1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Moisture stress mitigation in gladiolus (Gladiolus grandiflorus L.) using growth regulators(Department of Floriculture and Landscaping, College of Agriculture,Vellayani, 2026) Sreya, KThe investigation entitled ‘Moisture stress mitigation in gladiolus (Gladiolus grandiflorus L.) using growth regulators’ was conducted during 2024–2025 at the Department of Floriculture and Landscaping, College of Agriculture, Vellayani, to evaluate the impact of moisture stress and growth regulators on growth, flowering, yield, propagule production, physiological and biochemical responses, computed indices and postharvest quality in gladiolus. The experiment included the varieties Arka Amar, Arka Darshan and Arka Tilak under two moisture regimes and three growth regulator treatments; however, Arka Tilak was excluded after ten weeks due to corm rot. Overall, Arka Amar consistently outperformed Arka Darshan across most traits, and moisture stress at 75% FC reduced growth and quality, while melatonin effectively mitigated these reductions. Vegetative performance was highest in Arka Amar, with the maximum plant height of 114.63 cm recorded under 100% FC with melatonin, while Arka Darshan under stress without regulator registered the lowest height of 65.24 cm. Melatonin significantly increased shoot and root biomass, with the highest fresh and dry shoot weights (66.57 g and 43.69 g) and root weights (3.87 g fresh and 1.80 g dry) in Arka Amar under 100% FC, whereas the lowest values were recorded in Arka Darshan under stress without regulator. Flowering was advanced by melatonin and delayed by stress, with the earliest spike emergence and floret opening in Arka Amar × 100% FC × melatonin (85.37 and 96.17 days), while the maximum delay occurred in Arka Darshan × 75% FC × control (114.87 and 128.17 days). Spike quality traits were also superior in Arka Amar, with the longest spike length (97.05 cm), longest rachis (52.57 cm) and highest floret diameter (108.80 mm) under 100% FC with melatonin, whereas the poorest values were recorded in Arka Darshan under stress without regulator. Yield and propagule production showed similar trends. The highest spike weight (43.83 g) was obtained in Arka Amar under stress with melatonin and it was on par with 100% FC plus melatonin at 43.42 g, while Arka Darshan under stress control produced the 139 minimum at 22.85 g. Corm attributes were superior in Arka Amar and in melatonin-treated plants, with the largest corm diameter (4.77 cm) and maximum corm yield per plant (71.52 g) under Arka Amar × 100% FC × melatonin, whereas the lowest values were recorded in Arka Darshan × 75% FC × control. Melatonin also enhanced corm and cormel weights and sustained higher yields even under moisture stress. Postharvest quality followed the same pattern, with Arka Amar × 100% FC × melatonin achieving the longest vase life (10.50 days), highest water uptake (22.47 mL) and lowest physiological loss in weight (8.42 g). The poorest postharvest values were recorded in Arka Darshan × stress × control. Even under 75% FC, Arka Amar treated with melatonin produced flower quality comparable to well-watered plants. Physiological and biochemical analyses confirmed that melatonin improved photosynthetic activity, stomatal conductance, chlorophyll content and antioxidant enzyme activity while reducing electrolyte leakage. The best physiological performance occurred in Arka Amar × 100% FC × melatonin, which exhibited the highest photosynthesis, conductance and chlorophyll content, while the poorest functional status was seen in Arka Darshan × 75% FC × control. Stress-related biochemical markers such as proline, SOD, catalase and peroxidase increased under drought, with the strongest protective responses recorded in Arka Amar × stress × melatonin. Computed indices including leaf area index, water use efficiency and relative water content were also highest under melatonin, notably with a relative water content of 85 % in Arka Amar × 100% FC × melatonin, while the lowest value of 59.06 % occurred in Arka Darshan × stress × control. The study demonstrated that moisture stress adversely affects gladiolus growth, yield and quality. However, 100 μM melatonin and 0.3 mM brassinolide effectively alleviate these effects, with melatonin being superior. Arka Amar emerged as the most resilient and productive gladiolus variety under both optimal and water-limited conditions.Item Morphological characterisation and crop Management practices of cut foliage fern(Department of Floriculture and Landscaping, college of agriculture,Vellanikkara, 2026) Panchami. K P; Mini SankarFerns represent one of the most ancient and diverse groups of plants, valued for their ecological significance and ornamental beauty. These ferns have unique shapes, sizes, and textures, making them ideal for use in floral designs and urban landscaping. One of the major challenges in utilizing native ferns is the lack of detailed information about morphological traits and adaptability. Among different species of ferns, Rumohra adiantiformis G. Forst, commonly known as leather leaf fern, is the leading tropical foliage species with long, attractive fronds, and widely used in floral arrangements. Even though it is cultivated by farmers, the crop management practices are yet to be standardised. Hence, the current study was undertaken to evaluate different species of ferns for cut green and landscape uses and to standardize the crop management practices for leather leaf fern. In the first experiment, thirty fern genotypes were collected and evaluated for various quantitative and qualitative characters. Among quantitative characters, Nephrolepis exaltata cv. Fluffy ruffles exhibited the highest plant height (59.00 cm), Cristella dentata showed maximum