scholarly journals Beauveria bassiana: as a potential microbial biocontrol agent for tea mosquito bug, Helopeltis theivora Waterhouse (Hemiptera: Miridae) in Dooars and Darjeeling, India

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Bhabesh Deka ◽  
Azariah Babu ◽  
Arulmarianathan John Peter ◽  
Abhay Kumar Pandey ◽  
Kishor Chand Kumhar ◽  
...  
Keyword(s):  
Beauveria Bassiana ◽  
Crop Yields ◽  
Aqueous Suspension ◽  
Helopeltis Theivora ◽  
Tea Plantations ◽  
Phytotoxic Effect ◽  
Tea Mosquito Bug ◽  
Shoot Damage ◽  
Tea Plants ◽  
Test Insect

Abstract Background In the present study, the efficacy of two isolates of Beauveria bassiana namely, BKN20 and BKN1/14 was evaluated against the tea mosquito bug (TMB), Helopeltis theivora, Waterhouse (Hemiptera: Miridae) damaging harvestable shoots of tea plants in the Dooars and Darjeeling regions of West Bengal, India. Results Laboratory study revealed that, in both isolates, BKN20 was more pathogenic than BKN1/14, exhibiting 76% mortality of the test insect. The BKN20 isolate was formulated as an aqueous suspension (5%AS), and evaluated against TMB through micro-plot trials in tea plantations. The Micro-plot field study revealed a maximum of 72.19% reduction in the shoot damage due to TMB in plots sprayed with a 1000 ml/ha concentration of BKN20 5%AS containing 2 × 107 conidia/ml, as compared to the synthetic insecticide (Thiamethoxam 25%WG), where a 63.12% reduction in the shoots was recorded. Furthermore, different concentrations of the formulated BKN20 5%AS were evaluated against the test insect at 2 locations of tea gardens in the Dooars and Darjeeling regions. The results from both locations revealed that 1000 and 1200 ml/ha concentrations of BKN20 5%AS (each concentration containing 2 × 107 conidia/ml) significantly (p < 0.05) reduced the TMB population and they were more effective than Thiamethoxam 25%WG (120 g/ha). However, non-significant differences in crop yields were recorded. The formulation BKN20 5%AS was found to be non-pathogenic to non-target insects, i.e. natural enemies present in the tea ecosystem. BKN20 5%AS had no phytotoxic effect on the tea leaves, with acceptable organoleptic attributes. Conclusion The BKN20 isolate could be commercialized as an alternative microbial insecticide to reduce the load of chemical insecticides in the tea ecosystem.

scholarly journals Potential of the entomopathogenic fungus, Metarhizium anisopliae s.l. in controlling live-wood eating termite, Microtermes obesi (Holmgren) (Blattodea: Termitidae) infesting tea crop

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Bhabesh Deka ◽  
Azariah Babu ◽  
Arulmarianathan John Peter ◽  
Kishor Chand Kumhar ◽  
Suman Sarkar ◽  
...  
Keyword(s):  
Metarhizium Anisopliae ◽  
Entomopathogenic Fungus ◽  
Large Scale ◽  
Aqueous Suspension ◽  
Integrated Approach ◽  
Field Trials ◽  
Large Scale Field ◽  
Phytotoxic Effect ◽  
Major Pest ◽  
Tea Plants

Abstract Background In recent years, Microtermes obesi (Holmgren) (Blattodea: Termitidae) has been recorded as a major pest of tea crop, causes significant losses in production. Managing termite pests in tea crops through an integrated approach has been suggested, and the use of microbial biocontrol agent is one of the economical methods. The present study evaluated the pathogenic efficacy of an entomopathogenic fungus Metarhizium anisopliae s.l. (= M. anisopliae) against M. obesi damaging tea plants under field conditions. Results Metarhizium anisopliae s.l. was formulated as 5% aqueous suspension (AS). Large-scale field trials with formulated entomopathogen revealed that 1000 and 1200 ml concentrations of M. anisopliae s.l. 5%AS (each concentration containing 2 × 107 conidia/ml) each in 400 l of water/ha significantly (P < 0.05) reduced the population of M. obesi in tea gardens at Dooars and Darjeeling regions, India. In the field study, M. anisopliae s.l. was more effective than the standard insecticide and was non-pathogenic on the beneficial insects present in the tea gardens. In addition, M. anisopliae s.l. 5%AS had no phytotoxic effect on the tea leaves, with acceptable organoleptic attributes. Conclusion Metarhizium anisopliae s.l. isolate can be commercialized as an alternative natural termiticide to reduce the load of synthetic insecticides in the tea crop.

