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ThesisItem Open Access Controlling seedling height of cowpea (Vigna unguiculata (L.) Walp.) transplants using plant growth regulators(Department of Vegetable Science, College of Agriculture, Vellanikkara, 2022-04-28) Anu Latha Robi; KAU; C NarayanankuttyCowpea (Vigna unguiculata (L.) Walp) is an annual leguminous vegetable crop. It is grown throughout india for its tender green pods used as vegetable. Green cowpea seeds are boiled as a fresh vegetable or may be canned or frozen. The beans are nutritious and provide complementary proteins to cereals diets. Seedlings like cowpea, cucurbits having lanky growth growing in polyhouses is an undesirable quality, especially in plugs intended for mechanized planting and long distance transport. Seed treatment with growth retardants is an effective method for controlling seedling height .However limited studies have been conducted in vegetable crops The present study was undertaken with the objectives of controlling seedling height of vegetable cowpea and to assess the field performance of treated seedlings. The experiment was conducted at the Centre for Hi-Tech Horticulture and Precision farming, Vellanikkara KAU, Thrissur during the year 2020-2021 In seedling stage, highest germination was recorded in control treatment on 5th and 10th days after sowing (89%) and (91%) respectively in Vellayani Jyothika. Minimum germination percentage was recorded in Paclobutrazol @ 200 ppm on 5th and 10th day after sowing (64.3%) and (66.0%) respectively in cowpea genotype Vellayani Jyothika. Significantly lower germination percentage was recorded in treatments receiving Paclobutrazol @ 200 ppm on 5th and 10th day after sowing (70.0%) (72%) in the genotype Kashi Kanchan. In both the genotypes there were no significant difference between the treatments on 15th days after sowing. Paclobutrazol treatment took more number of days for emergence of seedling up to the first node compared to control treatment ie Paclobutrazol @ 200 ppm (8.13) and (8.00) respectively in both the genotypes. Highest shoot length was recorded in control treatment on 5th, 10th and 15 th days after germination in both the genotypes. Significantly lower shoot length was recorded in treatments receiving Paclobutrazol @ 200 ppm irrespective of the number of days after germination. Growth retardants in general reduce root growth, shoot weight and root weight of the seedlings. In both the genotypes (Vellayani Jyothika and Kashi Kanchan) significantly lower root length, shoot weight and root weight was obtained in Paclobutrazol treatments compared to non-treated control. Height of seedling up to the first node was directly linked to shoot length. In both the genotypes of the cowpea significantly lower shoot length was recorded in treatments receiving Paclobutrazol @ 200 ppm (4.09) and (4.03) respectively. Paclobutrazol treated seedlings had dark green leaves when compared to other growth regulator and control treatments on 5th ,10th and 15th days after germination. In both the cowpea genotypes, when compared to other growth retardant and control treatments highest stem girth of the seedlings was recorded in treatments receiving Paclobutrazol @ 200 ppm on 5th (3.19 mm) 10th (3.45mm) and 15th (3.7mm) in Vellayani Jyothika and on 5th (3.3mm ) 10th (3.4mm) and 15th (3.8mm) in Kashi Kanchan. There were no significant difference between the treatments on 5th (2) and 15th days (7-8) after germination in both the genotypes. The total chlorophyll content and carotenoid content was recorded highest in treatments receiving Paclobutrazol treatments on seedling stage. Minimum auxin content and gibberellic acid contents were observed in Paclobutrazol treatments. In the field experiment, in both the cowpea genotypes, plant growth regulator Ethrel recorded maximum plant height where as in Vellayani Jyothika minimum plant height was recorded in Cycocel@ 50 ppm (112.40 cm) .In Kashi Kanchan lowest plant height was recorded in Paclobutrazol @ 200 ppm (33.06 cm) in Kashi Kanchan. In vellayani Jyothika highest internodal length was recorded in Ethrel @100 ppm (3.13 cm) and Ethrel @50 ppm (3.04 cm). Minimum was recorded in Paclobutrazol@ 200 ppm (2.63 cm). In the genotype Kashi Kanchan maximum internodal length was recorded in Ethrel@ 200 ppm (3.34 cm) and minimum was recorded in Cycocel @ 100 ppm (2.53cm). Highest number of primary branches was recorded in treatments receiving Paclobutrazol @ 200 ppm which was on par with Paclobutrazol @ 100 ppm compared to control in Vellayani Jyothika. In Kashi Kanchan there were no significant differences found between the treatments. Growth retardants had significant effect on the viz days to first flowering, days to first harvest and crop duration. Early flowering results in early harvesting of pods. Plant growth retardant Cycocel @ 200 ppm (41day) and Cycocel @ 25 ppm (36.80 days) recorded earliest flowering in the field in both the genotypes. In