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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 Identification of graft transmissible resistant factors and development of si RNA mediated resistance in cassava against cassava mosaic geminivirus(Department of Plant Pathology, College of Agriculture, Vellayani, 2017) Asha, B Nair; KAU; Umamaheswaran, KThe present study entitled ‘Identification of graft transmissible resistant factors and development of siRNA mediated resistance in Cassava against Cassava mosaic virus’ was carried out during the period 2012-2017 at the Department of Plant Pathology, College of Agriculture, Vellayani. The study was carried out with the objective of identification of transferability of resistance factor from resistant cassava, Sree Padmanabha to susceptible, Vellayani Hraswa by grafting and to develop siRNA mediated technology for the development of cassava plant resistant to Cassava mosaic geminivirus. Grafting experiments were conducted using resistant Sree Padmanabha as root stock and susceptible Vellayani Hraswa as scion. Symptoms like leaf mosaic, chlorotic spots, reduction in leaflet size and stunting of plants were noticed in susceptible variety. Virus concentration was found to be less in grafted plants. Grafting experiments showed the expression of an extra protein by SDS-PAGE and Coomassie staining in grafted plants which is around 38 kDa. Molecular weight of the new protein revealed the presence of extracellular protein in grafted samples. The extra proteins found in the grafted plants are assumed to be transferred from Sree Padmanabha to Vellayani Hraswa by the process of grafting. The study also involved the development of an intron hairpin RNA vector against replicase gene of SriLankan cassava mosaic virus and introduction of this construct into embryogenic cells via Agrobacterium mediated transformation. A protocol for somatic embryogenesis in cassava variety, Vellayani Hraswa was developed by using immature leaf lobes as explants. The young leaf lobes from tissue culture plantlets produced through meristem culture was used for embryogenic callus formation. Cremish white calli was initiated in Murashige and Skooge (MS) medium supplemented with picloram 12 mg L-1 in dark. For embryogenesis, the calli were transferred to MS medium supplemented with BA 2µM and NAA 1µM which resulted in the production of glassy elongated somatic embryos. The germinated cotyledonary embryos were then regenerated into plantlets by culturing in MS medium supplemented with BA 1mg L-1. Effort was taken to construct an intron hairpin RNA vector and the gene targeted for silencing was the replicase gene of SriLankan cassava mosaic virus (SLCMV). Total DNA was extracted from virus infected plants and the whole replicase gene was isolated using gene specific primers. Sequencing of the whole gene was done. BLAST analysis showed 98% similarity to replicase gene of various isolates of SLCMV. The sequence was then subjected to miRNA target prediction and restriction mapping to select suitable region for the construct. Based on this information, a fragment of 397 bp towards the 5’ end was amplified by designing a set of primers with anchored restriction sites. The primers anchored with Xho and Kpn 1sites were used for the amplification of sense strand and the primers anchored with Xba and Cla 1sites were used for amplification of antisense strand. Selected region was amplified to form sense and anti-sense fragments and cloned to pTZ57R/T cloning vector. Inserts were then released from pTZ57R/T using the corresponding restriction enzymes. The sense and anti-sense fragments were then integrated in the primary vector pHANNIBAL on either side of the pdk intron which facilitated the formation of intron hairpin RNA construct. The intron hairpin RNA construct in pHANNIBAL contained CaMV35S promoter, sense strand, pdk intron, antisense strand and OCS terminator in the order with Not 1 restriction sites. After confirmation of integration by restriction digestion, the Not1 fragment with sense and anti-sense strand were released from pHANNIBAL and ligated to the digested Not1 site in the lacZ gene of binary vector pART27 containing antibiotic resistant marker nptII and spec. the binary vector was confirmed for the presence of insert by transferring to DH5α cells and colony selection by blue white screening. Plasmid DNA isolated from transformed colonies grown on Luria agar medium supplemented with 100 mg L -1 spectinomycin were confirmed for the presence of insert. After confirmation of insert in the binary vector, it was transformed to Agrobacterium tumefaciens strain LBA4404 via freeze thaw method. Transformed colonies were selected on kanamycin selection medium at 100 mg L -1 and confirmed for the presence of binary vector and ihpRNA insert using nptII primers and primer for sense and antisense strands by PCR reaction. Cotyledons excised from the somatic embryos were transformed with LBA4404 having pART 27 by co-cultivation and the transformed embryos were selected with antibiotic pressure (Kanamycin 100 mg L-1). DNA was isolated from the transformed somatic embryos and confirmed for the presence of insert using forward primer of sense fragment and reverse primer of antisense fragments. Transformed embryos were subjected to regeneration.ThesisItem Open Access Molecular characterization of virus causing infectious chlorosis disease of banana(Department of Plant Pathology, College of Horticulture Vellanikkara, 2017) Ahamed Mujtaba, V; KAU; Anita Cherian, KThe experiment entitled “Nutrient management in strawberry (Fragaria x ananassa Duch.)” was undertaken at Regional Agricultural Research