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ThesisItem Open Access Biomineral enriched composts (BOKASHI) - a tool for enhancing nutrient availability and enzyme activity in Rhizosphere(Department of soil science and agricultural chemistry, college of agriculture, Vellayani, 2023-08-05) Shilpa, S.; KAU; Aprna, BBiomineral enriched composts (Bokashi) – A tool for enhancing nutrient availability and enzyme activity in rhizosphere The study entitled “Biomineral enriched composts (Bokashi) – A tool for enhancing nutrient availability and enzyme activity in rhizosphere” was carried out during 2020-22 in the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani. The objective of the study was the production and evaluation of biomineral enriched composts for enhanced nutrient availability, yield of test crop (Bhindi) and enzyme activity in the rhizosphere. The study comprised of three parts viz., production and characterization of biomineral (Bokashi) composts from different organic sources, soil incubation study for evaluating the nutrient release pattern and field experiment for evaluating the performance of the biomineral enriched (Bokashi) compost. Bokashi composts were prepared from two substrates S1 (Aquatic weed Limnocharis flava) and S2 (Aquatic weed Limnocharis flava and banana pseudostem in 1:1 ratio). The substrates were allowed to ferment anaerobically using EM solution and the matured composts were enriched with three minerals like M1 (Calcium apatite), M2 (Epsom salt) and M3 (Sylvinite) at 2% rate in different combinations. The design followed was Completely Randomized Design with 14 treatments replicated thrice. The treatment combinations were T1 – Bokashi compost prepared from L.flava enriched with calcium apatite, T2 - Bokashi compost prepared from L.flava enriched with epsom salt, T3- Bokashi compost prepared from L.flava enriched with sylvinite, T4 –Bokashi compost prepared from 1:1 mixture of L.flava and banana pseudostem enriched with calcium apatite, T5 - Bokashi compost prepared from 1:1 mixture of L.flava and banana pseudostem enriched with epsom salt, T6 - Bokashi compost prepared from 1:1 mixture of L.flava and banana pseudostem enriched with sylvinite, T7- Bokashi compost prepared from L.flava enriched with calcium apatite and epsom salt, T8 - Bokashi compost prepared from L.flava enriched with epsom salt and sylvinite, T9 - Bokashi compost prepared from L.flava enriched with calcium apatite and sylvinite, T10 - Bokashi compost prepared from 1:1 mixture of L.flava and banana pseudostem enriched with calcium apatite and epsom salt, T11 - Bokashi compost prepared from 1:1 mixture of L.flava and banana pseudostem enriched with epsom salt and sylvinite, T12 - Bokashi compost prepared from 1:1 mixture of L.flava and banana pseudostem enriched with calcium apatite and sylvinite , T13 – Bokashi compost prepared from L.flava enriched with calcium apatite, epsom salt and sylvinite and T14 - Bokashi compost prepared from 1:1 mixture of L.flava and banana pseudostem enriched with calcium apatite, epsom salt and sylvinite. To all the treatments (T1 – T4) zeolite was added at a rate of 0.5%. The physico-chemical and biological properties of the produced composts were subjected to analysis. Based on the analysed parameters like major and minor nutrient, enzyme activity, C:N ratio, fertilizing index the best seven composts selected for incubation study and field experiment were T2, T7 , T10, T11, T12, T13 and T14. Among these T13 (Bokashi compost prepared from L.flava enriched with calcium apatite, epsom salt and sylvinite) was selected as the best compost with the highest values of nitrogen, phosphorous, micro nutrients and enzyme activity while the lowest value of C:N ratio was also reported by T13. In part 2 of the study a soil incubation was carried out to investigate the nutrient release pattern of selected composts. The design followed is CRD with 8 treatments which was replicated thrice. One kg soil was incubated at field capacity for four months. The treatments were T1 - Absolute control, T2 to T8 - selected best seven composts. The treatments were imposed at surface of the soil at 20 g kg-1 and thoroughly mixed. Soil sample was drawn at 1st, 4th, 8th, 12th and 16th week of incubation and analysed for organic carbon, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, dehydrogenase and cellulase activity. From the study, it was observed that nitrogen, phosphorous, potassium, calcium, sulphur, iron, copper, organic carbon and enzyme activity were found to be maximum at the 4th week of incubation. Zinc content was observed to be maximum during 12th week of incubation while magnesium content was highest during 16th week of incubation. Manganese availability was maximum during 8th week of incubation. In part 3 of the study a field experiment was conducted from February – May 2022 with Bhindi (var. Anjitha) as the main crop and Amaranthus (var. Arun) as the residual crop. In the field experiment 9 treatments were imposed viz. T1 - Absolute control, T2 to T8 – selected best seven composts and T9¬ - KAU POP recommendation. Analysis of postharvest soil for chemical properties revealed that the highest value of organic carbon (1.14 %) and nitrogen (319.86 kg ha-1) was recorded for T7. The highest value for available phosphorous (91.65 kg ha-1) was recorded for T8 which was on par with T6 (89.67 kg ha-1) and T7 (88.59 kg ha-1). The potassium content was found to be the highest for T6 (273.91 kg ha-1) which was on par with T8 (270.60 kg ha-1). T7 recorded the highest values of iron (48.54 mg kg-1), zinc (4.79 mg kg-1), copper (1.88 mg kg-1) and boron (0.832 mg kg-1). While manganese (25.62 mg kg-1) was reported to be the highest with regard to T8. The highest value of cellulase activity was recorded by T7 (45.53 µg glucose hydrolysed g-1 soil h-1) while T8 recorded the highest value of dehydrogenase activity (302.68 µg of TPF hydrolysed g-1 of soil 24 h-1). Analysis of rhizosphere soil showed the highest value of microbial biomass carbon (91.14 mg kg-1 soil), glomalin (14.27 mg g-1), humic acid (9.21 %), fulvic acid (9.98), fungi (5.52 log cfu g-1), actinomycetes (5.16 log cfu g-1) and soil respiration (4.17 mg CO2 g-1) for T7 while T8 recorded highest value for bacteria (7.90 log cfu g-1). T7 recorded the highest value for number of fruits per plant (30.67) which was on par with T5, T6, and T8. Fruit girth was found to be the highest for T7 (5.06 cm) which was on par with T6, T8 and T9. T7 also recorded the highest value for fruit length (23.81 cm), yield per plant (570.42 g) and total yield (21.05 t ha-1). The highest B: C ratio (2.26) was reported by T7. The highest yield of amaranthus (130.23 kg ha-1) was recorded for T7. From the study, T13 (Bokashi compost prepared from L.flava enriched with calcium apatite, epsom salt and sylvinite) was concluded as the best compost. T7 (Bokashi compost prepared from L. flava enriched with calcium apatite, epsom salt and sylvinite) and T8 (Bokashi compost prepared from the 1:1 mixture of L.flava and banana pseudostem enriched with calcium apatite, epsom salt and sylvinite) recorded the highest values for the available nutrient status during incubation period like nitrogen, phosphorous, magnesium, sulphur, iron, manganese, zinc, copper, organic carbon and enzyme activity. Considering both the soil parameters and yield parameters T7 (Bokashi compost prepared from L. flava enriched with calcium apatite, epsom salt and sylvinite) was recorded as the best treatment.ThesisItem Open Access Carrier based slow release fertilizer formulations for sustained nutrient release and enhanced crop production(Department of soil science and agricultural chemistry, Vellayani, 2023-08-10) Farha, M K.; KAU; Gladis, RThe study entitled “Carrier based slow release fertilizer formulations for sustained nutrient release and enhanced crop production” was conducted at the Department of Soil Science, College of Agriculture, Vellayani during the year 2022. In this study slow release fertilizer formulations were prepared, characterized and investigated for its nutrient release characteristics through leaching experiment with soil column and incubation study. Based on the stability and sustained release of nutrients throughout the leaching and incubation study, best formulations were selected and evaluated. A pot culture experiment was conducted in a completely randomized design replicated thrice using chilli variety Vellayani Athulya as test crop and evaluated the effect of slow release fertilizer formulations on nutrient availability, uptake, use efficiency, yield and quality of chilli. Carrier based slow release fertilizer formulations containing major, secondary and micro nutrients were prepared using compatible fertilizer sources (urea, rajphos, muriate of potash, phosphogypsum, magnesium sulphate, zinc sulphate and borax), carrier materials (zeolite, humic acid, charcoal, chitosan and nano zeolite) and binding/stabilizing agent carboxy methyl cellulose (CMC). The slow release fertilizer pellets prepared were, T1 - Fertilizer mix: Zeolite+ CMC (1:1), T2 - Fertilizer mix: Zeolite+ CMC (1:0.5), T3 - Fertilizer mix: humic acid+ CMC (1:1), T4 - Fertilizer mix: humic acid+ CMC (1:0.5), T5 - Fertilizer mix: charcoal+ CMC (1:1), T6 - Fertilizer mix: charcoal+ CMC (1:0.5), T7 - Fertilizer mix: chitosan+ CMC (1:1), T8 - Fertilizer mix: chitosan+ CMC (1:0.5), T9 - Fertilizer mix: nano zeolite+ CMC (1:1), T10- Fertilizer mix: nano zeolite+ CMC (1:0.5). The pellets prepared were found to be stable, disintegration time 9-13 hours, moisture 5.75- 8.68 %, pH 6.37- 6.90, EC 17.25- 23.17 dSm-1 , bulk density 0.5-0.58 Mg m-3 and weight 4.0- 4.5 g. They contained 8.21 to 9.02 % nitrogen, 5.36 to 5.76 % phosphorus, 3.0 to 3.50% potassium, 5.40 to 5.68 % calcium, 2.01 to 2.86 % magnesium, 4.10 to 5.30 % sulphur , 1.2 to 1.6 % zinc and 0.17 to 0.23 % boron. A soil column experiment was conducted for two weeks to study the nutrient leaching and to confirm the slow release tendency of formulations. The results showed a gradual increase in the release of nutrients from 2 to 14 days of leachate collected from slow release formulations while, fertilizer mix alone showed increasing trend initially and later decreased. A laboratory incubation study was carried out to investigate the nutrient release patterns of the formulations after addition to soil. The results revealed that the pH of soil remained acidic (5.30- 6.17) throughout the incubation period and the EC was found to be increasing from 0.11- 1.45 dSm-1 . The release of nutrients in soil was found to be increasing gradually from 0 to 90 days of incubation with maximum concentration was observed on 90th day for all the nutrients. Based on the stability of pellets and the release of nutrients throughout the leaching and incubation experiment three promising formulations were selected for the pot culture experiment. They were, T2 (FM: Z+CMC 1:0.5), T4 (FM:HA+CMC 1:0.5) and T5 (FM: CC+CMC 1:1) . The treatments of pot culture experiment were T1 -100% RDF as SRF 1 (FM: Z+ CMC -1:0.5) applied as basal,T2 -100% RDF as SRF 1 (FM: Z+ CMC -1:0.5) applied in two splits (basal & 1 