both the genotypes delayed flowering and maximum crop duration was recorded in Paclobutrazol treatments. Pod length and pod girth are related with pod weight. Ethrel treatment had highest pod length and pod girth compared to control .The higher number of flowers, pod girth and pod length contributed to production of more number of pods which in turn resulted in higher yield per plant. In both the cowpea genotypes, highest number of pods per plant and yield per plant was recorded in Ethrel treatments (Ethrel 100 ppm) in Vellayani Jyothika followed by Paclobutrazol treatment (Paclobutrazol 100 ppm) where as in Kashi Kanchan Paclobutrazol 100 ppm was on par with Ethrel 100 ppm. From the above study it could be concluded that, Paclobutrazol 100 ppm seed treatment was effective in controlling seedling height as well to obtain good yield in vegetable cowpea.ThesisItem Embargo Genetic diversity analysis for nutrient efficiency and identification of nutrient responsive genes in cassava (Manihot esculenta Crantz)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2023-02-10) Swathy Sivan; KAU; Arya, KThe present study entitled “Genetic diversity analysis for nutrient efficiency and identification of nutrient responsive genes in cassava (Manihot esculenta Crantz)” was carried out in the Department of Plant breeding and Genetics, College of Agriculture, Vellayani and Division of Crop Improvement, ICAR-CTCRI, Sreekariyam, during 2019-2022. The study was undertaken to screen and characterize N and K-efficient genotypes in cassava and identify the traits contributing to nutrient efficiency and study their gene expression. Thirty genotypes of cassava comprising of landraces, released varieties and pre-release accessions from ICAR-CTCRI and KAU were taken for the study. Field evaluation was done to identify low input nutrient efficient lines where analysis of variance revealed significant difference among the genotypes for all the characters studied except the girth of tuber. High GCV, PCV, heritability and genetic advance were observed for traits like tuber yield, N and K efficiency, plant height, number of leaves, number of branches, stem N and K content. Tuber yield was positively correlated to N and K efficiency, plant height, leaf and stem weight, stem girth, mean weight of tubers, number of nodes, girth and length of tubers, while negatively correlated to tuber starch and dry matter content. Path analysis showed that tuber length gave highest positive direct effect on yield followed by number of tubers, number of leaves, tuber starch content, plant height and nitrogen efficiency. Diversity studies grouped the genotypes into eleven clusters and the characters that gave the maximum contribution to divergence were tuber dry matter content, N and K efficiency. Root studies on thirty genotypes revealed that root traits like number of nodal roots, basal roots, adventitious roots, storage roots and root length displayed significant positive correlations with N and K efficiency. Evaluation of five highly nutrient efficient genotypes at the three levels of fertilizers (0%, 25% and 50% of the recommended dose of fertilizers) showed overall significance for traits like plant height, the number of leaves retained, stem weight per plant, girth of the stem, tuber yield, length of tuber, stem K content, tuber K content, total N and K uptake, N and K efficiency. The highest yielder was KBH 18 followed by 8S501-2. Maximum N efficiency was observed for KBH18 followed by 15S409, while maximum K efficiency was recorded for 8S501-2 followed by 15S409. Results showed that from 0 to 25 % there is an escalation in tuber yield as well as N and K efficiency, while the values at 25 and 50% are on par. All the selected four genotypes showed significant superiority over the K efficient check variety – Sree Pavithra – in terms of tuber yield, N efficiency and K efficiency. The study identified nine nutrient responsive genes in cassava which includes NRT1, NRT3, NLP1, GPT2, AMT1, TAR2 for nitrogen and KUP3, KUP4, KUP8 for potassium. Expression studies done using these genes in contrasting genotypes for N and K efficiency raised under field conditions showed significant upregulations and downregulations in their expression for efficient and less efficient genotypes. Allele mining for allelic variations in contrasting genotypes (15S409 and Export kappa) for two genes (AMT2 and NTR3) didn’t show much significant variation. Although SNP differences were observed for NRT3 gene, further functional studies are required to confirm this result. The study identified three main nutrient efficient genotypes viz., KBH18, which was the highest yielder, highest in N efficiency and third highest in K efficiency, 8S501-2, which was second highest in yield, highest in K efficiency, third highest in N efficiency and also exhibited early bulking and 15S409, which was the third highest yielder, second highest in N efficiency & K efficiency. The superior genotypes