Station, Ambalavayal, Wayanad during the year 2016-17. Performance of strawberry variety Winter Dawn was evaluated under nine treatments and a control in the open field viz., FYM 10 t ha-1 + NPK 50:20:50 kg ha-1 (T1); FYM 10 t ha-1 + NPK 75:30:75 kg ha-1 (T2 ); FYM 10 t ha-1 + NPK 100:40:100 kg ha-1 (T3); FYM 20 t ha-1 + NPK 50:30:100 kg ha-1 (T4); FYM 20 t ha-1 + NPK 75:40:50 kg ha-1 (T5); FYM 20 t ha-1 + NPK 100:20:75 kg ha-1 (T6); FYM 30 t ha-1 + NPK 50:40:75 kg ha-1 (T7); FYM 30 t ha-1 + NPK 75:20:100 kg ha-1 (T8); FYM 30 t ha-1 + NPK 100:30:50 kg ha-1 (T9) and an absolute control (T10), without any nutrient application. All the treatments were on par and superior over the control (T10) in case of plant height. In case of plant spread, T2, T3, T5, T6, T7, T8 and T9 were on par and superior over the control while T1 and T4 were on par with each other but differs with other treatments. All the treatments except T2 were on par and superior over the control with respect to number of leaves per plant. Application of treatments had no significant effect on days to first flowering. In case of number of flowers and clusters per plant, T1, T2, T3, T5, T6, T7, T8 and T9 were on par and superior over the control while T4 was on par with the control (T10). Days to first harvest was minimum in T6, T7, T8 and T9 which were on par while all other treatments were on par with the control (T10).In case of number of fruits and yield per plant, T7 (FYM 30 t ha-1 + NPK 50:40:75 kg ha-1) and T8 (FYM 30 t ha-1 + NPK 75:20:100 kg ha-1) were on par and superior over other treatments including T1, T2, T3, T4, T5, T6 and T9 which were on par and superior over the control. Average fruit weight recorded under T3, T5, T6, T7, T8 and T9 were on par which was followed by T2 on par with T4 and T1. Days to final harvest was not found to be influenced by the application of different treatments. Biochemical characters of fruits viz., TSS, acidity and TSS/acidity ratio were not having any significant effect due to the application of treatments. In case of total sugars, T3, T7, T8 and T9 were having the highest content and were on par which was followed by T5 on par with T1, T2, T4, T6 and T10. The overall sensory score was highest in T7 followed by T8. Application of different treatments had no significant effect on the shelf life of strawberry fruits. N, P, K and Ca content in the plant were not significantly affected by any treatment while Mg content was found to be on par in all treatments and superior over the control. Soil analysis after the harvest of the crop revealed that the values for soil EC, available P, K, Mg and S were found to be elevated while soil pH, organic carbon and available Ca content were found to be at lower levels than the initial values before planting. It was concluded that among different nutrient combinations evaluated, T7 (FYM 30 t ha-1 + NPK 50:40:75 kg ha-1) with a BC ratio of 3.06 can be recommended for further optimization and refinement.ThesisItem Open Access Management of cercospora leaf spot of vegetable cowpea (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt.)(Department of Plant Pathology, College of Agriculture, Vellayani, 2017) Chinnu Ravi; KAU; Radhakrishnan, N VThe study entitled “Management of Cercospora leaf spot of vegetable cowpea Vigna unguiculata subsp. ungiculata (L.) Verdcourt) was undertaken at the Department of Plant Pathology, College of Agriculture Vellayani and Coconut Research Station, Balaramapuram during 2015-2017 with the objective to study the symptomatology and etiology of Cercospora leaf spot of cowpea and to develop a management strategy. Symptomatology and etiology of Cercospora leaf spot disease was studied during the flowering or pod bearing stage of the crop from different locations near to College of Agriculture, Vellayani. Symptoms were observed on the leaves, pods and stem .Conidial dimension of the pathogen ranges from 24.64 to 57.6 µm x 1.06 to 2.7 µm and the conidial septation was around 10 to 18. Based on the conidial and mycelial characters, the pathogen was tentatively identified as Cercospora sp. The identity of the pathogen was further confirmed based on the morphological characteristics and the herbarium specimen send to National Fungal Culture Collection of India, (N.F.C.C.I), Pune as Pseudocercospora sp. aff. Pseudocercospora vignigena (F: Mycosphaerellaceae) In vitro pathogen suppression by spore germination assay revealed that the fungicide difenoconazole (0.1%) recorded 42.96 per cent reduction over control and was followed by propiconazole (0.1%) and hexaconazole (0.1%) which recorded 36.85 and 31.10 per cent reduction over control, respectively. The organic formulations, mineral oil (0.1%) and neem oil (0.5%) recorded only 21.88 per cent reduction over control and were statistically on par .KAU talc based formulation of Pseudomonas fluorescens at 2.0 % recorded 11.88 per cent reduction of spore germination over control. The pot culture studies conducted using eight best treatments (difenoconazole (0.1%), propiconazole (0.1%), hexaconazole (0.1%), carbendazim (0.05%), azoxystrobin (0.05%), mineral oil (0.1%) neem oil (0.5%) and P. fluorescens 2.0 %) selected from in vitro studies revealed that the foliar spray of 0.1 per cent difenoconazole recorded the minimum disease incidence (23.80%) and disease severity (8.23 %) that accounts to 54.80 and 76.06 per cent disease reduction over control respectively. In the case of organic formulations, mineral oil (0.1%) recorded the minimum disease incidence (30.04%) and disease severity (16.54%). The plant sprayed with KAU talc based formulation of P. fluorescens (2.0%) recorded 33.69 % disease severity