spread (47.50 cm), Nephrolepis exaltata cv. Furcans showed maximum frond length (59.00 cm), Asplenium nidus exhibited maximum stipe girth (5.5 mm), frond production interval (155 days), and longevity of frond (255 days). The number of fronds per plant was found to be highest (45.5) with Nephrolepis cordifolia cv. Duffi, and the maximum (58.00) number of pinnae was observed in Nephrolepis exaltata cv. Tiger fern. Among qualitative traits, most of the genotypes exhibited the smooth texture except Adiantum hispidulum and Cristella dentata. Genotypes were also evaluated for other qualitative characters such as the shape of the frond, nature of the margin and tip of pinnae, markings on the foliage, and foliar colour. Most of the ferns evaluated were unbranched except for Adiantum sp. Based on the performance, the suitability of ferns for various landscape uses was identified. All the species evaluated were found to be suitable for the pot plant purpose. Species such as Nephrolepis cordifolia cv. Duffi and Anemia rotundifolia were found suitable for hanging baskets. Fern species such as Pteris parkerii and Doryopteris concolor were found suitable for indoor gardens due to their lush green foliage. A climbing fern, Lygodium flexuosum was suitable for trailing on walls and pergolas. Fern species such as Adiantum latifolium, Adiantum peruvianum, and Adiantum hispidulum were low-growing and had soft-textured fronds. These species were ideally suited for ground cover purposes. Nephrolepis exaltata cv. Fluffy ruffles, Nephrolepis exaltata cv. Furcans were found suitable for border plants in landscaping due to their tall growing nature. Species such as Rumohra adiantiformis G Forst., Davallia fijiensis, and Nephrolepis exaltata were well-suited as fillers in bouquets and flower arrangements due to attractive fronds and good postharvest life. The second experiment was conducted to standardize the spacing and nutrient doses for Rumohra adiantiformis G. Forst. The study was carried out by adopting three different spacing viz, 45 x 30 cm (S1), 45 x 45 cm (S2) and 60 x 45 cm (S3) and four fertilizer schedules viz., 80:40 N: K2O kg/ha/year (N1), 100:60 N: K2O kg/ha/year (N2), 120:80 N: K2O kg/ha/year (N3) and absolute control (N4). FYM @ 5t/ha and P2O5 @ 30 kg/ha and NPK 1:1:1 (19:19:19) at 0.4% (as foliar spray) were applied uniformly in all treatments except control. The results showed that spacing had significant influence on the vegetative characters and the spacing S1 (45 x 30 cm) was found superior in terms of plant height, frond length, stipe length, longevity of the frond, whereas the treatment S3 (60 x 45 cm) was outperformed in the parameters such as plant spread, number of fronds per plant, number of fronds per harvest, interval between two harvests throughout the experimental period. The nutrient dose N3 (120:80 N: K2O kg/ha/year) was found to have a significant impact on plant height, plant spread, number of fronds, frond length, stipe length, days taken for first harvest, number of fronds per harvest, and interval between two harvests. Regarding the interaction effect, the treatment combination of S1 x N3 (45x 30 cm spacing and nutrient dose of 120:80 N: K2O kg/ha/year) was found to be best for plant height, frond length, and stipe length. In case of plant spread and the number of fronds per plant, the treatment S3 x N3 (60 x 45 cm spacing and nutrient dose of 120:80 N: K2O kg/ha/year) was found to be best. Considering the parameters such as the length of the frond, stipe length, vase life, yield of fronds per hectare, cost of production, and net return, a combination spacing of 45 x 30 cm and the nutrient dose of 120:30:80 N: P2O5: K2O kg/ha/year along with FYM @ 5t/ha and NPK 1:1:1 (19:19:19) at 0.4% (as foliar spray) can be recommended for the cultivation of leather leaf fern. Findings of the study establish a clear baseline for selecting landscape-specific native fern genotypes and optimizing spacing and nutrient application for Rumohra adiantiformis G. Forst. to maximize yield and commercial viability.Item Micronutrients and biostimulants for crop management in marigold (Tagetes erecta L.)(Department of Floriculture and Landscaping, College of Agriculture, Vellanikkara, 2025) Aparna, M Rajeev; Resmi PaulInvestigations on “Micronutrients and biostimulants for crop management in marigold (Tagetes erecta L.)” was undertaken at the Department of Floriculture and Landscaping, College of Agriculture, Vellanikkara during 2024 to 2025. Objectives of the study were to evaluate the influence of micronutrients, biostimulants, and plant growth promoting rhizobacteria (PGPR) on the growth, yield, and quality attributes of African marigold. Studies were carried out in the hybrid Royal Orange. The experiment was laid out in a randomized block design comprising of ten treatments with three replications each, involving combined application of recommended dose of fertilizers (RDF), boron (1 kg ha⁻¹), varying concentrations of humic acid (1%, 3%, and 5%), salicylic acid (50, 100, and 150 ppm), and PGPR Mix I and II (2% and 5%). Treatments were applied through soil application, foliar spray, soil drenching, and root dipping at different growth stages of the plants. Vegetative, floral, and biochemical parameters of the plants and soil nutrient characteristics of the experimental plot were studied. Significant variations among treatments were observed for all the traits studied except for the shelf life of flowers. Among the treatments, application of 5% humic acid along with RDF and boron (T5) recorded significant improvement in plant height (46.25 cm), plant spread (29.29 cm), number of branches per plant (15.67), and leaf count (15.5 per branch). This treatment also resulted in the highest fresh (464 g and 64 g respectively) and dry (95 g