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ThesisItem Open Access Fertigation studies in Papaya (Carica papaya L.)(Department of Fruit Science, College of Agriculture, Vellayani, 2021) Karishma, Sebastian; KAU; Bindu, BThe investigation entitled “Fertigation studies in papaya (Carica papaya L.)” was carried out in Instructional Farm, College of Agriculture, Vellayani during the period 2018 – 2020 with the objectives to standardize the nutrient level for yield improvement through fertigation and foliar nutrition in papaya variety Surya and to study the postharvest management practices for extending the shelf life of papaya fruits. The experiment was undertaken in two parts. In part I, standardization of nutrient level for fertigation and foliar nutrition was carried out in RBD with 14 treatments replicated thrice. A combination of four fertigation doses of 75 %, 100 %, 125 % and 150 % RDF of N (304.89, 406.52, 508.15 and 609.78 g urea plant⁻¹ year⁻¹ respectively based on soil test data in 76 fertigation) and K (426.25, 568.33, 710.42 and 852.50 g MOP plant⁻¹ year⁻¹ respectively based on soil test data in 76 fertigation) and three foliar sprays (1.0 % 19:19:19 at bimonthly interval starting from 4 MAP to 16 MAP, 0.5% ZnSO4 + 0.3% borax at 4 th, 8th, 12th and 16th MAP and water spray at bimonthly interval starting from 4 MAP to 16 MAP) were compared with soil application of recommended dose of NPK (187:170:341 g NPK plant-1 year-1 based on soil test data) (control 1) and 187:170:341 g NPK plant-1 year-1 based on soil test data as organic manures as combination of FYM, poultry manure and vermicompost in the ratio of 2:1:1 (control 2). In control 2, additional requirement of P and K were met through the application of rock phosphate and potassium sulphate respectively. Organic manure (15 kg FYM plant-1 ) was given uniformly to all treatments as basal. Lime and rock phosphate (500g and 850g respectively based on soil test data) was applied uniformly for all treatments as basal except controls. Urea and Muriate of Potash (MOP) were used as fertilizer sources for fertigation and applied weekly from 1 MAP to 20 MAP. Application of different levels of fertigation and different foliar sprays had significant effect on growth, yield and quality of papaya. Growth parameters viz., plant height, stem girth and number of leaves were significantly higher in plants receiving 100 % RD of N and K through fertigation and foliar sprays of 1.0 % 19:19:19 (T4) at bimonthly interval starting from 6 MAP to 16 MAP. T4 also recorded highest leaf area index at 6, 12, 18 MAP and at final harvest, flowering at the shortest height, highest number of female plants and highest fruit set (86.27 %). However, application of 100 % RD of N and K through fertigation and foliar sprays of 0.5 % ZnSO4 and 0.3 % borax at 4 th, 8th, 12th and 16th MAP (T5) initiated earliness in flowering (142.67 days) and harvest (275.00 days). Treatments T4 and T5 were on par in fruit length, fruit girth, fruit volume, pulp percentage, flesh thickness and yield contributing characters like fruit weight, number of fruits per plant and yield per plant (38.30 kg plant⁻1 and 37.60 kg plant⁻1 respectively). Fruit quality parameters viz., TSS, carotenoids, ascorbic acid, total sugar, reducing sugar and non reducing sugar were found highest in T5. Fruits from T5 also registered longest shelf life (5.78 days) and highest mean sensory score for all parameters. Index leaf analysis at 6 MAP revealed highest nitrogen and potassium content of leaf in T10 (150 % RD of N and K through fertigation and foliar sprays of 1.0 % 19:19:19). Calcium, magnesium and sulphur content of leaves were highest in T5, whereas boron and zinc content were highest in T8 (125 % RD of N and K through fertigation and foliar sprays of 0.5 % ZnSO4 and 0.3 % borax). Highest nitrogen and potassium of fruits were observed in T12 (150 % RD of N and K through fertigation with water spray). Highest nitrogen content in soil was noticed in T11 (150 % RD of N and K through fertigation and foliar sprays of 0.5 % ZnSO4 and 0.3 % borax) and T10 witnessed highest potassium content. T4 and T5 were at par regarding B : C ratio (2.58 and 2.54 respectively). In part II of the investigation, postharvest management for extending shelf life of papaya was carried out with nine treatments replicated thrice. Different postharvest treatments given were precooling - hydro cooling (S1), surface sanitization with 150 ppm sodium hypochlorite (S2), external coating with 1% chitosan (S3), precooling followed by external coating with 1% chitosan (S4), packaging with ethylene scrubber 8% KMnO₄ (S5), precooling followed by packaging with ethylene scrubber 8% KMnO₄ (S6), precooling followed by external coating with 1% chitosan and packaging with ethylene scrubber 8% KMnO4 (S₇), hot water treatment followed by waxing with 6% carnauba wax and packaging with ethylene scrubber 8% KMnO₄ (S8) and control (S9). Papaya variety Surya was raised at Instructional Farm, Vellayani and fruits at fully mature green stage were harvested, subjected to different postharvest treatments and packaging was done in CFB boxes and stored under ambient conditions till the end of shelf life. Papaya fruits subjected to precooling followed by external coating with 1% chitosan and packaging with ethylene scrubber KMnO₄ (S7) recorded the longest shelf life of 9.67 days, which was at par with S8 (hot water treatment followed by waxing with 6% carnauba wax and packaging with ethylene scrubber KMnO₄). Physiological loss in weight, ion leakage, percentage disease index, bacterial and fungal count were significantly lowest in S7 and S8 after three days of storage. These treatments also recorded maximum total carotenoids, total soluble solids, total sugar, reducing sugar and minimum acidity after nine days of storage which indicated extended shelf life. Highest mean rank score for sensory attributes were also recorded in treatments S7 and S8 after nine days of storage. In conclusion, application of 100 % recommended dose of N and K (406.52 g urea plant⁻¹ year⁻¹ and 568.33 g plant⁻¹ year⁻¹ respectively) through weekly fertigation from one to 20 months after planting and foliar sprays of 0.5 % ZnSO4 + 0.3 % Borax at 4 th, 8th, 12th and 16th MAP, along with basal application of 850g rock phosphate and 15 kg FYM resulted in increased growth, yield and quality characters of papaya variety Surya with highest B: C ratio. Fruits at fully mature green stage when subjected to precooling followed by external coating with 1% chitosan and packaging with ethylene scrubber 8% KMnO₄ in CFB boxes exhibited a shelf life of 9.67 days in storage under ambient condition in papaya variety Surya.ThesisItem Open Access Evaluation of hybrids and clonal variants in pineapple(Ananas comosus L.)