reduction over control. With regard to pod yield, the plants treated with difenoconazole (0.1%) registered the maximum (0.523 kg/pot) yield with 88.80% yield increase over control while ,the untreated control plants registered the lowest yield (0.277kg/pot). Based on the results of pot experiment, a field study was conducted at Coconut Research Station, Balaramapuram to evaluate the efficacy of five best treatments (difenoconazole (0.1%), propiconazole (0.1%), mineral oil (0.1%) neem oil (0.5%) and P. fluorescens 2.0 %) selected from the pot culture studies. Among the fungicides, difenoconazole (0.1%) recorded the minimum (31.88%) disease incidence and disease severity (13.97%) compared to all other treatments. In the case of organic formulations, mineral oil (0.1%) gave the maximum (14.32%) disease suppression and the lowest disease incidence of 40. 57 %. With regard to yield, maximum pod yield was from the plot sprayed with difenoconazole (1620 kg /ha) followed by propiconazole (1386.5 kg /ha) treated plants. Even though, the application of P. fluorescens gave only 29.23 per cent of the disease suppression, it enhanced the yield by 52.27 per cent yield over the control. It was concluded that foliar application of difenoconazole ( 0.1% ) at an interval of 35, 50 and 65 DAS was found to be the most effective treatment in managing Cercospora leaf spot in vegetable cowpea besides supporting proportionately attractive pod yield (1620 kg/ha) at an acceptable B:C ratio (2.44:1).Among the organic formulations, mineral oil (0.1%) was found to be the effective treatment in controlling leaf spot with a pod yield of 1293 kg/ha . While, P. fluorescens recorded a pod yield of 1318 kg/ha with B: C ratio of 2.02:1ThesisItem Open Access Exploration of natural products from botanicals and fungal root endophytes for the management of cowpea mosaic virus(Department of Plant Pathology, College of Agriculture, Vellayani, 2017) Theresa Alex; KAU; Umamaheswaran, KThe present study entitled “Exploration of natural products from botanicals and fungal root endophytes for the management of Cowpea mosaic virus” was carried out at Department of Plant Pathology, College of Agriculture, Vellayani during 2014-2016, with the objective to develop serological and molecular tools for the early detection of Cowpea mosaic virus; and its management using natural products from botanicals and fungal root endophytes. Cowpea mosaic virus was maintained in local lesion host Chenopodium amaranticolor and cowpea (Vigna unguiculata var. sesquipedalis (L.) Verdcourt) variety Sharika by mechanical inoculation. On the newly emerged trifoliate leaves of cowpea, typical symptoms like mosaic and vein banding followed by leaf distortion were expressed seven days after inoculation (DAI). In C. amaranticolor, symptoms were expressed five DAI and on the inoculated leaves, localized yellow chlorotic lesions were observed. Fungal root endophytes Piriformospora indica and Fusarium pallidoroseum were maintained by continuous subculturing in Potato dextrose agar medium. The P. indica produced nine centimetre radial growth on nine DAI whereas F. pallidoroseum produced nine centimetre radial growth on five DAI in petri dishes. Serological studies carried out using Direct antigen coating – Enzyme linked immunosorbent assay (DAC-ELISA) and Dot immunobinding assay (DIBA) and molecular detection viz., Reverse transcription-polymerase chain reaction (RT- PCR), identified the mosaic causing virus in cowpea as Blackeye cowpea mosaic virus (BlCMV). Botanicals for the management of BlCMV were first screened on C. amaranticolor to find out their efficiency. Among the seven botanicals, Phyllanthus niruri recorded more than 80 per cent inhibition of local lesions in C. amaranticolor even at one per cent concentration. Highest inhibition (94.84 per cent) was observed for pre inoculation application of P. niruri at five per cent concentration. Standardization of co-cultivation method for the fungal root endophytes with C. amaranticolor and cowpea were conducted in jam bottles but no colonization of any fungal endophytes were observed in both C. amaranticolor and cowpea. Colonization studies in vermiculite-perlite (3:1) medium at the rate of 1% (w/v) conducted in protrays showed no colonization during the co-cultivation studies of F. pallidoroseum with both cowpea and C. amaranticolor. In case of P. indica, no colonization was observed for C. amaranticolor whereas 40.70 per cent root colonization was recorded in cowpea. In a study conducted to determine the effect of age of seedlings on colonization pattern observed using compound microscope, the highest efficiency (42.30 per cent) was recorded for five day old seedlings at twenty days after co-cultivation. Root biomass, number of secondary roots, tertiary roots, number of leaves and leaf area also showed high values for five day old seedlings at twenty days after co-cultivation whereas shoot biomass and root hairs per unit area showed highest values for seven day old seedlings at twenty days after co-cultivation. The best antiviral principle (AVP) and fungal endophyte viz., Phyllanthus niruri and Piriformospora indica respectively were evaluated in cowpea against BlCMV. Vulnerability of cowpea plants to BlCMV was found to reduce with P. niruri and P. indica treatments compared to that of control plants. The biochemical analysis to study the mechanisms involved revealed that cowpea plants pre inoculated with P. niruri was found to be superior followed by pre inoculation treatment with P. indica except for total sugar where maximum values for healthy was followed by pre inoculation treatment with P. niruri. Many defense and pathogenesis