identified in the present study can be subjected to field trials for confirming their superiority and release as a variety.ThesisItem Open Access Soil quality index and nutrient balance in rice-rice cropping system under long-term fertilizer experiment(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellanikkara, 2021) Drishya, D S; KAU; Thulasi, VLong-term experiments provide the best possible platform for studying the changes in soil properties and processes, identifying emerging trends in nutrient imbalances and deficiencies and help to formulate future strategies for maintaining soil health and quality. The present study entitled “Soil quality index and nutrient balance in rice-rice cropping system under Long Term Fertilizer Experiment” was undertaken at RARS, Pattambi and College of Agriculture, Vellanikkara. The objectives were set out to estimate soil quality index and NPK balance in rice-rice cropping system as affected by nutrient management practices under Long Term Fertilizer Experiment. The Long Term Fertilizer Experiment (LTFE) in rice-rice cropping system maintained (since 1997) at RARS Pattambi has been laid out in RBD consists of 12 treatments viz.,T1 : 50 per cent NPK, T2 : 100 per cent NPK, T3 : 150 per cent NPK, T4 : 100 per cent NPK + 600 kg ha -1 CaCO3 , T5 : 100 per cent NPK, T6 : 100 per cent NP, T7 : 100 per cent N, T8 : 100 per cent NPK + Farm Yard Manure (FYM) @ 5 t ha -1 , T9 : 50 per cent NPK + FYM @ 5 t ha -1 , T10 : 100 per cent NPK + in situ growing of Sesbania aculeata, T11 : 50 per cent NPK + in situ growing of Sesbania aculeata and T12 : Absolute control (No fertilizer or manures). The soil samples from 0-15 cm depth were collected from the different treatments of LTFE after the harvest of Virippu crop, 2020 and were analysed for various physical, chemical and biological properties. Principal Component Analysis (PCA) was performed to arrive at the Minimum Data Set (MDS) and Soil Quality Index (SQI) was formulated for different nutrient management practices. Integrated nutrient management with FYM and in situ green manuring with daincha recorded higher grain and straw yields of rice. The increase in fertilizer load into the soil resulted in increase in yields while the omission of primary nutrients resulted as decline in yields. Integrated Nutrient Management practice (INM) of application of FYM along with 100 percent NPK had lower bulk density (1.17 Mg m-3 ) and higher water holding capacity (43.65 %), higher levels of available nutrients and enzyme activities in the soil. However, dehydrogenase activity did not follow the same trend as that of microbial biomass carbon in treatments wherein fertilizers alone were applied indicating the chances of shift in the microbial populations as a result of the long term application of nutrient management practices. Principal Component Analysis (PCA) was performed for 28 soil attributes to develop the MDS and SQI was formulated using non linear scoring method. The MDS included bulk density, porosity, soil pH, permanganate oxidizable carbon, available N, total N, available sulphur, microbial biomass carbon, acid phosphatase and aryl sulfatase activities. The SQI ranged from 1.82 to 3.01. The SQI declined in the order of: T8> T10 >T9> T11> T4> T3> T2= T1> T5> T6 >T7> T12. The highest SQI was observed in T8 where 100 per cent NPK and FYM were applied. When the dosage of fertilizers was increased from 50% to 100% NPK on integration with FYM, the SQI increased. The soil quality index of the INM treatments (55.50 to 62.11%) and lime incorporation (52.98%) were categorized under medium category as per the computed Relative SQI (RSQI) values. The virippu crop (2020) under LTFE maintained at RARS Pattambi was monitored and various inputs and outputs regarding primary nutrients were assessed for balance predictions using NUTMON toolbox. The NUTMON toolbox includes five inflows, viz., mineral fertilizers (IN1), manure (IN2), atmospheric deposition (IN3), biological N fixation (IN4), and sedimentation (IN5), and five outflows, viz., harvested product (OUT1), crop residues (OUT2), leaching (OUT3), gaseous losses (OUT4), and erosion (OUT5). Nutrient flows like fertilizers, manures, crop residues and harvested outputs were monitored and measured during the experiment. Other flows like nitrogen fixation, leaching, and erosion were estimated by means of regression models from the data related to climate and crop parameters. Available NPK content of soils, rice grain, straw, stubbles, weeds and all inputs were analysed and stored in background database. The data were fed into the data processing module of the NUTMON toolbox to arrive at the partial and total balance of N, P and K in the experimental soil. The total balance of N, P and K were found to decline in order of: T3>T7>T8>T6>T5>T2>T4>T10>T9>T1>T11>T12 for N, T3>T8>T6>T10>T2>T5>T4>T9>T1>T11>T12>T7 for P and T3>T2>T5>T8>T9>T10>T4>T11>T1>T12>T7>T6 for K Summarizing the results, integrated