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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access Gene action and gene expression analysis in yardlong bean(Vigna unguiculata ssp. sesquipedalis(L.) Verdcourt) for drought tolerance(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2022) Rahana, S N; KAU; Beena ThomasYard long bean (Vigna unguiculata ssp. sesquipedalis (L.) Verdcourt) is a highly remunerative legume vegetable of Kerala. Due to climate change and erratic rainfall, in summer season the crop growth and pod production is heavily affected by moisture stress. Development of high yielding varieties of yard long bean with drought tolerance is essential for its sustainable production. In this context, the present study entitled "Gene action and gene expression analysis in yard long bean (Vigna unguiculata ssp. sesquipedalis (L.) Verdcourt) for drought tolerance" was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, with an objective to identify drought tolerant genotype from the available germplasm and to understand the nature and magnitude of gene action and gene expression involved in the inheritance of drought tolerance in yard long bean. The study comprised four experiments. First experiment dealt with the seedling stage evaluation of 100-yard-long bean genotypes for drought tolerance in field. The moisture stress was imposed by withholding irrigation and later irrigation was restored in order to ensure the survival of the tolerant lines. The results of the analysis showed significant variations among genotypes. Out of the 100 genotypes screened, 15 drought tolerant genotypes were identified based on their better performance in terms of high RLW, low PWP, more number of days for reaching critical stress level and high recovery percentage. The genotypes identified were G1 (Acc 5), G5 (Acc 1339), G6 (Adoor local), G14 (Anchal local II) G15 (Aranmula local), G24 (Elamadu local), G36 (Kattampally local), G42 (Kollam local), G45 (Kottarakara local), G46 (Kottayam local), G50 (Kulashegarapuram local), 051 (Kulathupuzha local), G60 (Muttathukonam local), G74 (Nilamcl local) and G89 (Pongamoodu local). The fifteen selected genotypes from the first experiment were evaluated for drought tolerance in the second experiment by imposing moisture stress at the reproductive stage. Based on the biometric and physiological evaluations, the top seven genotypes with high yield and drought tolerance A4 (Anchal local II), A5 (Aranmula local), A7 (Kattampally local). All (Kulashegarapuram local), A13 (Muttathukonam local), A14 (Nilamel local), and A15 (Pongamoodu local) were selected as parents for further hybridization in experiment in. In the third experiment, LxT crosses were performed by using seven selected tolerant genotypes as lines with three popular yard long bean varieties as testers to generate twenty one hybrids. The genetic analysis of hybrids and parents were evaluated based on eight morphological and eight physiological parameters. Mean performance, combming ability, gene action and heterosis were estimated. Based on the mean performance and gca effects, L4 (Kulashegarapuram local) and L3 (Kattampally local) are identified as outstanding general combiners and can be exploited as parents for drought tolerance breeding in yard long bean. Three superior crosses, Kattampally local x Vellayani Jyothika (L3 x T3), Nilamel local X Lola (L6 X T2) and Kulashegarapuram local x Lola (L4 x T2) were identified as promising combinations for drought tolerance and yield xmder water stress. In the final experiment quantitative real time PCR was conducted to analyze the gene expression of drought responsive genes in tolerant hybrids and parents. The elevated expression of DREBs and NCEDl genes in tolerant hybrids and genotypes in gene expression analysis reflects the increased drought tolerance ability of those genotypes. The gene expression analysis was in conformity with the field studies. All the hybrids mamfested significant amount of dominance variance for commercial exploitation. Existence of significant amoimt of dominance variance and non-additive gene action suggests that hybridization as the best strategy for improving the drought tolerance character in yard long bean. The identified genotypes can be used for isolation of purelines with enhanced drought tolerance and the transgressive segregants from the identified crosses can be used for the development of drought tolerant high yielding cultivars in the fixture. The work can be continued with the identified genotypes and crosses for the development of climate smart drought tolerant varieties of yard long bean.ThesisItem Open Access Exploration on the links between soil carbon storage and root biomass and elucidation of drivers of carbon stabilization(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2022) Geethu Jacob; KAU; Manorama Thampatti, K CThe study entitled ―Exploration on the links between soil carbon storage and root biomass and elucidation of drivers of carbon stabilization‖ was conducted at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani during November 2019 to September 2021 with the objective to study the links between soil carbon storage and root biomass in soils of different agro ecological units and to identify the key drivers of C stabilization and NP fluxes under different management practices. The study area comprised of three Agro ecological units (AEUs) of Southern Kerala viz. Southern and Central Foot Hills (AEU 12), Southern High Hills (AEU 14) and Kumily High Hills (AEU 16). The study was carried out in three parts namely exploration on the links between soil organic C and NP pools with root biomass in soils of different AEUs, assessment of carbon storage under different land use system and identifying the drivers of C stabilization and field experiments to study the effect of management practices on the link between root and shoot biomass C and SOC and NP pools. For the study exploration on the links between soil organic C and NP pools with root biomass in soils of different AEUs, the study area was surveyed and geocoded soil samples from 0-20 cm and 20-60 cm depth were collected using core samplers. The root biomass from the soil samples were separated out and weighed. The soil samples were analyzed for its various physical, chemical and biological properties. For assessment of carbon storage under different land use system and identifying the drivers of C stabilization, the most prominent land use system of each AEU was identified and five samples were collected from each system. The sampling size was one sq.m to a depth of 60 cm. The plants of the same area were uprooted and their shoot and root biomass were recorded. Both the soil and plant samples were collected and analysed for various parameters. The field experiment in split plot design on grain cowpea – fodder maize cropping sequence was laid out with the main plot treatments as m1: conventional tillage, m2: deep tillage (30 cm depth) and m3: no till and sub plot treatments as s1: POP recommendation, s2: soil test based POP, s3: organic nutrient management (TOF-F), s4: POP + AMF, s5: soil test based POP + AMF, s6: TOF-F + AMF and s7: absolute control. After the harvest of grain cowpea, shoot biomass were removed and roots were retained in three replications and in the other three replications total biomass of grain cowpea were added into the soil and left for decomposition. After that fodder maize was raised in the field and the crop and soil samples were collected and analysed for various parameters. The results of the Part I revealed that the physical properties like bulk density (BD) and gravel per cent of all the AEUs showed an increase towards depth while the electrochemical properties showed a decrease. Among the different AEUs, AEU 16 recorded lowest BD (1.22 Mg m-3 ) and gravel per cent (30.53 %) and had a subsoil increase of 12 per cent and 17 per cent for BD and gravel per cent respectively. The different fractions of soil C and N showed a decrease with depth for all AEUs. The soil total organic carbon (TOC-5.94 %) and recalcitrant C (RC-1.64 %) content were highest for AEU 14 with a decrease of 26 per cent and 31 per cent respectively for subsoil. The highest dissolved organic C (DOC-54.63 mg kg -1 ) and labile C (LC- 877.50 mg kg -1 ) content were for AEU 16 with a subsoil decrease of 45 per cent and 27 per cent respectively. AEU 12 recorded lower values for C fractions which may be due to decreased root biomass by 38 per cent and 25 per cent in surface soil and 55 per cent and 70 per cent in subsoil than that of AEU 14 and AEU 16 respectively. The root biomass and soil C fractions were positively and significantly correlated at both sampling depths. The highest correlation coefficients between root biomass and soil C fractions were recorded by DOC (0.976) followed by RC (0.931) and LC (0.975) followed by DOC (0.953) for surface and subsoil respectively. From the regression analysis perfect fit towards linear regression model, expressed as R2 value, was highest for DOC (0.95) and LC (0.94) at sampling depths of 0-20 cm and 20-60 cm respectively. The different fractions of N were highest for AEU 12 and surface soil showed an increase in total nitrogen (TN) by 6 per cent and NH4-N by 20 per cent, NO3 – N by 18 per cent and organic N (ON) by 5 per cent than subsoil. For soil P fractions an increase was observed with depth and AEU 12 recorded highest values for P fractions. Among soil N and P fractions, ON and labile P (LP) were found to be more correlated to root biomass and with higher R2 values at both sampling depths. The MBC (26.89 mg kg -1 ) and DHA (34.94 µg TPF g-1 24 hr-1 ) were highest for AEU 16 and surface soil showed an increase in MBC by 28 per cent and DHA by 30 per cent, than subsoil. For part II, the most prominent land use system of each AEU were identified as rubber plantations for AEU 12 and AEU 14 and cardamom plantations for AEU 16. The rubber plantations of AEU 14 recorded highest C storage (434.0 t ha-1 ) and lowest value was observed for cardamom plantations of AEU 16 (329.9 t ha-1 ). The soil physical properties and electrochemical properties behaved similar to that of Part I. Cardamom plantations of AEU 16 recorded lowest BD (0.97 Mg m-3 ) and gravel content (28 %) while AEU 12 had highest pH (5.61) and lowest EC (0.39 dS m-1 ). Among the different land use systems, rubber plantations of AEU 14 recorded highest values for soil TOC (6.72 %) and DOC (55.16 mg kg-1 ) content while cardamom plantations had highest soil LC (910.91 mg kg-1 ) and surface soil RC (1.92 %) content but subsoil RC content was more for rubber plantations of AEU 14. In rubber plantations the root biomass were correlated to all C fractions and more correlated to RC and TOC and in cardamom plantations root biomass were significantly correlated to TOC (0.98) and DOC (0.95) fractions only. A significant and positive correlation between root lignin and soil C fractions (RC and TOC) was also observed. The different fractions of N and P were highest for cardamom plantations of AEU 16 and surface soil showed an increase in TN by 5 per cent, NH4-N by 14 per cent, NO3– N by 22 per cent and ON by 4 per cent than subsoil and a subsoil increase of TP by 12 per cent, LP by 29 per cent and NLP by 11 per cent were also observed. The shoot biomass were more correlated to soil N and P fractions than root biomass and were more correlated to ON and TN and to TP and NLP among soil N and P fractions respectively. A significant positive correlation between N and P removal and soil NP pools were also obtained. The MBC and DHA were highest for cardamom plantations of AEU 16 and surface soil showed an increase in MBC by 25 per cent and DHA by 23 per cent than subsoil. In the field experiment, among the various nutrient management treatments, soil test based POP + AMF (s5) recorded the highest plant height, shoot biomass and grain yield plant-1 (107.70 g) and TOF-F + AMF (s6) showed highest values for root characteristics and quality parameters for grain cowpea. Similarly for fodder maize grown under both conditions, the treatment soil test based POP + AMF (s5) gave highest shoot biomass, fodder yield and quality parameters while highest root biomass were recorded by the treatment, TOF-F + AMF (s6). Among the tillage levels, the no till treatment (m3) performed best in connection with growth, yield and quality characteristics throughout the cropping period. Tillage and nutrient management had significantly influenced various soil properties. The lowest soil BD and higher WSA per cent and soil pH were reported by the treatment TOF-F + AMF (s6) throughout the cropping sequence. Among tillage levels, deep tillage (m2) remained superior for soil BD and pH and no till treatment (m3) for WSA per cent respectively. The treatment, TOF-F + AMF (s6) remained superior for soil C fractions viz., TOC, LC and RC content, mineralizable N fractions (NH4-N and NO3-N), labile P and MBC content and dehydrogenase activity throughout the cropping sequence. The treatment, soil test based POP +AMF (s5) recorded higher values for NP fractions like TN, ON, TP and non labile P (NLP). Among the tillage levels, the no till treatment (m3) remained superior in connection with soil chemical and biological properties especially towards the end of cropping period. As the cropping sequence advances an improvement in soil physical, chemical and biological properties were observed and this is mainly attributed to the crop residue addition of grain cowpea and more improvement was observed for total residue incorporation than root residue alone addition. The soil C pools were highly linked to root biomass and NP pools to shoot biomass. The root biomass and root lignin were the main drivers of C stabilization. The treatments with AMF remained superior in various soil properties and yield and growth attributes emphasizing the favourable role of AMF in C storage and nutrient cycling in soils. With regard to nutrient management, soil test based POP + AMF recorded the highest yield in cropping sequence while organic nutrition (TOF-F) + AMF contributed more to soil properties indicating the need for further research on nutrient translocation and