and 29 g respectively) shoot and root biomass, indicating enhanced nutrient absorption and root development. The same treatment (T5) also advanced the onset of flowering, with the earliest bud emergence (31.67 days) and 50% flowering (31.83 days), while the control treatment (RDF alone) showed delayed flowering (41.08 days). Floral attributes such as number of flowers per plant (18.67), flower diameter (6.03 cm), individual flower weight (8.8 g), and flower yield per plant (159.93 g) were also maximized in T5 (RDF + boron + 5% humic acid), followed by treatments with RDF + boron + PGPR (T9 and T10) and RDF + boron + salicylic acid (150 ppm) (T8). The duration of flowering (71.08 days) and field life of flowers (7.58 days) were prolonged under T5 (RDF + boron + 5% humic acid), reflecting improved physiological activity. Biochemical analysis revealed that treatments consisting of RDF + boron + salicylic acid and RDF + boron + PGPR improved biochemical composition of leaves and flowers. The treatment with RDF + boron + 150 ppm salicylic acid (T8) exhibited highest chlorophyll a (1.313 mg g⁻¹ FW), chlorophyll b (1.295 mg g⁻¹ FW), and total chlorophyll (2.61 mg g⁻¹ FW), suggesting improved photosynthetic efficiency. PGPR Mix II (5%), along with RDF and boron (T10), significantly increased phenolic (21.78 mg GAE/g and 54.23 mg GAE/g respectively) and flavonoid (0.307 mg QE/g and 4.51 mg QE/g respectively) contents in leaves and flowers, and carotenoid content (0.051 mg/g FW) in flowers, indicating higher antioxidant potential and stress tolerance. Nutrient uptake studies indicated that plants which received RDF + boron + 5% humic acid (T5) exhibited superior uptake of nitrogen (3.04 g plant⁻¹), phosphorus (0.238 g plant⁻¹), iron (0.219 g plant⁻¹), and zinc (0.029 g plant⁻¹). Potassium uptake was not significantly correlated with yield, suggesting that other nutrients played a more decisive role in flower production. Soil analysis after harvest of flowers showed improved macronutrient and micronutrient availability in plots receiving RDF + boron + PGPR and RDF + boron + biostimulants. Correlation studies demonstrated that yield per plant had a significant positive association with key vegetative and floral traits such as plant spread, number of branches and flowers, flower diameter and weight, duration of flowering, and total chlorophyll content, while being negatively correlated with the number of days to bud emergence and 50% flowering. Similarly, flower yield showed significant positive correlations with the uptake of nitrogen, phosphorus, iron, manganese, zinc, and boron, underscoring the role of balanced nutrition in the enhancement of productivity. Combined use of micronutrients and biostimulants improved growth, yield and quality attributes of African marigold. Integrated application of RDF + boron + humic acid (5%) enhanced the overall growth, yield and floral characteristics of African marigold. The use of RDF + boron + salicylic acid proved beneficial in enhancing chlorophyll content, flower longevity, and stress resilience, whereas RDF + boron + PGPR combinations improved secondary metabolite accumulation, contributing to superior flower colour and quality. Combinations and concentrations of micronutrients and biostimulants along with RDF identified in the present study could be utilized in further investigations.Item Morphological and molecular characterization of nerium (Nerium oleander L.)(Department of Floriculture and Landscaping, College of Agriculture, Vellayani, 2025) Jisna Johnson; Reshmi, C RThe study entitled "Morphological and molecular characterization of nerium (Nerium oleander L.) genotypes" was conducted at the Department of Floriculture and Landscaping, College of Agriculture, Vellayani, Thiruvananthapuram, during the period 2022-2024. The primary objective was to evaluate the performance of fifteen nerium genotypes and to characterize them using morphological descriptors and molecular markers for assessing their genetic variability and diversity. Analysis of variance revealed significant differences among the genotypes for all morphological traits, including plant height, leaf blade length, and leaf blade width. Among the fifteen genotypes, twelve (T1, T2, T3, T4, T5, T6, T8, T9, T10, T11, T13 and T15) flowered during the experimental period. Floral characteristics, such as the number of flowers per plant at full flowering stage (i.e. two months after first flowering), flower diameter, corolla throat length, corolla throat diameter, corolline appendage length, and sepal length, also showed significant variations among the genotypes. Leaf blade width showed the highest phenotypic and genotypic coefficients of variation (PCV and GCV) among the plant traits, while the number of flowers per plant at the full flowering stage (i.e., two months after flower initiation) showed maximum variation among the floral traits. Heritability was high across all traits (69.6%–100%), with leaf blade length and single flower weight recording the maximum values. Notable genetic advance was observed, especially in the number of flowers per plant and corolla throat diameter. Traits with high heritability and genetic advance indicate strong genetic control, making them ideal for selection in breeding programmes. Correlation analysis revealed that flower diameter exhibited a significant positive genotypic correlation with plant height, length and width of leaf blade, corolla throat diameter, single flower weight, and shelf life. However, a negative correlation was observed between flower diameter and both the number of flowers per plant and overall flower yield. Additionally, plant height showed a significant 126 positive phenotypic correlation with flower diameter, corolla throat diameter, and single flower weight. Although