nutrient management with FYM and in situ green manuring with daincha recorded higher yield and available nutrients in the soil. The incorporation inorganic fertilizers with FYM, daincha and lime maintain the soil quality index in the long run while, SQI was poor in control, imbalanced nutrition as well as in treatments where only fertilizers were incorporated. The balance sheet of P establishes the need for maintenance dose of P fertilizers in rice-rice cropping system. The negative balance of N and K indicate the need for supplementing the nitrogen pool and the possibility of mining of K on long term intensive cropping, respectively. Further study should be focused on monitoring the soil quality index at regular intervals and analyzing the effect of nutrient management practices on microbial diversity in rhizosphere and phyllosphere.ThesisItem Open Access Modelling habitat suitability and climate change impacts on endemic birds of Southern Western Ghats, Kerala, India(Department of wildlife sciences, College of Forestry,Vellanikkara, 2021) Sreehari K Mohan; KAU; Nameer, P OThesisItem Open Access Institutional intervention by dairy co-operatives in Palakkad District(Department of Co-operative Management, College of Co-operation, Banking & Management,Vellanikkara, 2021) Maria Poulose, T; KAU; Veerakumaran, GKerala currently represents the twelfth largest dairy market in India. The share of livestock in Gross State Value Added (GSVA) from the agriculture sector in Kerala is above 27 percent. The livestock population in Kerala was 38.36 lakh in the year 2020 (Economic Review Report, 2020). Dairy co-operatives are functioning to support dairy farmers in the processing and selling of milk and milk products. The common need of milk producers is to obtain a fair price for their milk and this is fulfilled through collective marketing. Milk is considered to be one of the most sensitive products under agriculture and allied sector, requiring special and timely care and this can be provided through the collective operation of dairy co-operative societies. The present study was undertaken with the following objectives viz., to analyze the performance of selected dairy co-operatives, to evaluate the services rendered by the selected dairy co-operatives, to assess the extent of utilization of services by the member farmers, to assess the role of selected dairy co-operatives in the empowerment of member farmers, and to study the problems faced by the dairy farmers. The sample size consists of 256 (Active members-200, BOD-36, Employees 20) were selected from four dairy co-operative societies from Palakkad district namely, Moolathara Ksheerolpadaka Sahakarana Sangam Ltd. No. P 65 (D), Kunnamkattupathy Ksheerolpadaka Sahakarana Sangam Ltd. No. P 126 (D), Menonpara Ksheerolpadaka Sahakarana Sangam Ltd. No. P 281 (D) and Attappadi Ksheerolpadaka Sahakarana Sangam Ltd. No. P 558 (D). The performance of selected dairy co-operatives was analyzed through the variables namely farmer member participation, financial indicators, structural factors, managerial factors, legal, political factors, technological factors, functional factors, human resource factors, and co-operative governance. The percentages and index methods with graphical representations were used for the study. The membership was more in Moolathara DCS and less in Menonpara DCS. The milk procurement and milk supply were more in Moolathara DCS and less in Attappadi DCS. The local milk sale was more in Menonpara DCS and less in Moolathara DCS. The farmer participation levels in dairy co-operatives were higher among the respondents. The financial indicators, structural factors, managerial factors, legal, political factors, technological factors, functional factors, human resource factors, and co-operative governance also showed a positive result in the study. But, the absence of trained Artificial Insemination (AI) and Veterinary First Aid (VFA) workers was the major problem faced by the dairy farmers in the dairy co-operative societies. The services offered by the selected dairy co-operative societies were evaluated by using the index method and percentage methods. The offered schemes and services are grouped into production enhancement services, Flood and COVID-19 related services, and dairy farmer welfare board services. Out of these schemes, the level of utilization was more for production enhancement services compared to other schemes. The participated dairy farmers opined positively for the effectiveness of schemes and services by the dairy co-operatives. The empowerment of dairy farmers was analyzed by using the index method. The different types of empowerments studied were social empowerment, Economic empowerment, Psychological empowerment, and Political empowerment. The opinion towards all types of empowerments except political empowerment was higher. The political empowerment level was marked as low. It indicates less political empowerment through the dairy