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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 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 Foliar nutrition with calcium and micronutrients for growth and yield enhancement in papaya (Carica papaya L.)(Department of Fruit Science, College of Agriculture, Vellayani, 2020) Anju, P; KAU; Bindu, BThe study entitled “Foliar nutrition with calcium and micronutrients for growth and yield enhancement in papaya (Carica papaya L.)” was conducted at Department of Fruit Science, College of Agriculture Vellayani, from 2019 April to 2020 April. Micronutrients and secondary nutrients like calcium play a major role in crop production due to their essentiality in plant metabolism and adverse effect that manifest due to their deficiency. The present work was undertaken to assess the effect of foliar application of micronutrients and calcium on growth, yield and quality of papaya. The field experiment was laid out in Randomized Block Design (RBD) with 9 treatments and 3 replications. Surya, IIHR (Indian Institute of Horticultural Research) gynodioecious variety was used for the research purpose. Treatments were T1- Borax (0.5%), T2 - Zinc sulphate (0.5%) and T3 - Calcium nitrate (0.5%), T4 - T1 + T3, T5 - T1 + T2, T6 - T2 + T3, T7 - T1 + T2 + T3, T8 - Water spray and T9 – Control (KAU POP). Treatments from T1 to T8 were applied at 4th and 7th months after planting. Organic manure (10 kg FYM plant-1) and NPK (240: 240: 480 g plant-1 year-1) were given uniformly to all treatments as soil application as per KAU POP recommendation. Treatment with foliar application of Borax (0.5%), Zinc sulphate (0.5%) and Calcium nitrate (0.5%) increased the biometric parameters like plant height and number of leaves at 6 MAP, 8 MAP,10 MAP and 12 MAP. A significant increase in plant girth at all stages of growth was observed for the same treatment. From the present investigation, it was found that foliar application of Borax (0.5%), Zinc sulphate (0.5%) along with Calcium nitrate (0.5%) reduced the height at first flowering, days to flowering, duration for harvest of papaya fruit and increased the number of female plants than that of bisexual plants, fruit set percent and number of flowers per cluster. The results indicated that yield characters such as fruit weight, fruit length, fruit girth, fruit volume, pulp percentage, flesh thickness, number of fruits per plant and total yield per plant were highest with the combined application of Borax, Zinc sulphate and Calcium nitrate @ 0.5% respectively as foliar spray, where, number of seeds per fruit and days taken for maturity of fruits reduced significantly for the same treatment. With regard to qualitative attributes studied TSS, total carotenoids, ascorbic acid, total sugar, reducing sugar, colour of pulp and peel and firmness of pulp were shown positive response with the spray of Borax (0.5%), Zinc sulphate (0.5%) along with Calcium nitrate (0.5%) however, reduction in acidity was found with the same treatment. Water spray recorded the highest value for non-reducing sugar content in papaya. The foliar application of Borax (0.5%), Zinc sulphate (0.5%) and Calcium nitrate (0.5%) increased the organoleptic qualities like appearance, colour, texture, taste, flavour and overall acceptability. Shelf life of papaya fruits were longer with the same treatment. From this study it was observed that soil parameters like soil pH, EC, organic carbon, available nitrogen, phosphorous, potassium, boron, zinc and calcium did not show any significant variation with the foliar application of micronutrients and calcium. Data from the plant analysis and fruit analysis of papaya showed that nitrogen, phosphorous, boron, zinc and calcium content was highest with the foliar application of Borax (0.5%), Zinc sulphate (0.5%) and Calcium nitrate (0.5%). But Potassium content in both leaf petiole and fruit was highest for the plants treated with Borax (0.5%) and Zinc sulphate (0.5%) foliar