related (PR) proteins were induced in response to various treatments. The induction of novel proteins were more in cowpea leaves which were treated with P. niruri and P. indica than in control plants. Thus it is proved by serological and molecular detection methods that the virus causing mosaic disease in cowpea is BlCMV. For the management of this virus pre inoculation treatment of P. niruri (extract of one gram sample in 100 ml water) and pre inoculation treatment of P. indica (one gram mycelia in 100 ml vermiculite-perlite media) has been proved to be effective. It can be further validated under field condition.ThesisItem Open Access Enhancement of systemic resistance to soil borne pathogens of ginger by enriched spent mushroom substrate of pleurotus sajor-caju(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2017) Remya, J S; KAU; Beena, SSpent mushroom substrate (SMS) is the composted organic material retained after a crop of mushroom. The world mushroom industry needs to discard more than 50 million tons of SMS every year. The latest research throw light on the efficient use of SMS for the disease management of crop plants. A preliminary study on the use of SMS of Pleurotus spp. as mulch for the management of rhizome rot complex disease of ginger under pot culture condition was carried out in the Department of Plant Pathology, College of Horticulture, Vellanikkara. In this study, among the various SMS used, the paddy straw SMS of P. sajor-caju as mulch recorded the highest biometric characters and least disease incidence compared to control. Hence this project was proposed as the continuation of the above study to evaluate the efficacy of enriched SMS of P. sajor-caju in enhancing growth and systemic resistance for the management of soil borne pathogens of ginger under field conditions. SMS of P. sajor-caju was produced during three different periods viz., March-April, June-July and November-December (2013) at six different locations of Kerala viz., College of Horticulture, Vellanikkara (Thrissur dist.), farmer’s field at Kodakara (Thrissur dist.), Perinjanam (Thrissur dist.), Krishnagiri (Wayanad dist.), Mananthavady (Wayanad dist.) and College of Agriculture, Vellayani (Thiruvananthapuram dist.). Enumeration of microflora of these SMS was carried out and a total of 47 fungal and 45 bacterial isolates were obtained. The antagonistic efficiency of these isolates were evaluated against the five pathogens viz., Pythium aphanidermatum, Fusarium oxysporum, Rhizoctonia solani, Sclerotium rolfsii and Ralstonia solanacearum under in vitro conditions. All the isolates from SMS showed antagonistic property against one or the other soil borne pathogens, with varying degree of inhibition. Mutual compatibility between the most efficient fungal and bacterial antagonists was evaluated to develop an effective microbial consortium for enriching the SMS and could be used against the soil borne diseases of ginger. Biosoftening efficiency of selected fungal and bacterial antagonists on SMS was evaluated. Two separate experiments were carried out with the selected antagonists effective against fungal and bacterial pathogens. For each experiment, five fungal antagonists, five bacterial antagonists and three compatible pairs were selected based on the in vitro evaluation of antagonistic efficiency and mutual compatibility studies. SMS was enriched separately with different antagonists and standardized the period for biosoftening of SMS as mulch for ginger cultivation. A period of 15 days was selected as most suitable for biosoftening the SMS as mulch with optimum antagonistic fungal and bacterial population. Wide range of C:N ratio was recorded by the SMS enriched with each antagonists. By considering the C:N ratio along with external appearance, the treatments having C:N ratio of 30:1 to 45:1 were selected, since it was the most suitable stage to be used as mulch in ginger. The effectiveness of biosoftened SMS against rhizome rot and bacterial wilt diseases of ginger was evaluated in two pot culture experiments. Three fungal and bacterial antagonists each and one compatible pair of antagonists which were selected based on the in vitro evaluation of antagonistic and biosoftening property were used for enriching the SMS. After enrichment, the SMS were kept for 15 days for biosoftening and were applied as mulch in the experiments. Observations on germination percentage and other growth parameters viz., number of tillers/plant, number of leaves/tiller and height of tillers were recorded at one month intervals from two months after planting (MAP). Challenge inoculation of pathogens was done at 45 days after germination and per cent disease incidence was recorded at 7 and 14 days after inoculation (DAI). In the experiment for the management of P. aphanidermatum, the lowest disease incidence was observed in T7 (SMS softened with P1F1+ M1F2) on 14th day after inoculation (DAI). This treatment also recorded the highest number of tillers, number of leaves/ tiller and height of tillers and rhizome yield. In the experiment for the management of R. solanacearum, the treatment T2 (SMS softened with T1F2) was found to be the most efficient one, which recorded the least disease incidence at 14 DAI, whereas the highest values for biometric characters and rhizome yield were recorded by T7 (SMS softened with K1B1 + T2B1). The activity of phenol and defense related enzymes such as peroxidase (PO), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were estimated by spectroscopy, before challenge inoculation with pathogen and at one, three and five days after the challenge inoculation. For estimation, leaf samples were collected