MAP), T3 -75% RDF as SRF 1 (FM: Z+ CMC -1:0.5) applied as basal, T4 -75% RDF as SRF 1 (FM: Z+ CMC -1:0.5) applied in two splits (basal & 1 MAP), T5 -100% RDF as SRF 2 (FM: HA+ CMC -1:0.5) appliedas basal, T6 -100% RDF as SRF 2 (FM: HA+ CMC -1:0.5) applied in two splits (basal & 1 MAP), T7-75% RDF as SRF 2 (FM: HA+ CMC -1:0.5) applied as basal, T8 -75% RDF as SRF 2 (FM: HA+ CMC -1:0.5) applied in two splits (basal & 1 MAP), T9-100% RDF as SRF 3 (FM: CHAR+ CMC -1:1) applied as basal, T10-100% RDF as SRF 3 (FM: CHAR+ CMC -1:1) applied in two splits (basal & 1 MAP), T11-75% RDF as SRF 3 (FM: CHAR+ CMC -1:1) applied as basal, T12-75% RDF as SRF 3 (FM: CHAR+ CMC -1:1) applied in two splits (basal & 1 MAP), T13-Soil test based POP recommendation, T14- Control (No fertilizers). The analysis of post harvest soil showed the highest content of available N (320.8 kgha-1 ), P (87.15 kgha-1 ), K (214.3 kgha-1 ), Ca (351.1 mg kg-1 ), Mg (106.5 mg kg-1 ), S (9.32 mg kg-1 ), Zn (4.25 mg kg-1 ) and B (0.46 mg kg-1 ) in T8 receiving 75% RDF as SRF 2 (FM: HA+ CMC -1:0.5) applied in two splits (basal & 1 MAP). With regard to nutrient content and uptake, the treatment T8 registered the highest value. The growth and yield parameters like plant height (56.52 cm), number of branches per plant (9.5), number of fruits per plant (56.70), fruit length (13.44 cm), fruit girth (6.89 cm), fruit weight (11.03), fruit yield (581.2g plant -1 ) and total dry matter production (89.07 g) were found to be the highest in T8. Quality parameters of chilli such as ascorbic acid and capsaicin content were also found to be the highest in T8.The fertilizer use efficiency, agronomic efficiency, apparent recovery of major nutrients and partial factor productivity were found to be the highest recorded in treatment T8.The highest B:C ratio of 2.41 was recorded by treatment T8. Slow release fertilizer formulations containing macro and micro nutrients can be prepared using compatible fertilizer materials (urea, rajphos, MOP, phosphogypsum, magnesium sulphate, zinc sulphate and borax), carrier agents(zeolite, humic acid, charcoal, chitosan and nanozeolite) and binding agent (CMC). The slow release fertilizer pellets were found to be superior with respect to stability, disintegration time, nutrient content and release of nutrients. From the results it can be concluded that the slow release fertilizer formulations containing fertilizer mix: humic acid+ CMC in the ratio of 1:0.5 applied at 75% RDF in two splits as basal & 1 MAP was able to significantly increase the yield, uptake of nutrients, NUE, B:C ratio and quality of chilliThesisItem Open Access Molecular characterization of promising isolates of trichoderma spp. and their field evaluation against fusarium wilt of vegetable cowpea(Department of plant pathology, college of agriculture,Vellayani, 2023-08-07) Jeevidha, M; KAU; Sible, George VargheseThe present study entitled “Molecular characterization of promising isolates of Trichoderma spp. and their field evaluation against Fusarium wilt of vegetable cowpea” was conducted at the Department of Plant Pathology, College of Agriculture, Vellayani during 2020-2022. The study aimed at molecular characterization of potential Trichoderma isolates and their evaluation against Fusarium wilt of vegetable cowpea under field conditions. Five potent isolates of Trichoderma viz., TRMW-2, TRKR-2, TRPN-3, TRPN-11 and TRPN-17 were obtained from the previous study. The analysis of Trichoderma isolates for cell wall degrading enzymes like chitinase, protease and lipase revealed that TRPN-17 recorded the highest chitinase activity of 88.38 U ml-1 . Protease activity was found to be higher in TRPN-11 (165.86 U ml-1 ) whereas highest lipase activity was exhibited by TRPN-3 (4.86 U ml-1 ). The compatibility test among the five isolates showed that all the combinations exhibited antibiosis, lysis and overgrowth except the isolates TRPN-3 and TRPN-11 which displayed only overgrowth. A mild level of antibiosis and overgrowth was observed in the combination of the isolates TRKR-2 and TRPN-17. Assessment of competitive saprophytic ability of the Trichoderma isolates showed that per cent colonization of TRKR-2 was found to be higher (67.50 %) than other isolates and was followed by TRPN-3 and TRPN-17 (56.25 %) with no significant difference among all five isolates. In vitro screening of Trichoderma isolates by dual culture technique revealed that the per cent inhibition of TRPN-17 (63.71 %) was found to be higher, followed by TRKR-2 (58.76 %) and TRPN-3 (58.21 %). Based on the in vitro studies the effective isolates TRKR-2, TRPN-17, TRPN-3, consortia of isolates TRKR-2 and TRPN-17 and consortia of isolates TRPN-3 and TRPN-17 were selected for the in vivo evaluation against Fusarium wilt of vegetable cowpea. Molecular characterization of the isolates were done using the primers for Internal Transcribed Spacer (ITS) regions 1 and 4. All the five isolates produced a single, intact amplicon of size 600 bp approximately. The nucleotide sequences of all the ITS PCR products obtained from the five isolates were confirmed through bidirectional sequencing using the Sangers DNA sequencing. The best match of the amplified sequences was obtained from the GenBank database using NCBI-BLAST and their phylogenetic positions were explored along with the referral sequences from BLAST analysis. The oligonucleotide set of genus-specific primer TvP was used for genus-specific PCR analysis and an amplicon of approximately 245 bp was obtained. The DNA barcoding of the amplicon confirmed the genus identity of all the