assimilation under organic nutrition. The no tilled condition with total residue incorporation responded better than root residue alone incorporation, hinting to the fact that more organic matter contributing practices improved the physicochemical and biological conditions of soils favourably.ThesisItem Open Access Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs(Department of Agricultural Entomology, College of Agriculture ,Vellayani, 2022) Anitha, N; KAU; Mithra, MohanThe study on “Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs” was conducted at College of Agriculture, Vellayani during 2017 to 2020 with the objectives to identify mealybugs and their natural enemy fauna in solanaceous and cucurbitaceous vegetables, to carry out the molecular characterization of mealy bugs in solanaceous and cucurbitaceous vegetables and to find out the tritrophic interactions of mealybugs infesting brinjal. An investigation on mealybug diversity in solanaceous and cucurbitaceous crops of Kerala revealed a total of six mealybug species viz., Coccidohystrix insolita, Ferrisia virgata, Paracoccus marginatus, Phenacoccus solenopsis, Planococcus citri and Pseudococcus jackbeardsleyi. Besides, four mealybugs viz., Crisicoccus hirsutus, Maconellicoccus hirsutus, Planococcus lilacinus and Rastrococcus iceryoides infesting other vegetable crops were also recorded from Kerala. The study also revealed that the population of mealybug, C. insolita collected from different regions of Kerala exhibited significant morphological variation. The molecular characterization studies proved that the population belongs to C. insolita and the variations may be environmental induced. An exploration of the host range of mealybugs infesting solanaceous and cucurbitaceous vegetables in Kerala revealed a total of 113 plants under 73 genera belonging to 31 families, out of which 14 plants were recorded as new host reports. A rich natural enemy fauna on mealybugs belongs to five orders viz., Coleoptera, Lepidoptera, Diptera, Neuroptera and Hymenoptera were documented from Kerala. Twenty species of mealybug predators from five different families were recorded, among which the predominant family was Coccinellidae with 16 species under six genera. Among the various predators collected, Cacoxenus sp. was recorded for the first time as a predator of P. jackbeardsleyi. Eleven hymenopteran parasitoids belonging to five families were documented from mealybugs, of which the majority belongs to the family Encyrtidae. Four new host-parasitoid associations were also recorded for the first 288 time. The study also identified six hyperparasitoids under the family Encyrtidae, of which two species were recorded as new report which includes Cheiloneurus sp. and Prochilonerus sp. associated with the mealybug P. solenopsis. The ants associated with mealybugs in different agroecosystems were also investigated and a total of 14 species of ants belonging to nine genera under three subfamilies were recorded, of which the most dominant subfamily was Formicinae followed by Myrmicinae and Dolichoderinae. The present study also revealed 15 new ant-mealybug associations for the first time. The molecular characterization of eight mealybug species was carried out that complemented the morphological identification of species. A total of eight nucleotide sequences were submitted to NCBI GenBank and accession numbers were generated. The sequences were also submitted to BOLD and illustrative barcodes were generated. The barcodes of C. insolita, C. hirsutus and P. jackbeardsleyi were generated for the first time. The diversity of endosymbionts of the mealybug C. insolita was carried out for the first time. The study revealed a total of 15 phyla of endosymbionts on C. insolita, of which Proteobacteria was the predominant one. An experiment was conducted at Instructional Farm, Vellayani to identify the tritrophic interaction in brinjal, C. insolita and its natural enemies. The study revealed that out of the ten brinjal cultivars evaluated, the lowest mean population of mealybugs was observed in Pusa Uttam whereas the hybrid cultivar, Udit recorded the highest number of mealybugs. The lowest mean per cent leaf infestation was recorded in Pusa Purple Long which was statistically on par with Pusa Uttam whereas the hybrid cultivar, Udit was severely damaged by the mealybugs. Among the tested cultivars, Pusa Purple Long was recorded under the group resistant whereas Udit and Haritha were included under the highly susceptible group based on the mean per cent leaf infestation caused by C. insolita. The cultivar Haritha attracted the highest number of predators whereas the maximum mean population of spiders were observed in Pusa Purple Long. 289 The correlation analysis on the mean population of mealy bugs with biophysical parameters revealed that trichome density, length width ratio of leaf and number of branches exhibited a significant positive correlation with mean population of mealybugs. Correlation studies on the mean population of natural enemies with biophysical parameters revealed that plant height exhibited a significant negative correlation whereas leaf thickness and number of branches revealed a non-significant negative correlation with the mean population of natural enemies. Among the biochemical parameters of brinjal cultivars, total phenol content exhibited a significant negative correlation with the mean population of mealybugs whereas total chlorophyll content showed a significant positive correlation. The correlation between biochemical parameters of brinjal cultivars with the mean population of natural enemies revealed that total phenol and carotenoid content exhibited a non-significant negative correlation whereas total protein content, reducing sugar and total chlorophyll content showed a nonsignificant positive correlation. The info-chemical mediated interactions in brinjal cultivars, mealybug and its natural enemies were studied using a multi-armed olfactometer and Y-shaped olfactometer assay. The results revealed that the cultivar Udit attracted the highest number of natural enemy Chrysoperla zastrowii sillemi while the cultivar Pusa Uttam attracted the lowest number. The variation in preference shown by the natural enemies may be related to the difference in volatile compounds emanating from the host cultivar. The GC-MS analysis of the synomonal compounds of the cultivar, Udit revealed a total of eleven compounds whereas the cultivar Pusa Uttam was recorded with a total of five compounds. The Y shaped olfactometer studies revealed that C. zastrowi sillemi adults showed more preference towards the synomonal compounds of mealybug infested plants than that of healthy plant synomonal extracts. On comparing the volatile profile of synomones of mealybug infested and healthy plants revealed that the synomonal extracts of the mealybug infested cultivar Udit comprised of 11 compounds whereas healthy plant synomonal extracts contained nine compounds. 