co-operatives. The problems related to milk production, procurement, the impact of flood and covid-19 in dairying, and constraints in availing services and schemes were examined by using the index method. The climatic variation has highly affected the quantity of milk production. The non-availability of labor and Lack of sufficient veterinary services is the major problem faced by dairy farmers. The flood of 2018, 2019 didn’t affect the dairy farmers. But COVID-19 lockdown affected milk transportation to DCS and it affected the quantity of milk procured by the dairy co-operative society. It finally leads to a decrease in profit from the sale of milk. The study can be concluded that the performance of the dairy co-operatives shows strong farmer member participation, financial, structural, managerial, legal, political, technological, functional, and human resource factors, and co-operative governance in the dairy sector. All the services rendered by the co-operative societies were utilized by the farmers based on their requirements. By providing the services by the dairy cooperatives, they assured the economic, social, psychological empowerment except for political empowerment. Still, the farmers were facing the problems in dairying like the absence of trained Artificial insemination and Veterinary First Aid worker to provide veterinary services, Climatic problems, and scarcity of labour. The recommendation of the study includes the appointment of trained Artificial insemination and Veterinary First Aid worker to provide veterinary services, the conduct of awareness program for the dairy farmers related to the health problems faced by the cattle, and also conduct of awareness classes for attracting youth towards dairy farming and create labour groups by the dairy co-operatives to solve the problem of scarcity of labours.ThesisItem Open Access Standardization of technology for microgreen production(Department of Vegetable Science, College of Agriculture, Vellanikkara, 2021) Arya, K S; KAU; Sangeetha Kutty, MMicrogreens are new class of vegetables that are gaining popularity in the recent years due to their attractive appearance coupled with vivid flavors. They are young immature greens produced from seeds of vegetables or herbs which are harvested at its true leaf stage. Most of the research works in this area are carried out with temperate species of crops whose seeds are very expensive. Hence there is a need to popularize the microgreens of tropical species at an affordable price with minimum inputs, so that it is easily accessible to common people. The study entitled “Standardization of technology for microgreen production” was conducted at the Department of Vegetable Science, College of Agriculture, Vellanikkara during January to October 2021. The study was experimented with wheat, ragi, green gram, horse gram, amaranthus and mustard whose seeds were collected from the local market. It was conducted as four experiments (standardization of seed treatment, standardization of media, standardization of seed density and to assess the nutritional value and yield under different growing conditions). The first experiment was to standardize seed treatment done using two chemicals hydrogen peroxide and vinegar treated at different concentrations. The observations on germination percentage, seedling vigour and yield were recorded. The seed treatment did not show any effect on growth of microgreens when compared to the control on the parameters recorded. The microscopic observation of freshly harvested microgreens for fungal contamination indicated absence of any contamination in the fresh microgreens. The experiment on standardizing growing media was carried out using five media viz, sterile sand, cocopeat, coir mat, tissue paper and newspaper. The observation on yield, seedling height, nutritional value of microgreens and microscopic observation on fungal growth were recorded. Yield was observed to be highest in microgreens grown on cocopeat media and lowest was recorded in microgreen grown on newspaper media and among the crops it was highest for green gram microgreens (1.03 to 1.49 kg/m2). The seedling height showed a slight decrease in ragi and mustard microgreens grown on newspaper and comparing the crops, it was observed to be maximum in green gram microgreens (10.23- 10.54 cm). The nutritional parameters recorded were not showing any difference when sown in different media. The wheat microgreens were observed to rich source of vitamin C, beta carotene and protein, ragi microgreens were showing more calcium and vitamin C and beta carotene content, green gram microgreen were rich in protein, vitamin C and calcium, horse gram microgreens were rich in vitamin C, chlorophyll, beta carotene and crude protein, amaranthus microgreens possess high iron, calcium, beta carotene and vitamin C content and mustard microgreens were rich in protein and beta carotene, iron and vitamin C. Microscopic observation on freshly