1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Influence of cold plasma and nano zinc oxide seed treatment on the growth development of seedless watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai](Department of Vegetable Science, College of Agriculture,Vellanikkara, 2025-11-02) Bhagya Prakash.Watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai] is one of the important crop belonging to the family Cucurbitaceae. Globally, it is considered as one of the most consumed cucurbit fruits. Triploid (seedless) watermelon has gained significant market share due to consumer preference, accounting for about 60 per cent of fresh cut and whole watermelon products in retail stores. The major problems with growing seedless watermelons are poor, inconsistent germination and the high seed cost. Triploid watermelon, like its tetraploid parent, has a hard and thick seed coat, which could serve as a physical barrier to radicle protrusion and contribute to seedcoat adherence to the cotyledons after emergence. Cold plasma (CP) treatment of seeds is a new approach that is being proposed to improve the germination and survival of seedlings. Plasma, the fourth state of matter, is a partially or fully ionized gas consisting of neutral and excited atoms, free radicals, negative and positive ions and UV photons. It increases water permeability through surface coat etching and stimulation of seed germination and seedling growth. Similarly, seed treatment with nanoparticles is an emerging technology which positively influences the seed metabolism and signaling pathways. Seed treatment with nano zinc oxide (nZnO) effectively improves seed germination, seedling vigour, yield and quality of the crop. Due to their plant growth-enhancing properties, nZnO has emerged as the most widely produced, utilised and studied nano zinc formulations in recent years. In this study, the optimum voltage and treatment time for two methods of CP exposure (direct CP and seed-in-water CP) were standardised. With respect to characteristics like germination percentage, germination velocity index, length of shoot and root, fresh and dry weight of shoot and root, seedling vigour index 1 and 2, direct CP at 20 kV for 30 min and seed-in-water CP at 25 kV for 15 min were positively influenced. Among these two methods, direct CP was found to be superior, hence this method was followed for further experiments. Seed treatment with nZnO at 20 ppm exhibited the highest germination percentage, germination velocity index, shoot and root length, fresh weight of shoot and root, dry weight of shoot and root, seedling vigour index 1and 2. The individual seed treatments with CP and nZnO were compared with their combination treatment (CP+nZnO) to ascertain any complementary effect. However, the individual CP treatment was found to be superior to combination and nZnO seed treatment with respect to seedling growth characteristics like shoot and root length, fresh weight of shoot and root, dry weight of shoot and root. The same treatment showed an increase in the biochemical characteristics of the seedlings like chlorophyll a and b, carotenoid content, catalase content, DPPH free radical scavenging activity, peroxidase content and phenol content. In the field evaluation, the plants raised from CP treated seeds showed greater vigour and earliness of the crop which was evident from the observations, viz. more number of primary branches, highest internodal length, lowest nodal position for first female flower, less number of days for first female flower opening and for first harvest. The growth characters like number of primary branches, internodal length, days to first female flower opening and node number of the first female flower of the plants under CP+nZnO treatment were found to be on par with CP treatment. The fruits of plants raised from CP treated seeds were harvested 58.3 days after pollination as well as enhanced the yield and quality attributes like TSS, lycopene, beta carotene, citrulline content, potassium and sodium content compared to the untreated control plants. The mode of action of CP is by increasing the porosity of the seeds by creating micropores and channels on the seed surface which was confirmed by scanning electron microscopy (SEM) imaging. The present study provides insights into an innovative method of seed treatment by exposing the seeds to CP resulting in enhanced seed germination, growth, yield and quality in triploid watermelons. The study also explores the effects of nZnO and the combined effect of CP and nZnO on seed germination and plant growth. Upon evaluating the morphological and biochemical traits of the seedlings, it was found that seeds treated with CP were better than those treated with nZnO alone or in combination with CP. Hence CP treatment could be used as a