290 The relative response of C. zastrowi sillemi towards the kairomonal compounds of C. insolita was evaluated in a Y tube olfactometer and the results revealed that the highest mean number of adult lacewings were attracted to the kairomonal compounds of mealybug compared to control. The kairomonal extracts of the mealybug comprised of seven compounds and the composition of these hydrocarbons may determine the selectivity of natural enemies towards the preferred host. The present study recorded a total of six mealybug species infesting solanaceous and cucurbitaceous vegetables and its host range, natural enemies and associated ants in different agro ecological regions of Kerala. The molecular characterization studies supported the morphological taxonomy and the sequences were submitted to NCBI Genbank and BOLD. The study also elucidated the interactions mediated by plant traits and info-chemicals in brinjal-mealybugnatural enemy tritrophic systems. The study recorded Pusa Purple Long as resistant cultivar and Udit and Haritha as highly susceptible cultivar to C. insolita. The plant traits viz., trichome density, length width ratio of leaf, number of branches, total phenol content and total chlorophyll content exhibited significant correlation with mean population of mealybugs whereas plant height exhibited significant correlation with mean population of natural enemies. The study on info-chemical mediated tritrophic interactions revealed that the concentration and composition of volatile compounds determine the differential selectivity of natural enemies. The volatile compounds identified in this study can also be used as a cue in moderating the behavior of natural enemies in the ecosystems. So a thorough knowledge on the tritrophic relations in the ecosystem will aid in manipulating these interactions to devise a better pest management strategy.ThesisItem Open Access Jackfruit (Artocarpus heterophyllus Lam.) as a potential source of bioactive compounds(Department of Post Harvest Technology, College of Agriculture, Vellayani, 2022) Viresh; KAU; Mini, CAn investigation on “Jackfruit (Artocarpus heterophyllus Lam.) as a potential source of bioactive compounds” was carried out at Department of Post Harvest Technology, College of Agriculture, Vellayani from 2017-2020 with the objectives to standardize the extraction procedure for maximizing the antioxidant, anti-cancerous and anti-hyperglycemic properties of fruit wastes from varikka and koozha jackfruit types, phytochemical profiling, encapsulation and commercial exploitation of encapsulated extracts for fortification of fruit juice beverages. Experiments were carried out in four parts. Standardization of extraction procedure was carried out in the first part by evaluating the extracts for antioxidant, anti-hyperglycemic and anti-cancerous properties. Both varikka and koozha types were harvested at optimum maturity and were utilized at ripe stage independently. Except bulb, seed and peel without horny portion, all other parts were dried in cabinet (D1) and freeze (D2) driers, pulverized to fine powders and extracts were prepared using solvents viz., methanol at 90 (S1), 80 (S2), 50% (S3) and ethanol at 60 (S4), 80 % (S5) with solid to solvent ratios of 1:30 (R1), 1:40 (R2) and 1:50 (R3). Extract of freeze dried varikka samples using 60 per cent ethanol at 1:50 solid to solvent ratio (D2S4R3) had highest Total flavonoid content (TFC) (15.66 mg QE 100g-1 ), Total phenolic content (TPC) (156.10 mg GAE 100g), DPPH scavenging activity (69.29 per cent inhibition) and α-glucosidase inhibition activity (90.24 per cent). The same extract, D2S4R3 from koozha also exhibited highest TFC (15.88 mg QE 100 g -1 ), TPC (164.63 mg GAE 100g), DPPH scavenging activity (68.64 per cent inhibition) and α-glucosidase inhibition activity (92.28 per cent). Freeze dried varikka samples extracted using 90 per cent methanol at 1:50 solid solvent ratio (D2S1R3) recorded the highest (45.88 mg 100g-1 ) ascorbic acid content and freeze dried koozha samples extracted using 90% methanol at 1:40 solid solvent ratio (D2S1R2) had the highest ascorbic acid content of 47.37 mg 100g-1 . 310 Based on the efficiency and economics, extraction of freeze dried samples using 60% ethanol at 1:40 solid to solvent ratio (D2S4R2), similar samples using 60% ethanol at 1:50 solid to solvent ratio (D2S4R3 ) and cabinet dried samples with 60% ethanol at 1:50 solid to solvent ratio (D1S4R3) were selected as three superior extraction methods . The MTT system which is a simple, reproducible and accurate means of measuring the activity of living cells via mitochondrial dehydrogenases was utilized to assess the anti-cancerous properties of the selected three extracts viz., D2S4R2, D2S4R3 and D1S4R3 on HeLa cell lines with doxorubicin as control. Freeze dried varikka and koozha samples extracted in 60 percent ethanol at 1:50 solid to solvent ratio (D2S4R3) had the lowest IC50 value of 129.30 and 157.60 µg mL-1 respectively whereas the IC50 value for doxorubicin (positive control) was18.85 µg mL-1 . When the three superior extracts were subjected to phytochemical profiling in the second part of the experiment using LCMS/MS (Waters UPLC H class system fitted with TQD MS/MS system) for sugars, organic acids, phenolic acids and flavonoids, they were significantly influenced by extraction methods and jack fruit types. Fifteen sugars, ten organic acids, eighteen phenolic acids and fifteen flavonoids were fractionated and identified from the extracts. Extract of freeze dried sample using 60% ethanol in 1:50 solid to solvent ratio (D2S4R3) had highest sugars, organic acids, phenolic acids and flavonoid content. The major sugars identified were fructose, glucose, mannose, sucrose and sorbitol and; organic acids were citric acid, malic acid, shikimic acid, succinic and hydroxycitric acid; phenolic acids were ferulic acid, p-coumaric acid, caffeic acid, benzoic acid, o - coumaric acid; myricetin, catechin, naringenin, quercetin and epicatechin were the major flavonoids. The three superior extracts selected were encapsulated independently by spray and freeze drying in the third part of the study. Two maltodextrin (MD) levels (10 and 20 dextrose equivalence, DE), three carrier to extract ratio (1:10, 1:15 and 1:20), two inlet- outlet temperature of spray drier (180 - 80º C inlet - 311 outlet and 190 - 90º C inlet - outlet) were the process variables for spray encapsulation, whereas for freeze encapsulation, maltodextrin (MD) levels and carrier ratio were selected as process variables. The extract D2S4R3 from varikka and koozha, spray encapsulated using MD 20 DE at 1:20 carrier to extract ratio (Cr3) at inlet and outlet temperature of 180 and 80º C (T1) recorded highest TPC of 115.47 and 117.92 mg GAE 100 g-1 respectively. Varikka and koozha extracts spray encapsulated using MD 20 DE at 1:10 carrier to extract ratio at 190 - 90ºC inlet - outlet temperature (C2Cr1T2) produced encapsulate with highest per cent recovery (83.77 and 82.09 % respectively). Lowest moisture content of 2.46 and 2.55 per cent were recorded by the extracts spray encapsulated using 10 DE MD at 1:20 carrier to extract ratio at inlet - outlet temperature of 190 - 90º C (C1Cr3T2) from varikka and koozha respectively. Based