(Department of Fruit Science, College of Agriculture, Vellanikkara, 2022) Lalit, Dhurve; KAU; Ajith Kumar, KThe present investigation entitled “Evaluation of hybrids and clonal variants in pineapple (Ananas comosus L.)” was conducted during August 2017 to August 2021 at Department of Fruit Science, College of Agriculture, Thrissur, Kerala. The objectives of the research work were to evaluate the somaclonal variants and hybrids of pineapple for yield and quality for identifying novel genotypes and to generate DNA fingerprints of the genotypes using ISSR markers for varietal identification and assessment of genetic resemblance. The plant material for Experiment-I comprised of 75 somaclonal variants derived from the pineapple cultivar Mauritius. They were field planted and evaluated at FCRS. The material for Experiment-II comprised of 25 numbers of Mauritius x Kew and 10 numbers of Kew x Mauritius hybrids which were selected and evaluated at FCRS, by adopting RBD with two replications during the normal season along with the cultivars Mauritius, Kew, and Amritha. For Experiment-III, molecular characterization of 11 superior somaclones along with the parental source was carried out using fifty ISSR markers. Similarly molecular characterization of 10 promising hybrids and three check varieties namely Mauritius, Kew, and Amritha were carried out using fifteen ISSR markers. All the somaclonal variants of Mauritius and their field evaluated hybrids were scored based on the most desirable and undesirable characters. Statistical analysis was performed by using the different selection criteria for somaclones and hybrids. Somaclones were selected by calculating index scores (Singh and Chaudhary,1985) and hybrids were selected based on selection index (Smith, 1937). With relation to this, the scores of individual genotypes were judged and those genotypes which ranked with the highest index values in the selection indices were carried forward for further study. The statistical analysis was performed by using the selection criteria for somaclones using index scores as suggested by Singh and Chaudhary (1985). It was observed that the sum of index values of somaclones which secured rank with the highest index scores within the eleven were identified. Accordingly, eleven somaclones T-4, T-17, T-71, T-47, T-43, T-25, T-22, T-24, T-75, T-10 and T-69 were selected for further molecular characterization. Among the 50 ISSR markers that were used for PCR amplification, only 30 showed polymorphic amplification. The unique amplicons (1-6) and PIC (0.32-0.94) were recorded from ISSR marker profiles. A UPGMA based dendrogram, minimum (0.58) similarity was showed by the parent genotype Mauritius with the somaclonal variants T71 and T-75, indicating the existence of significant genetic variation among these three variants. The selection index developed by Smith (1937) was used to discriminate the genotypes based on selected characters. As per the selection index of Mauritius x Kew hybrids, it was found that the indices have identified the six hybrids. Accordingly, six numbers of Mauritius x Kew hybrids T-1 (H-17), T-7 (H-43), T-8 (H-66), T-14 (H-70), T15 (H-59), and T-24 (H-35) were selected for further molecular characterization. All the 15 ISSR markers that were used for PCR amplification showed polymorphic amplification. The uniqueness of amplicons (1-7) and PIC (0.43-0.93) were recorded. A UPGMA based dendrogram showed that the hybrids H-17, H-35, and H-43 had the high level of Jaccard’s genetic similarity relationship with parent sources Mauritius and Kew, with a similarity coefficient of 0.72. With the selection index of Kew x Mauritius hybrids, it was found that the indices have identified the four hybrids. Accordingly, four hybrids T-9 (H-121), T-2 (H-118), T-4 (H-101), and T-3 (H-115) were selected for further molecular characterization. All the fifteen ISSR markers used for PCR analysis showed polymorphic amplification. The uniqueness of amplicons (1-6) and PIC (0.41-0.81) were recorded for the ISSR primers. A UPGMA based dendrogram showed that the H-115, H-118, and H-121 have registered a high level of Jaccard’s genetic similarity values with parent source Kew and Mauritius, with a genetic similarity coefficient of 0.66. Thus, this study has analyzed 75 somaclones derived from cv. Mauritius, 25 hybrids of Mauritius x Kew, and 10 hybrids of Kew x Mauritius. Based on the selection indices developed, the superior somaclones and hybrids were identified. The identified lines were characterized using the ISSR molecular marker system which had revealed the genetic relativeness among the selected somaclones and the hybrids.ThesisItem Embargo Evaluation of banana cultivars for sheath fibre yield and quality(Department of Fruit Science, College of Agriculture, Vellanikkara, 2021) Asish, Benny; KAU; Pushpalatha, P BThe research work “Evaluation of banana cultivars for sheath fibre yield and quality” was carried out in the Department of Fruit Science, College of Agriculture, Vellanikkara during the academic year 2019-2021. As part of this experiment, biomass produced by different banana cultivars and their fibre yield were recorded. The fibre obtained from different cultivars were analysed for their physical and biochemical characters. Significant variation was observed among the cultivars belonging to different genomic groups with regard to biomass production. The highest values for whole plant weight (45.20 kg), pseudostem weight (30.19 kg) and leaf weight (6.42 kg) were recorded in Elavazha, whereas the highest rhizome weight was recorded in Karpooravally (10.63 kg). Maximum plant biomass production was noticed in cultivars with BB genome (42.24 kg) and least in cultivars with AA genome (12.08 kg). In general, cultivars with ‘B’ genome were found to produce higher biomass than cultivars with ‘A’ genome. The number of fibre extractable sheaths were found to vary (10-16) among the different cultivars. The maximum number of fibre extractable sheaths was recorded in cultivars Kunnan, Njalipoovan, Mysore Poovan and Monthan (16 each) followed by Elavazha and Grand Naine (15 each). The percentage of fibre extractable pseudostem among the different cultivars was found to be in the range of 41.52% (Kunnan) to 76.18% (Grand Naine). Sheath