spray. Foot rot and leaf spot incidence were observed in the papaya field. Proper plant protection measures controlled the infestation which was less than 1 percent. The highest net income and B:C ratio was observed with the foliar application of Borax (0.5%), Zinc sulphate (0.5%) and Calcium nitrate (0.5%). From the above findings, it was concluded that foliar application of Borax (0.5%), Zinc sulphate (0.5%), Calcium nitrate (0.5%) at 4th and 7th months after planting along with the application of organic manure (10 kg FYM plant-1) and NPK (240: 240: 480 g plant-1 year-1) had increased the growth, yield and quality characteristics of papaya and it was economically viable too.ThesisItem Open Access Production technology and crop improvement of passion fruit (Passiflora edulis Sims.)(Department of Fruit Science, College of Agriculture, Vellanikkara, 2020) Annjoe V, Joseph; KAU; Shobana, APassion fruit (Passiflora edulis Sims.) belonging to the family Passifloraceae is most accepted for fresh consumption and for various processed products. Passion fruit cultivation is gaining popularity among farmers due to its adaptability under humid tropical conditions and presence of nutritional and therapeutic components. The present study was undertaken in passion fruit with the objectives to evaluate performance of different genotypes, hybridization for development of superior types, standardize the nutrient requirement and propagation method through stem cuttings. Eight passion fruit accessions collected from different locations of Kerala were evaluated for vegetative, flower, yield and fruit characters. Flower characters did not show significant variation, while, the yield and fruit characters exhibited variations among the eight accessions evaluated. Pollen storage studies conducted revealed that passion fruit pollen can be stored over calcium chloride in a desiccator under refrigerated condition for 72 hours with 50.88 per cent pollen viability. Accessions 7 and 5, which were early to flower (157.33 days and 160.33 days), early to fruit (159.67 days and 163.33 days) and early to harvest (63 days and 67 days) were identified as early bearing types. The number of fruits per vine per year recorded was maximum in Accession 4 (155.33), which was on par with Accession 2 (149.33) and Accession 6 (146.67). Peak fruiting was observed from the month of June to September. Accession 3 (yellow) and Accession 4 (purple) were found to be superior in fruit characters. Accessions 2, 4, 5 and 8 with high juice content and thin rind can be utilized for processing and value addition. Accession 5 with improved quality parameters like high non-reducing sugar (5.92 %), sugar acid ratio (4.97), TSS (17.33 ◦Brix), total sugars (13.55 %) and lower acidity (2.73 %) was identified as a superior selection based on quality parameters. Correlation studies showed that yield/vine had significant and positive correlation with fruit diameter, fruit girth, fruit weight, pulp weight and juice weight. Rind thickness was found to have significant positive correlation with shelf life. The study revealed that considerable variability existed among the different accessions of passion fruit. The accessions which recorded high yield viz., Accession 2, 4 and 6 can be used for further crop improvement programmes to develop superior passion fruit varieties. Hybridization work was carried out using six selected superior accessions maintained at Malanadu passion fruit plantation, Idukki, which resulted in the development of one selfed progeny and 8 hybrids. The hybrids and selfed progeny were evaluated for three months at nursery stage and in the field in the college orchard, COH, Vellanikkara for one year. Peak flowering and fruiting periods were observed during March - May. Maximum number of fruits were recorded in hybrids viz., H3 (P4 x P6), H4 (P5 x P4), H5 (P6 x P1) and H8 (P6 x P5). With regard to fruit characters, hybrid H6 (P6 x P2), was observed to be the best, with highest