Jeyaraman M.,UPASI Tea Research Institute |
Robert P.S.A.,UPASI Tea Research Institute
Journal of Plant Diseases and Protection | Year: 2017
A field study was conducted to screen the integrated disease management practices against branch canker disease caused by Macrophoma sp. In the present study, screening of four fungicides, two bacterial and fungal biocontrol agents were used at 0.05%. Benomyl with Bacillus sp. (DPS, 5.07 cm) found to be superior to copper oxychloride alone (DPS, 1.03 cm) in controlling branch canker disease. Tebuconazole + Bacillus sp. (DPS, 3.14 cm) and copper oxychloride + Bacillus sp. (DPS, 3.03 cm) excelled well. Botanical fungicide of Expel (5%) (DPS, 2.07 cm) significantly reduces the canker size as compared with other treatments. Trichoderma viride (DPS, 1.27 cm) and Trichoderma harzianum (DPS, 1.30 cm) usage in disease management showed the branch canker disease at very low level. The treatment with Benomyl along with Pseudomonas sp. (DPS, 2.73 cm) and tridemorph + Bacillus sp. (DPS, 2.70 cm) exhibits the reduction in the size of canker followed by copper oxychloride with Pseudomonas sp. (DPS, 2.39 cm) and tridemorph with Pseudomonas sp. (DPS, 2.37 cm). Without the usage of biocontrol, Benomyl (DPS, 4.83 cm), higher values of branch canker disease were observed in the control. Thus, management of the branch canker disease with Benomyl along with bacterial biocontrol of Bacillus sp. found to be very effective (DPS, 5.07 cm). In the case of untreated control, the canker size was increased than the treated plants. © 2017, Deutsche Phythomedizinische Gesellschaft.
Ajay D.,UPASI Tea Research Institute |
Baby U.I.,UPASI Tea Research Institute |
Baby U.I.,SGS India P Ltd.
Phytoparasitica | Year: 2010
The effect of two chemical elicitors (acibenzolar-S-methyl benzo-[1,2,3]- thiadiazole-7-carboxylic acid S-methyl ester [Boost 500SC]) and salicylic acid in inducing resistance in tea plants against blister blight disease caused by Exobasidium vexans Massee, was studied. Treatments with elicitors resulted in reduced severity of blister blight disease in nursery plants on challenge with the pathogen. There was a significant increase in the activities of defense enzymes like phenylalanine ammonia lyase, peroxidase and β-1,3-glucanase on elicitor treatments in tea leaves challenged with the pathogen than on unchallenged leaves. Acibenzolar-S-methyl (ASM) at 0.14% registered the lowest disease severity (25.2%), whereas treatments with salicylic acid were inferior. Under field conditions, the application of ASM at 0.14% resulted in disease protection of 25%. When ASM was applied in alternate rounds with a standard fungicide, the disease protection improved to 46.8%. The importance of incorporating ASM as a component in integrated disease management and also its importance in organic tea cultivation is discussed. © Springer Science & Business Media B.V. 2009.
Vanitha K.,Directorate of Cashew Research |
Bhat P.S.,Directorate of Cashew Research |
Raviprasad T.N.,Directorate of Cashew Research |
Srikumar K.K.,UPASI Tea Research Institute
International Journal of Pest Management | Year: 2016
The biology and behaviour of a common predator in cashew plantations, Ephestiasula pictipes (Wood-Mason), were studied under captivity for three seasons using greater wax moth larvae as prey. During Feb–May, incubation and nymphal developmental period were shorter when compared with Jun–Sep and Oct–Jan. The female mantids laid ootheca once in every 3–4 days, for a period of 70–77 days. Adult longevity and oviposition period were significantly higher during Feb–May, while no significant difference was observed in sex ratio, oviposition interval and pre oviposition period during different seasons. Sexual behaviour consisted of preliminary courtship and copulation, involving 14 activities in sequence. Duration of mounting, copulation and riding around on the female by the male widely varied from 2 min to 28 h; 5.15 to 6.10 h; and 2 to 74 h, respectively. High fertility, high fecundity, shorter life cycle, multivoltinism and feasibility of laboratory rearing throughout the year are the advantageous features of E. pictipes that permits for its mass rearing and emergence as a viable biocontrol agent in future. © 2016 Informa UK Limited, trading as Taylor & Francis Group
Palanisamy S.,UPASI Tea Research Institute |
Palanisamy S.,SRM University |
Mandal A.K.A.,UPASI Tea Research Institute |
Mandal A.K.A.,Vellore Institute of Technology
Applied Biochemistry and Biotechnology | Year: 2014
Reactive oxygen species (ROS) production is the first level of response by a host during stress. Even though the ROS are toxic to cell, when present in a limited amount, they act as a signalling molecule for the expression of defence-related genes and later are scavenged by either enzymatic or non-enzymatic mechanisms of the host. The different anti-oxidative enzymes like glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APO), peroxidase (POD) and polyphenol oxidase (PPO) were estimated, and their activities were compared between infected and healthy leaves of the tolerant and susceptible cultivars of tea. The infected leaves of the susceptible cultivars registered higher amount of enzyme activity when compared with the tolerant cultivars. The study reveals that the more anti-oxidative enzymes, the more susceptible the cultivar will be. © 2013 Springer Science+Business Media New York.
