerala. Among the identified pests 27 pests were recorded from the order Hemiptera, 21 from Lepidoptera, 6 from Coleoptera, 4 from Hymenoptera and 2 from Diptera. Rambutan has been documented to have 14 pests from the order Lepidoptera, 11 from Hemiptera, 5 from Coleoptera, and 2 from Hymenoptera. Dragon fruit pests include 5 from Hemiptera, 1 from Lepidoptera, 1 from Diptera, and 1 from Hymenoptera. Mangosteen pests belong to the order Hemiptera (3), Lepidoptera (3), and Hymenoptera (1). Passion fruit pests include 2 from Hemiptera, 1 from Lepidoptera, and 1 from Diptera. Minor exotic fruits have pests from Hemiptera (6), Lepidoptera (3), and Coleoptera (1).Spiders emerged as the predominant predators associated with the exotic fruit pests. Hymenopteran pollinators stood out as the most abundant contributors to pollination where stingless bee (T. travancorica) was the most abundant and frequent flower visitor of rambutan and carpenter bee (Xylocopa sp.) was the frequent visitor of passion fruit flowers. The pest incidence in rambutan showed a positive correlationItem Managerial efficiency of cashew growers in Kerala and Tamil Nadu: a comparative analysis(Department of Agricultural Extension Education, College of Agriculture, Vellayani, 2025) Mohamed Aseemudheen, M.; Esakkimuthu, MThe research work entitled “Managerial efficiency of cashew growers in Kerala and Tamil Nadu: A comparative analysis” conducted at the College of Agriculture, Vellayani, Thiruvananthapuram, Kerala during the academic year 2022-24. The study objectives are to assess managerial efficiency of cashew growers; perception of cashew growers on area expansion, replanting senile and unthrifty cashew plantations; extent of adoption of technological interventions in cashew cultivation; knowledge and attitude of cashew growers on product diversification and value addition. The study employed analytical research design and followed a multi-stage purposive sampling method for diverse representation in Kerala and Tamil Nadu. Kannur and Cuddalore, the top cashew-producing districts, were selected. In Kannur, 80 growers were chosen, 40 from Iritty block across Kacherikadavu (20) and Payam (20) Gram Panchayat and 40 from Peravoor block across Kelakam (20) and Kottiyoor Gram Panchayat (20). In Cuddalore, 80 growers were selected, 40 from Panruti block across Alagappasamuthiram (20) and Arasadikuppam (20) and 40 from Kammapuram block across Kotteri (20) and Muthanai (20). Data collection involved a pre-tested and structured interview schedule. It was analyzed using statistical techniques such as frequency, percentage, mean, standard deviation, quartile deviation, Rasch-Andrich analysis, t-test and correlation analysis. The socio-economic findings revealed notable differences between Kerala and Tamil Nadu cashew growers. In Kerala, 30.00% of respondents were in late adulthood, while Tamil Nadu had a more balanced age distribution with 28.75% in late adulthood and 27.50% in early adulthood. Male dominance was evident in both states, with 95.00% of growers in Kerala and 92.50% in Tamil Nadu being male. Kerala exhibited higher literacy with no illiteracy, while Tamil Nadu had broader educational diversity, including 7.50% illiteracy and more technical diploma holders (13.75%). Landholding patterns showed Kerala’s dominance of smallholders (62.50%), whereas Tamil Nadu had 36.25% marginal landholders and 11.25% leasing land. Kerala’s growers operated smaller plots (48.75%), while Tamil Nadu utilized more leased land (16.25%). Proficient farmers were more common in Kerala (27.50%), while Tamil Nadu had more advanced beginners (38.75%). Family sizes were larger in Kerala The managerial efficiency of cashew growers varied across eight components, reflecting regional strengths and weaknesses. In Kerala, 31.20% of farmers were efficient in planning and 33.80% were moderately efficient in decision-making, while organizing and coordinating posed challenges, with 36.20% and 41.30% being less efficient, respectively. Tamil Nadu growers performed better in organizing (33.75% highly efficient), budgeting (37.50% efficient) and marketing (31.25% highly efficient), supported by established processing industries and market integration. Kerala had 33.75% of growers categorized as efficient overall, while Tamil Nadu had 26.25% in the highly efficient category, indicating a need for region-specific interventions to enhance overall efficiency. Entrepreneurial ability among cashew growers was predominantly at a medium level, with 55.00% in Kerala and 57.50% in Tamil Nadu falling into this category. High entrepreneurial ability was observed in 23.75% of growers in Kerala and 22.50% in Tamil Nadu, while low ability was reported among 21.25% and 20.00% of growers, respectively. Perception of area expansion and replantation was medium for 57.50% of Kerala respondents and 61.25% in Tamil Nadu. Adoption of technological interventions showed a medium level in both states, though Tamil Nadu (18.75%) had higher adoption rates than Kerala (7.50%). Knowledge of product diversification and value addition was medium for 53.75% of Kerala growers and 62.50% of Tamil Nadu (76.25% with large families), contrasting with Tamil Nadu (60.00% small families). Annual income placed 40.00% of Kerala farmers in the lower-middle-income group, compared to 52.50% in Tamil Nadu. Training attendance was low in both states, with 93.75% of Kerala growers and 86.25% in Tamil Nadu participating minimally. Information-seeking behavior revealed Kerala’s reliance on family and acquaintances (46.56%) and Tamil Nadu’s greater use of social media (54.38%). Market intelligence was average for 73.75% of Kerala farmers, while Tamil Nadu had 38.75% with superior intelligence. Economic motivation was medium for most growers in both states, though Tamil Nadu had a higher proportion of highly motivated farmers (33.75%). Kerala farmers were more confident (42.50% very confident) and had higher achievement motivation (77.50% medium motivation) compared to Tamil Nadu. Major constraints included pest and disease infestations (100.00%) in both states. Kerala struggled with limited labour availability (97.50%) and market monopolies (92.50%), while Tamil Nadu faced climate variability (93.75%) and high input costs (87.50%). In both states, inadequate irrigation and insufficient infrastructure for value addition further hindered growers' ability to enhance productivity and profitability. Policy recommendations include youth engagement, infrastructure development, market intelligence and climate resilience. Future research could explore broader cashew-growing regions, evaluate policy effectiveness and investigate advanced practices in value addition, climate resilience and digital tools to enhance cashew cultivation sustainability. growers. Similarly, attitudes toward value addition were predominantly medium in both states.