fruit weight, fruit girth, fruit diameter and pulp weight, which also had maximum overall acceptability in sensory evaluation. Fertilizer trial was conducted at four different levels of NPK in the variety 134P. Among the phenological characters, duration of flowering to harvest varied significantly. Higher number of fruits per vine (165.50) was recorded with application of 50 N: 20 P2O5: 50 K2O g vine-1 (T4), which was on par with the treatments applied with 37.5 N: 15 P2O5: 37.5 K2O g vine-1 (T3) and 25 N: 10 P2O5: 25 K2O g vine-1 (T2). The treatment which received 50 N: 20 P2O5: 50 K2O g vine-1 was found to be significantly superior with respect to fruit diameter, fruit girth and rind weight. Application of 50 N: 20 P2O5: 50 K2O g vine-1 resulted in high TSS (19.15 °Brix), total sugars (13.38 %) and reducing sugars (8.76 %). In the organoleptic evaluation, maximum score was observed for the fruits from the plots which received fertilizers of 37.5 N:15 P2O5: 37.5 K2O g vine-1. The presence of number of nodes in the stem cuttings, different concentrations of NAA and their interaction were found to have significant effect on the survival percentage and shoot and root parameters of the rooted cuttings. Four noded cutting recorded maximum survival per cent (70.60 %), total leaf area (166.15 cm2) and shoot length (28.75 cm). Among the different concentrations of NAA, survival percentage, root length and total leaf area, NAA 800 ppm was found significantly superior. The study revealed that four noded cuttings dipped (quick dip method) in 600 ppm NAA could be used for the large scale multiplication of passion fruit plants for commercial cultivation.ThesisItem Open Access Evaluation of promising accession of papaya (Carica papaya L.) cultivation in north Kerala(Department of Fruit Science, College of Agriculture, Padannakkad, 2020) Akhil, P; KAU; Satheeshan, K NPapaya (Carica papaya L.), is an important fruit crop cultivated in the tropical and subtropical regions due to its versatile uses, high palatability, nutritional and health benefits. Even though India is a major producer of papaya in the world, in Kerala, it is yet to assume the status of a commercial fruit crop. Lack of availability of varieties/types adapted to climatic conditions in Kerala and dependency on private breeders for seeds are the challenges for its commercial cultivation. However, there is a growing interest among farmer’s in Kerala to take up its cultivation in an orchard scale recently due to its ease of growing and economic potential. In this context, the present investigation on evaluation of selected papaya cultivars/types/varieties is proposed with an objective to find out genotypes suitable for cultivation in Northern zone of Kerala. The study entitled “Evaluation of promising accessions of papaya (Carica papaya L.) for cultivation in North Kerala” was conducted at the Department of Pomology and Floriculture, College of Agriculture, Padannakkad, Kasaragod and Regional Agricultural Research Station, Pilicode during the period from 2017 to 2019. The experiment was laid out in RBD with 12 treatments and 3 replication. The treatments included six promising papaya genotypes selected from the Kasaragod district, one accession already found to be promising from the KAU main campus, Vellanikkara., four released varieties namely Pusa Nanha, Arka Prabhath, CO-8, CO-2 and Red lady (F1 hybrid) from private breeder company. Among the accessions/varieties, Pusa Nanha (1.70 m), Acc. 6 (1.84 m) and Red lady (1.88 m) were shorter in terms of plant height. Flowering and fruiting occurred at the lowest height in Pusa Nanha followed by Acc. 6, which is a positive character for easy harvesting of fruits. Maximum fruit weight was recorded in PusaNanha(1866.67g), Acc.5 (1766.67g), Acc. 4 (1346.67 g). Highest number of fruits was recorded in KAU Acc. 1 (20.67), Acc.6 (20.27) and Acc.4 (19.40). Fruit yield per plant was highest in Acc.5 (26.93kg), Acc.4 (26.23kg) and Acc.6 (23.50kg), PusaNanha (22.47kg). Shelf life of fruits at ambient conditions was maximum in Acc.6(8.70) which was on par with Acc.2 (8.53) and Arka Prabhath (8.23). Among the 12 papaya accessions/varieties evaluated for organoleptic analysis, the most preferred taste and overall acceptance was recorded by Acc.6 followed by Red lady. When value added to papaya jam, best taste, flavour and overall acceptance was recorded in Red lady followed by Acc. 6. Biochemical analysis revealed that the highest fibre content was observed in Acc.6 (1.27%) followed by CO 8 (1.19) and Acc.2 (1.11%) which were on par with Acc.6. The maximum per cent of reducing sugar was recorded by Red lady (9.46 %) which was on par with CO 8 (9.45 %), Acc. 2 (9.39 %), KAU Acc. 1 (9.32%), Acc. 6 (9.32 %) and Arka Prabhath (9.13 %). Total sugar content was maximum in Red lady (10.12 %) which was on par with Acc.6 (10.10%), CO 8 (9.95%), Arka Prabhath (9.75%) and KAU Acc. 1 (9.71%). The highest carotenoid content was observed in CO 8 (3.18 mg/ 100g) which was on par with Arka Prabhath (3.14 mg/ 100g) followed by Acc. 6 (2.87 mg/100g) and Red lady (2.50 mg/100g). The lycopene content was maximum in CO 8 (1.72 mg/ 100g)which was on par with Red lady(1.62 mg/ 100g) followed by Arka Prabhath (1.36mg/ 100g), and Acc. 6 (1.12 mg/ 100g) which were on par. Highest ascorbic acid content was observed in Acc.4 (93.37 mg/ 100g). In this study, six accessions, five varieties and one promising accession reported earlier from the main campus, Vellanikkara, KAU were evaluated and the study revealed that Acc. 6 (local genotype collected from Kasaragod) as the most promising compared to all other genotypes for higher yield with consumer preference for cultivation in North Kerala. This accession was found to be better with respect to short stature (1.84 m), number of fruits (20.27), yield (23.50 kg) , Organoleptic test (Score-8.52) and good shelf life (8.70 days) and nutritional qualities such as high fibre content, carotenoid content and lycopene content.ThesisItem Open Access Developement of micropropagation protocol for jackfruit (Artocarpus heterophyllus Lam.)(Department of Fruit Science, College of Agriculture, Padannakkad, 2020) Karishma, N A.; KAU; Meera Manjusha, A VThe present study entitled, “Development of micropropagation protocol for jackfruit (Artocarpus heterophyllus Lam.)” was conducted at tissue culture laboratory, Regional Agricultural Research Station, Pilicode, Kasaragod, during 2018-2020. All the experiments were laid out in completely randomized design. The first experiment was done with the objective to find out the best medium for culture establishment. The treatment combinations include T₁: MS medium with 2 mg/L BA, T₂: ½ MS medium with 2 mg/L BA, T₃: Modified with 2 mg/L BA, T₄: Woody plant medium with 2 mg/L BA, T₅: Gamborge B₅ medium with 2 mg/L BA replicated four times. The result revealed that T1 took minimum days for shoot emergence (13.16), shoot multiplication & branching (15.83), produced maximum no. of shoots/ explant (1.83), Shoot length (1.13cm) and no. of leaves/ shoot (1.66). Second experiment was done with the objective to find out effect of growth regulator for shoot multiplication with 5 treatments replicated four times. The treatment combinations included T₁: Selected basal medium, T₂: Best medium from the 1st experiment, T₃: T₂ + 1 mg/L BA, T₄: T₂ + 2 mg/L BA, T₅: T₂ + 3 mg/L BA. The study clearly indicated that T₃ showed better response in multiplication in terms of minimum days for shoot emergence (13), no. of shoots/ explant (1.99), no. of leaves/ shoot (1.66) and highest shoot length was noticed in T2 (1.13). Another combination of growth regulators were also tried for multiplication with 8 treatments replicated thrice. The treatment combinations included T1 : MS medium + 1mg/L BA + 0.35mg/L GA3, T2 : MS medium + 1.5mg/L BA + 0.35mg/L GA3, T3 : MS medium + 2mg/L BA + 0.35mg/L GA3, T4 : MS medium + 2.5mg/L BA + 0.35 mg/L GA3, T5 : MS medium + 3mg/L BA + 0.35mg/L