viable technique in alleviating the low germination problem in seedless watermelon, which is a major bottleneck in seedless watermelon cultivation as well as improving the yield and quality.Item Influence of Piriformospora indica on the growth, yield and quality of watermelon (Citrullus lanatus (Thunb.) Mastum. & Nakai)(Department of Vegetable Science, College of Agriculture, Vellanikkara, 2023) Aparna Kaladhar; Sangeeta Kutty, MPiriformospora indica is a novel, and adaptable root endophyte which colonizes a wide range of plant species. The colonisation of P. indica in the roots results in improved plant performance including seed germination, seedling development, early blooming, improved fruiting, increase in secondary metabolites as well as resistance to biotic and abiotic stress. Watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) is one of the most important crops coming under the family Cucurbitaceae. It is rich in vitamins and minerals, nutritional components and other polyphenolic components. About 93 per cent of the fruit contains water. However, there is no report on the association of P. indica with watermelon. Considering the several benefits of the fungus for crop production, the present investigation entitled “Influence of Piriformospora indica on the growth, yield and quality of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) was conducted out at the Department of Vegetable Science, College of Agriculture, Kerala Agricultural University, Vellanikkara, during December-April 2020-2021. Four different watermelon varieties viz., Swarna, Shonima, Sugarbaby, and Durgapur Lal were used in the experiment, both with and without P. indica colonisation. It was conducted as two experiments (Influence of P. indica on seed germination and seedling growth and Influence of P. indica on yield and quality of watermelon). Analysis variance revealed significant differences among most of the characters studied. In the evaluation of the influence of P. indica on seed germination and seedling growth, except days taken to germination and germination percentage all the other parameters like root length, shoot length, fresh and dry weight of root and shoot and phytohormones were highly variable with respect to P. indica colonisation. P. indica colonized Swarna and Shonima possessed the longest shoot and root (10.63 and 19.53 cm respectively). P. indica colonized Shonima had the heaviest fresh root weight (0.12 g) and the highest dried root weight (0.007g) whereas fungal inoculated Sugarbaby had the highest fresh and dry shoot weights (0.96 g and 0.06 g, respectively). The presence of chlamydospores in the stained root bits after 10 days of germination interpreted the presence of fungus which was absent in the non-colonized plants. P. indica colonized Shonima had the greatest levels of auxin and Gibberellic acid (22.53 µg /g and 0.19 µg /g, respectively). Similarly, the effect of colonisation was highly significant with respect to days to the first female flower, the node number of the first female flower, the number of flowers, the number of fruits per plant, average fruit weight, fruit girth, rind thickness, no of seeds per fruit, yield per plant, TSS, lycopene, beta carotene, citrulline and pest and diseases. P. indica colonized Durgapur Lal took the fewest days to first female flower (24.46). P. indica colonized Swarna (5.26) was the earliest in the node number of the first female flower. The highest number of fruits was observed in P. indica colonized Shonima (6.40) whereas the highest yield per plant (10.33 kg), TSS (11.770 B) and the number of seeds (862.33) were seen in P. indica colonized Sugarbaby. Lycopene and beta carotene were highest in P. indica-colonized Shonima (5.43 mg/g and 0.65 mg/g respectively). Citrulline content was higher in P. indica colonized Swarna (2266.00 ppm). Under field conditions, P. indica colonisation reduced the prevalence and severity of pests and diseases. Moreover, it showed a marked decline in the severity of the Bud necrosis virus and the least affected was the P. indica colonized plants (33.33%). It also reduced some physiological disorders like white heart. Correlation analysis revealed that the shoot length of plants indicated a significant and positive correlation for auxin (0.56). The number of female flowers exhibited a significant positive correlation with Gibberellic acid (0.81). The percentage disease index displayed a profound and significant negative correlation with yield per plant (-0.80). The number of seeds of seeded varieties had a strong positive correlation (0.94) with fruit girth. Thus, the present study reveals that P. indica is most effective for promoting the growth, yield and quality parameters of watermelon. The study also revealed that the fungus is very efficient in managing pests and