weight was found to be correlated with the weight of leaves, pseudostem, rhizome and whole plant and the average sheath weight was highest in Karpooravally (1083.57 g) and Elavazha (1072.89 g) followed by Attikol (1026.43 g). It was observed that, sheath weight was higher in the middle layers and showed a trend reducing towards outer and inner layers in all banana cultivars except for Chenkadali in which sheath weight of the outer layers were also higher. Among the methods of extraction, mechanical extraction was found to be better compared to manual method with respect to fibre yield. Fibre yield was directly correlated with sheath weight in each cultivar and as in the case of sheath weight, fibre yield was also found to be higher from middle sheath layers than that from outer and inner sheath layers. In cultivar Chenkadali, higher fibre yield was recorded from both outer sheaths and middle sheaths. Apart from such exception, the superiority of ‘B’ genome with respect to fibre yield was unravelled through higher yield and higher recovery percentage in Elavazha and Attikol. Fibre yield from the whole plant was comparatively high in Elavazha (157.38 g) followed by Chenkadali (146.97 g). Physical characters of banana fibres such as tex and diameter did not vary with respect to the method of extraction. However, variation was there among cultivars and also depending upon the position of sheath layer in pseudostem. Tex of fibre from different cultivars ranged from 5.50 to 21.70, whereas diameter ranged from 0.06 mm to 0.18 mm. Tex and diameter of the fibre were found to be positively correlated. With regard to TSS content of pseudostem juice, it was found to be very less in all the cultivars, with a comparatively higher value in Elavazha (1.37ºBrix). The values recorded for pH (5.32 to 6.87) and acidity of pseudostem juice of different cultivars indicated that the juice is slightly acidic in nature. Moisture content in freshly extracted fibre ranged from 49.98% to 77.78% and was found to be high in cultivars belonging to AB and ABB genomic groups. Significant variation was observed among the cultivars with respect to cellulose, lignin, carbohydrates and pectin in dry fibre. The cellulose content in fibre of different cultivars ranged between 43.86% and 68.70%, lignin content ranged between 11.64% and 39.23%, carbohydrate content ranged between 1.05% and 2.76% and pectin content ranged between 1.40% and 3.80%. The cellulose content in fibre was found to be high in cultivars with BB genome and lowest in cultivars with AAA genome. Lignin content was negatively correlated with cellulose content and ‘A’ genome was found to contribute more towards lignin content than ‘B genome. Pectin content was also positively correlated with lignin content. Among sheath layers, cellulose content was higher in fibre from inner sheath layers, whereas lignin and pectin content was higher in the outer sheath layers.ThesisItem Open Access Production dynamics of strawberry (Fragaria x ananassa Duch.) in Kerala(Department of Fruit Science, College of Agriculture, Vellanikkara, 2020) Anu Kurian; KAU; Ajith Kumar, KStrawberry is a unique soft fruit crop known for its tantalizing aroma, bright red colour, juicy texture, sweetness and high nutritive value. This is a highly remunerative crop and give quickest returns with in a short period of six months. Temperature and photoperiod are the most important environmental factors that affect the transition from vegetative to flowering phase of strawberry. Previous studies conducted in the department have proved that strawberry can be grown in the plains as well as in hills of Kerala during September to March even in the open condition. The suitable genotypes and good management practices are of paramount importance for successful cultivation of strawberry. With this brief background, the present investigation titled “Production dynamics of strawberry (Fragaria x ananassa Duch.) in Kerala” was undertaken to identify suitable cultivars, better nutrient management, better spacing, suitable growing systems and media for the homestead cultivation of Kerala. Total of four experiments were designed for the study. The study was conducted using eight strawberry varieties under two different agroclimatic zones of Kerala. In Central mid-lands, cv. Winter Dawn recorded signficantly higher number of leaves and number of crowns per plant, whereas in High ranges, cv. Winter Dawn was found significantly superior for maximum plant height, number of leaves and number of crowns per plant. The attributes viz., number of clusters, flowers and fruits per plant were recorded in cv. Winter Dawn which was followed by cv. Sabrina-1 in both locations. Maximum harvesting period was recorded in cv. Winter Dawn in Central mid-lands while it was maximum in cv. Sabrina-1 in High ranges. Quality attributes such as TSS/acidity ratio was recorded maximum in cv. Sweet Charlie under both locations. Winter Dawn recorded maximum ascorbic acid content in both locations while cv. Crystal recorded maximum anthocyanin content. Maximum β-Carotene content was recorded in cv. Sabrina-1 in Central mid-lands while it was maximum in cv. Hadar in High ranges. Evaluating all the parameters during crop period, both Sabrina-1 and Winter Dawn showed stability in their sensory qualities in Central mid-lands. In High ranges, it was recorded in cv. Sweet Charlie. Nine different nutrient combinations were studied using cv. Winter Dawn in Central mid-lands of Kerala. Among the different nutrient combinations, FYM (30 t ha-1), N, P2O5, K2O @ 75:20:100 kg ha-1 (T8) recorded maximum vegetative attributes, number of flowers, fruits and yield per plant (79.92 g) and quality parameters such as TSS and TSS/acidity ratio. Maximum content of total sugars, ascorbic acid and highest sensory score were recorded in the nutrient combination FYM (30 t ha-1), N, P2O5, K2O @ 100:40:50 kg ha-1 (T9). Physiological attributes such as leaf area index was found to maximum in the nutrient combination FYM (t ha-1), N, P2O5, K2O kg ha-1@ 30:100:40:50 (T9), while the relative growth rate was recorded maximum in FYM (30 t ha-1), N, P2O5, K2O @ 75:20:100 kg ha-1 (T8) and 20 t ha-1, 50:40:100 kg ha-1 (T4). Among the nutrients, uptake was maximum in nitrogen and it ranges from 10.66 to 58.65 kg ha-1. The nutrient potassium which favours fruit formation was found maximum in the nutrient combination FYM (30 t ha-1), N, P2O5, K2O @ 75:20:100 kg ha-1 (T8) which ultimately resulted in maximum yield per plant. Different nutrient