on the superior physico-chemical properties, spray encapsulate of freeze dried varikka and koozha extracts prepared using 60 per cent ethanol at 1:50 solid to solvent ratio (D2S4R3), using 20 DE maltodextrin at 1:20 carrier to extract ratio with 180 - 80°C inlet - outlet temperature (C2T1Cr3), was selected for Part 4 of the experiment. D2S4R3 extract from varikka and koozha, when freeze encapsulated with MD 20 DE at 1:20 carrier to extract ratio had highest TFC of 11.62 and 11.75 mg QE 100 g-1 respectively. Koozha extract, freeze encapsulated with MD 20 DE at 1:20 carrier to extract ratio had highest TPC of 134.38 mg GAE 100 g-1 DPPH scavenging activity of varikka and koozha extracts were highest when freeze encapsulated with MD 20 DE at 1:20 carrier to extract ratio (per cent inhibition of 71.66 and 77.48 respectively). Ascorbic acid content and per cent recovery of encapsulates were not influenced by levels of MD or carrier to extract ratio. The extracts freeze encapsulated with MD 10 DE at 1:10 carrier to extract ratio had lowest moisture content of 2.22 and 2.51% respectively. Based on the superior physico-chemical properties, freeze encapsulate of the freeze dried varikka and koozha extract prepared with 60 per cent ethanol at 1:50 solid to solvent ratio (D2S4R3), using 20 DE maltodextrin at 1:20 carrier to extract ratio, was selected for part 4 of the experiment. 312 The encapsulated extracts were utilized @ 0.01 to 0.1 per cent for development of fortified mango RTS beverages as per FSSAI standards and compared with commercial fortified beverage in the fourth part of study. Mango RTS beverage enriched with the freeze encapsulate of the extracts @ 0.05 per cent was found to be superior with respect to Total Soluble Solids, total phenolic content, antioxidant activity and total sugar content and these were on par with the beverage enriched with spray encapsulates @ 0.05 per cent and commercial fortified beverages. The highest TPC of 41.05 and 41.12 mg GAE 100 ml-1 were recorded in mango RTS beverage enriched with 0.05 per cent freeze encapsulate of varikka and koozha respectively which were found to be on par with the mango RTS beverage enriched with 0.05 per cent spray encapsulate. The highest scavenging activity (76.29 per cent inhibition) was noticed in RTS beverage enriched with 0.05 per cent freeze encapsulate, followed by the beverage mixed with 0.05 per cent spray encapsulate (73.21%). The lowest scavenging activity (55.19 per cent inhibition) was observed in control sample. From the study, it was proved that the extracts prepared from combined inedible parts of both varikka and koozha jackfruit types are potential source for bioactive compounds. Extraction of freeze dried varikka and koozha types using 60 per cent ethanol at 1:50 solid to solvent ratio was standardized as the best extraction method for retention of phytochemicals, antioxidant activity, antihyperglycemic and anti-cancerous properties. Phytochemical profiling of the superior extracts revealed the presence of 15 sugars, 10 organic acids, 18 phenolic acids and 15 flavonoids. Extracts from varikka and koozha spray encapsulated using 20 DE maltodextrin at 1:20 carrier to extract ratio with 180 - 80°C inlet - outlet temperature and freeze encapsulated by using 20 DE maltodextrin at 1:20 carrier to extract ratio retained maximum phytochemicals and antioxidant properties. These spray and freeze encapsulates could be utilized for fortifying mango RTS beverage @ 50 mg 100 ml-1 without affecting the sensory parameters with an enhanced antioxidant activity of 13-16% compared to commercial fortified mango RTS beverage.ThesisItem Open Access Development and quality evaluation of a jackfruit based nutri flour(Department of Community Science, College of Agriculture, Vellanikkara, 2022) Soumya, P S; KAU; Suma, DivakarThe study entitled “Development and quality evaluation of a jackfruit based nutri flour” was carried out at the Department of Community Science, College of Agriculture, Vellayani, during the period 2018-2021. The main objectives of the study were to formulate and standardize a jackfruit based nutri flour comprised of all the edible parts of the fruit and to evaluate its qualities and invitro therapeutic efficacy. Jackfruit cv. Koozha and varikka based nutri flour was developed on the basis of glycemic index of the various parts of the fruit. Raw jack fruits (12 weeks maturity) were selected. Weight of bulbs, perigones, seeds, rind, core and testa were recorded separately to get the final yield, wet and dry weight, moisture percentage, processing loss and dry matter percentage of the product. The order of glycemic index of jackfruit parts were observed as KJRF˃ KJTF ˃VJTF ˃VJRF ˃ KJPF ˃ VJPF ˃KJCF ˃VJCF ˃ KJBF ˃KJSF ˃ VJBF ˃VJSF. The major flour was constituted with greater percentage of fruit parts with low glycaemic index (50 – 60 %) and 40 % was formed by other components in different proportions. Ten formulations of nutri flour and control were evaluated for their sensory qualities. For these three popular breakfast dishes like “puttu”, “ada” and “oratti” were developed. On the basis of analysis of mean scores of sensory parametersF9 was selected as the best combination. Among the three products based on overall acceptability scores ‘oratti’ was found to be more acceptable. Analysis of functional quality revealed that nutri flour had lower swelling power (7.65g), solubility (1.48%), water absorption capacity (4.36%) and bulk density (1.04g/ml) compared to jackfruit bulb flours. The proximate composition of carbohydrate (31.59 g/100g), protein (7.03g/100g), dietary fiber (13.58 g/100g) were significantly high in nutri flour compared with koozha and varikka bulb flours. The moisture content of nutri flour was lower (0.96%), than koozha jackfruit bulb flour and varikka jackfruit bulb flour (1.28% and 1.39%) respectively. The mineral content such as, total minerals (0.98g), calcium (114.32mg), phosphorus (47.92mg), sodium (10.21mg), potassium (418.10mg), iron (1.67mg), manganese (1.59mg), copper (0.457mg) and zinc (0.923mg) content were higher in nutri flour in comparison to koozha and varikka jackfruit bulb flours. The nutraceutical components like phenol (3.03mg) phytic acid (166.77mg), tannin (19.45mg), β carotene (65.98 μg) and antioxidant content (35.85 μg) was significantly higher in nutri flour compare to koozha and varikka jack bulb flours. The developed jackfruit nutri flour formulation (F9) was packed in metallised laminated pouches and kept for storage studies under ambient conditions for a period of six months storage. During the storage period moisture content, microbial profile and organoleptic qualities were found to be acceptable. To reduce the level of oligosaccharides and to increase the starch digestibility the flour was fermented with Saccharomyces cerevisiae @ 5g/kg for 8hrs. In HPLC analysis, at a retention time of 6.93 minutes standard stachyose, untreated and treated nutri flour. Nutri flour treated with Saccharomyces cerevisiae @ 8 hrs was found to be low in oligosaccharides compared to control. In vitro starch digestibility was