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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 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.