combinations had significant difference on nutrient content of strawberry fruits except copper content. The highest B/C ratio (0.91) was recorded for the nutrient combination, FYM (30 t ha-1), N, P2O5, K2O @ 75:20:100 kg ha-1 (T8). Six different spacing trials were studied using strawberry cv. Winter Dawn in both Central mid-lands and High ranges. Vegetative attributes viz., plant height, number of leaves and number of crowns were maximum in closer spacing of 20 cm x 20 cm in both Central mid-lands and High ranges which have led to the maximum production of flowers, clusters, fruits and yield per plant (100.03 g; 271.69 g) in both locations. Quality attributes viz., TSS, TSS/acidity ratio and total sugars were found maximum in wider spacing of 30 cm x 50 cm (T2) in Central mid-lands. In High ranges, maximum total sugars was recorded at a spacing of 30 cm x 60 cm (5.37 %) while maximum ascorbic acid and β-Carotene content were recorded at a spacing of 30 cm x 50 cm (T2). The total sensory score was found maximum in 30 cm x 50 cm (T2) in Central mid-lands while it was maximum in 30 cm x 60 cm (T1) in High ranges. Closer spacing of 20 cm x 20 cm did not have significant influence the quality attributes however it recorded highest B/C ratio in both Central mid-lands (1.21) and High ranges (3.28). Six different growing systems viz., hanging pots, hanging pipes, hanging bottles, vertical garden, grow bags and raised beds and four different growing media viz., Soil: Cocopeat: FYM, Soil: Cocopeat: Vermicompost, Cocopeat: Perlite: FYM and Cocopeat: Perlite: Vermicompost in 1:1:1 ratio were studied using cv. Winter Dawn in Central mid-lands. Vegetative attributes viz., plant height, number of leaves, plant spread and number of crowns were recorded maximum in growbags and raised beds with growing medium, Soil: Cocopeat: Vermicompost (1:1:1) which led to the maximum production of number of flowers, clusters, fruits and yield per plant (86.26 g). Quality attributes viz., TSS, TSS/acidity ratio and total sugars were recorded maximum in raised beds with growing medium Cocopeat: Perlite: Vermicompost (1:1:1). The overall sensory score was found maximum in fruits grown in raised beds with medium Soil: Cocopeat: FYM (1:1:1). The highest B/C ratio (1.36) was recorded with raised beds with Soil: Cocopeat: Vermicompost (1:1:1) as growing medium. On evaluation, it is found that cv. Winter Dawn showed significantly superior performance in vegetative, flowering, fruit and yield attributes with resistance to serious pests and diseases. Hence, it can be recommended as a best variety for strawberry cultivation in Kerala. Among the different nutrient combinations, FYM (30 t ha-1), N, P2O5, K2O @ 75:20:100 kg ha-1 (T8) was found suitable for better nutrient recommendation for strawberry. Though closer spacing of 20 cm x 20 cm recorded maximum yield but wider spacing would enhance the quality of fruits. Grow bag is found the best suitable growing system with growing medium Soil: Cocopeat: Vermicompost at 1:1:1 ratio, for home gardening of strawberry.ThesisItem Open Access Ecophysiology of mango (Mangifera indica L.) under high density planting system in Muthalamada area(Department of Fruit Science, College of Horticulture, Vellanikkara, 2020) Reshma Ravi, P; KAU; Ajith Kumar, KThe experiment on “Ecophysiology of mango (Mangifera indica L.) under High Density Planting System in Muthalamada area” was conducted in a farmer’s orchard in Muthalamada located in Kollengode block panchayath of Palakkad district during October 2018 to May 2020. The objective of the study was to evaluate the response of different varieties of mango to climatic conditions prevailing in Muthalamada area and study the phenological cycles of growth and production. Four varieties namely, Alphonso, Banganapalli, Imam Pasand and Sindhooram, which were extensively cultivated by the farmers of Muthalamada were selected as the material for study for the study. Five trees each from the four varieties under study, maintained under high density planting system were selected at random for the study. The varieties in the orchard were of four years of age and were maintained under good management practices. Observations on tree characters, inflorescence characters, phenological stages, leaf nutrient status, physiological and biochemical characters and yield were recorded. In addition to these, observations on meteorological data, soil nutrient status and incidence of pests and diseases were recorded during the period under study and correlation studies were done to evaluate the effects of parameters on the flowering and yield of the varieties. Among the four varieties, early flowering was noticed in the variety Banganapalli, followed by the varieties Imam Pasand, Alphonso and Sindhooram. Fruit set was observed in all the varieties except Imam Pasand. Among the three varieties which had fruited, the variety Alphonso recorded the maximum fruit weight (274.62 g) and the variety Sindhooram recorded the maximum fruit yield (11.27 kg). Correlation coefficient analysis was carried out to identify the factors which influenced the flowering and fruiting behaviour in Muthalamada region. The level of potassium content in the leaves was significantly correlated with earliness in flowering with a correlation coefficient of -0.769 and flowering duration exhibited a positive correlation with leaf C:N ratio and boron content with a significant correlation coefficient of 0.509 and 0.530. The inflorescence length and width showed a significant negative correlation with the carbohydrate: nitrogen ratio, magnesium content and boron content in the leaves. The physiological parameter transpiration rate was negatively correlated with the number of days taken from pruning to flowering with a significant correlation coefficient of -0.520. The time taken (days) to attain flowering was having a significant positive correlation with leaf proline content before flowering and canopy air temperature. This suggested that the trees tend to flower earlier under higher canopy temperatures and proline content in the leaves. It was observed that the weather parameters in Muthalamada region influenced the flowering behaviour in the varieties. The earliness in flowering and flowering duration were positively correlated with average maximum temperature before flowering and the heat units accumulated by the resting bud with a significant correlation coefficient of 0.869 and 0.973 respectively. This indicated the effect of higher temperatures in stimulating