diseases. Hence there is a vast scope for further improvement of watermelon through P. indica inoculation.Item Influence of Piriformospora indica on the growth, yield and quality of watermelon (Citrullus lanatus (Thunb.) Mastum. & Nakai)(Department of Vegetable Science, College of Agriculture , Vellanikkara, 2023) Aparna Kaladhar.; Sangeeta Kutty, M; Dhanya M KPiriformospora indica is a novel, and adaptable root endophyte which colonizes a wide range of plant species. The colonisation of P. indica in the roots results in improved plant performance including seed germination, seedling development, early blooming, improved fruiting, increase in secondary metabolites as well as resistance to biotic and abiotic stress. Watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) is one of the most important crops coming under the family Cucurbitaceae. It is rich in vitamins and minerals, nutritional components and other polyphenolic components. About 93 per cent of the fruit contains water. However, there is no report on the association of P. indica with watermelon. Considering the several benefits of the fungus for crop production, the present investigation entitled “Influence of Piriformospora indica on the growth, yield and quality of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) was conducted out at the Department of Vegetable Science, College of Agriculture, Kerala Agricultural University, Vellanikkara, during December-April 2020-2021. Four different watermelon varieties viz., Swarna, Shonima, Sugarbaby, and Durgapur Lal were used in the experiment, both with and without P. indica - colonisation. It was conducted as two experiments (Influence of P. indica on seed germination and seedling growth and Influence of P. indica on yield and quality of watermelon). Analysis variance revealed significant differences among most of the characters studied. In the evaluation of the influence of P. indica on seed germination and seedling growth, except days taken to germination and germination percentage all the other parameters like root length, shoot length, fresh and dry weight of root and shoot and phytohormones were highly variable with respect to P. indica colonisation. P. indicacolonized Swarna and Shonima possessed the longest shoot and root (10.63 and 19.53 cm respectively). P. indica colonized Shonima had the heaviest fresh root weight (0.12 g) and the highest dried root weight (0.007g) whereas fungal inoculated Sugarbaby had the highest fresh and dry shoot weights (0.96 g and 0.06 g, respectively). The presence of chlamydospores in the stained root bits after 10 days of germination interpreted the presence of fungus which was absent in the non-colonized plants. P. indica colonized Shonima had the greatest levels of auxin and Gibberellic acid (22.53 µg /g and 0.19 µg /g, respectively). Similarly, the effect of colonisation was highly significant with respect to days to the first female flower, the node number of the first female flower, the number of flowers, the number of fruits per plant, average fruit weight, fruit girth, rind thickness, no of seeds per fruit, yield per plant, TSS, lycopene, beta carotene, citrulline and pest and diseases. P. indica colonized Durgapur Lal took the fewest days to first female flower (24.46). P. indica colonized Swarna (5.26) was the earliest in the node number of the first female flower. The highest number of fruits was observed in P. indicacolonized Shonima (6.40) whereas the highest yield per plant (10.33 kg), TSS (11.770 B) and the number of seeds (862.33) were seen in P. indica colonized Sugarbaby. Lycopene and beta carotene were highest in P. indica-colonized Shonima (5.43 mg/g and 0.65 mg/g respectively). Citrulline content was higher in P. indica colonized Swarna (2266.00 ppm). Under field conditions, P. indica colonisation reduced the prevalence and severity of pests and diseases. Moreover, it showed a marked decline in the severity of the Bud necrosis virus and the least affected was the P. indica colonized plants (33.33%). It also reduced some physiological disorders like white heart. Correlation analysis revealed that the shoot length of plants indicated a significant and positive correlation for auxin (0.56). The number of female flowers exhibited a significant positive correlation with Gibberellic acid (0.81). The percentage disease index displayed a profound and significant negative correlation with yield per plant (-0.80). The number of seeds of seeded varieties had a strong positive correlation (0.94) with fruit girth. Thus, the present study reveals that P. indica is most effective for promoting the growth, yield and quality parameters of watermelon. The study also revealed that the fungus is very efficient in managing pests and diseases. Hence there is a vast scope for further improvement of