flower diameter was negatively correlated with the number of flowers per plant, it displayed a strong positive correlation with plant height, corolla throat diameter, and single flower weight, making it a crucial trait for selecting loose flowers. Genetic diversity analysis using the ‘Average method’ and ‘Euclidean distance measures’ clustered the genotypes into four groups based on floral characteristics. The maximum inter-cluster distance was observed between cluster 3 and cluster 4, suggesting that hybridization between these clusters would be most effective. Scoring based on DUS guidelines revealed the highest score for genotype T13 and it was followed by T1 and T4. Molecular characterization of the fifteen genotypes was carried out using ten ISSR primers, all of which generated polymorphic bands. Among the 98 amplicons obtained, 81 exhibited polymorphism, whereas 17 were found to be monomorphic. Among the primers, UBC 826 yielded the highest number of alleles (14), while UBC 814 produced the fewest (3). The primer UBC 855 exhibited the highest polymorphic information content (PIC) value of 0.38, whereas UBC 814 showed the lowest PIC value of 0.15. Based on the cluster analysis of the molecular data, the genotypes were grouped into three distinct clusters: Cluster 1 consisting of seven genotypes (T1, T2, T4, T7, T8, T9, T12), Cluster 2 also containing seven (T3, T6, T10, T11, T13, T14, T15) and Cluster 3, comprising a single genotype (T5). Among the genotypes, T3 exhibited the highest yield of fragrant flowers, followed by T1, making them ideal for loose flower production and potential parental genotypes for breeding programmes. T5 was identified as a dwarf genotype, suitable for potted plant applications. Seasonal variations in flower production were observed across all the genotypes which flowered during the experimental period. These findings provide valuable insights into the morphological and genetic diversity of nerium genotypes, aiding in the selection of superior genotypes for floriculture and breeding purposes.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 Nutrient management for cut flower roses under rain shelter(Department of Floriculture and Landscaping, College of Agriculture, Vellanikkara, 2024-03-04) Apoorva, M N; Shajma Nafeesa BasheerRose (Rosa spp.) is the top-ranking and largest traded cut flower in the world and it is saluted as the queen of flowers due to its majestic fragrance brilliant colours, attractive shape, varying size, and excellent keeping quality. A balanced supply of nutrients ensures maximization of productivity and quality. Therefore, an efficient and judicious use of fertilizers along with micronutrient application is essential for attaining higher yield per unit area. However, a nutrient management schedule for roes under Kerala conditions is not yet standardized. Hence the present study entitled “Nutrient management for cut flower roses under rain shelter” was carried out in the Department of Floriculture and Landscaping, College of Horticulture, Vellanikkara during 2021-2023. The objective of the study was to assess of response of the rose variety Taj Mahal to different levels of NPK and foliar supplements for commercial production of cut roses in agro-climatic conditions of Kerala. The experiment consisted of 13 treatments, which included different combinations of 3 doses of fertilizers viz; 4:1.5:5 N: P2O5: K2O g/plant/year, 8:3:10 N: P2O5: K2O g/plant/year and 12:4.5:15 N: P2O5:K2O g/plant/year and three levels each of foliar supplements viz; BA 200 ppm, 2% seaweed extract, 0.5% Sampoorana KAU vegetable multimix and control (without fertilizers and FYM). Six months old grafts of the rose variety ‘Taj Mahal’ were used for the study. Observations on vegetative characters, floral characters, post-harvest aspects as well as nutrient status of the growing media and plant nutrient uptake were recorded. Throughout the observation period, different doses of fertilizers, foliar supplements, and the interactions between fertilizers and foliar supplements had a significant impact on vegetative characteristics. Among the fertilizer treatments, plant height was significantly highest in A3 (12: 4.5: 15 N: P2O5: K2O) (55.94 cm) at 10 MAP. Application of 0.5% Sampoorna (54.58 cm) and BA 200 ppm (53.02 cm) resulted in the highest plant height at 10 MAP. Application of fertilizers and foliar sprays significantly influenced plant spread. The fertilizer treatments A3 (12: 4.5: 15 N: P2O5: K2O) (27.95 cm) and A1 (4: 1.5: 5 N: P2O5: K2O) (26.96 cm) recorded the highest plant spread at 10 MAP. Among the foliar supplements, B4 (0.5% Sampoorna) (27.71 cm) and B2 (BA at 200 ppm) (27.54 cm) were superior compared to other treatments at 10 MAP. Different levels of fertilizer had no significant effect on the number of branches per plant throughout the experiment. The maximum number of branches were produced by B2 (BA 200 ppm) at 8 MAP (3.37) which was on par with B3 (2% seaweed extract) (3.1), and B4 (0.5% Sampoorna) (3.08). A3 (12: 4.5: 15 N: P2O5: K2O) produced more number of leaves per branch (8.2) which was on par with A2 (8:3:10 N: P2O5: K2O) (8.07) at 10 MAP. Among the foliar supplements, BA 200 ppm produced the maximum leaves per branch (8.34) which was on par with B3 (8.05) and B4 (8.03) during the same period. The treatment combination of A3 x B2 (12:4.5:15 N: P2O5: K2O and BA 200 ppm) was however found to record increased plant height, plant spread and number of leaves per branch throughout the observation period. A3 x B4 (12:4.5:15 N: P2O5:K2O and 0.5% Sampoorna) was found to be superior with regard to number of branches per plant. The floral characters were significantly influenced by different doses of fertilizers. Among the floral characters, the least number of days taken for flower bud