flowering. Earliness in flowering showed a significant negative correlation to the average rainfall obtained from pruning to flowering, which indicated the requirement of low rainfall for flowering. The inflorescence length and width were having negative correlation with average minimum temperature and average rainfall with a significant correlation coefficient of -0.690 and -0.775 respectively. This indicated that the inflorescence attains better length and width under higher daily minimum temperatures and rainfall. Flowering duration exhibited positive correlation with average maximum and minimum temperatures. It also exhibited a significant positive correlation with the heat units accumulated. The accumulation of proline before flowering was positively correlated to the average maximum temperature and heat units accumulated. A strong negative correlation was observed between leaf proline content and average rainfall. This suggested that the accumulation of proline is associated with higher temperatures and lower rainfall regimes. Overall perusal of the results indicated that the earliness in flowering in Muthalamada area is due to the influence of the weather conditions prevailing in the region and the growing degree days required by the varieties. The variety Sindhooram was superior in terms of yield but was comparatively late to the other varieties. Considering the earliness in fruit maturity, the variety Banganapalli fetches maximum price and is the most profitable variety for this region.ThesisItem Open Access Reproductive biology and evaluation of kokum (garcinia indica (thouars) choisy) genotypes(Department of Fruit Science, College of Agriculture, Vellanikkara, 2021) Manjunath Sharanappa, Tondihal; KAU; Vikram, H CKokum (Garcinia indica (Thouars) Choisy) is a valuable yet underutilized perennial fruit tree. It is gaining importance due to multifarious uses mainly in the preparation of pleasant and attractive beverages which have rich medicinal properties. Kokum is one of the native species exhibiting a complex nature of flowering and fruiting behaviour. In the present investigation, twenty nine genotypes of kokum maintained at College Orchard, Department of Fruit Science as well as ICARNBPGR, Regional Station, Vellanikkara were studied systematically for phenological growth stages, floral characters, growth, yield and quality parameters during the period 2019-2021. In kokum, a total of 7 principal growth stages and 35 secondary growth stages were identified and described by using extended Biologische Bundesantalt, Bundessortenamt and Chemische Industrie (BBCH) scale (Meier, 2001). The principal growth stage 0- the vegetative bud development recorded 17 days, stage 1- the leaf development stage took 48 days, stage 3- the shoot development extended for 65 days, stage 5- the reproductive bud development took 32 days, stage 6- flowering lasted for 11 days, stage 7- which represented the fruit development had the longest duration of 103 days and stage 8- the fruit maturity and ripening took 5 days. Among the twenty nine genotypes studied for floral characters, twelve genotypes were female, fifteen were male and one genotype produced bisexual flowers. Male flowers were of two types, type I male flowers were present in all the fifteen male trees, whereas type II male flowers were present in seven male trees. Variation was observed among the genotypes for qualitative characters of flower viz., position of inflorescence (axillary, terminal or both), calyx colour (greenish yellow to yellowish green), corolla colour (yellow to yellowish orange), nature of stamens (free in all male and bisexual flowers), presence of pistillode (present in type II male flower and absent in type I male flower), staminodes were observed in female flowers only and it ranged from 3.7 to 11.8 in number, stigmatic rays was tuberculate and it found to be similar in all the female genotypes. The genotypes varied significantly with respect to quantitative characters of flowers such as number of flowers per m2 (10.90 to 25.20), length (3.48 mm to 6.64 mm) and breadth (4.78 mm to 8.05 mm) of flower. Majority of the female trees produced solitary or in groups of two to three, whereas male and bisexual trees produced flowers in clusters. Female flowers were sessile or with small pedicels, whereas in male flowers, pedicel length ranged from 3.41 to 5.73 mm. The time of anthesis in all three types of flowers found to occur from 19.30 to 21.00 hours. The anther dehiscence in male and bisexual flowers were found to start simultaneously from 19.00 hours and it continued till 20.30 hours. Stigma receptivity was observed at the time of anthesis and it remained receptive for about 12 to 14 hours. Both type I and type II male flowers had round shaped pollen which measured about 5 µm diameter. The pollens of bisexual flowers were elongated with prominent ridges on the surface and showed same size as that of male pollen. Acetocarmine test revealed that 84.07 to 98.49 per cent of pollen were found to be viable in male and bisexual flowers of kokum. Controlled pollination was performed in different combinations, female tree as receptors and male (type I and type II flowers) as well as bisexual trees as donors for understanding pollination and fruit set behaviour in different sex form of kokum. Female trees crossed with type II male and bisexual flowers recorded 100 per cent fruit set. Female trees crossed with type I male flower recorded 60 per cent of fruit set, whereas bisexual flowers on selfing exhibited 50 per cent fruit set. In the present study, variation was noticed among the kokum genotypes with regard to the growth and leaf characters. Fruit characters were recorded from thirteen bearing genotypes and all these genotypes were found to vary significantly for the fruit characters. Fruit weight ranged from 12.17 to 40.14 g, fruit volume varied from 34.22 to 45.60 cm3 , fresh weight of rind varied from 7.15 to 21.01 g, dry weight of rind ranged from 1.09 to 3.07 g, rind to seed ratio ranged from 0.81 to 1.77 and rind thickness varied from 2.46 to 3.41 mm. Genotype, IC552528-3 recorded maximum number of fruits per m2 (71.10), ACC.FSC-9 had produced the highest number of fruits per tree (2258) and fruit yield per tree (60.64 kg). Kokum genotypes differed significantly for all the biochemical parameters except moisture content. Moisture content ranged from 82.91 to 90.34 per cent, titratable acidity ranged from 2.30 to 4.47 per cent, total sugars varied from 4.32 to 10.60 per cent, TSS ranged from 