isolates as Trichoderma. The species-specific identification tried with translational elongation factor- 1 (tef1) and RNA polymerase II (rpb2) gene specific primers did not yield any amplicon indicating that the isolates did not belong to the species T. virens, T. longibrachiatum, T. harzianum and T. asperellum. Application of talc-based formulations of the isolates TRKR-2, TRPN-3, KAU strain and consortium of TRPN-3 and TRPN-17 as seed treatment @ of 20 g kg-1 of seed followed by soil drenching @ 2 per cent at 20, 40 and 60 DAS effectively reduced the incidence of Fusarium wilt of vegetable cowpea in pot culture study. The application of isolate TRPN-3 produced highest pod number (19) in pot culture experiment and also yield per plant (369.57 g) on par with the yield per plant produced by consortia application of TRPN-3 and TRPN-17 (344.52 g). Under field conditions, the disease was most effectively reduced by isolates TRKR-2, TRPN-3, KAU strain and consortia of TRKR-2 and TRPN-17. Lengthy pods (48.16 cm) and highest number of seeds per pod (21.73) were recorded by the application of consortium of TRPN-3 and TRPN-17 whereas application of TRPN-3 resulted in highest yield (1172.63 g/plant), number of pods per plant (19) and reduced days of flowering. Enumeration of population of Trichoderma spp. from soil in different treatments at 90 DAS revealed that, highest population was in treatment with isolate TRPN 3 under pot culture (7 ×104 cfu g-1 ) and field conditions (4 ×104 cfu g-1 ) . In the present study, Trichoderma isolates TRKR-2, TRPN-3, and consortium of TRPN-3 and TRPN-17 were found effective against Fusarium wilt of vegetable cowpea under field conditions. The genus of the isolates under study was identified as Trichoderma. The efficacy of the isolates against other soil-borne diseases of vegetable cowpea and species level identification need to be exploredThesisItem Open Access Cataloguing and documentation of diseases of sympodial orchids in kerala(Department of plant pathology,Vellanikkara, 2023-07-15) Anjali, P; KAU; Deepa, JamesOrchids are valued for their exotic beauty and long vase life, making them one of the most popular cut flowers and ornamental plants worldwide. Currently, orchids hold sixth position among the top ten cut flowers in the world, among which, sympodial orchids rank higher in the export market. However, orchid cultivation is challenged by many biotic factors especially fungal, bacterial and viral diseases, which reduce production potential and economic value. Hence, the present study, ‘Cataloguing and documentation of diseases of sympodial orchids in Kerala’ was proposed with the objective to document various diseases affecting sympodial orchids in Kerala. A purposive sampling survey in orchid growing areas of three districts viz., Thrissur, Ernakulam and Thiruvananthapuram conducted revealed the incidence of leaf blight, leaf spot, wilt, black rot, soft rot, twig blight, petal blight and flower spot diseases in four different sympodial orchids such as Dendrobium spp., Cattleya spp., Oncidium spp. and Spathoglottis spp. Among the 49 diseased samples collected from eight different locations, 21 diseased samples were obtained from Dendrobium spp., 16 from Oncidium spp., six from Cattleya spp. and six from Spathoglottis spp. PDS and PDI were calculated for each symptom from Dendrobium spp., and the highest PDI and PDS were recorded for VY DLB (76.47 %) and MT DLB1 (36.67 %) respectively. In Cattleya spp. highest PDI and PDS were recorded for VY CLS (70.80 %) and VP CSR (48.5 %) respectively. In Cattleya spp. highest PDI and PDS were recorded for VY CLS (70.80 %) and VP CSR (48.5 %) respectively. In Oncidium spp., the highest PDI and PDS were recorded for VK OLS1 with 76.92 per cent and 46.90 per cent respectively. In Spathoglottis spp., highest PDI (48.0 %) and PDS (29.79 %) were recorded for MT SLB1. From the PDS and PDI data, it was found that, leaf blight symptoms were more common and severe in Dendrobium spp. whereas leaf spot symptoms were more severe in Oncidium spp. In Cattleya spp., leaf spot symptoms were most frequently noticed, and soft rot symptom showed highest disease severity. In Spathoglottis spp., leaf blight symptoms were most frequent and severe. PDS and PDI values were correlated with light intensity at different survey locations, and a negative correlation was observed. Isolation of pathogens from diseased samples yielded 52 fungal isolates and one bacterial isolate from different sympodial orchids. A total of 21 fungal isolates were obtained from Dendrobium spp.,18 fungal isolates from Oncidium spp., five fungal isolates and one bacterial isolate from Cattleya spp. and nine fungal isolates from Spathoglottis spp. All the isolates showed different symptoms upon artificial inoculation and these isolates could be reisolated and confirmed as pathogens. The pathogens were identified at generic level based on cultural and morphological characteristics. Different fungal isolates, such as Fusarium spp. (9 nos.), Colletotrichum spp. (6 nos.), Alternaria spp. (2 nos.), Sclerotium spp. (2 nos.), Phytophthora sp. (1 no.) and Curvularia sp. (1 no.) were obtained from various symptoms collected from Dendrobium spp. The pathogens isolated from Oncidium spp. were Colletotrichum spp. (11 nos.), Diplodia sp. (1 no.), Diaporthe sp. (1 no.), Pestalotia sp. (1 no.), Alternaria sp. (2 nos.), Phytophthora sp. (1 no.) and Fusarium sp. (1 no.). Fungal isolates such as Colletotrichum spp. (2 nos.), Fusarium sp. (1 no.), Lasiodiplodia sp. (1 no.), and a bacterial isolate, Pectobacterium