separately from the pot culture experiments I and II for the management of P. aphanidermatum and R. solanacearum respectively. The treatments which recorded less disease incidence in both the pot culture experiments exhibited the highest activity of defense related enzymes and phenol. The highest activity of defense related enzymes and phenol was recorded at 5 DAI. Thus the present study showed that in addition to direct antagonism and plant growth promotion, induction of defense related enzymes was also contributed by SMS to enhance resistance against invasion of soil borne pathogens of ginger. Field evaluation of the selected treatments from pot culture experiments showed the lowest disease incidence in the treatment T2 (SMS softened with T1F2) followed by T5 (SMS softened with P1F1+M1F2). Statistically these were on par with each other. The treatment T5 (SMS softened with P1F1+M1F2) recorded the highest germination percentage, number of tillers, number of leaves/tiller and rhizome yield also. Analysis of primary nutrients viz., nitrogen, phosphorus and potassium in SMS, plant and soil from field experiment was conducted. Among these, SMS softened with P1F1+M1F2 recorded the highest percentage of N, P and K. This treatment recorded the highest nutrient content in ginger rhizome and soil also. Attempts were also made to identify the fungal and bacterial antagonists selected for field experiment. Based on the cultural and morphological characters, the fungal antagonists viz., Kr1F4, T1F2, P1F1 and M1F2 were tentatively identified as Trichoderma viride (Pers.), T. viride (Pers.), T. koningii (Oudem.) and T. harzianum (Rifai) respectively. The identification got confirmed from National Centre for Fungal Taxonomy (NCFT), New Delhi. The bacterial antagonists selected for field experiment were also identified based on cultural, morphological, biochemical and 16s rRNA sequence analysis. The three bacterial antagonists P3B2, T2B1 and K1B1 were identified as Bacillus safensis, B. methylotrophicus and Burkholderia gladioli respectively. Spent mushroom substrate is rich in microflora and these microflora exert antagonistic activities against soil borne pathogens. It stimulates the natural defense system in plants, provide necessary nutrients for plant growth and also improve soil physical condition. From field evaluation it was found that the SMS softened with T. viride recorded the lowest disease incidence and which enhanced systemic resistance to soil borne pathogens of ginger by defense related enzymes and phenol. The results were on par with the SMS softened with consortium of antagonists, T. koningii and T. harzianum (P1F1+M1F2). The highest rhizome yield and other growth parameters were also contributed by the SMS softened with T. koningii and T. harzianum. The content of nitrogen, phosphorus and potassium were also recorded the highest in this SMS. So from the present study it can be concluded that the SMS softened with T. koningii and T. harzianum can be used as mulch in ginger which was found equally effective to induce systemic resistance against soil borne pathogens and to enhance growth parameters and rhizome yield.ThesisItem Open Access Characterization and exploitation of jelly mushrooms (auricularia spp./ Tremella spp.)(Department of Plant Pathology, College of Agriculture, Vellayani, 2017) Priya, R U; KAU; Geetha, DThe present study entitled “Characterization and exploitation of jelly mushrooms (Auricularia spp./ Tremella spp.)” was carried out in College of Agriculture, Vellayani during 2014-2017, with the objective of standardization of techniques for production of jelly mushrooms (Auricularia spp./ Tremella spp.) in agricultural wastes and to study their morphological, physiological and cultural characteristics as well as nutritional and organoleptic qualities. Survey was conducted in ten different locations of Thiruvananthapuram and Kollam districts of Kerala during 2014-2016. Sporocarps of Auricularia spp. and Tremella spp. were collected from tree stumps, predominantly Mango, Coconut, Drumstick, Teak wood and Rubber. All the mushrooms collected from all the locations were gregarious in nature and lignicolous in habitat. Morphological studies of jelly mushrooms showed that the sporocarps were light brown to dark brown in colour with incurved margin, ear shaped, soft and velvety in texture and devoid of stipe. The internal stratification of hyphae showed eight different zonations. Basidiospores were hyaline, oval and sub cylindrical to cylindrical shaped. Two fast growing isolates selected based on the time taken for complete mycelial growth and nature of mycelial growth, designated as A1 and A2 were sent to Directorate of Mushroom Research, Solan for identification. These were identified as Auricularia polytricha (Mont.) Sacc. (Accession number of A1 was DMRO-825 and A2, DMRO-826). The maximum mycelial growth was recorded on malt extract agar medium and a temperature of 250C, pH 7 and light conditions were found favourable for mycelial growth. Evaluation of different substrates for spawn production revealed that paddy grain was the best substrate followed by sorghum. Rubber sawdust spawn recorded maximum keeping quality. Malt extract broth was found to be the best for submerged culture production of both A1 and A2. Evaluation of different substrates for mushroom production revealed that rubber sawdust was the best substrate for cultivation which recorded maximum Biological Efficiency (BE) of 14.8% for A1 and 12.2% for A2. The minimum time for spawn run was taken by paddy straw and the maximum was taken by neopeat. Major insect pests observed were Megaselia sp., Seira sp. and Staphylinus