5.65 to 14.15 0Brix and anthocyanin content varied from 11.12 to 25.01 mg per 100 g. Genotypes were ranked based on the biochemical composition of the fruit rind. Genotypes, IC552528-3 and IC136687-3 which had significantly high TSS and low acidity were ranked as superior quality genotypes and these genotypes can be utilised for value addition. Based on the yield and quality parameters nine genotypes were selected for organic acid profiling of kokum rind. The Liquid Chromatography Mass Spectrometry (LCMS) analysis revealed that eleven major constituents are present in kokum rind. Total organic acids in the genotypes varied from 47.12 (IC342319-2) to 759.29 mg/g (ACC.FSC-1). Among the different organic acids, hydroxycitric acid (HCA) was predominant (1908.48 mg/g) followed by citric acid (1254.89 mg/g). Significantly the highest HCA (652.52 mg/g) was recorded in ACC.FSC-6. It has antiobesic, anticholesterol and UV protecting properties and hence, genotypes which are found rich in HCA can be utilised by the pharmaceutical industries. Cluster analysis of kokum genotypes based on organic acids formed five different clusters. Genotypes under the same cluster showed more similarity in bioactive compounds. Principal component analysis distinguished distribution of organic acid constituents into two axes. The axes first two principal components explained 63.03 per cent of total variance. The knowledge on variability of chemical constituents has vital role in identification of chemotypes which pave way for investigation on therapeutic potential of genotypes.ThesisItem Open Access Evaluation of dragon fruit (hylocereus spp.) genotypes grown in Kerala(Department of Fruit Science, College of Agriculture, Vellanikkara, 2021) Keerthana, Sethunath; KAU; Jyothi, BhaskarDragon fruit (Hylocereus spp.) commonly known as the pitaya, is a perennial climbing vine belonging to the Cactaceae family. The present work carried out in the Department of Fruit Science during the period 2019-2021 to study the morphology, flowering, yield and quality attributes of dragon fruit grown in four districts of Kerala (Thiruvananthapuram, Pathanamthitta, Ernakulam and Thrissur) is of vital importance with respect to the popularity dragon fruit has gained within a very short span of time in Kerala. A total of 100 plants, 10 each from 10 different locations were evaluated based on the UPOV descriptor guidelines to characterise the different genotypes that are being cultivated in Kerala. The plants were denoted as P1 to P10, prefixed with the first two letters of the location to which they belong. The commercial cultivation of dragon fruit in Kerala was found to be dominated by the dark pink/purple fleshed dragon fruit (Hylocereus costaricensis). Within this species, more than one genotype was identified. The stem, flower, yield and quality attributes were found to vary widely. The stem characters included stem segment length (33-210 cm), stem segment width ((1.80-6.60cm), distance between areoles (2.00-5.50 cm), arch height (1.00-4.20 cm), stem waxiness (strong and weak), stem sturdiness (high and low), margin of rib (convex and flat), number of spines per areole (3-5), spine colour (medium brown and dark brown), height of the pole (6.5-8 ft with 1-2 ft buried underground), number of branches (numerous) and number of stem segments per branch (1-6). Variations were also observed for the flower characters such as bud shape (ovate and elliptic), shape of bud apex (acute and rounded), secondary colour pattern of sepal (slightly red edged and red edged), intensity of red colour on bracts (weak, medium and strong), length of style (23.50-31.00 cm) and number of stigma lobes (26-36). The yield characters studied were fruit weight (84-896g), length of fruit (4.60-10.40 cm), width of fruit (4.40-10.40 cm), length/width ratio of fruit (1.00-1.21), number of bracts (18- 50), length of apical bract (3.00-6.30cm), width of base of the bract(1.40-5.70 cm), position of bracts towards the peel (adpressed, slightly held out and strongly held out), fruit weight without peel (52-592 g), fruit shape (oval or spherical), colour of peel 2 (medium pink and dark pink), flesh colour (dark pink and purple) and yield per post (5- 20 kg per year based on the age of the plants). The values ranged from 11 to 18 °B with respect to the TSS of the fruits whereas the titrable acidity was found to be 0.12 per cent in all the fruits. The plants KoP1 to KoP10 from Kozhenchery received the maximum score for appearance, taste, flavour, after taste and overall acceptance. Plants came into bearing within 1.5 to 2 years of planting when stem cuttings were used as the planting material. The duration from flower bud initiation to anthesis was 12-15 days in general and anthesis took place during the night time after 10 p.m. If the pollination was successful, fruit could be visible after 5 to 7 days of anthesis and the harvest was possible in 23-25 days from fruit set i.e., one month after anthesis. When the phenology of the plants was studied, flowering started in the month of March in two locations (Athikkayam and Vaniyampara) whereas in all the other locations, it started in the month of April. The flowering season extended till September to October. The fruiting season started exactly one month after the anthesis and ceased one month after the flowering has stopped, i.e., April to November. As dragon fruit was a perennial crop, different orchards were grouped into three phases based on the age of the plants, namely the establishment phase (0-2 years), yield increasing phase (2-4 years) and yield stabilizing phase (4 years and above). Considering the phases, total cost of cultivation was calculated and it was found to be ₹8,29,393 per year per hectare. The maximum cost during establishment phase was incurred for the planting material and construction of posts. During the maintenance phase, maximum expenditure was for the manure and fertilizer application. Average yield per year per hectare was observed to be around 21 tonnes and the average price received by farmers was ₹174 per kg. Net return from one hectare was around ₹27,32,768. The B:C ratio was 4.29 when the farmers received ₹174 per kg fruit. The B:C ratio obtained with the least price (₹120 per kg) was 3.04. Being a highly remunerative crop, area under dragon fruit cultivation was found to be expanding year after year, as more under-utilized lands are being brought under this crop. Major constraint identified in the cultivation of dragon fruit was the bud and flower drop due to