sp. were isolated from Cattleya spp, and Colletotrichum spp. (7 nos.), Fusarium sp. (1 no.) and an unidentified fungal culture were obtained from Spathoglottis spp. Molecular characterisation of major pathogens from Dendrobium spp., Oncidium spp., Cattleya spp. and Spathoglottis spp. was done for species level identification. Leaf blight pathogens, VL DF1, VY DF, IK DF1 and MT DF1 were identified as Colletotrichum boninense, Fusarium proliferatum, Fusarium oxysporum and Sclerotium rolfsii respectively, and the leaf spot pathogen, VP DF1 was identified as Alternaria alternata. The leaf spot pathogens, VK OF3 and IK OF1 from Oncidium were identified as Colletotrichum sp. and Diaporthe tulliensis respectively. The isolate, VY CF2 causing leaf spot disease in Cattleya was identified as Lasiodiplodia theobromae and the fungus MT SF1, causing leaf blight symptom in Spathoglottis was identified as Colletotrichum gloeosporioides. The bacteria (VP CB) causing soft rot symptom in Cattleya was identified as Pectobacterium aroidearum. In vitro studies were carried out using chemicals and biocontrol agents against seven fungal pathogens and one bacterial pathogen. Based on the data, hexaconazole was the most effective among the systemic fungicides, which showed 100 per cent inhibition of Colletotrichum boninense (VT DF1), Fusarium proliferatum (VY DF), Sclerotium rolfsii (MT DF1), Alternaria alternata (VP DF1) and Colletotrichum gloeosporioides (MT SF1) at all three doses. The fungicide also showed 100 per cent inhibition of Lasiodiplodia theobromae (VY CF2) at higher dose, while it was least effective (38.33-79.58 %) against Colletotrichum sp. (VK OF3). Bordeaux mixture (1 %) was found to be the most effective contact fungicide, which showed complete inhibition of all pathogens under study except Alternaria alternata (76.25 %). Among two combination fungicides evaluated, carbendazim 12 % + mancozeb 63 % could inhibit all fungal pathogens except Alternaria alternata (52.91 to 65 %). Among the chemicals evaluated against Pectobacterium aroidearum, copper hydroxide showed a maximum per cent inhibition (25.92 %) followed by 1 % Bordeaux mixture (15.5 %) while streptocycline showed per cent inhibition ranging from 0-16.67 per cent. Among the biocontrol agents evaluated, PGPM showed maximum inhibition per cent against the fungal pathogens (60.41-100 %) followed by PGPR-II (50.41-100 %) and Trichoderma asperellum (20.41-91.16 %), while Pseudomonas fluorescens was found to be least effective. In the case of Pectobacterium aroidearum, no inhibition was found when evaluated with P. fluorescens, PGPR-II and PGPM. However, Trichoderma asperellum exhibited a lower inhibition percentage (26.67 %) against the bacterial pathogen. Bioassay studies revealed that carbendazim 12 % + mancozeb 63 % was highly effective against Colletotrichum boninense (VT DF1), followed by Fusarium proliferatum (VY DF), S. rolfsii (MT DF1) and Colletotrichum sp. (VK OF3), whereas the fungicide was found least effective in controlling Lasiodiplodia theobromae (VY CF2) under in planta condition. Hence the study has thrown light upon the diseases affecting sympodial orchids in Kerala and disease management by chemicals and biocontrol agents under in vitro condition.ThesisItem Open Access Development of technology for preparation of soft cheese (Paneer) from jackfruit seed milk(Department of community science, vellayani, 2023-09-29) Fathima,Sanam; KAU; Krishnaja, UThe study entitled “Development of Technology for Preparation of Soft Cheese (Paneer) from Jackfruit Seed Milk” was conducted at the department of Community Science, College of Agriculture, Vellayani, during the period 2020-2023. The objective of the study was to develop a dairy analogue using jackfruit seed milk and to evaluate its quality and sensory attributes. Seeds from jackfruit cultivars Varikka and Koozha with two maturity indices (m1) fully ripe, (m2) fully matured, were selected for the study. The jackfruit seeds were manually peeled off using a stainless-steel knife. Seeds were soaked in different soaking media such as (s1) water, (s2) 2% sodium bicarbonate, (s3) 3% sodium hydroxide, (s4) 2% salt water Treatments: 2x2x4 =16, Replication: 3. The seeds from both varieties were cleaned and white arils was peeled off for further processing. The two varieties of seeds with different maturity indices were undergone two heat treatments (h1) steaming, (h2) pressure cooking. Treatments: 2x3= 8, Replication: 3 The extraction of jackfruit seed milk was done by washing and weighing the Pre-processed jackfruit seeds and blend with water (ratio 1:1.5 w/v). The blended mixture was then filtered through cheese cloth into a glass jar, the extracted jackfruit seed milk was stored in refrigerator at 4°C. The screening of the jackfruit seed milk obtained from the 24 treatments were tested for yield ratio, sensory attributes and curd setting properties. The soaking time was standardised to 24 hours. The heat treatments (steaming and pressure cooking) were standardised at 100°C for 20 minutes. Functional characters like yield ratio, sensory attributes, curd setting of the samples were examined. After statistical analysis of sensory evaluation, yield ratio and curd setting properties of the 24 samples varikka fully ripe soaked in water (v1m1s1) with no heat treatments was chosen as the best milk for the preparation of paneer. For the preparation of paneer four combinations of milk was extracted (f1) jackfruit seed milk (100%), (f2) jackfruit seed milk (50%) + groundnut milk (50%), (f3) jackfruit seed milk (50%) + soymilk (50%) and (f4) jackfruit seed milk (50%) + soymilk (25%) + groundnut milk (25%) and selection of coagulum for paneer preparation was done. (c1) vinegar, (c2) lemon juice and (c3) 10% citric acid, these combinations were tested for yield ratio sensory evaluation and coagulation. (c1) vinegar had the highest coagulation among the 3 coagulants. jackfruit seed milk (50%) + soy milk (50%) was selected as the best combination for the preparation of paneer. The preparation of paneer was done by soaking and blending the selected combination and straining it through cheese cloth, extracted milk was coagulated using vinegar and the coagulated mass was collected by keeping weight, the collected paneer was cut into 7-6-inch pieces and immersed in cold water, the paneer was then wrapped in butter paper and stored in polyethylene pouches and refrigerated at ambient temperature. The quality analysis of the paneer show (9.1g/100g) protein, crude fiber (2.38 %), carbohydrate (1.8 mg/100g), calcium (132.40 g/100mg), fat (3.4 g/100g) moisture content (8.75%) and total solid content (12.17±1.3%) the total bacterial count, total fungal count, total coliform count was accessed using microbiological methods. The presence of bacterial colonies, fungal growth and coliforms was not observed in the initial stage (TLTC) but after one-week bacterial count (43x106), fungal count (42x107) and coliform count (36x102) was detected. The preparation of the jackfruit seed milk + soy milk paneer is convenient to prepare, nutritious and will becomes more in demand as a diary alternative once introduced to the market therefore jackfruit seed milk paneer is a great choice as a dairy analogue without preservatives and harmful chemicals to target broader consumer base.ThesisItem Open Access Biochemical response of okra to bhendi yellow vein mosaic virus and production of virus free plants(Department of plant pathology,Vellayani, 2023-11-14) Swetha, B Nair.; KAU; Ayisha, R; KAUThe research entitled ‘Biochemical response of okra to Bhendi Yellow Vein Mosaic Virus and production of virus free plants’ was undertaken at the College of Agriculture, Vellayani, Thiruvananthapuram during the years 2021 to 2023 with the objective of host pathogen interaction of Bhendi yellow vein mosaic virus (BYVMV)infecting okra, screening of different genotypes of okra cultivars for disease resistance and production of virus free plants using meristem culture. Purposive sampling survey was done and samples were collected from AEU8 and AEU 10. The disease incidence of virus infected okra plants in surveyed locations ranged from 37 to 100 %. And vulnerability index varied from 23.40 to 85.20. Highest V. I. was observed in Arka Anamika (85.2) followed by varieties, Varsha Uphar(80) and Anakomban (83.53). The okra variety, Anjitha, recorded lowest disease incidence of 37.20 per cent and vulnerability index of 23.40. Disease incidence was observed to be high at the flowering and fruiting stage. The virus causing BYVMD was serologically detected using ELISA and DIBA and found that BYVMV isolate have close relationship with tomato leaf curl New Delhi virus. The molecular detection of virus was done using PCR and an expected amplicon of size 520 bp was obtained using Deng primer. The BLAST analysis of the sequence of amplicon from okra with vein clearing symptom and enation symptom showed 96.27 % and 96.67 % similarity with DNA-A segment of bhendi yellow vein mosaic virus isolate. Out of 286seeds collected from infected plants seeds sown, only 57.14 % germination was observed. None of the seedlings established symptoms till flowering stage. Molecular analysis of random samples taken from asymptomatic leaves of grow out plants also showed negative reaction to the virus. ELISA also showed negative results confirming absence of seed transmission. But, presence of virus was detected molecularly on whole seeds taken randomly from the seeds collected from infected plants. Out of 20 seeds examined only four seeds showed positive reaction. The presence of virus was also not detected on any of the seed parts examined. Hence it can be inferred that the virus is present on seed samples but there is no seed transmission. On screening of 15varieties, Phule Vimukta variety (V.I.-13.34) was found to be moderately resistant to BYVMD and Anjitha variety (V. I.- 38.30) was moderately susceptible to BYVMD. Arka Anamika, Anakomban, Arka Nikitha and ten NBPGR accessions studied were found to be highly susceptible to BYVMD.(IC 052303, IC 00780, IC 588166, IC 002134, IC 006101,IC 002024, IC 043279, IC 093771, IC 093688, IC 045820)Defense-related enzymes activities varied with genotypes and also with the growth stages of the crop. Tolerant varieties were found to possess the highest content of defence enzymes compared to susceptible varieties. PO activity of moderately resistant variety Phule Vimukta was observed with 270.29 % and 35.02 % more enzyme activity than the susceptible variety, Anakomban at 90 days after sowing and 45 days after graft inoculation respectively. PO and PPO activity showed an increasing trend on inoculation with virus while PAL showed a decreasing trend. Standardisation of production of virus free plants using meristem culture was done. Meristem culture can be successfully done using MS media with BAP (0.5µM), NAA(0.1 µM) and GA3(0.1µM). Virus indexing of meristem cultured plants by PCR confirmed the absence of virus in regenerated plants. Based on the present study, the virus causing BYMD showing symptoms of vein clearing and enation was found to be BYVMV. Presence of virus was detected on seed (20 %) but seed transmission was not observed in grow out test. Breakdown of resistance was observed in Varsha Uphar and Arka Anamika which were earlier reported as resistant. The variety Phule Vimukta, with disease resistance and high defense related enzyme activity can be used for breeding purposes for the development of disease resistant varieties. Meristem culture can be successfully used for the production of disease-free planting materials and production of quality seeds.ThesisItem Open Access Genotype evaluation and production technology development for high density planting system in papaya(Carica papaya L.)