Characteristic variation in pigment composition, photosynthetic carbon assimilation and phytonutrients content of Dendrophthoe falcata, a hemiparasite growing on host trees of saline and non-saline environments
Arumugam R.,Government of Tamilnadu |
Venkatesalu V.,Annamalai University |
Rajkumar R.,UPASI Tea Research Institute
Russian Journal of Plant Physiology | Year: 2015
The Indian Mistletoe Dendrophthoe falcata (L.f) Ettingsh is highly specialized perennial flowering plant adapted to parasitic life on aerial parts of their hosts. Photosynthetic characteristics in leaves of D. falcata growing on a halophilic (Rhizophora mucronata) and a glycophilic (Albizia lebbeck) host trees were determined. The chlorophyll a/b ratio was lower (1.0–1.5) and showed no significant difference between the leaf samples collected from both the host species. The CO2 assimilation rate (PN) was significantly lower (5.2 µmol/(m2 s)) in the parasite growing on R. mucronata, compared to the other host A. lebbeck (6.7 µmol/(m2s)). There was no host-specific variation in the activity of ribulose-1,5-bisphosphate carboxylse (Rubisco) and phosphoenolpyruvate carboxylase (PEPC); however, D. falcata infecting R. mucronata showed significantly higher activity of Rubisco (6.63 mmol CO2/(s kg protein)). The Fourier transform infrared (FTIR) spectral studies revealed the presence of quercitrin in the leaf samples of D. falcata, which is reported as a taxonomic marker of the Loranthaceae family. The non host-specific hemiparasite, D. falcate, exhibited significant variation among the halophilic and glycophilic host trees, particularly in photosynthetic activity and nutrients accumulation. © 2015, Pleiades Publishing, Ltd.
Maria John K.M.,Konkuk University |
Premkumar R.,UPASI Tea Research Institute
Research Journal of Phytochemistry | Year: 2012
Tea is one of the popular beverages which immensely have therapeutic activity against various diseases. The biochemical and therapeutic properties of tea was observed to be varying because of its seasonal and varietal difference which will reflect in the quality of the end product. Yield and quality are the major factors determining the profit. So, research is still going on to search high quality tea plant among the huge tea seedling population. This process is basically a time involving (in years) or cost of selection will be high. The present study, grouping of tea plant was made by using total catechins and polyphenols activity against free radicals such as DPPH and Hydroxyl radicals. UPASI-17 registered the highest polyphenol, catechin content as well as its scavenging activity against free radicals than that of other tea cultivars. When considering the catechin and polyphenols scavenging activity, catechin influence higher than that of polyphenols against DPPH and Hydroxyl radicals. IV distinct groups were observed through Principal Compound Analysis (PCA) and dendrogram analysis based on individual clones free radical scavenging activity. By this analysis all clones have high free radical scavenging property was grouped separately. By adapting this method of analysis, it will reduce the time and cost involvement in the screening of new tea varieties from the seedling population and help in the production of high free radical scavenging black tea. © 2012 Academic Journals Inc.