excessive and continuous rainfall during the flowering season. Weed 3 growth was also found to be a major problem. The source of planting material in all the locations under study were found to be either from Malaysia or Cambodia. Since dragon fruit was a crop introduced recently to India, the incidence of pests and diseases were less compared to other fruit crops. But the menace caused by ants was common and rarely, mealy bugs and beetles were found. Fruits were found to be damaged by birds. Disease symptoms similar to canker were observed on the fruits and stem in one of the locations. Physiological disorder like yellowing during extreme summer was common in most of the orchards and these symptoms vanished immediately after a shower or with irrigation. The variability within the species was analysed using statistical techniques like factor analysis and cluster analysis. Maximum variability (59.38%) in the stem and flower characters was explained by two dimensions. The characters that contributed to the variability were intensity of red colour of bract, stem waxiness, stem sturdiness, margin of rib, spine colour, bud shape, bud apex shape, number of stigma lobes, length of style and distance between areoles. Similarly, maximum variability (62.74%) in the quality attributes were contributed by the first two dimensions out of four significant dimensions. The characters responsible for creating the variability were fruit weight, position of bract towards peel, fruit width, fruit weight without peel, fruit length, flesh colour, fruit shape, width of base of bract, length of apical bract, outer TSS, TSS-acid ratio and core TSS. Cluster analysis of the qualitative traits formed six different clusters. When the mixed data with both qualitative and quantitative characters were analysed through clustering, there were three clusters based on the stem and flower characters and four clusters based on the yield and quality attributes, which indicated variability within the species. Other species of Hylocereus namely H. undatus and H. megalanthus, and other types known as Bruni and Frankis Red imported from countries like Thailand and Vietnam are also under cultivation by farmers and are getting popular in different parts of Kerala.ThesisItem Open Access Response of banana Musa (AAB) 'Nendran' to nutrient sources(Department of Fruit Science, College of Agriculture, Vellanikkara, 2021) Manohar Lal Meghwal; KAU; Jyothi, M LBanana is the leading tropical fruit in the world market today with a highly organized and developed industry. Banana having a root system spread in the top 60 cm soil, is heavy feeder of nutrients and requires large quantities of nutrients for its growth, development and yield. Nutrient removal from soil by crops must be replenished. Under good management conditions and adequate supply of biofertilizers and organic manures, the nutrient removal can be replenished and soil physical, chemical and biological properties can be improved. Organic and inorganic sources of nutrients have significant influence on fruit quality and soil characteristics. The current agricultural policy emphasize a shift towards safe agricultural practices for which organic management is the best option. However the crop behaviour under organic and inorganic management needs elaborate studies. Hence the research entitled ‘Response of banana Musa (AAB) 'Nendran' to nutrient sources was formulated to elucidate response of banana in terms of growth, yield and quality to nutrient sources and to compare the fruit quality of banana grown under organic and conventional systems in farmer’s field. The study revealed that vegetative growth of Musa Nendran banana was not influenced by different sources of nutrients in early stage in both the years but later differences were recorded between the treatments. Plant height, number of leaves and pseudostem girth showed significant differences from 90 DAP. At bunching stage plant height and pseudostem girth were higher in organic treatments. There was significant difference in pseudostem girth between the treatments throughout the growth stage of Nendran banana. Among the treatments, T8 resulted in better growth of plants. Leaf characters like number of leaves and leaf area index were not influenced significantly between organic and integrated nutrient management. Early leaf production was also noticed in treatment T8 as indicated by the observations on phyllocron. Growth was delayed in control where no manures and fertilizers. In general more number of leaves per plant and lesser duration for leaf emergence was recorded in both the years in organic treatments. Chlorophyll production in the index leaf of banana was influenced with organic and inorganic nutrition. Chlorophyll a, b and total chlorophyll in the index leaf were distinctly higher in treatment T8 (fertigation with FYM) which was on par with treatments T3 and T5 where organic manures alone were applied. Early flowering and early harvesting were observed in organic treatments. Higher total biomass production was recorded in organic treatments. Yield and yield attributing characters like bunch weight, number of finger, finger weight were highest in treatments with organic sources of nutrients. The mean bunch weight was influenced significantly by organic and inorganic sources of nutrients. Fertigation with organic sources of nutrients resulted in the production of heavier bunches in both years. Maximum bunch weight was recorded from treatment T8 which was on par with other organic treatments as well as integrated management with fertilisers applied as fertigation as well as based on soil test results. No significant variation was observed between treatments on number of hands per bunch and finger characters like finger length and girth. Peel thickness of fruits were not significantly influenced but the pulp to peel ratio was significantly influenced by the treatments. Pulp to peel ratio was higher in all treatments other than T1 and control where T1 is the POP recommendation for TC banana under integrated nutrient management. Yield per plant was positively correlated with available N, P, K, Calcium, magnesium, sulphur, Zn, Cu, B, content of the soil. Yield was also positively correlated with soil properties like pH, organic carbon content, CEC, Bulk density, and Dehydrogenase enzyme activity. Higher biomass production was recorded in plants that received nutrients from organic sources compared to integrated nutrient management and control. Shelf life of fruits were improved in organic