(Department of fruit science, college of agriculture,Vellanikkara, 2023-07-21) Amrita Manohar; KAU; Anu, G Krishnan; KAUPapaya (Carica papaya L.) is an evergreen, tropical, herbaceous fruit crop valued for its taste, medicinal, and dietary benefits. Lack of suitable high-yielding dessert purpose papaya genotypes, scarcity of irrigation water, high cost of fertilisers and limitation with respect to land area available for cultivation are the major factors limiting commercial cultivation of papaya in Kerala. In this background, the present investigation on "Genotype evaluation and production technology development for high density planting system in papaya (Carica papaya L.)" was undertaken at the college orchard attached to the Department of Fruit Science, College of Agriculture, Vellanikkara, during 2021-2022. The study consisted of two separate experiments, experiment I and experiment II. In experiment I, evaluation of genotypes for table purpose under Kerala conditions was carried out in RBD using 25 genotypes. The seeds were collected from research stations and homesteads in Kottayam, Emakulam, Thrissur, Palakkad, and Malappuram districts. The nutrient management was done as per PoP recommendations for papaya (KAU, 2016).ThesisItem Open Access Process optimization of fruit blended boba tea pearls from cassava (Manihot esculenta)(Department of community science, college of agriculture ,Vellayani, 2023-09-11) Gayathri, D.; KAU; Anitha ChandranThe study entitled “Process Optimization of fruit blended Boba Tea Pearls from cassava(Manihot esculenta)”was conducted at the department of Community Science, College of Agriculture, Vellayani during the period 202O-2022.The objective of the study was to develop fruit blended Boba tea pearls from cassava and to evaluate its quality attributes”. Matured M4 cassava was selected and collected from CTCRI, Sreekaryam. Five fruits like dragon fruit, passion fruit, pineapple, jackfruit and mango were selected to make fruit blended boba tea pearls. Cassava was properly cleaned, washed , cut into small cubes and grinded using water for extracting the starch content using a muslin cloth. The slurry was kept for 6-7 hours and the supernatant was discarded . The sediment was then oven dried at 60 C for 2-3 days until it reached moisture content between 5-7 per cent. Fruit pulp was taken after removal of seeds. Fruit blended tapioca pearls was developed by gelatinizing cassava starch powder blended with fruit pulp in the proportions 40:60, 35;65, 70:30, 75:25 and 80: 20 with 10 gram of sugar and was oven dried until the moisture content of the pearls between 5-7 per cent. The dried pearls was then packed in HDPE covers for further sensory studies. For the selection of one best proportion from each fruit,100 grams of the developed fruit blended pearls was subjected to cook in 10 gram of sugar syrup in 100 0C till the pearls become transparent, chewy and jelly like form. Five proportions along with the control of fruit blended tapioca pearls were subjected to sensory evaluation and the best one from each fruit blended tapioca pearls was selected. From the sensory evaluation it was found that T1M(40 ; 60) was the best proportion for mango blended tapioca pearls, T5P (20;80) for passion fruit tapioca pearls, T4P(30: 70 ) for Pineapple blended tapioca pearls, T3J(30: 70) for jackfruit tapioca pearls and T3D(35:65)for dragon fruit tapioca pearls. Nutritional analysis showed that Pineapple blended tapioca pearls T3PI(2.62g/100g) contain highest carbohydrate content and the lowest carbohydrate content was observed for plain tapioca pearls(control).Phenol concentration was highest for control compared to fruit blended tapoca pearls. TAA content was observed highest for passion fruit (9.15g/100g) compared to other treatments and was low in mango blended tapioca pearls. Jackfruit blended tapioca pearls have highest oxalate content compared to other fruit blended pearls and it low in mango and pineapple pearls. On mineral composition it was showed that Jackfruit blended tapioca pearls (T4J) has more potasuim content and lowest for passion fruit tapioca pearls. Phosphorus content was highest in passion fruit blended tapioca pearls P6 (0.013g/100gm)and lowest for control. Calcuim content was highest in mango (3.1g/100gm)and was lowest in Pineapple and passion fruit. For magnesium it was observed that pineapple blended tapioca pearls have highest calcium content(1.8g/100gm). While analysing the PH of fruit blende tapioca pearls it was found that highest pH value is for passion fruit blended tapioca pearls(4.8g/100gm) and pineapple blended tapioca pearls(4.2g/100gm) and the lowest pH was observed for control or plain blended tapioca pearls. Physical properties like swelling power of tapioca starch powder and yield was analysed. Swelling power of tapioca starch powder was found to be 13.08. Total bacterial count, Total fungal count and total coliform count was assessed using microbiological