harvested produce revealed that there is absence of fungal contamination in microgreens. The seed density for microgreen production was standardized in the third experiment. The seeds were sown at three densities viz, low, medium and high density for each crop. The observations recorded included yield, seedling height and microscopic observation on fungal growth. The yield was recorded to be highest when sown at high density for wheat (705 g seeds/m2), ragi (520g seeds/m2) and amaranthus(120g seeds/m2) microgreens and medium density planting yielded highest for green gram (850g seeds/m2), horse gram (617 g seeds/m2) and mustard (440 g seeds/m2) microgreens. The seedling height recorded was observed to be on par except for green gram and horse gram microgreens, where highest seedling height was found in medium density planting. No fungal contamination was observed in microscopic observation of fresh produce. Nutritional value and yield of microgreens grown under two conditions (room condition and rain shelter) were studied in fourth experiment. The parameters recorded were yield, seedling height, nutrient content under two conditions, organoleptic evaluation and shelf life of microgreens. The yield was observed to be significantly high when raised under rain shelter condition than room condition. Among the crops it was highest for green gram microgreens (2.261 kg/m2). The seedling height was observed to reduce under rain shelter condition. Nutritional content was also observed to be high when planted under rain shelter for all parameters viz, iron, calcium, beta carotene, vitamin C, crude protein, crude fibre, chlorophyll, oxalates and nitrates. Organoleptic evaluation revealed highest total mean rank for mustard microgreens (54.56) raised under room condition. The shelf life study revealed that the storage period of microgreens can be extended when it is stored in ziplock PPE bag under low temperature condition. In this study, several aspects of microgreens production viz, seed treatment, growing media, seed density, growth conditions and shelf life were standardized. The results indicate that microgreen cultivation can be recommended both as a commercial and household venture.ThesisItem Open Access Evaluation of tomato genotypes for tomato leaf curl virus (tolcv) resistance(Department of Plant Breeding and Genetics, College of Agriculture, Vellanikkara, 2021) Anjitha, A R; KAU; Deepthy Antony, PTomato (Solanum lycopersicum, 2n=24) is a widely grown vegetable in India, exhibiting wide variability for plant traits. Worldwide, tomatoes are susceptible to many diseases like damping off, bacterial wilt, early blight, leaf curl virus disease, leaf spot etc. Among them, tomato leaf curl virus disease (ToLCD), caused by whitefly-transmitted begomoviruses is more severe and it can cause up to 100 per cent yield loss. Although, the cultivated tomatoes are susceptible to Tomato leaf curl virus (ToLCV), different levels of resistance were identified in wild relatives of tomato. Utilization of these natural resources will aid ToLCV management through crop improvement. The present study entitled ‘Evaluation of tomato genotypes for Tomato Leaf Curl Virus (ToLCV) resistance’ was carried out at Department of Plant Breeding and Genetics, College of Agriculture, Vellanikkara during 2019-21. The experimental material consisted of 27 tomato genotypes including eight NBPGR (National Bureau of Plant Genetic Resources) accessions, five breeding lines from the World Vegetable Centre, Taiwan, nine commercial hybrids, four KAU varieties and one local collection from Idukki. All 27 genotypes were screened for ToLCV resistance under natural conditions in randomized block design with two replications during January- May 2021. The disease response was assessed after 30 days of transplanting by adopting the score chart suggested by Banerjee and Kalloo (1987). Among the genotypes tested, Ansal was found to be highly resistant, Kaustubh, EC 519806 (S. pimpinellifolium), Arka Rakshak and local collection (Idukki) were identified as resistant genotypes. The genotypes found to be highly resistant and resistant were subjected to whitefly mediated artificial inoculation. The resistant and highly resistant genotypes remained asymptomatic, whereas the susceptible genotypes (Anagha and Manuprabha) exhibited ToLCV symptoms after artificial inoculation. The morphological growth characters such as plant height, number of primary branches per plant, days to flowering and trichome density differed significantly among the genotypes evaluated in the present study. Density of both glandular and non-glandular trichomes on both abaxial as well as adaxial leaf surfaces were recorded. Correlation analysis between trichome density, and disease severity index and per cent disease incidence showed that glandular trichome density on abaxial and adaxial surfaces of leaf was significantly and negatively correlated with per cent disease incidence and disease severity