significantly high in yeast treated nutri flour (82.81%) when compared to untreated nutri flour (54.84%). Anti-diabetic activity of nutri flour was investigated through α-glucosidase and α-amylase inhibitory activity, by using different solvents. A maximum inhibitory activity was observed in petroleum ether extracted of nutri flour at a concentration of 100 μg/mL in α -amylase (47.17%) and α -Glucosidase (63.93%) enzymes. Hypolipidemic activity of nutri flour showed, highest inhibition percentage with petroleum ether (78.06%) and lowest with distilled water (39.53%). Hepato protective effect of nutri flour was higher in cells treated at 50% concentration. From the above study, it can be concluded that jackfruit based nutri mix has hypoglycemic, hypolipidemic as well as hepatoprotective properties. The nutri mix is formulated from all edible parts of jackfruit, which adds on to the therapeutic value of the product. The entire fruit utilization answers the answers the problem of environmental contamination with these underutilized fruit parts.ThesisItem Open Access Mapping the QTL for yield traits in bitter gourd (Momordica charantia L.)(Centre for Plant Biotechnology and Molecular Biology, College of Agriculture, Vellanikkara, 2022) Lavale, Shivaji Ajinath; KAU; Deepu, MathewBitter gourd (Momordica charantia), being a rich source of phytonutrients such as carbohydrates, minerals, vitamins, and other medicinal compounds, has a great importance in healthy dietary habits. Breeders always seek to breed bitter gourd varieties for the traits such as early maturity and high yield. However, limited investigations have been made to identify the genetic loci governing yield related traits. Marker assisted selection (MAS) assures the presence of favourable alleles and fast recovery of recurrent parent genome in the cultivar under improvement. The success of MAS mainly depends on the availability of a marker-dense genetic linkage map locating quantitative trait loci (QTL) for the target traits. The present study “Mapping the QTL for yield traits in bitter gourd (Momordica charantia L.)” was carried out during October, 2018 to December, 2021 with the objective to map the quantitative trait loci and to develop chromosome-wise maps for the yield traits in bitter gourd. To develop the mapping population, high yielding bitter gourd cultivar Priyanka (Momordica charantia var. charantia) and a wild bitter gourd accession IC634896 (M. charantia var. muricata), were used as parents. A set of 450 microsatellites were screened for polymorphism using genomic DNA of parents and 47 were found polymorphic. Bitter gourd genome (GenBank acc. no. GCA_013281855.1) was scanned and new hypervariable microsatellites were identified using Genome wide Microsatellite Analysing Tool (GMATo) and named as KAUBG_n where n is a serial number. From the 75 microsatellites identified, 69 were validated through successful PCR amplification and 38 among them were polymorphic between the parents. This led to the development of a set of 85 markers polymorphic between the parents. Crosses were made between the parental lines and hybrids from the cross Priyanka × IC634896 yielded more number of fruits and total fruit produce compared to the reciprocal hybrid. An F2:3 population was developed through single seed descent method from the cross Priyanka × IC634896. A panel of 200 F2:3 plants were evaluated for twenty seven traits, including fruit-, flower-, seed-, vine-, and leaf-related traits, contributing directly or indirectly to the total yield. Wide variation was observed among the F2:3 plants for the traits studied. A group of ninety plants was selected from 200 F2:3 plants such that they represent the variation of the base population. Genomic DNA of these plants were genotyped using 85 polymorphic markers. Genotypic data from the screening of 85 markers in the mapping population were used to generate a linkage map spanning 1287.99 cM distance across eleven linkage groups (LGs) corresponding to eleven chromosomes, using IciMapping software. LG 7 (28 markers) consisted of maximum number of markers followed by LG 2 and LG 9, each having 11 markers. LG 1 had 10 markers whereas LG 3, 4 and 8 had seven markers each. LG 5, 6, 10 and 11 had only one marker each. LG 7 covered maximum map distance of 384.19 cM where LG 8 covered least map distance of 68.58 cM. The genetic map and phenotypic data were used to generate the QTL maps, using Inclusive Composite Interval Mapping (ICIM) method to locate twenty seven traits on Momordica genome. Sixty QTL, including 37 major QTL with LOD values ranging from 3.1 to 15.2, explaining 1.8 to 35.9 per cent of the phenotypic variation were identified for 24 traits, on seven chromosomes. Twenty three QTL were identified for fruit-traits with LOD values ranging from 3.1 to 7.6, explaining 5.5 to 35.9 per cent of phenotypic variation. Thirteen QTL were identified for flower-related traits with LOD value ranging from 3.1 to 15.2, explaining 7.0 to 26.0 per cent of phenotypic variation. Seven QTL each were identified for seed and leaf-related traits with LOD values ranging from 3.2 to 10.8 and 3.5 to 6.5, explaining 5.6 to 26.3 and 3.2 to 15.8 per cent of phenotypic variation, respectively. Ten QTL were identified for vine-related traits with 3.2 to 8.7 LOD values and explaining 1.8 to 17.6 per cent of phenotypic variation. Single marker analysis was performed to identify markers co-segregating with the yield contributing traits. There were 129 hits for the marker-trait association with LOD values more than 3.0, explaining 11.62 to 29.34 per cent of the phenotypic variation. Using the least and best performing F2:3 plants, markers S13, KAUBG_5 and KAUBG_11 were validated for co-segregation with fruit breadth, first pistillate flower node, and number of pistillate flowers and fruits per plant, respectively. This study gives insights into the relative locations of microsatellites and major effect QTL for yield traits in Momordica genome. QTL with shorter marker interval (qFrtL-8-1, qDPF-3-1, qDSF-3-1, qDSF-7-1, qFrtShp-8-1) can be directly used in MAS for improving yield characters. Linkage observed between microsatellites identified in this study with yield traits signifies their importance in further fine mapping as well as marker assisted selection. The linkage map constructed in this study, being the first with microsatellites from Momordica genome, paves the path for comparative and consensus map generation with other marker types. Further, fine mapping using markers within the identified QTL hotspots can lead to possible identification and cloning of genes underlying the yield traits.