watermelon through P. indica inoculation. List(s) this item appears inItem Standardisation of fertigation and evaluation of chitosan as a bio stimulant on the biochemical and morphological traits of seedless watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai](Department of Vegetable Science, College of Agriculture, Vellanikkara, 2023-03-13) Jayalakshmi, T; Aswini, AWatermelon [Citrullus lanatus (Thunb.) Matsum and Nakai] is a popular dessert vegetable of the Cucurbitaceae family. Even though the demand for fruit is very high, watermelon production confines to a limited area of 100 hectares with a production of 840 metric tonnes in Kerala. Precision farming is gaining importance in vegetable production and fertigation is an integral part of it. Watermelon responds well to fertigation in terms of growth and yield enhancement at different stages of crop like establishment phase, vegetative phase, flower initiation and at the time of harvesting. Erratic rainfall is the main limiting factor for watermelon cultivation in southern Kerala. Chitosan as a bio stimulant has a potential role in improving yield, quality, biotic and abiotic stress resistance of agricultural crops which can be exploited in the production of watermelon also. Researchers reported that bio stimulant effect of chitosan on plants was not much clear and it might be due to the increased photosynthetic rate by its application. Hence the present study was undertaken with an objective to standardise fertigation and to evaluate the effect of chitosan on biochemical and morphological characters of triploid seedless watermelon hybrid, Shonima from December 2021 to March 2022 at the Department of Vegetable Science. The experiment was conducted in split plot design with four levels of fertigation (50 % RDF, 75 % RDF, 100 % RDF and 125 % RDF) in main plots and three chitosan concentrations as foliar application (0.1 %, 0.2 % and 0.3 %) in subplots. Control was maintained with a level of fertilizer application @ 70: 25: 25 kg NPK/ha (KAU POP) and without any foliar application of chitosan. Fertigation was scheduled at three days interval and foliar application of chitosan was done at the pre flowering and fruit setting stages. Weather parameters like maximum temperature, minimum temperature, relative humidity and rainfall were recorded. As the crop duration during the summer season was shortened from 120 days to 90 days, only 25 splits of fertigation (6, 12, 7 during establishment, vegetative and fruiting stages respectively) were completed out of 40 (6, 12, 22 during establishment, vegetative and fruiting stages respectively). Fertigation doses given were 21.87: 15.62: 37.5 kg NPK/ha (50% RDF), 32.81: 23.44: 56.25 kg NPK/ha (75 % RDF), 43.75: 31.25: 75 kg NPK/ha (100% RDF) and 54.68: 39.06: 93.75 kg NPK/ha (125 % RDF). Fertigation levels significantly influenced vegetative and floral characters of watermelon. Longest vine length (3.87m) was recorded by 125% RDF. Male flower anthesis (24.39 days) was found to be early in 50 % RDF. Fruit and yield characters along with quality parameters were significantly influenced by fertigation doses. 100% RDF recorded maximum equatorial diameter (16.90 cm), polar diameter (17.55 cm), fruits/plant (4.52), average fruit weight (1.61 kg), yield/plant (5.97 kg/plant) and lycopene content (5.76 mg/100g). Maximum TSS (8.64°Brix) was recorded in 75 % RDF and maximum total sugar (5.38%) in 50 % RDF which was on par with 75 % and 100 % RDF. Chitosan concentrations influenced fruit, yield and quality parameters of watermelon. Foliar application of 0.1 % chitosan recorded maximum fruit equatorial diameter (16.76 cm), polar diameter (17.43 cm), fruits/plant (4.25), average fruit weight (1.94 kg), yield/plant (6.23 kg/plant), TSS (8.87 °Brix), lycopene content (4.96 mg/100g), reducing sugar (3.54 %) and total sugar content (5.38 %). 50% RDF recorded lowest rind thickness (1.17 cm). Interaction effect of fertigation doses and chitosan concentrations on fruit and yield characters and quality parameters was found to be significant. Treatment combination of 100 % RDF + 0.1 % chitosan spray recorded maximum equatorial diameter (18.08 cm), polar diameter (18.87 cm), average fruit weight (2.38 kg), yield/plant (8.06 kg/plant) and lycopene content (6.72 mg/100g). Maximum TSS (9.46 °Brix) and reducing sugar (3.98 %) was recorded by 75 % RDF + 0.1 % chitosan spray. Maximum total sugar content (5.67 %) was observed by 50 % RDF + 0.1 % chitosan spray. BC ratio (2.01) was found to be maximum with 100 % RDF + 0.1 % chitosan. Soil nutrient status was increased after the crop duration. Vulnerability index of watermelon bud necrosis virus, percentage disease index (PDI) of fusarium wilt and gummy stem blight reduced after foliar application of chitosan. The crop duration was reduced