methods under 1 month interval. The presence of bacteria , fungus and E-coli was not detected until 3 months of storage studies. It shows the quality and the shelf stability of the product. To increase the physiological and nutritional characteristics of Boba pearls ,there is a need for new interventions which increases its properties Addition of fruits will increase its nutritive value along with sensory appeal without adding any artificial colours or flavours. Compared to fruits , cassava is low in dietary fiber, vitamins and minerals etc. So addition of fruit based boba pearls not only give an additional texture and flavour ,but also provide nutritive values compared to plain tapioca pearls. The development of process protocols for cassava boba pearls and its technology transfer will benefit cassava growers as well as micro-enterprises to strengthen enterprenurship under One District One product scheme.ThesisItem Open Access Evaluation of native arbuscular mycorrhizal fungi for growth and management of rhizome rot of ginger (Zingiber officinale)(Department of agricultural microbiology,Vellanikkara, 2023-06-21) Revathy, S.; KAU; Preetha, RMycorrhizae are mutualistic symbiotic associations based on bidirectional nutrient transfer between soil fungi and the roots of vascular plants. Over 80% of terrestrial plants can form symbiotic relationship with AMF in the natural environment. AMF being an obligate symbiont, it is completely dependent on the host plant for their life cycle and their relationship always been linked with improved plant performance. Colonisation of plant roots with mycorrhizal fungi greatly increases the root surface area which helps in water and nutrient uptake by plants. The mycorrhizal fungi not only provides the host plant with nutrients, such as phosphate and nitrogen, but also contributes to abiotic (drought, salinity, heavy metals) and biotic (root pathogens) stress tolerance of the host. The present study was undertaken to assess the effect of native arbuscular mycorrhizal fungi for the growth promotion and management of rhizome rot in ginger (Zingiber officinale). The rhizospheric soil samples were collected from ten different ginger growing areas of Wayanad district namely Kalpetta (KAL), Pachilakkad (PAC), Edakkal (EDA), Varadoor (VAR), Anappara (ANA), Vaduvanchal (VAD), Ambalavayal (AMB), Malavayal (MAL), Nenmeni (NEN), and Poomala (POO). Isolation of AMF spores, identification through morphological character and mass multiplication of selected spores were carried out at the Department of Agricultural Microbiology, College of Agriculture, Vellanikkara. Totally 74 types of AMF spores were isolated from the ten samples and tentatively identified at genus level based on morphological characters like colour, size, shape, nature of hyphae, bulbous suspensor, number of spore walls, surface ornamentation. Among 74 isolates, 47 isolates showed characteristics similar to Glomus, 15 to Scutellospora, 9 to Gigaspora, and 3 to Acaulospora. From among these isolates, five most predominant AMF species were selected based on abundance. They included brown spore from PAC AMF 2 sample (28 spores /100 g of soil), dark brown spores from EDA AMF 1 sample (30 spores /100 g of soil), black spore from ANA AMF 5 sample (35 spores /100 g of soil), yellow spores from NEN AMF 2 sample (32 spores /100 g of soil), and brownish orange spores from POO AMF 3 sample (27 spores/100 g of soil). Mass multiplication of selected spores were carried out with maize as host plant in vermiculite – perlite medium. Percent root colonization of maize roots ranged between 80 % to 100 % and spore count of the inoculum ranged from 10 spores / 10 g of inoculum to 22 spores / 10 g of inoculum. Glomus sp. (Black spore) selected from ANA AMF 5 sample showed highest root colonization and maximum number of spores in mass multiplied inoculum. The pot culture experiment was conducted in a completely randomized block design (CRD) with two experiments with eight treatment and five replication at Regional Agricultural Research Station, Ambalavayal of Wayanad district. First experiment was conducted to assess the effect of AMF on the growth and yield promotion of ginger and the treatment consisted of T1 (PAC AMF 2), T2 (EDA AMF 1), T3 (ANA AMF 5), T4 (NEN AMF 2), T5 (POO AMF 3), T6 (POP of KAU, 2016), T7 (Organic POP of KAU, 2015), T8 (Absolute control). The second experiment was conducted to assess the efficacy of AMF in the management of soft rot of ginger. For this, the above treatments were repeated along with the challenge inoculation with Pythium myriotylum, the causal organism of rhizome rot. In the experiment for growth and yield promotion of ginger, T5 (POO AMF 3 - Glomus sp.) significantly higher in ginger yield (T5 on par with T1) and performed better in growth parameters like number of tillers and leaf area (T5 followed by T1) and T1 performed better in growth parameters like plant height, number of leaves. In second experiment (rhizome rot management), T1 performed better in plant height, number of tillers, leaf area and yield of ginger. T1 also recorded lesser disease incidence of soft rot. Final spore count and per cent root colonization was also recorded highest in the T1. Finally T1 (Glomus sp. selected from PAC GRS - AMF 1) was identified as the best AMF isolate which performed better in growth promotion as well as in disease suppression. However, extensive field studies are needed under different season and agro ecological zone, in order to develop an efficient AMF isolate for ginger in high range zones of Wayanad district