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 Open Access Exploratory study for resilient wheat farming in Nigeria(Department of Agricultural Extension, College of Agriculture, Vellanikkara, 2022) Salisu, Ahmad Dambazau; KAU; Jayasree Krishnankutty, MWheat growing has been the most difficult aspect of Nigerian agriculture for decades. Certain issues remain unresolved, posing a threat to the country's goal of diversifying revenue and lowering its growing reliance on imported wheat. Low wheat production, insecurity in Nigeria's wheat region, a lack of mechanized and updated farming techniques, and uncompetitive pricing are among the issues. This study for resilient wheat farming in Nigeria was conducted with the specific objectives of exploring the sociopolitical situation affecting wheat farming, studying the perceived effects of climate change on production of wheat and livelihoods of wheat farmers, analysing the government policies and schemes on wheat production, examining the marketing behaviour of wheat farmers, and arriving at policy options for resilient wheat farming in Nigeria. In view of the key research objectives, an ex-post facto research design was employed. A multi-stage sampling technique was adopted where three states (Jigawa, Kano and Yobe) and six local government areas (Ajingi, Bade, Garun Malan, Kafin Hausa, Nguru and Ringim), two from each state, were selected for the study. Furthermore, forty respondents were randomly selected from each local government area, making the total sample size of 240. Personal interviews and focus group discussions were used to collect primary data. A pre-test was also conducted to ensure the validity of the instruments. Secondary data was gathered from policy documents, relevant literature, government reports, newspapers, and so on. The elicited data was tabulated, analyzed, and interpreted by the use of descriptive statistics, inferential statistics, likert scale of summated rating, content analysis techniques (MAXQDA 2022 statistical software), price spread analysis, compound growth rate analysis, Kruskal-Wallis test, discriminant function analysis, and the Kendell coefficient of concordance test. The study revealed that the farmers were within their active age, married, and living below the poverty line, have low levels of education, mostly explored additional sources of income, and have enough years of experience in wheat farming. The farmers have marginal land size and acquired it through one method, using mostly certified and non-certified seeds and sourcing it mostly from two places while in contact with an extension agent most of the time. The respondents also participated in other activities for livelihood earning and have a larger number of household members, mostly with one earning member. The study revealed that the most common biotic, abiotic, social and political stress affecting wheat crops and farmers differ with regard to location. The major stresses affecting wheat farmers in Nigeria were pests and diseases, wild birds, marketing of their produce, rodents and domestic animal attacks. The social and political situations affecting wheat production were identified as internal social factors, external social factors, and political factors. Lack of good cultivation practices and the knowledge level of the farmers were the major internal social factors. These, among others, prevented the farmer from fully adopting the recommended agronomic practices. While the major external social factors were consumer food habits, consumer demand for convenience, lower produce prices, and high input costs, The political factors identified were social security issues, inconsistent government policies, intricacies in implementation, the role of the media in publication, role-playing by the milling industries, international trade interests, and lack of political will. No doubt, wheat millers imported more than required in 1986. It may have been a means for them to sabotage AWPP's success. The present approach employed by the milling industry, if sustained, will surely boost the wheat crop production in the country. Further findings indicated that the overall growth rate during the study period was -1% for production and only a minimal growth rate of 2% for harvested area, while a 5% positive growth rate was recorded in imports. It was a clear indication of the low yield of the wheat crop in Nigeria. The findings affirmed that the respondents were aware of climate change, with the majority of them having a medium perception of its effects on wheat production in Nigeria. There was a significant difference among the respondents with regard to the climate change perception which was influenced by their age, educational level, secondary occupation, years of experience, contact with extension agents, and household size. Additionally, Nigeria’s climate has no or little effect on wheat crop production. However, it may be that wheat production in Nigeria has been affected largely by human action rather than climatic and environmental factors. The findings inferred that the wheat production policies were domiciled in Kano state and that there was no equal distribution and allocation of resources among the states. The Anchor Borrower Program (ABP) is the only program having participants across the study areas. This may be because there is advancement in policy handling among the implementing agencies. The ABP failed to capture sustainability in production as well as rural infrastructural development in the program statement. The Agricultural Promotion Policy (APP) document left no stone unturned, the Federal Ministry of Agriculture and Rural Development is driving the implementation of the policy. The policy document gives priority to stakeholders’ roles and responsibilities and is more concerned about sustainability in the production of the priority crops as well as reliability in the marketing channels. The document considers modern day agricultural approaches through the involvement of private sectors in all areas of the agricultural commodity value chain. For the improvement of rural livelihoods, the policy considered the development of the farming communities’ infrastructure. However, the respondents have a medium perception of government policy and scheme on wheat production in Nigeria which influenced by their age, educational level, secondary occupation, years of experience, contact with extension agent, farm size, household size and monthly income, and there was no significant difference in their perception. The majority of the respondents sell their produce immediately after harvest if the price is favourable due to financial urgency for both wholesalers and retailers in the case of Jigawa and Yobe, and consumers in the case of Kano. The majority sell in the local market due to proximity and using trucks as their main transportation facility. The study also inferred that the majority of the respondents relied on informal sources of market information and utilized them regularly. This revealed the kind of trust the respondents gave to those sources and affirmed the weakness of the extension system in the study areas, especially in Yobe state. There were four marketing channels in Jigawa and Kano, while three were identified in Yobe. The producers received the highest percent of the marketing share in channel I (producer –consumer) and a higher amount in channel II (producer–retailer–consumer). The marketing margin was higher in channel III (producer–wholesaler–retailer–consumer) and the producers received a lower amount when compared with