sp. The competitor moulds observed were Coprinus sp, Aspergillus spp., Penicillium sp. and Trichoderma sp. Among the different amendments, wheat bran (2.0 and 4.0 %) and groundnut cake (2.0%) were found to be the best for enhancing the growth parameters whereas, rice bran (2.0% and 4.0%) was the best for increasing yield parameters. Analysis for the proximate constituents in A. polytricha (A1 and A2) revealed that it contained appreciable amount of carbohydrate (47.1 and 48.8%), protein (18.06 and 20.75%), polyphenols (9.53 and μg), fibre (17.69 and 15.49%), total anti oxidants (116 and 74μg), β carotene (0.178 and 0.150 μg) and the energy value was 251.49 and 264 respectively. Sensory evaluation of mushroom products made from A. polytricha (A1 and A2) indicated that mushroom tomato sauce scored maximum for overall acceptability. Under refrigeration (40C) in perforated poly propylene covers mushrooms could be kept fresh for three days. Indoor cultivation of both A1 and A2 showed significant results for growth parameters as well as yield parameters compared to outdoor cultivation. Comparative performance of A. polytricha with two ruling mushrooms of Kerala namely oyster mushroom (Pleurotus florida (Mont.) Singer.) and milky mushroom (Calocybe gambosa (Fr.) Donk.) indicated that oyster mushroom took minimum days for spawn run, pinhead formation and first flush compared to milky mushroom and A. polytricha. Milky mushroom recorded highest BE (66.1%) compared to others. Studies on medicinal activities of A. polytricha indicated that it possessed anticancerous activities for cervical, colon and liver cancer cell lines and higher activity was recorded in 100 μg/ml concentration. Based on the results of present investigation, A. polytricha can be cultivated successfully in tropical areas on locally available materials. Paddy grain was the most suitable substrate for spawn production and Rubber sawdust amended with 2% rice bran, the most suitable growing medium. Mushrooms possessed significant nutritional and medicinal activities. The findings of the above investigations recommend the adoption of a suitable cultivation package for jelly mushrooms (A. polytricha), a highly prized mushroom.ThesisItem Open Access Cataloguing, Documentation and Management of fungal diseases of strawberry (Fragaria x ananassa Duch.)(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2017) Amrutha, P; KAU; Reshmy VijayaraghavanStrawberry (Fragaria x ananassa Duch.), hybrid species of genus Fragaria, cherished for its characteristic flavour, colour and tentalizing aroma, is becoming an important table fruit of millions of people around the world. However, the crop is inflicted by several fungal diseases that reduce its commercial value. Hence, the present investigation was carried out to identify and catalogue the major fungal diseases of strawberry growing in Kerala. Purposive sampling surveys were carried out in strawberry growing tracts of Kerala viz., Wayanad, Idukki and Malappuram to collect infected samples and also to assess the incidence of fungal diseases during different periods viz., December-January, March-April and July-August. During the survey, four leaf spots (LSW-1, LSI-1, LSM-1 and LSI-2), four leaf blights (LBW-1, LBI-1, LBI-2 and LBM-1), one fruit rot (FRW-1) and two crown and root rots (CRI-1 and CRM-1) were noticed. Among the crown and root rot diseases, CRM-1 recorded the highest per cent disease incidence (PDI) of 82 per cent. Leaf blight (LBW-1) recorded maximum severity of 25.2 per cent among foliage diseases. Correlation studies were carried out to elucidate the influence of weather parameters on disease development. Symptomatology of different diseases was studied both under natural and field conditions. Pathogenicity was proved by mycelial bit inoculation and spore suspension method. Cultural and morphological characterisation of the isolates were carried out and for further confirmation of the identity upto species level, the isolates were sent to National Centre for Fungal Taxonomy (NCFT), New Delhi. The pathogens causing LSW-1, LSI-1 and LSM-1 were identified as Colletotrichum gloeosporioides, LSI-2 as Alternaria alternata, LBW-1 as Rhizoctonia solani, LBI-1 as Phoma exigua, LBI-2 as Curvularia lunata, LBM-1 as Pestalotiopsis longisetula and FRW-1 as Rhizoctonia solani. The two crown and root rot pathogens, CRI-1 and CRM-1 were confirmed as Fusarium oxysporum and Lasiodiplodia theobromae respectively. In order to recommend an appropriate management strategy for the aforesaid diseases, in vitro and in vivo evaluation were carried out using fungicides, biocontrol agents and organic formulations. Fungicides viz., carbendazim 12% + mancozeb 63%, propineb 70 WP, Bordeaux mixture, cymoxanil 8% + mancozeb 64%, difenoconazole 25EC and carbendazim 50WP were found effective against various foliage diseases. Carbendazim 12% + mancozeb 63%, cymoxanil 8% + mancozeb 64%, copper hydroxide 77WP and carbendazim 50 WP recorded cent per cent reduction in mycelial growth of Fusarium oxysporum (CRI-1). Similarly, carbendazim 12% + mancozeb 63%, copper hydroxide 77WP, cymoxanil 8% + mancozeb 64% recorded 93-100 per cent reduction of Lasiodiplodia theobromae (CRM-1). Results of dual culture studies with Trichoderma asperellum and Pseudomonas fluorescens against pathogens revealed 66.67 to 100 and 0 to 70.55 per cent control respectively. Likewise, organic formulations like Calphomil recorded an inhibition ranging from 13.3 to 75.33 per cent, whereas neem oil, panchagavya and baking powder + vegetable oil mixture could restrict the growth of pathogen only upto 34 per cent. In vivo experiment was conducted to study the efficacy