treatments. Fruit quality parameters like TSS, Total sugars, ascorbic acid and β carotene of ripe banana fruits were improved in organic treatments compare to inorganic system. Sensory score of ripe fruits and fruit chips were maximum in organic treatments. The taste of ripe banana fruits was improved in plants grown under organic treatments. Fertigation with organic manures (T8) resulted in improved fruit quality of Nendran banana in both the years. Different soil physical and chemical properties also improved when nutrients were supplied through organic sources. Soil pH, electrical conductivity, organic carbon content, cation exchange capacity, available, N, P, K, Mg, Iron, Copper, Zinc, Mn and boron were better in soils receiving organic manures alone. Similarly the soil biological properties like dehydrogenase activity, nitrogenase activity, microbial biomass carbon, and viable counts of total fungi, bacteria and actinomycetes were better in organic treatments. Bulk density of soil was low in soils receiving organic manures alone compared to integrated nutrients. Total uptake of nutrients in organic and integrated nutrient management system was compared. Uptake of N, Ca, S, Fe, Mn, Zn and Cu was higher in organic system of cultivation of banana compared to integrated system. Higher benefit cost ratio was recorded banana grown in organic system. The study revealed that organic sources of nutrients improved soil properties and thereby improved growth, yield and quality of banana.ThesisItem Open Access Ecophysiology of mango (Mangifera indica L.) under high density planting system in Muthalamada area(Department of Fruit Science, College of Horticulture, Vellanikkara, 2020) Reshma Ravi, P; KAU; Ajith Kumar, KThe experiment on “Ecophysiology of mango (Mangifera indica L.) under High Density Planting System in Muthalamada area” was conducted in a farmer’s orchard in Muthalamada located in Kollengode block panchayath of Palakkad district during October 2018 to May 2020. The objective of the study was to evaluate the response of different varieties of mango to climatic conditions prevailing in Muthalamada area and study the phenological cycles of growth and production. Four varieties namely, Alphonso, Banganapalli, Imam Pasand and Sindhooram, which were extensively cultivated by the farmers of Muthalamada were selected as the material for study for the study. Five trees each from the four varieties under study, maintained under high density planting system were selected at random for the study. The varieties in the orchard were of four years of age and were maintained under good management practices. Observations on tree characters, inflorescence characters, phenological stages, leaf nutrient status, physiological and biochemical characters and yield were recorded. In addition to these, observations on meteorological data, soil nutrient status and incidence of pests and diseases were recorded during the period under study and correlation studies were done to evaluate the effects of parameters on the flowering and yield of the varieties. Among the four varieties, early flowering was noticed in the variety Banganapalli, followed by the varieties Imam Pasand, Alphonso and Sindhooram. Fruit set was observed in all the varieties except Imam Pasand. Among the three varieties which had fruited, the variety Alphonso recorded the maximum fruit weight (274.62 g) and the variety Sindhooram recorded the maximum fruit yield (11.27 kg). Correlation coefficient analysis was carried out to identify the factors which influenced the flowering and fruiting behaviour in Muthalamada region. The level of potassium content in the leaves was significantly correlated with earliness in flowering with a correlation coefficient of -0.769 and flowering duration exhibited a positive correlation with leaf C:N ratio and boron content with a significant correlation coefficient of 0.509 and 0.530. The inflorescence length and width showed a significant negative correlation with the carbohydrate: nitrogen ratio, magnesium content and boron content in the leaves. The physiological parameter transpiration rate was negatively correlated with the number of days taken from pruning to flowering with a significant correlation coefficient of -0.520. The time taken (days) to attain flowering was having a significant positive correlation with leaf proline content before flowering and canopy air temperature. This suggested that the trees tend to flower earlier under higher canopy temperatures and proline content in the leaves. It was observed that the weather parameters in Muthalamada region influenced the flowering behaviour in the varieties. The earliness in flowering and flowering duration were positively correlated with average maximum temperature before flowering and the heat units accumulated by the resting bud with a significant correlation coefficient of 0.869 and 0.973 respectively. This indicated the effect of higher temperatures in stimulating flowering. Earliness in flowering showed a significant negative correlation to the average rainfall obtained from pruning to flowering, which indicated the requirement of low rainfall for flowering. The inflorescence length and width were having negative correlation with average minimum temperature and average rainfall with a significant correlation coefficient of -0.690 and -0.775 respectively. This indicated that the inflorescence attains better length and width under higher daily minimum temperatures and rainfall. Flowering duration exhibited positive correlation with average maximum and minimum temperatures. It also exhibited a significant positive correlation with the heat units accumulated. The accumulation of proline before flowering was positively correlated to the average maximum temperature and heat units accumulated. A strong negative correlation was observed between leaf proline content and average rainfall. This suggested that the accumulation of proline is associated with higher temperatures and lower rainfall regimes. Overall perusal of the results indicated that the earliness in flowering in Muthalamada area is due to the influence of the weather conditions prevailing in the region and the growing degree days required by the varieties. The variety Sindhooram was superior in terms of yield but was comparatively late to the other varieties. Considering the earliness in fruit maturity, the variety Banganapalli fetches maximum price and is the most profitable variety for this region.
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