Radhakrishnan B.,UPASI Tea Research Institute |
Vasanthakumar D.,UPASI Tea Research Institute
Pestology | Year: 2012
Abamectin is one of the broad spectrum microbial insecticides derived from the soil actinomycete, Streptomyces avermitilis and is effective against several pests in many of crops. Field studies were conducted to evaluate the efficacy of Abamectin 1.9 EC against the red spider mite (RSM) infesting tea. Different dosage rates of Abamectin 1.9 EC (80,100,120,140 &280 ml/ha) were tested with the standard treatment of Propargite 57 EC @ 500 ml/ha. Studies were also conducted to assess the impact of the application of Abamectin 1.9 EC on Phytotoxicity to tea leaves and natural enemies (Sthethorus sp.) of RSM. Results of the study revealed that Abamectin 1.9 was very effective against RSM, non phytotoxic and safer to natural enemies of RSM.
Thomas J.,UPASI Tea Research Institute |
Ajay D.,UPASI Tea Research Institute |
Kumar R.R.,UPASI Tea Research Institute |
Mandal A.K.A.,UPASI Tea Research Institute
Plant Cell, Tissue and Organ Culture | Year: 2010
The effects of native isolates of Pseudomonas fluorescens, Azospirillum brasilense, and Trichoderma harzianum on rooting and acclimatization of in vitro-grown shoots and plantlets of tea were evaluated. In vitro bacterization of P. fluorescens failed to establish, while both T. harzianum and A. brasilense retarded shoot growth, eventually overtaking shoot cultures in in vitro rooting. Acclimatization of rooted plantlets in soil amended with bioinoculants, either individually or in various combinations, promoted plantlet survival. Moreover, efficiency of nutrient uptake of plantlets was higher in the presence of microorganisms. Root rot or wilting of tissue culture-derived plants was not observed in bioinoculant-treated plants, as they possessed relatively higher activities of defense enzymes, including peroxidase and phenylalanine ammonia lyase. © 2010 Springer Science+Business Media B.V.
Jayaganesh S.,UPASI Tea Research Institute |
Venkatesan S.,UPASI Tea Research Institute
American Journal of Food Technology | Year: 2010
Field experiment was laid out in Randomized Block Design (RBD) at UPASI tea experimental farm, with eight treatments and three replications. Amino acid content in tea leaves increased due to soil application of magnesium, but the 50% potassium reduction fields are reduced the amino acid content. The amino acid content significantly increased the soil applied magnesium when compared to the standard practices. The blocks which received the foliar application of micronutrient along with magnesium decreased the amino acid content when compared to the standard practices and control. The externally added magnesium increased the formation of 2-oxoglutarate and simultaneously another product aspartate/alanine was increased. The catechins content increased in 300 kg soil applied magnesium treatment and then decreased in 50% reduction of potassium fertilizer treatments. The TF value of made tea increased in 300 kg magnesium application plots and but decreased in the case of 50% reduction of potassium fertilizer. The control blocks having lower TF value when compared to the standard practices, because the K fertilizer is the important to increase the TF value. The maximum quantity of TF value obtained in the case of 300 kg soil applied blocks. The similar kind of trend was observed in TR values. Flavour index was made tea was higher in magnesium treated blocks, when compared to the control and NPK application. The magnesium content of tea leaves positively correlated with amino acid and amino acid transferase enzymes. This study further confirmed that antagonism exiting between K and Mg and synergism existing between P and Mg. © 2010 Academic Journals Inc.
PubMed | UPASI Tea Research Institute
Type: Journal Article | Journal: Applied biochemistry and biotechnology | Year: 2014
Reactive oxygen species (ROS) production is the first level of response by a host during stress. Even though the ROS are toxic to cell, when present in a limited amount, they act as a signalling molecule for the expression of defence-related genes and later are scavenged by either enzymatic or non-enzymatic mechanisms of the host. The different anti-oxidative enzymes like glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APO), peroxidase (POD) and polyphenol oxidase (PPO) were estimated, and their activities were compared between infected and healthy leaves of the tolerant and susceptible cultivars of tea. The infected leaves of the susceptible cultivars registered higher amount of enzyme activity when compared with the tolerant cultivars. The study reveals that the more anti-oxidative enzymes, the more susceptible the cultivar will be.