GA3, T6 : MS medium + 3.5mg/L BA + 0.35mg/L GA3, T7 : MS medium + 4mg/L BA + 0.35mg/L GA3, T8 : MS medium + 4.5mg/L BA + 0.35mg/L GA3. Results shows that MS medium + 2.5mg/L BA + 0.35 mg/L GA3 found to be superior in terms of minimum days for shoot emergence (8.22 days), highest shoot length(2.26 cm), no. of leaves/ explant (4.44) and MS medium + 3mg/L BA + 0.35mg/L GA3 produced maximum no. of shoots/ explant (3.88). Third experiment was conducted with the objective to find out best growth regulator for rooting with nine treatments replicated thrice. Treatment combinations included T₁: ½ strength of selected basal medium, T₂: T₁ + 1 mg/L NAA, T₃: T₁ + 3 mg/L NAA, T₄: T₁ + 0.5 mg/L IBA, T₅: T₁ + 1 mg/L IBA, T₆: T₁ + 1 mg/L NAA + 0.5 mg/L IBA, T₇: T₁ + 1 mg/L NAA + 1 mg/L IBA, T₈: T₁ + 3 mg/L NAA + 0.5 mg/L IBA,T₉: T₁ + 3 mg/L NAA + 1 mg/L IBA. 0.4 g/L of activated charcoal was added to each treatment. None of the treatments produced roots. Another combination of growth regulators were also tried for rooting with eight treatments replicated thrice. The treatment combinations include T₁: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 1 mg/L NAA, T₂: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 3 mg/L NAA, T₃: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 0.5 mg/L IBA, T₄: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 1 mg/L IBA, T₅: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 1 mg/L NAA + 0.5 mg/L IBA, T₆: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 1 mg/L NAA + 1 mg/L IBA, T₇: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 3 mg/L NAA + 0.5 mg/L IBA, T₈: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 3 mg/L NAA + 1 mg/L IBA. Rooting was not observed in all the treatment. It can be concluded that among the basal medium, MS medium fortified with 2 mg/L BA is good for culture establishment. MS medium fortified with 2.5-3 mg/L BA along with 0.35 mg/L GA3 can be used for shoot multiplication. Rooting was not observed because of basal callus formation and phenolic exudation.ThesisItem Open Access Development of micropropagation protocol for jackfruit (Artocarpus heterophyllus Lam.)(Department of Fruit Science, College of Agriculture, Padannakkad, 2020) Karishma, N A; KAU; Meera Manjusha, A VThe present study entitled, “Development of micropropagation protocol for jackfruit (Artocarpus heterophyllus Lam.)” was conducted at tissue culture laboratory, Regional Agricultural Research Station, Pilicode, Kasaragod, during 2018-2020. All the experiments were laid out in completely randomized design. The first experiment was done with the objective to find out the best medium for culture establishment. The treatment combinations include T₁: MS medium with 2 mg/L BA, T₂: ½ MS medium with 2 mg/L BA, T₃: Modified with 2 mg/L BA, T₄: Woody plant medium with 2 mg/L BA, T₅: Gamborge B₅ medium with 2 mg/L BA replicated four times. The result revealed that T1 took minimum days for shoot emergence (13.16), shoot multiplication & branching (15.83), produced maximum no. of shoots/ explant (1.83), Shoot length (1.13cm) and no. of leaves/ shoot (1.66). Second experiment was done with the objective to find out effect of growth regulator for shoot multiplication with 5 treatments replicated four times. The treatment combinations included T₁: Selected basal medium, T₂: Best medium from the 1st experiment, T₃: T₂ + 1 mg/L BA, T₄: T₂ + 2 mg/L BA, T₅: T₂ + 3 mg/L BA. The study clearly indicated that T₃ showed better response in multiplication in terms of minimum days for shoot emergence (13), no. of shoots/ explant (1.99), no. of leaves/ shoot (1.66) and highest shoot length was noticed in T2 (1.13). Another combination of growth regulators were also tried for multiplication with 8 treatments replicated thrice. The treatment combinations included T1 : MS medium + 1mg/L BA + 0.35mg/L GA3, T2 : MS medium + 1.5mg/L BA + 0.35mg/L GA3, T3 : MS medium + 2mg/L BA + 0.35mg/L GA3, T4 : MS medium + 2.5mg/L BA + 0.35 mg/L GA3, T5 : MS medium + 3mg/L BA + 0.35mg/L GA3, T6 : MS medium + 3.5mg/L BA + 0.35mg/L GA3, T7 : MS medium + 4mg/L BA + 0.35mg/L GA3, T8 : MS medium + 4.5mg/L BA + 0.35mg/L GA3. Results shows that MS medium + 2.5mg/L BA + 0.35 mg/L GA3 found to be superior in terms of minimum days for shoot emergence (8.22 days), highest shoot length(2.26 cm), no. of leaves/ explant (4.44) and MS medium + 3mg/L BA + 0.35mg/L GA3 produced maximum no. of shoots/ explant (3.88). Third experiment was conducted with the objective to find out best growth regulator for rooting with nine treatments replicated thrice. Treatment combinations included T₁: ½ strength of selected basal medium, T₂: T₁ + 1 mg/L NAA, T₃: T₁ + 3 mg/L NAA, T₄: T₁ + 0.5 mg/L IBA, T₅: T₁ + 1 mg/L IBA, T₆: T₁ + 1 mg/L NAA + 0.5 mg/L IBA, T₇: T₁ + 1 mg/L NAA + 1 mg/L IBA, T₈: T₁ + 3 mg/L NAA + 0.5 mg/L IBA,T₉: T₁ + 3 mg/L NAA + 1 mg/L IBA. 0.4 g/L of activated charcoal was added to each treatment. None of the treatments produced roots. Another combination of growth regulators were also tried for rooting with eight treatments replicated thrice. The treatment combinations include T₁: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 1 mg/L NAA, T₂: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 3 mg/L NAA, T₃: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 0.5 mg/L IBA, T₄: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 1 mg/L IBA, T₅: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 1 mg/L NAA + 0.5 mg/L IBA, T₆: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 1 mg/L NAA + 1 mg/L IBA, T₇: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 3 mg/L NAA + 0.5 mg/L IBA, T₈: MS + 2.5 mg/L BA + 0.35 mg/L GA3 + 3 mg/L NAA + 1 mg/L IBA. Rooting was not observed in all the treatment. It can be concluded that among the basal medium, MS medium fortified with 2 mg/L BA is good for culture establishment. MS medium fortified with 2.5-3 mg/L BA along with 0.35 mg/L GA3 can be used for shoot multiplication. Rooting was not observed because of basal callus formation and phenolic exudation.ThesisItem Open Access Characterization of avocado(Persea americana Mill)(Department of fruit science, College of Horticulture, Vellanikkara, 2020) Anu Ann, Augustine; KAU; Jyothi, BhaskarAvocado (Persea americana Mill.) popularly known as butter fruit, is a subtropical fruit belonging to family Lauraceae. The present work undertaken in the Department of Fruit Science during the period 2018-19 to study the morphology, flowering pattern and fruit set in avocado (Persea americana Mill.) grown in high ranges of Kerala is the pioneer study done in avocado. Basic characterization of 25 accessions of avocado maintained at Regional Agricultural Research Station, Ambalavayal in Wayanad district was carried out. Morphological and phenological characters of tree, leaf, inflorescence, fruit and seed were evaluated as per the IPGRI descriptor for avocado (Persea spp.). The age of accessions ranged from 6-51 years and hence wide variability with respect to tree characters such as tree height (5.87 to 14.50 cm), trunk girth (33.10 to 274 cm), crown shape (circular, columnar, obovate and irregular), branching pattern (axial, ascendant, horizontal and verticillate), leaf blade length (15.46 to 23.47 cm), leaf width (5.54 to 13.15 cm), leaf blade colour (dark green and green), leaf shape (lanceolate and narrowly obovate), shoot length (89.60 to 42.02 cm) and internodal length ((1.82 to 5.78 cm) were observed among the accessions. Out of the 25 accessions studied, 23 accessions flowered during the period of study. Avocado is known to exhibit a distinct flowering pattern and both A type (in 8 accessions) and B type (in 15 accessions) flowering pattern were noticed. Greenish yellow inflorescence were found to be borne terminally on shoots. Average number of flowers per inflorescence was 137.20 with average inflorescence length of 8.16 cm and width of 10.25 cm. Flushing in avocado occurred during the months of February (3 accessions), March (2 accessions) and September (2 accessions) and flushing was noticed twice in a year during August and February (6 accessions), September and February (6 accessions) and September and March (6 accessions). All the 23 accessions flowered during September to October and 18 out of 23 accessions flowered again in February to March. Flowering continued from 25 to 45 days and flowers were found to set fruits in 12 to 35 days and fruits reached harvest maturity in 109 to 164 days. Both single fruiting season (47.7 %) and double fruiting season (51.8 %) were observed. On an average, yield per tree was 89.29 kg and number of fruits per tree was 904. Variability was observed in fruit characters such as fruit weight (152.40 to 434.20g), fruit shape (narrowly obovate, clavate, obovate, ellipsoid, spheroid and pyriform), fruit length (7.68 to 14.66 cm), diameter (5.30 to 8.42 cm), base shape (depressed and inflated), apex shape (flattened or rounded), apex position (asymmetric or central) and pedicel position (central or asymmetrical). Fruit skin characters observed were thickness (1 mm and 2 mm), ridges (absent or entire), glossiness (weak or intermediate), surface (smooth, intermediate and rough) and colour (purple or light green). Fruit pulp was buttery in texture with light green colour near to skin and yellow or light yellow near to seed in all the 23 accessions. The fruits ripened in 3 to 15 days and had short shelf life of 1 to 2 days. Avocado seeds showed variability in terms of weight (26.20 to 100.10g), length (3.40 to 5.57 cm), diameter (2.37 to 5.82 cm) and total phenolic content (2.4 to 37.37mg g–1). Variability was also observed for qualitative characters of seeds such as seed shape, cotyledon surface, cotyledon colour, seed position and free space of cavity. Quality attributes such as TSS (6.3 0Brix to 10.4 0Brix), titrable acidity (0.64 to 1.28 %), TSS/acidity ratio (5.92 to 15.78) and fats (2.63 to 6.78 %) were estimated. When organoleptic evaluation of the fruits were conducted, the accessions AV-24 and AV-10 were found to be more acceptable. Principal Component Analysis (PCA) was done for different characters and the first three components accounted for variability in tree, inflorescence and fruit characters, whereas first two components accounted for variability in seed and quality characters. Clustering based on first two components for tree, inflorescence, fruit, seed and quality characters led to the grouping of accessions into six, eight, six, six ad five clusters respectively. From the present study, accessions AV-3, AV-11, AV-25, AV-2, AV-10 and AV-24 were identified to be the most promising accessions in terms of yield, quality and sensory attributes.ThesisItem Open Access Responses of mango (Mangifera indica L.) to chemical regulators under high density planting system(Department of fruit science, College of Horticulture, Vellanikkara, 2020) Anju, Jayachandran; KAU; Ajith Kumar, KThe experiment on “Response of mango (Mangifera indica L.) to chemical regulators under high density planting system” was conducted to evaluate the response of different mango varieties (Alphonso, Banganapalli, Sindhuram and Nadashala) to chemical regulators under high density planting system in the agro climatic conditions of Muthalamada and also to study the cost effectiveness. The study was undertaken in the farmers’ field in the Muthalamada region of Palakkad district of Kerala during 2019-2020. The experiment was laid out in Completely Randomized Design (CRD) with five treatments and four replications. The treatments comprised of T1 -paclobutrazol (soil drenching @ 8 ml in 10 litres of water/tree), T2 - KNO3 (4 % foliar spray), T3 - ethephon (200 ppm foliar spray), T4 - salicylic acid (2000 ppm foliar spray) and T5 - control. Application of KNO3 (4 %) had significant influence on growth, flowering, yield and quality of four mango varieties under study. In Banganapalli, Sindhuram and Nadashala, the days for first flowering