channels I and II. This indicates that the more the actors, the less the producers share. There was no additional information obtained from channel IV as it involved industrial processes. Moreover, the study shows that there was significant variation between the states with regard to the variables under study among the respondents between the states. The variable marketing behaviour had the most prominent effect in predicting membership in the group between Kano and other states, while farm size was the most prominent effect between Jigawa and Yobe. The variability in net income of a wheat farmer in Nigeria could be predicted with 99.3% accuracy using age, total output, selling price, straw price, quantity of pesticide used, frequency of irrigation, and total cost of production. The study confirmed that the major constraints affecting wheat farmers in Nigeria were a lack of government intervention, a weak extension system, high input and pest and disease costs, a low output price, insufficient credit facilities, a lack of high-yielding varieties, poor yield, and a lack of a regular market. There was strong agreement on the most important constraints among the respondents of different states. For Nigeria to achieve the desired outcome, focused commitments and the adoption of a multi-dimensional approach are required. Political factors were the major concerns surrounding the wheat production sector and would be overcome through a yearly stakeholders' round table meeting to review the situation. External social factor issues would be addressed by raising awareness and establishing a commodity board to ensure remunerative prices for farmers and reasonable prices for consumers, as well as a consistent supply of raw materials to milling industries. Extension should be intensified to enhance the knowledge level of the farmer for better understanding and increased adoption of new varieties. This could help to overcome internal social issues. More young people need to be persuaded to work in wheat farming in order to increase production and sustainability. Resilient wheat farming in Nigeria could be achieved through focused commitments across the stakeholders’ line. Legislation should be enacted to deal with saboteurs, and the adoption of a multi-dimensional approach toward solving any unforeseen circumstances, should be resorted to.ThesisItem Open Access Post harvest characterisation and management of avocado(Persea americana Mill.)(Department of Post Harvest Technology, College of Agriculture, Vellanikkara, 2022) Geethu, M; KAU; Saji GomezAvocado is a subtropical fruit crop, belonging to the family Lauraceae, and is rich in proteins, vitamins, minerals and monounsaturated fatty acids such as oleic acid, contributing to its high nutritive and therapeutic value. Even though there are a large number of genotypes with widely varying characteristics, inadequate characterisation and identification result in the lack of awareness, improper utilisation and insufficient post harvest management of avocado. Hence, the present study titled, „Post harvest characterisation and management of avocado (Persea americana Mill.)‟ was carried out in the Department of Post Harvest Technology, College of Agriculture, Vellanikkara during 2018-2021. The main objectives of the study were to characterise avocado accessions collected from different parts of Kerala and to evaluate the effect of post harvest management practices to extend the shelf life of avocado fruits and to study the effect of food additives on the quality of frozen slices, fruit pulp, freeze dried fruit powder and subsequently to standardise an instant avocado fruit shake. For the characterisation of avocado genotypes, 27 accessions were collected, among which 14 accessions were from RARS, Ambalavayal in Wayanad and 12 from Kanthaloor in Idukki and one accession was collected from Thanniyam in Thrissur. Characterisation of avocado genotypes based on the horticultural and biochemical traits, accession 25 from Idukki had comparatively higher TSS, vitamin C, total carbohydrates, total flavonoids, oleic acid, calcium, potassium, iron, total ash and crude fibre content. Hence, accession 25 was selected for subsequent post harvest management studies. Antioxidant activity of the methanolic extract of fresh fruit of accession 25 was evaluated by DPPH, FRAP and ABTS assays. Greatest free radical scavenging activity was observed in ABTS assay with lowest IC50 value of 0.10 μg/mL. Fresh and mature avocado fruits, surface sanitised with 2 ppm ozone and pretreated with 2 % calcium chloride, followed by shrink packaging with 25 μ polyolefin film and subsequently stored in refrigeration (T8) as well as cool chamber (T9) were found to be the ideal storage conditions with longest shelf life of 27 days. Calcium chloride pre-treated fruits with shrink packaging, stored under refrigeration had lowest physiological lossin weight, respiration rate, ethylene evolution rate and decay per cent, with better retention of firmness. Fruits of this treatment retained significantly higher total carbohydrates, total protein and total phenols during storage. Avocado slices pre-treated with 40 % sucrose, ascorbic acid (0.5 %) and potassium metabisulphite (0.1 %), quick frozen to -20 ºCin 30 minutes followed by packing in 200 gauge LDPE pouches and held under frozen temperature (-18 0C) was the most ideal pre-treatment for storage. This treatment recorded significantly higher TSS, vitamin C, total carbohydrates, total protein and organoleptic acceptability throughout storage and lowest water activity, peroxide value and microbial population. For preparation and storage of avocado pulp, pre-treatments with ascorbic acid (0.5%) and KMS (0.1%) followed by vacuum packaging LDPE bags (T10) as well as in glass jars (T12), stored under refrigeration resulted in longest shelf life and better quality. Total protein, total phenols, total carbohydrate, total fat, viscosity and organoleptic scores were highest in these treatments with lowest water activity, polyphenol oxidase activity and microbial population during storage. For preparation of avocado fruit powder, addition of 5% maltodextrin, ascorbic acid (1%), tricalcium phosphate (0.15%), EDTA (0.05%) and potassium sorbate (0.05%) followed by freeze drying at -70 ºCand 100 mtorr vacuum for 36 hours followed by packing in LDPE laminated aluminium pouches (T14) and glass jars (T16) stored under refrigeration were the ideal methods with longest shelf life and quality. Significantly higher bulk density, solubility, colour value L*, TSS, vitamin C, total carbohydrates, total fat and organoleptic scores were recorded in these treatments during storage along with lowest hygroscopicity, colour value a* and b*, peroxide value, water activity and microbial population. An instant avocado shake was standardised by combining avocado fruit powder with skimmed milk powder, sucrose and water in the proportion of 1:2:1:2 with appealing appearance, light yellowish colour, unique blend of taste and flavour of avocado fruit and skimmed milk powder.
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