initiation was recorded in A3 (12: 4.5: 15 N: P2O5: K2O) (21.95 days), and the least number days taken from bud initiation to commercial stage of harvest was in A3 (12: 4.5: 15 N: P2O5: K2O) (13.37 days) which was on par with A2 (8:3:10 N: P2O5: K2O) (13.69). The highest flower bud circumference was recorded in A3 (12: 4.5: 15 N: P2O5: K2O) (3.75 cm). The longest neck length was found in A3 (12: 4.5: 15 N: P2O5: K2O) (3.94 cm) which was on par with A2 (8:3:10 N: P2O5: K2O). The longest stalk length was recorded in A3 (12: 4.5: 15 N: P2O5: K2O) (28.16 cm). The highest neck girth (0.29 cm), and stalk girth (0.32 cm) were observed in fertilizer treatment A3 (12: 4.5: 15 N: P2O5: K2O) which was on par with A2 (8:3:10 N: P2O5: K2O) (0.29 and 0.32 cm respectively). However, the number of flowers per plant and the length of flower bud were not significantly influenced by the different doses of fertilizers. Foliar supplements also significantly influenced the floral characters. Among the floral characters, the least number of days taken for flower bud initiation (21.24 days), the least number of days taken from bud initiation to commercial stage of harvest (12.90 days), the maximum circumference of flower bud (3.67 cm), and the highest stalk length of flower (28.4 cm) was recorded in BA 200 ppm. The highest number of flowers per plant (40.38) and neck length (4.1 cm) was however recorded in 2% seaweed extract which was on par with BA 200 ppm. The length of flower bud was also the highest (1.8 cm) in 2% seaweed extract. In terms of days taken for flower bud initiation (20.67 days), days taken from bud initiation to commercial stage of harvest (12.45 days), flower bud circumference (3.96 cm), number of flowers per plant (40.53), neck length (4.33 cm), neck girth (0.31 cm), stalk length (32.36 cm) and stalk girth (0.33), the treatment combination of 12:4.5:15 N: P2O5: K2O and BA 200 ppm produced better results. The treatment combination of 8:3:10 N: P2O5: K2O and BA 200 ppm was observed to produce the maximum vase life and total water uptake (7.37 and 25.63 days respectively). The pH, EC, organic carbon, and available N, P, and K in the growing media were all analyzed both before and after the experiment. The pH in T9 (12: 4.5: 15 N: P2O5: K2O and 2% Seaweed extract) and T12 (8:3:10 N: P2O5: K2O and 0.5 % Sampoorna) was reduced after the experiment (5.18). T5 (8:3:10 N: P2O5: K2O and BA 200 ppm) and T7 (4: 1.5: 5 N: P2O5: K2O and 2% seaweed extract) (0.13 dS/m) had the lowest EC after the experiment. T6 (12:4.5:15 N: P2O5: K2O and BA 200 ppm) recorded the highest available K (872.04a kg/ha), and available P (590.93 kg/ha) whereas T12 (12:4.5:15 N: P2O5: K2O with 0.5% Sampoorna) recorded the highest available N (677.38 kg/ha). T1 (4:1.5:5 N: P2O5: K2O), T6 (12:4.5:15 N: P2O5: K2O and BA 200 ppm), and T12 (12:4.5:15 N: P2O5: K2O and 0.5% Sampoorna) resulted in higher plant nitrogen (1.88%), potassium (1.01%), and phosphorous (1.84%), contents respectively. T6 (12:4.5:15 N: P2O5: K2O and BA 200 ppm) treatment resulted in the highest plant uptake (N, P, and K) (0.73, 0.8, and 0.4 g/plant). From the results of the present study it can be concluded that the treatment combination A3 x B2 (12:4.5:15 N: P2O5: K2O and BA 200 ppm) of resulted in better plant height, plant spread, and number of leaves per branch, days taken for flower bud initiation, days taken from bud initiation to commercial stage of harvest, flower bud circumference, number of flowers per plant, neck length, neck girth, stalk length, stalk girth water uptake and vase life. Thus for commercial rose cultivation in Kerala under protected conditions, a combination of fertilizer dose of 12:4.5:15 N: P2O5:K2O g/plant/year as 3 split doses and BA 200 ppm application at fortnight intervals can be suggested.Item Characterization and compatibility studies in waterlily (Nymphaea spp.)(Department of Floriculture and Landscaping, College of Agriculture , Vellayani, 2024-02-27) Aiswarya, P; Sheena, AThe research programme entitled ‘Characterization and compatibility studies in waterlily (Nymphaea spp.)’ was carried out in the Department of Floriculture and Landscaping, College of Agriculture, Vellayani, Thiruvananthapuram during the period 2022-2023 to evaluate the performance of thirty waterlily varieties based on growth, flowering and floral attributes. Out of the thirty waterlily varieties, flowering was observed in 28 varieties viz., Micrantha, Chompu, Taweekan, Bull’s Eye, Hilary, Doris Holt, Carla Sonshine, Siam Jasmine, Wanvisa, Mexicana, King of Siam, Blue Whistle, Purple Joy, Dauben, Poonsub, Clyde Ikins, Virginalis, Peach Blow, Islamorada, Siam Pink, Supranee Pink, Jalueang Sub, Tropic Sunset, Miami Rose, Colorado, Almost Black, Paranee, Siam Amber, Perry’s Baby Red. The flower of Nymphaea exhibited strong protogyny, wherein they expressed stigma receptivity on the initial day, followed by the release of pollen on the subsequent two days. The analysis of variance revealed significant differences among the 21 genotypes for all the floral characters except for days to appearance of flower bud and days to flower opening. Significant varietal differences were observed among the thirty genotypes with respect to the vegetative characters. Among the vegetative characters, the highest PCV was recorded for number of leaves (30.04 per cent) and the lowest for the longevity of the leaf (16.59 per cent). The number of leaves exhibited the highest GCV (27.31 per cent) and the lowest for the number of days from visual observation to full expansion of leaf lamina (8.03 per cent). Maximum PCV and GCV were observed for number of leaves per plant (PCV 30.04% and GCV 27.31%) followed by length of lamina (PCV 20.71% and GCV 20.53%) and minimum PCV and GCV for longevity of leaves (16.59 and 8.36 per