of fungicides and biocontrol agents under natural conditions also. Accordingly, four major selected pathogens viz., C. gloeosporioides, P. longisetula, F. oxysporum and L. theobromae were subjected to molecular characterisation prior to in vivo studies. The sequence homology on molecular studies revealed that the isolates showed similarity to C. gloeosporioides, Neopestalotiopsis clavispora, F. oxysporum and L. theobromae. Results of the pot culture experiment revealed that Trichoderma asperellum showed better control against C. gloeosporioides compared to other treatments followed by carbendazim 12% + mancozeb 63%. Propineb 70 WP, T. asperellum and carbendazim 12% + mancozeb 63% reduced the severity caused by Neopestalotiopsis leaf blight disease. The combination fungicide carbendazim 12% + mancozeb 63% (0.2%) was found equally efficient against F. oxysporum and L. theobromae. Thus, the study has enlightened our knowledge on the various fungal diseases inflicting strawberry as well as the role of weather in disease development and the management practices using plant protection chemicals and bioagents both under in vitro and in vivo conditions. Hence, further studies should be focused to carry out multilocational trials in strawberry growing tracts of Kerala.ThesisItem Open Access Characterization and management of fungal pathogens of cabbage (Brassica oleracea var. capitata L.) and cauliflower (Brassica oleracea var. botrytis L)(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2017) Nusrath Beegum, C H; KAU; Yamini Varma, C KCabbage (Brassica oleracea var. capitata L.) and cauliflower (Brassicaa oleracea var. botrytis L.) are the most popular and widely cultivated cruciferous vegetables in Kerala. One of the main constraints in the production of these crops is the occurrence of fungal diseases, on which no detailed systematic studies have been conducted in Kerala. The study was carried out during 2015-2017 at College of Agriculture, Padannakkad with the objective to identify and characterize the fungal diseases of cabbage and cauliflower occurring in the selected districts of Kerala and to study the management of most severe and predominant diseases under in vitro and in vivo conditions. Purposive sampling surveys were conducted for the occurrence of fungal diseases in cabbage and cauliflower in Thrissur, Wayanad, Idukki and Kasargod districts and diseased plant samples were collected. Results of survey showed prevalence of eight different fungal diseases with a range of 5.4-69.3 per cent disease incidence and 8.1-68.3 percent disease severity in case of cabbage. In cauliflower, PDI and PDS were with a range of 3.1-52.2 percent and 4.9-44.2 percent respectively. Isolations done from the infected specimens collected during the survey yielded eight genera of fungal pathogens. For selecting the most potent isolate, virulence test was conducted, and used for further studies. Characterisation of the selected pathogens were carried out based on the cultural and morphological characters and identified up to generic level. Further identification of species of each genus was done by molecular characterization by sequencing the ITS region of each fungus by in silico analysis and confirmed as Alternaria brassicicola, Rhizoctonia solani, Collectotrichum gloeosporioides, Curvularia lunata, Choanephora cucubitarum, Pythium aphanidermatum and Fusarium equiseti. Symptomatology of these fungal diseases were studied in detail both under natural and artificial conditions. In vitro evaluation of fungicides and biocontrol agents was done against the selected sever pathogens. Ten fungicides at three concentrations and three bio control agents were selected for the studies. In vitro studies showed that against A. brassicicola the most effective fungicides at the recommended concentration were, trifloxystrobin 25% + tebuconazole 50%, tebuconazole 5EC and Bordeaux mixture with 100 percent inhibition. Against R. solani and C.lunata six fungicides viz., tebuconzole 5EC, copper oxy chloride 50 WP, trifloxystrobin 25%+tebuconazole 50%, propineb 70 WP and Bordeaux mixture produced 100 percent inhibion. Trifloxystobin 25%+tebuconazole 50%, tebuconazole 5EC and Bordeaux mixture were the three effective fungicides against C.gloeoporioides, F.equiseti and C. cucurbitarum which recorded 100 percent inhibition over control. But against P.aphanidermatum from cauliflower, copper fungicides showed a lead in the inhibition viz., copper oxycholride 50WP, copper hydroxide 77WP, Bordeaux mixture followed by mancozeb 75 WP. In vitro evaluation of biocontrol agents showed that T.viride was the most effective for controlling P.aphanidermatum with 75 percent inhibition followed by A.brassicicola with 67 percent inhibition. Antagonistic reaction of T.asperellum was mostly overgrowth on test pathogen. Similarly, P.fluorescens also showed maximum inhibition against P.aphanidermatum (50%). Effectiveness of the bacterial bioagent, B.subtilis showed maximum inhibition against R.solani. Three major pathogens viz., A. brassicicola, R.solani in cabbage and P.aphanidermatum in cauliflower were selected for the in vivo studies. Three biocontrol agents and funficides which showed inhibition above 60 percent were selected for in vivo evaluation. In vivo evaluation of fungicides for the management of Alternaria leaf blight of cabbage showed that trifloxystrobin 25%+tebuconazole 50% (0.03%) and tebuconazole 5EC (0.1%) were the best two fungicides showed 50 percent disease reduction over control followed by Bordeaux Mixture(1%). Yield of cabbage was also highest for these three treatments. Among biocontrol agents, T. viride was most effective in controlling