during the summer season hence, the recommended dose of fertigation for Shonima (90 days duration) was 43.75: 31.25: 75 kg NPK/ha. The recommended chitosan concentration was 0.1 % and treatment combination 100 % RDF + 0.1 % chitosan was found to the best for yield and quality parameters of watermelon. Fertigation enhanced the nutrient uptake thereby improved the growth, yield and quality of watermelon. Chitosan having potential role in biotic stress tolerance by regulating the jasmonic acid responsible for this by generating hydrogen peroxide. Enhanced yield and quality of fruits with foliar application of chitosan could be studied further with reference to physiological aspects like photosynthetic rate, stomatal conductance, transpiration rate etc. Biochemical and morphological traits of seedless watermelon was improved with influence of fertigation and foliar application of chitosan compared to conventional method of fertilizer application without any foliar spray of chitosan.Item Standardization of agrotechniques for vertically trained watermelon [Citrullus lanatus (Thunb.)Matsum. & Nakai](Department of Vegetable Science, College of Agriculture ,Vellayani, 2023-05-30) Naveda Murthy; Nisha, S KThe experiment entitled “Standardization of agrotechniques for vertically trained watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] under rain shelter” was carried out at Department of Vegetable Science, College of Agriculture, Vellayani, Kerala, during the period 2021-2022, to study the effects of spacing, training and pruning on yield and quality of watermelon hybrid ‘Saraswati’ under rain shelter. The treatments were factorial combinations of three planting densities viz., D1- 1.5 m × 0.6 m, D2- 1.5 m × 0.45 m and D3-1.5 m × 0.3 m; two training levels viz., T1– nipping into single vine and T2– nipping into double vine) and two pruning heights viz., P1- pruned at 2 m and P2- unpruned) arranged in randomized block design with two replications and control with horizontal training of vines in open condition. Planting densities significantly influenced all growth parameters while training affected only flowering characters and number of leaves. Plants at wider spacing, D1 recorded longest vine (3.84 m), earliest flowering (15.56 for male flower and 22.41 for female flower), lowest node of flowering (4.68 for male flowers and 13.64 for female flowers), highest number of leaves (14.21 at 20 DAT and 34.63 at 45 DAT), highest chlorophyll content (1.69 mg 100 g-1 at 20 DAT and 2.93 mg 100 g-1at 45 DAT) and highest dry matter production at harvest (29.15 g). Highest leaf area per plant (2211.50 cm2 at 20 DAT and 2266.02 cm2 at 45 DAT) and longest internodes (7.84 cm) were recorded in closer spacing, D3. The chlorophyll content was found to be higher in open condition (3.00 mg 100 g-1) than under rain shelter. All yield parameters other than rind thickness, fruits per plant and seed characters were significantly influenced by spacing. Plants at wider spacing recorded highest value for fruit equatorial diameter (15.15 cm), fruit polar diameter (18.90 cm), fruit weight (2.84 kg), yield per plant (5.50 kg), harvest 86 index (0.79) and longest crop duration (102.62 days). Medium spacing noted least days to first harvest (46.84 days). Closer spacing, D3 had fruits at lower nodes (15.31) and recorded highest values for yield per plot (78.37 kg). Training to single vine recorded earliest flowering (16.79 days for male flower and 23.14 days for female flower) and lowest node of flowering (5.36 for male flowers and 14.36 for female flowers). Training to two vine noted highest number of leaves (13.37 at 20 DAT and 34.43 at 45 DAT) and highest dry matter production at harvest (28.14 g). Plants trained to single vine produced fruits with highest fruit weight (2.84 kg) and longest polar diameter (18.17 cm). However, plants trained to double vine recorded highest number of fruits (2.56), yield per plant (5.28 kg), yield per plot (72.32 kg) and harvest index (0.79). Pruning had significant influence on vine length, days to flowering and number of leaves at 45 DAT. Unpruned plants recorded longest vine (5.00 m), higher number of leaves at 45 DAT (32.98) and highest dry matter production (27.88 g). Pruned plants noted earliest flowering (16.88 days for male flower and 23.24 days for female flower). Pruned pants recorded highest value for fruit polar diameter (18.39 cm) and fruit weight (2.56 kg) while unpruned plants had highest number of fruits per plant (2.26), yield per plant (3.03 kg), yield per plot (69.47 kg) harvest index (0.74) and longest crop duration (115.38). Seeds per fruit and weight of 100 seeds were not significantly influenced by any of the treatments. Among treatment interactions, D×T significantly influenced chlorophyll content at 45 DAT, leaf area index, days