index. However, the negative correlation was stronger between the abaxial glandular trichome density and ToLCV incidence. The glandular trichome density of the resistant genotypes identified in the field screening was found to be high. Non-glandular trichome density on abaxial and adaxial side of the leaf was significantly and positively correlated with per cent disease incidence and disease severity index. Screening for the reported Ty genes using the primers TG178 (SCAR), SCAR-2, P6-25, TY-1/3_K (SCAR), 18IY13 (Indel), SLM 4-34 (SSR) and SLM 10-46(SSR)linked to the ToLCV resistance genes Ty-1, Ty-2, Ty-3, Ty-1/3, Ty-4, Ty-5 and Ty-6 respectively was done in the present study. Seventeen genotypes produced amplicon using TG178 and ten genotypes produced amplicons using SLM4-34. However, there was no pattern in the amplification of the markers TG178 and SLM 4-34. Seven genotypes recorded the presence of Ty-1/3 in homozygous condition (AVTO 1727, AVTO 1726, AVTO 1706, AVTO 1707, EC 538153, EC 620428 and EC 620486) and seven genotypes in heterozygous condition (Ansal, Virang, Aryaman, Durg, Raymond, Abhiraj, Pranay). Four genotypes each carried the resistant allele for Ty-2 in the homozygous state (AVTO 1726, AVTO 1706, AVTO 1707 and AVTO 0922) and in the heterozygous state (AVTO 1727, Ansal, Arka Rakshak and Aryaman). Resistant allele for Ty-3 was present in the genotype AVTO 1726 and AVTO 1707 in homozygous state. Whereas, it was in heterozygous condition in AVTO 1727. None of the genotypes evaluated in the present study revealed the presence of amplicons corresponding to resistant allele of Ty-4 and Ty-6. The resistant genotypes identified in the present study viz., Ansal, Kaustubh, Arka Rakshak, EC 519806 and local collection (Idukki) can be used for resistance breeding. The present study revealed that trichome density can be used as a reliable morphological marker for ToLCV resistance. The donors for Ty-2, Ty-3 and Ty-1/3 identified in this study can be used for gene pyramiding in future breeding programmes.ThesisItem Open Access Salicylic acid and Piriformospora indica induced modulation of stress resistance mechanism in Tomato (Solanum lycopersicum L.)(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2021) Deepthi Mohan; KAU; Roy StephenThe study entitled “Salicylic acid and Piriformospora indica induced modulation of stress resistance mechanism in tomato (Solanum lycopersicum L.).” was conducted at College of Agriculture, Vellayani, Thiruvananthapuram, during 2020 – 2021. The primary objective of this study was to analyse the salicylic acid induced NPR1 gene expression as well as Piriformospora indica induced resistance modulation to stress and its persistence and transmission through seeds. The induced resistance in plants can be classified as Systemic Acquired Resistance (SAR), mediated by the signalling molecule salicylic acid and Induced Systemic Resistance (ISR) which was induced by the presence of non-pathogenic plant growth promoting fungi or bacteria. In the present study two treatments, plant growth promoting endophytic basidiomycete fungus Piriformospora indica (biological inducer) and salicylic acid (chemical inducer) were applied on bacterial wilt resistant (Vellayani Vijay, KAU) and susceptible (Pusa Ruby, IARI) varieties of tomato and the expression rate of Non-expresser of pathogenesisrelated genes1 (NPR1) gene was evaluated using q-RTPCR. In first generation, one set of seed were inoculated with P. indica (1%) by incorporating it into the potting mixture before filling the pot-tray cavities. After confirming endomycorhizal root colonization, leaf samples were collected for analyzing NPR1 expression. Seeds from these plants were collected and progeny seedlings were maintained for analysing transgenerational expression of NPR1 gene. Second set of seeds were sown in the nursery and two weeks old seedlings were transplanted in to pots. Salicylic acid(100ppm) was sprayed at flowering stage and NPR1 gene expression was analysed on 5th day and 7th day after treatment in leaves and compared to next generation (in two weeks old seedlings) for understanding transgenerational expression. The evaluation of stress tolerance of the treated (P. indica and S.A) plants was done on progeny seedlings of Vellayani Vijay by treating it with a low density inoculum of virulent Ralstonia solanacearum (106 cells/ ml). Similarly abiotic stress tolerance evaluation was carried out by subjecting the plants to a higher temperature in polyhouse. Physiological and biochemical observations showed that application of P. indica and salicylic acid can induce resistance by regulating the enzyme activities and other physiological parameters. The resistant variety (Vellayani Vijay) gave a relative change of 7 fold and 4 fold for NPR1 expression (on 5th day and 7th day respectively) on the application of salicylic acid. The susceptible variety (Pusa ruby) showed a relative change of 6 fold and 2 fold for NPR1 expression