cent respectively). Among the floral characters, number of petals recorded the highest PCV (74.25%) and GCV (74.49%) followed by width of petal with PCV (27.42%) and GCV (27.61%). The minimum PCV and GCV were observed for the length of flower bud (7.14 per cent and 7.47 per cent). The genotypes were grouped into four clusters based on vegetative quantitative characters (length of lamina, width of lamina, number of leaves per plant, longevity of leaves, petiole diameter and number of days from visual appearance to full expansion of leaf lamina). Cluster 1 comprised of 13 genotypes, cluster 2 comprised of 15 genotypes, cluster 3 and 4 comprised of 1 genotype each. Maximum inter cluster distance with respect to vegetative characters was observed between C1 and C 3 which is 18.48 while minimum distance between C 2 and C 4 which is 7.94. The genotypes were grouped into five clusters based on floral quantitative characters (length of flower bud, flower diameter, length of sepal, breadth of sepal, number of petals, length of petal and breadth of petal). The Cluster 1 composed of 3 genotypes, cluster 2 composed of 5 genotypes, cluster 3 composed of 7 genotypes, cluster 4 composed of 4 genotypes and cluster 5 composed of 2 genotypes. Maximum inter cluster distance among the floral characters was observed between the clusters C2 and C3 which is 75.19 and minimum distance between C1 and C3 which is 7.36. The greater the distance between two clusters the greater is the divergence between genotypes belonging to the two clusters and vice versa. All the genotypes exhibited four consecutive days of anthesis. The anthesis timings of waterlily flowers were affected by environmental factors. Cloudy and rainy weather conditions led to delayed flower opening and early flower closing. Significant variations were observed in the number and length of stamens in all the varieties, except in King of Siam and Taweekan where stamen production was not observed. The majority of the studied pollen displayed a prolate spheroidal shape and fell within the medium-sized category. Highest pollen fertility was observed in the varieties Doris Holt (84%) followed by Peach Blow (73%), Hilary (68%), Micrantha (65%), and Bull’s Eye (48%) and these varieties were selected as the male parent for the compatibility study. Based on preliminary hybridization, maximum stigma receptivity was observed for the varieties Poonsub, Wanvisa, Siam Amber, Siam Jasmine and Blue Whistle and these varieties were selected as the female parent for the compatibility study. Maximum percentage of fruit set were observed when Siam Amber x Doris Holt (100%) followed by Poonsub x Micrantha (80%) and Poonsub x Wanvisa (80%). The fruit weight and seed size of Siam Amber x Doris Holt was larger compared to other varieties. The hybrid seeds took eight days for germination and they flowered in 25 to 29 days. The hybrid plants are in flowering, near flowering and pre flowering stages. Vegetative and floral characters of the hybrids that flowered when compared with their parents, revealed variations in the parameters studied. The hybrids obtained in the present study can be further assessed for floral attributes and selected for cultivationItem Integrated nutrient management for ornamentals in vertical garden(Department of Floriculture and Landscaping, College of Agriculture, Vellayani, 2024-04-20) Chanchal Gireesh, S; Priya Kumari,IThe research programme entitled ‘Integrated Nutrient Management for ornamentals in vertical garden was carried out in the Department of Floriculture and Landscaping, College of Agriculture, Vellayani, Thiruvananthapuram during the period 2022-2023 to evaluate the growing media components, biofertilizer, and foliar nutrient spray for improving growth of foliage ornamentals in vertical garden system This study comprises of two objectives the first objective is to standardise the growing media composition and biofertilizer in Nephrolepis cordifolia and the second objective is to standardize the foliar spray for ornmanetal foliage plants such as Chlorophytum comosum, Tradescantia fluminensis, Rheo discolor, Peperomia obtusifolia and Epipremnum aureum The first experiment was “ Standardization of growing media composition and biofertilizer”, laid out in Completely randaomized design with 15 treatments involving 5 different media such as M1-Control (soil + sand + FYM) (1:1:1), M2- (soil + rock sand + coirpith + vermicompost ) ( 1:0.5:0.5:1), M3- (soil+ rock sand + vermicompost )(1:1) + Hydrogel (25g), M4- (coirpith + vermiculite + perlite + vermicompost )(1:0.5:0.5:1) and M5 - (coirpith + newspaper bits + charcoal bits + vermicompost)(1:0.5:0.5:1) and three biofertilizers (B1 – Control (without biofertilizer), B2 – VAM (3g / container ) and B3 – PGPR-1(2g/ container ) for improving growth of foliage ornamental Nephrolepis cordifolia Notably, treatment combination M4B1 comprising coirpith, vermiculite, perlite and vermicompost in the ratio 1:0.5:0.5:1 and biofertilizer , B2 (VAM ) at 3g/ container, exhibited superior performance across various parameters such as plant spread, plant height, number of divisions, leaf number, leaf production interval, total biomass production, chlorophyll content and ornamental value index. Conversely, M3(soil: rocksand : vermicompost) (1:1 ) with the addition of Hydrogel (25 g) demonstrated the least favourable outcomes in terms of plant spread, number of leaves , leaf production interval , total biomass production and ornamental value index . In the second experiment, for “standardization of foliar spray for ornamentals”, the media which was standardized from the first experiment were taken and 5 foliage ornamentals were planted in the prescribed media and foliar fertilizers such as F1 – control – 19:19:19 (1%) @ 25ml/ plant at fortnightly