to first harvest, number of fruits per plant, fruit weight and dry matter production at harvest. D×P combinations had significant effect on vine length, fruit polar diameter chlorophyll content at 45 DAT, days to first harvest, number of fruits per plant, fruit weight, yield per plant, yield per plot and harvest index. Interaction of P×T and D×T×P influenced chlorophyll content at 87 45 DAT, number of fruits per plant, yield per plant, yield per plot and harvest index. On analysis of economic parameters, highest net returns (Rs. 10,06,729) and B:C ratio (3.02: 1.00) were recorded in double vine unpruned plants at closer spacing (D3) under rain shelter. The study revealed growing watermelon vertically trained watermelon at 1.5 m × 0.3 m resulted in highest yield per unit area (78.37 kg) and B:C ratio (3.02: 1.00). Unpruned plants trained as two vines recorded highest number of fruits per plant, yield per plant, yield per plot and harvest index. So, the present study suggests cultivation of vertically trained watermelon under rain shelter as double vine at closer spacing without pruning the main vineItem Standardisation of fertigation and evaluation of chitosan as a bio stimulant on the biochemical and morphological traits of seedless watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai](Department of Vegetable Science, College of Agriculture , Vellanikkara, 2023-03-13) Jayalakshmi, T; Aswini, AWatermelon [Citrullus lanatus (Thunb.) Matsum and Nakai] is a popular dessert vegetable of the Cucurbitaceae family. Even though the demand for fruit is very high, watermelon production confines to a limited area of 100 hectares with a production of 840 metric tonnes in Kerala. Precision farming is gaining importance in vegetable production and fertigation is an integral part of it. Watermelon responds well to fertigation in terms of growth and yield enhancement at different stages of crop like establishment phase, vegetative phase, flower initiation and at the time of harvesting. Erratic rainfall is the main limiting factor for watermelon cultivation in southern Kerala. Chitosan as a bio stimulant has a potential role in improving yield, quality, biotic and abiotic stress resistance of agricultural crops which can be exploited in the production of watermelon also. Researchers reported that bio stimulant effect of chitosan on plants was not much clear and it might be due to the increased photosynthetic rate by its application. Hence the present study was undertaken with an objective to standardise fertigation and to evaluate the effect of chitosan on biochemical and morphological characters of triploid seedless watermelon hybrid, Shonima from December 2021 to March 2022 at the Department of Vegetable Science. The experiment was conducted in split plot design with four levels of fertigation (50 % RDF, 75 % RDF, 100 % RDF and 125 % RDF) in main plots and three chitosan concentrations as foliar application (0.1 %, 0.2 % and 0.3 %) in subplots. Control was maintained with a level of fertilizer application @ 70: 25: 25 kg NPK/ha (KAU POP) and without any foliar application of chitosan. Fertigation was scheduled at three days interval and foliar application of chitosan was done at the pre flowering and fruit setting stages. Weather parameters like maximum temperature, minimum temperature, relative humidity and rainfall were recorded. As the crop duration during the summer season was shortened from 120 days to 90 days, only 25 splits of fertigation (6, 12, 7 during establishment, vegetative and fruiting stages respectively) were completed out of 40 (6, 12, 22 during establishment, vegetative and fruiting stages respectively). Fertigation doses given were 21.87: 15.62: 37.5 kg NPK/ha (50% RDF), 32.81: 23.44: 56.25 kg NPK/ha (75 % RDF), 43.75: 31.25: 75 kg NPK/ha (100% RDF) and 54.68: 39.06: 93.75 kg NPK/ha (125 % RDF). Fertigation levels significantly influenced vegetative and floral characters of watermelon. Longest vine length (3.87m) was recorded by 125% RDF. Male flower anthesis (24.39 days) was found to be early in 50 % RDF. Fruit and yield characters along with quality parameters were significantly influenced by fertigation doses. 100% RDF recorded maximum equatorial diameter (16.90 cm), polar diameter (17.55 cm), fruits/plant (4.52), average fruit weight (1.61 kg), yield/plant (5.97 kg/plant) and lycopene content (5.76 mg/100g). Maximum TSS (8.64°Brix) was recorded in 75 % RDF and maximum total sugar (5.38%) in 50 % RDF which was on par with 75 % and 100 % RDF. Chitosan concentrations influenced fruit, yield and quality parameters of watermelon. Foliar application of 0.1 % chitosan recorded maximum fruit equatorial diameter (16.76 cm), polar diameter (17.43 cm), fruits/plant (4.25), average fruit weight (1.94 kg), yield/plant (6.23 kg/plant), TSS (8.87 °Brix), lycopene content (4.96 mg/100g), reducing sugar (3.54 %) and total sugar content (5.38 %). 