on the application of salicylic acid. A relative change of 7 fold and 5 fold was shown respectively for first generation and second generation on treatment with salicylic acid, which confirms a transgenerational expression of the defence related gene. Similarly P.indica also showed transgenerational expression with a relative change of 5 fold and 2 fold respectively for first and second generation. P. indica treatment and exogenous application of salicylic acid can induce resistance in plants and thus induced resistance can be transferred to progenies. Transgenerational induction might be vital to the long-term survivorship of plant species on novel environments or adapt to other forms of environmental change.ThesisItem Open Access Micrometeorological modification with mulches to enhance the yield of Turmeric (Curcuma longa L.)(Department of Agricultural Meteorology, College of Agriculture,Vellanikkara, 2021) Abin Divakaran, A; KAU; Lincy Davis, PTurmeric (Curcuma longa L.) is one of the most important rhizomatous spices, belonging to Zingiberacea. It is an annual herbaceous plant native to tropical SouthEast Asia. Turmeric has high medicinal properties and it is wildly used in pharmaceutical, cosmetics and food industries. Due to the high value of the crop, it is getting good demand all over the world. India is one of the largest producer and consumer of turmeric around the world. In India turmeric is mainly planted in the hot summer months and grown as a rainfed crop, but due to the drastic changes in the agroclimatic conditions its production is influenced detrimentally. Mulching is an important cultural practice in turmeric, which helps to maintain an optimum microclimatic condition, reduce weed growth, add organic matter and conserve moisture throughout the high evaporative periods. Due to these changing climatic conditions assessment of an effective date of planting and finding a most suitable mulching practice are required for the effective production of turmeric. Hence, the goal of this study is to determine how planting dates and micrometeorological modifications with mulches affect turmeric yield. Turmeric variety Kanthi was raised in Plantation Crops and Spices farm, College of Agriculture, KAU, Vellanikkara with four different dates of planting (1st May, 15th May, 1 st June and 15th June) and four different mulching treatments (white polythene mulch, black polythene mulch, paddy straw mulch and green leaf mulch). The experiment was laid out in split plot design with four dates of planting as main plot treatments and four mulching practices as subplot treatments. Crop weather analysis was done by using SPSS software and crop yield prediction model was developed with the help of Principal Component Analysis (PCA) and regression analysis. The total crop period was divided into four phenophases (P1-planting to germination, P2-germination to initiation of active tillering, P3-initiation of active tillering to bulking, P4- bulking to physiological maturity). The days to reach each phenophases were different in every date of planting. May 1st planting took more days to reach 100 per cent germination and to reach physiological maturity both 1st and 2nd dates of plantings took more time. The plant biometric characters like plant height, number of leaves, leaf area, number of tillers and dry matter accumulation were found to be more in earlier dates of planting (May 1st and May 15th) in almost all the time. In mulching practices paddy straw mulch was superior and it was followed by green leaf mulch. The yield produced by May 1st and May 15th dates of planting were on par and in case of mulching treatments paddy straw mulch produced superior yield than any other mulching practice. In mulching treatments polythene mulches recorded more soil temperature and moisture content than organic mulches in almost all the time. The first phenophase of 1st date of planting recorded high maximum, minimum and soil temperature along with less rain fall and rainy days. This might have influenced the late emergence of turmeric. The increase in maximum temperature, wind speed, sunshine hours and evaporation reduced the plant height in third phenophase. Soil moisture content and relative humidity inside the plant canopy showed a positive correlation with yield, whereas soil temperature showed a negative correlation with yield during the bulking stage of turmeric. The decrease in maximum temperature, bright sunshine hours, wind speed and evaporation and the increase in the minimum temperature, forenoon and afternoon relative humidity and rainfall during bulking stage enhanced the yield in turmeric. The development of yield prediction model with principal component analysis of mulching treatments and dates of planting of four phenophases were done and the yields of turmeric crop with these equations were predicted. This showed that, the predicted yield was in accordance with the observed yield in all mulching treatments.