intervals, F2- Complex fertilizer 19:19:19 (1%) monthly, F3 – Urea (1%) monthly and F4 – Complex fertilizer 30:10:10 (1%) monthly were studied Among the interaction effect, treatment combination F3P2 revealed significantly higher value for plant spread and plant height, whereas it was significantly lower in F1P5. For total biomass production and air pollution tolerance index F2P4 showed significantly higher values and it was lower for F4P4. For total chlorophyll content F1P4 was having significantly higher values and lower value was observed in F4P2. Among the various foliage plants studied Peperomia obtusifolia (Baby rubber plant) showed less tolerance to pollution plant spread, plant height and number of branches were found significantly higher for Tradescantia fluminensis (wandering jew) The study concludes that media comprising coirpith, vermiculite, perlite and vermicompost in the ratio (1:0.5:0.5:1) along with biofertilizer, VAM at 3g/ container, exhibited superior performance in Nephrolepis cordifolia under vertical garden system. The same media composition (coirpith, vermiculite, perlite and vermicompost in the ratio 1:0.5:0.5:1) along with monthly application of foliar fertilization of urea (1%) recorded better performance in growth of other foliage ornamental foliages such as Chlorophytum comosum, Tradescantia fluminensis, Rheo discolor, Peperomia obtusifolia and Epipremnum aureum under vertical garden systemItem In vitro clonal propagation of ornamental foliage Aglaonema commutatum Schott(Department of Floriculture and Landscaping, College of Agriculture,Vellayani, 2025) Aswathi, T P.; Priya Kumari, IThe study entitled "In vitro clonal propagation of ornamental foliage Aglaonema commutatum Schott." was conducted at the Department of Floriculture and Landscaping, College of Agriculture, Vellayani, Thiruvananthapuram, during the period 2024-2025. The primary objective was to standardize the in vitro clonal propagation protocol of two high-value Aglaonema cultivars. The study focused on the standardization of in vitro propagation protocols for two commercially important cultivars of Aglaonema commutatum ‘Silver Queen’ and ‘Red Star’, with special emphasis on surface sterilization, culture establishment, shoot multiplication, in vitro rooting, and ex vitro establishment. This study was conducted to address the critical need for a reliable micropropagation method to facilitate rapid and large-scale multiplication of elite Aglaonema cultivars. Nine different sterilization treatments involving varied concentrations (0.1%, 0.5%, 1.0%) and durations (5 or 10 minutes) of mercuric chloride (HgCl₂), with or without a 70% ethanol pre-treatment, were tested. Complete explant survival (1.00) was achieved in treatments such as, T2, T4, T5, T7, T8 and T9 (Mercuric chloride 1.0 % for 5 minutes, T1 + 70 % ethyl alcohol, T2 + 70 % ethyl alcohol, Mercuric chloride 0.5 % for 5 minutes + 70 % ethyl alcohol, Mercuric chloride 0.1% for 5 minutes + 70 % ethyl alcohol, Mercuric chloride 0.1 % for 5 minutes) for both cultivars, while treatments T3 and T6 (1.0% HgCl₂ for 10 minutes, T3 + 70 % ethyl alcohol) resulted in total mortality, indicating phytotoxicity at higher exposure. The most effective decontamination was observed in treatments T7, T8, and T9 (Mercuric chloride 0.5 % for 5 minutes + 70 % ethyl alcohol, Mercuric chloride 0.1% for 5 minutes + 70 % ethyl alcohol, Mercuric chloride 0.1 % for 5 minutes), each recording 100% contamination-free cultures. These results confirm that moderate to low HgCl₂ concentrations combined with ethanol pre-treatment effectively balance sterility and tissue viability. Among the 23 treatment combinations (T0-T22) tested, treatments T1 and T22 (BA 2.0 mgL-1, BA 4 mgL-1 + NAA 2 mgL-1) were superior, achieving 100% survival and the most rapid culture establishment across both cultivars. Notably, ‘Red Star’ responded quicker under TDZ treatments (e.g., TDZ 1.0 mgL-1, TDZ 1.0 mgL-1 + NAA 0.1 mgL-1), while ‘Silver Queen’ exhibited faster initiation in BA + NAA combinations (T22). Shoot initiation was significantly enhanced in treatments T1 and T22 BA 2.0 mgL-1,BA 4 mgL-1+ NAA 2 mgL-1), with T1 showing the highest shoot count per explant (3.00 in ‘Silver Queen’ and 2.67 in ‘Red Star’), as well as the earliest first leaf emergence. These results underscore the importance of cytokinin-auxin synergy (BA+NAA) for efficient shoot organogenesis. Early shoot emergence was observed under T16 (TDZ 2.0 mgL-1+ NAA 0.5 mgL-1 - 17.33 days in ‘Silver Queen’) and T14 (TDZ 1.0 mgL-1 + NAA 0.5 mgL-1- 21.67 days in ‘Red Star’). Shoot elongation was most pronounced in T9 and T10 (BA 4.0 mgL-1+ NAA 0.1 mgL-1, BA 4.0 mgL-1+ NAA 0.5 mgL-1) for ‘Silver Queen’, and T1 and T10 (BA 2.0 mgL-1, BA 4.0 mgL-1+ NAA 0.5 mgL-1) for ‘Red Star’, reflecting the favorable influence of hormonal balance in these treatments. Leaf formation remained limited, with T1 and T2 showing slight advantages across both cultivars. Root initiation varied significantly between treatments. T3 and T4 (IBA 2 mgL-1 and NAA 0.25 mgL-1) showed consistent and early rooting in both cultivars, with ‘Red Star’ demonstrating better rooting efficiency, producing up to 6 roots per explant and root lengths of 7.2 cm. In contrast, ‘Silver Queen’ exhibited fewer and shorter roots. Treatments T1, T7, and T9 (IBA 0.5 mgL-1, NAA 2 mgL-1, IAA 1 mgL-1) consistently failed to induce rooting, indicating suboptimal auxin conditions. Among the four substrates tested, vermiculite, perlite, sand, and LECA balls, vermiculite was the most effective for both survival and growth of plantlets. LECA balls failed, indicating their unsuitability for acclimatization. Though differences in ex vitro responses were not statistically significant, vermiculite provided the most promising environment for