the disease with a higher yield. For the management of Rhizoctonia leaf blight of cabbage, same two fungicides viz., trifloxystrobin 25%+tebuconazole 50% (0.03%) and tebuconazole 5EC(0.1%) were found to be most effective. B.subtilis was more effective than other two biocontrol agents which was significantly higher than control treatment. In vivo studies for the management of Pythium curd rot of cauliflower showed that trifloxystrobin 25%+tebuconazole 50% could produce 79 percent of disease reduction over control with higher yield. Among the bioagents, T.viride produced higher yield with 62 percent disease reduction. The present work resulted a detailed systematic study on the fungal pathogens of cabbage and cauliflower in selected districts of Kerala and emphasizes that trifloxystrobin 25%+tebuconazole 50% (0.03%) is the best chemical and T.viride is the effective biocontrol agent for field application for the management of these fungal diseases. Future line work should be concentrated on the residue analysis of these fungicides and formulation of a bio-intensive management strategy.ThesisItem Open Access Management of collar rot of cowpea caused by rhizoctonia solani kuhn using biofumigants(Department of Plant Pathology, College of Agriculture, Vellayani, 2017) Aparna, K P; KAU; Girija, V KThe study entitles “Management of collar rot of cowpea caused by Rhizoctonia solani kuhn using biofumigants” was undertaken in the Department of Plant Pathology, College of Agriculture, Vellayani during 2015-2017 with the objective to evaluate biofumigant nature of plants, plant oils and oil cakes against Rhizoctonia solani and to develop an ecofriendly management strategy for collar rot of cowpea using biofumigation. The pathogen causing collar rot disease of cowpea was isolated from the infected cowpea plants collected from the Instructional Farm, College of Agriculture, Vellayani. Pathogenicity was confirmed, virulence rating was done and the collar rot isolate R1 was found to be the most virulent one. Based on morphological and cultural characteristics, the pathogen was identified as the Rhizoctonia solani kuhn (Accession no. EF429212). This was further confirmed using molecular identification by ITS sequencing and showed 100 per cent similarity with Thanatephorus cucumeris, the perfect stage of R. solani. The antifungal and biofumigant action of ten different plants, four plant oils and four oil cakes/seed meals on mycelial growth of R.solani was evaluated under in vitro conditions in petridishes. Among these, incorporation of the leaf extracts of cabbage/ garlic creeper, lemongrass oil/ tea tree oil and mustard oil cake extract in PDA medium caused 100 per cent suppression of the pathogen. The invitro biofumigant activity of cabbage/cassava/garlic creeper/mustard, lemon grass oil/tea tree oil and the mustard oil cake was found to be statistically superior to all other treatements, and resulted in 100 per cent suppression of mycelial growth. The biofumigant action of ten different plants, four plant oils and four oil cakes with biocidal principles was tested by subjecting the sclerotia of R.solani to biofumigant action under confined conditions in sealed containers. Biofumigation with plants, plant oils and oil cakes, in general, exerted suppression of mycelial regeneration from sclerotia. The extent of suppression was found to increase with increase with increase in period of incubation with the biofumigants. Cabbage, cassava, garlic creeper and mustard were found to completely suppress the regeneration of mycelial growth from the treated sclerotia. Biofumigation with lemongrass oil/ tea tree/ mustard oil cake resulted in 100 percent suppression of regeneration of mycelium. Accordingly, plants such as cabbage, cassava, garlic creeper and mustard, plant oils such as lemongrass oil and tea tree oil, oil cakes such as mustard and groundnut oil cake were selected for further in vivo studies. An experiment was conducted under pot culture conditions to evaluate the efficacy of selected biofumigants involving 11 treatments and 5 replications in C.R.D. The treatments included the selected plants (50 g kg-1 soil), plant oils (5% soil drench) and oil cakes (10 g kg-1 soil) for suppression of collar rot of cowpea. The inoculated untreated control showed severe collar rot incidence (94.44%) compared to the treated pots. The maximum disease suppression (100%) was observed in cowpea plants grown on soil biofumigated with mustard plant/mustard oil cake which was on par with both chemical control check (0.1% carbendazim) and un-inoculated control. But the highest pod yield was recorded form plants grown on soil biofumigated with mustard oil cake (209.0 g) followed by treatment with mustard plant (185.4 g), which were significantly superior to the chemical control check (155.0 g) and un-inoculated control (143.0 g). These results revealed the enhanced effects of biofumigation for both disease suppression and growth enhancement. The population of soil microflora exhibited a decrease in the biofumigated treatements and an increasing trend after raising the crop. Among the predominant saprophytic fungi obtained from biofumigated soil, the isolated F1 exhibited 47.44% and among the two bacterial isolates, the isolate B2 caused 44.44% inhibition of the pathogen. The experiments revealed the scope of biofumigation for the management of R. solani under in vitro as well as in vivo. The collar rot caused by soil-brone pathogen, R. solani could be successfully managed by incorportation of either mustard plant (50g kg-1 soil) or tea tree oil (5% soil drench) or mustard/groundnut oilcake (10 g kg-1 soil)two weeks before raising cowpea.