and flowering duration was found to be minimum. The maximum inflorescence length and width was observed in Banganapalli and Nadashala. The maximum density of flowers in the inflorescence was observed in Sindhuram. In Alphonso, the time taken from flowering to fruit set and fruit set to fruit maturity was observed to be minimum. The fruit bearing intensity was found to be medium in Alphonso, Banganapalli and Sindhuram and shelf life observed was maximum in Sindhuram (7.0 days). The highest TSS (22.62 ⁰Brix) was observed in Banganapalli with minimum acidity in Alphonso (0.18 %). Total sugars and reducing sugars were found to be maximum in Banganapalli and Sindhuram. When the C/N ratio during flowering and two months after flowering were compared, it was found to be maximum in Sindhuram and Nadashala. The total chlorophyll content was found to be maximum in Banganapalli, Sindhuram and Nadashala. With the application of ethephon (200 ppm), the density of flowers in the inflorescence was found to be medium in Alphonso, Banganapalli and Nadashala. In Banganapalli, the time taken from flowering to fruit set, fruit set to fruit maturity and fruiting duration was found to be minimum. The fruit bearing intensity was found to be medium in Banganapalli and Sindhuram. The highest stomatal index and stomatal frequency were observed in Nadashala and Sindhuram respectively. In Sindhuram and Nadashala, stomatal conductance was found to be the maximum. The highest C/N ratio during flowering and two months after flowering were found to be maximum in Banganapalli. 115 With the application of salicylic acid (2000 ppm), it was observed that in Alphonso, the number of days for first flowering and flowering duration were minimum and inflorescence length was found to be maximum. The highest sex ratio was observed for this treatment in Alphonso (41.62), Banganapalli (37.75), Sindhuram (42.75) and Nadashala (35.12). The maximum density of flowers in inflorescence were observed in Alphonso and Sindhuram. Fruit characters like fruit length, fruit diameter, fruit weight, pulp to stone ratio and pulp to peel ratio were found to be maximum. Maximum shelf life was observed in Alphonso (9.0 days). The highest TSS (22.37 ⁰Brix) was observed in Sindhuram and minimum acidity (0.21 %) in Banganapalli. Maximum ascorbic acid, total sugars and reducing sugars were observed in Alphonso. The stomatal frequency was highest in Alphonso, Banganapalli and Nadashala, whereas highest stomatal conductance was observed in Sindhuram and Nadashala. The highest C/N ratio during flowering and two months after flowering and also maximum chlorophyll content were recorded in Alphonso. When compared to control, soil application of paclobutrazol (8 ml) recorded minimum number days for first flowering in Alphonso, Banganapalli and Nadashala. The density of flowers in the inflorescence and fruit bearing intensity were found to be medium in Banganapalli. Application of KNO3 (4%) gave maximum yield per tree in Banganapalli (15.53 kg/year) and Sindhuram (20.50 kg/year), whereas it was salicylic acid (2000 ppm) in Alphonso (14.62 kg/year). The yield per tree was lowest in Alphonso (11.06 kg/year), Banganapalli (13.00 kg/year) and Sindhuram (13.87 kg/year) with soil application of paclobutrazol (8 ml). The highest B: C ratio were recorded in Alphonso (1.98) and Sindhuram (1.32) with salicylic acid (2000 ppm), whereas in Banganapalli (1.88), it was highest with ethephon (200 ppm). In Banganapalli and Sindhuram, the yield per tree was higher with KNO3 (4 %) application followed by salicylic acid (2000 ppm) application. But when the economic returns were compared, the trees sprayed with salicylic acid (2000 ppm) was found to be economically feasible as the total cost of cultivation was found to be 30 per cent lower than that of KNO3. So, it can be concluded that foliar application of salicylic acid (2000 ppm) is the best for chemical regulation of mango under high density planting system in Muthalamada.