early plantlet establishment. This study successfully established an efficient, reproducible in vitro propagation protocol for Aglaonema commutatum cultivars ‘Silver Queen’ and ‘Red Star’. Treatment T8, T9 (Mercuric chloride 0.1% for 5 minutes + 70 % ethyl alcohol and Mercuric chloride 0.1 % for 5 minutes) for surface sterilization, T1 and T22 (T1 - BA 2.0 mgL-1 and T22 - BA 4 mgL-1+ NAA 2 mgL-1) for culture establishment, T1 (BA 2 mgL-1 + NAA 0.5 mgL-1) emerged as the most effective for shoot multiplication and organogenesis, while T3 and T4Item Niche modeling to predict suitable habitat for threatened and endangered potential ornamentals of lateritic hillocks of Kerala(Department of Floriculture and Landscaping, College of Agriculture, Vellanikkara, 2024-10-10) Soujanya Halagatti.; Sheron FernandezHillocks of Kerala are rich abodes of wide variety of flowering plants including grasses, herbaceous perennials, shrubs and trees. Many of these plants which were utilized in traditional medicine are either endangered or critically vulnerable due to human interventions. The habitat destruction is extremely fast and the loss of nearly 50% area has been observed during last decade. So, protection of this ecosystem and identifying suitable habitats where it could be introduced are very important. Mapping the geographical locations and predicting the potential distribution of a species is useful in identifying critical regions that may need conservation action. The study titled “Niche modeling to predict suitable habitat for threatened and endangered potential ornamentals of lateritic hillocks of Kerala” was conducted at the Department of Floriculture and Landscaping, College of Agriculture, Vellanikkara, Thrissur and at the Marine Biodiversity and Fishery Environment Management Division, Central Marine Fisheries Research Institute, Kochi, Kerala during the period from 2023-24, with an objective to identify the influencing bio-climatic variables and to predict the habitat distribution of threatened and endangered potential ornamentals of lateritic hillocks of Kerala using MaxEnt model. Frequency, Density, Importance Value Index (IVI), Shannon Diversity Index, Simpson Diversity Index and Pielous Evenness Index have been estimated for phytosociological assessment. The species which showed highest frequency were Spermacoce alata (Kumbla, Puranttukara and Puthige), Pogostemon quadrifolius (Pazhayangadi), Exacum bicolor (Periyaram, Vazhayur and Kannamvettikavu), Naregamia alata (Kudalmarkala, Neerchal, Dharmatadaka and Vazhayur), Eriocaulon sexangulare (Seethangoli), Curculigo orchiodes (Cheemeni and Kudalmarkala), Habenaria marginata (Thalakottukara and Chowwannur), Lepidogathes keralensis (Kumbla) and Habenaria diphylla (Thalakottukara, Puthige, Cheemeni). Frequency of species differed in different locations, which could be due to the high degree of dispersion of species, habitat preference for growth and evolutionary processes occurring naturally in these plants. Locations such as Thalakottukara (Thrissur), Seethangoli (Kasargod), Neerchal (Kasargod), Kannamvettikavu (Malappuram) had maximum density of herbaceous species of ornamentals because these locations had undistributed hillocks with minimum human activity and did not have forest cover. Importance value index (IVI) is used to determine the overall importance of each species in the community structure. Naregamia alata and Pogostemon quadrifolius had maximum IVI in majority of rocky hard lateritic hillocks in Malappuram and Kannur districts of Kerala. This could be due to their ability to withstand drought and extreme conditions. The highest Shannon Diversity Index and Simpson Diversity Index recorded for the location Kumbla (Kasargod) indicated that high species richness could be found in this region and the highest Pielous Evenness Index was recorded for Thalakottukara (Thrissur), indicating that all the species present in that habitat were more even. An attempt was made to study the current and future distribution of E. bicolor, H. diphylla, N. alata, P. quadrifolius, J. malabaricum and S. caryophyllatum using MaxEnt modeling. The extent of highly suitable habitat predicted by MaxEnt model for these mentioned species under current scenario was 1302 km2, 1525 km2, 1344 km2, 1738 km2, 3632 km2 and 835 km2 respectively. These species were primarily found in Thrissur, Kasargod, Kannur, Malappuram, Kozhikode and Palakkad districts of Kerala. The bioclimatic variables that contributed to the habitat modeling of different species were annual precipitation (Bio12), precipitation of the driest quarter (Bio17), mean diurnal range (Bio2), precipitation seasonality (Bio15), solar radiation (January, March, July and September) and water vapour pressure (January). Topographic variables that contributed to the model were elevation (Digital Elevation Model), Topographic Position Index (TPI), Terrain Ruggedness Index (TRI), slope and aspect. Along with bioclimatic and topographic variables, agroecological zones, soil types and Normalized Difference Vegetation Index (NDVI) had also contributed to the habitat model. Future predictions showed that under SSP370 and SSP585, the extent of high habitat suitability decreased by the period 2080-2100, and the districts such as Kannur, Malappuram, Thrissur and Kozhikode will become less suitable for the growth of E. bicolor, N. alata, H. diphylla, P. quadrifolius, J. malabaricum and S. caryophyllatum. The findings suggest that if climate continues to warm, species potential distribution areas could shrink by 2080-2100. This highlights the need for effective conservation strategies to protect plants with valuable medicinal and aesthetic properties from overexploitation and the impacts of climate change.
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