50% RDF recorded lowest rind thickness (1.17 cm). Interaction effect of fertigation doses and chitosan concentrations on fruit and yield characters and quality parameters was found to be significant. Treatment combination of 100 % RDF + 0.1 % chitosan spray recorded maximum equatorial diameter (18.08 cm), polar diameter (18.87 cm), average fruit weight (2.38 kg), yield/plant (8.06 kg/plant) and lycopene content (6.72 mg/100g). Maximum TSS (9.46 °Brix) and reducing sugar (3.98 %) was recorded by 75 % RDF + 0.1 % chitosan spray. Maximum total sugar content (5.67 %) was observed by 50 % RDF + 0.1 % chitosan spray. BC ratio (2.01) was found to be maximum with 100 % RDF + 0.1 % chitosan. Soil nutrient status was increased after the crop duration. Vulnerability index of watermelon bud necrosis virus, percentage disease index (PDI) of fusarium wilt and gummy stem blight reduced after foliar application of chitosan. The crop duration was reduced during the summer season hence, the recommended dose of fertigation for Shonima (90 days duration) was 43.75: 31.25: 75 kg NPK/ha. The recommended chitosan concentration was 0.1 % and treatment combination 100 % RDF + 0.1 % chitosan was found to the best for yield and quality parameters of watermelon. Fertigation enhanced the nutrient uptake thereby improved the growth, yield and quality of watermelon. Chitosan having potential role in biotic stress tolerance by regulating the jasmonic acid responsible for this by generating hydrogen peroxide. Enhanced yield and quality of fruits with foliar application of chitosan could be studied further with reference to physiological aspects like photosynthetic rate, stomatal conductance, transpiration rate etc. Biochemical and morphological traits of seedless watermelon was improved with influence of fertigation and foliar application of chitosan compared to conventional method of fertilizer application without any foliar spray of chitosan.Item Evaluation of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] genotypes for growth, yield and quality(Department of Vegetable Science, College of Agriculture, Vellayani, 2021) Pavithra, M O; Nisha, S KThe present investigation entitled “Evaluation of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] genotypes for growth, yield and quality” was carried out at the Department of Vegetable science, College of Agriculture, Vellayani from December 2020 to April 2021 to evaluate the performance of watermelon genotypes for growth, yield and quality. The experimental material consisted of 30 watermelon genotypes, including seventeen hybrids and thirteen varieties. Saraswati, the best performing hybrid and Sugar Baby the best performing variety from the previous research work conducted at Department of Vegetable Science was used as standard check for hybrids and varieties respectively. The experiment was laid out in RBD with two replications. Analysis of variance revealed significant difference among the seventeen hybrids and the thirteen varieties for all the characters studied. Among hybrids and check, the longest vine length was observed in Swarna (5.99 m) and the shortest in Jannat (2.84 m). The hybrid Prachi produced highest number of branches per vine (16.84). The highest internodal length was recorded in Jannat (12.95 cm). Jannat was the earliest to first male and female flower production (31.40 DAS and 37.70 DAS respectively), which was on par with Mannat, WHS-20011 and Saraswati. The lowest node to first male flower was recorded in Yellow Lion (3.20) and the hybrids WHS-20011 (3.50), Prachi and Yellow Angel (3.60) were on par with it. The hybrid Yellow Angel produced the first female flower at earliest node (8.00), which was on par with Prachi (8.10). The highest fruit equatorial diameter was observed in the hybrid Devyani (17.60 cm), which was on par with Shabari (17.50 cm), Jannat (16.85 cm), Anmol (16.75), Yellow Queen (16.75 cm) and Swarna (16.55 cm). The hybrid WHS-20011 recorded the highest fruit polar diameter (28.75 cm) and rind thickness (2.15 cm). The highest fruit weight was recorded in the hybrid Mannat (3.34 kg). Prachi (62.00 DAS) took lowest number of days to first harvest and Jannat (65.00 DAS) was on par with it. Shabari recorded the highest number of fruits per plant (4.20), yield per plant (11.84 kg), yield per plot (82.90) and marketable yield per plot (79.95 kg). The longest crop duration was observed in Swarna (120.50 days) and the shortest in Prachi (87.00 days). The highest number of seeds per fruit was noticed in the hybrid Yellow Lion (315.00), whereas Shonima and Swarna were seedless. Hybrid Mannat exhibited the highest 100 seed weight of 5.05 g, which was on par with Anmol (4.90 g), Jannat (4.85 g) and Devyani (4.70 g). T.S.S content was highest for the hybrid Saraswati (12.25 0B), which was on par with Shabari (11.50 0B). The highest lycopene content was recorded by Mannat (7.61 mg 100g1 ). The highest ascorbic content was noticed in the hybrid Prachi (6.35 mg 100g-1). Reducing sugar content was highest in the hybrid Shabari (3.23 per cent). The highest non reducing sugar content was recorded in hybrid Jannat (3.75 per cent). Among varieties and check, AHW 19 recorded the highest vine length of 5.18 m. Best of All (7.50) produced highest number of branches per vine. Arka Shyama was the earliest for male and female flower production (29.90 DAS and 35.80 DAS respectively). The lowest node to first male flower was recorded in Arka Muthu (3.30) and female flower in Asahi Yamato (10.40), which was on par with Thar Manak (10.60). Durgapura Lal had the highest fruit equatorial diameter of 24.05 cm and AHW 65 recorded highest fruit polar diameter (27.80 cm). Check variety Sugar Baby had the highest rind thickness of 2.10 cm, which was on par with Arka Manik (1.95 cm). The highest fruit weight was noticed in Durgapura Meetha (4.76 kg), which was on par with Sugar Baby (4.67 kg). The variety Arka Shyama (59.00 days) was the earliest for first harvest, which was on par with Thar Manak (62.50 days) and Arka Muthu (63.50 days). Arka Shyama recorded the highest number of fruits per plant (3.00), yield per plant (9.82 kg), yield per plot (98.18 kg) and marketable yield per plot (86.84 kg) and the lowest number of seeds (219.50) The highest crop duration was observed in Durgapura Lal (122.00 days). Crimson Sweet recorded the highest 100 seed weight (12.50 g), which was on par with Thar Manak (12.11 g). Arka Shyama recorded the highest T.S.S (12.65 0B) and lycopene contents (6.40 mg 100g-1). The highest reducing sugar (3.23 per cent) and non reducing sugar (3.85 per cent) was observed in Arka Manik. High phenotypic and genotypic coefficients of variation (PCV and GCV) were observed for the characters vine length, number of branches per plant, internodal length, node to first male and female flower, node to first fruit, fruits per plant, yield per plant, yield per plot, marketable yield per plot, seeds per fruit and lycopene in both hybrids and varieties. High estimates of heritability coupled with moderate to high genetic advance as per cent of mean were recorded for all the yield components, indicating additive gene action. Yield per plant exhibited significant positive correlation at genotypic and phenotypic levels with fruit equatorial diameter, fruit weight and fruits per plant in hybrids, whereas in varieties, fruit weight and fruits per plant exhibited positive correlation with yield. Path analysis of hybrids revealed that fruits per plant exerted the highest positive direct effect on yield followed by days to first harvest, fruit equatorial diameter, node to first female flower, fruit weight, fruit polar diameter and vine length. In varieties, fruits per plant exhibited highest direct effect on yield followed by days to first harvest, weight of hundred seeds, fruit weight and seeds per fruit. Based on the mean performance and sensory evaluation, the hybrids Shabari, Saraswati and Devyani and the varieties Arka Shyama, Arka Muthu and Sugar Baby were found best performing and suitable for growing under Kerala conditions.Item Standrdisation of population density in watermelon (Citrullus lanatus (Thunb.) Mansf.)(Department of Horticulture, College of Agriculture, Vellayani, 2000) Bindukala, A R; Abdul Vahab, MItem Evaluation of netted musk melon (Cucumis melo var. cantalupensis Naudin.) for growth , yield and quality(Department of Vegetable Science, College of Agriculture, Vellayani, 2019) Shivakumara, Y B; Sarada, SItem Studies on the effect of F. W-450 and MH as male gametocides in chillies (Capsicum frutescens L.)(Division of Agricultural Botany, Agricultural College and Research Institute, Vellayani, 1967) Sadasivan Pillai, S; Kumara Pillai, PThe present investigation was undertaken in the Division of Agricultural Botany, Agricultural College and Research Institute, Vellayani during 1966-1967, with a view to evaluate the selectiveness of F.W 450 and MH on chillies as male gamotocides and to study their side effects on the general growth and yield of the crop. F.W -450 at 0.10, 0.15, 0.20, 0.25 and 0.30 and MH at 25, 50, 100, 200 and 400 ppm were applied as foliar spray at three stages of plant growth. The first spraying was given when the first flower was undergoing anthesis. Subsequent sprayings were given at an interval of 15 days in between two sprayings. Control plants (no spray) and plants sprayed with distilled water thrice, at the same stages of plant growth as the chemical spray, were also studied. Plants were raised in a randomised block design.