scholarly journals Evaluación de la actividad biocontroladora de Beauveria bassiana y Metarhizium anisopliae sobre larvas de Ancognatha scarabaeiodes (Coleoptera: Scarabaeidae)

2004 ◽  
Vol 5 (1) ◽  
pp. 43
Author(s):  
Any Mercedes Lucero Mafla ◽  
Luis Alberto Peña Villamil ◽  
Tito Bacca Ibarra
Keyword(s):  
Beauveria Bassiana ◽  
Metarhizium Anisopliae ◽  
Crop Yields ◽  
Integrated Management ◽  
White Grubs ◽  
Promising Alternative ◽  
Fungal Entomopathogens ◽  
Biocontrol Activity ◽  
Mortality Percentage ◽  
Lethal Doses

<p>Actualmente, en los municipios del departamento de Nariño (Colombia), en los cultivos de trigo y papa que son los principales sistemas de producción, se presentan altas infestaciones de poblaciones de chisas encontrándose hasta 350 larvas/m2, representando un factor limitante para la producción de los cultivos. Una alternativa promisoria para el manejo de esta plaga es la utilización de métodos biológicos que incluyen el uso de hongos entomopatógenos. El objetivo del presente trabajo fue el de evaluar el efecto de <em>Beauveria bassiana, Metarhizium anisopliae </em>sobre larvas de <em>Ancognatha scarabaeoides </em>en laboratorio e invernadero. Los aislamientos de hongos se obtuvieron de larvas infectadas en los municipios de Yacuanquer y Ospina. En el laboratorio, se seleccionaron 5 de 9 aislamientos de hongos: Mt1, Bb cosmo, Mt2, Bb4 y Bb10 que presentaron mortalidades superiores al 50%, éstas se evaluaron a concentraciones de 1x105 a 1x1010 esporas/ml. El porcentaje acumulado de mortalidad a los 18 días después de la inoculación fueron: del 100% para Bb cosmo, Mt1 y Mt2 en la concentración de 1x1010 esporas/ml y del 90% para Bb4 y Bb10 en la concentración de 1x109 esporas/ml, presentando concentraciones letales 90(CL90) de 1.1x1010, 7.3x109, 2.2x1010, 3.9x1010 y 4.3x1010 esporas/ml respectivamente. En invernadero se evaluaron los mismos microorganismos con sus respectivas concentraciones letales 50(CL50) y 90(CL90), encontrándose porcentajes de mortalidad del 76.00%, 67.50%, 63.50%, 59.00% y 53.50% para Mt1, Bb cosmo, Mt2, Bb4 y Bb10. Estos resultados indican la posibilidad de incluir estos biocontroladores nativos en el manejo integrado de las chisas en Nariño.</p><p> </p><p><strong>Evaluation of the biocontrol activity of <em>Beauveria bassiana, Metarhizium anisopliae</em>, on larvae of <em>Ancognatha scarabaeoides </em>(Coleoptera: Scarabaeidae).</strong></p><p>High grub populations of coleopteran, frequently attack crops of wheat and potato in the Department of Nariño, Colombia. Reports indicate that infestations levels reach more than 350 larvae/ m2, which severely reduce crop yields. Use of biological control measurements as fungal entomopathogens seems to be a promising alternative for management of this pest. The present work aimed to evaluate the effect of <em>Beauveria bassiana </em>and <em>Metarhizium anisopliae </em>on larvae of <em>Ancognatha scarabaeoides </em>both in laboratory and greenhouse conditions. Isolates of entomopathogen fungus were obtained from infected larvae in the municipalities of Yacuanquer and Ospina. A sample of 5 isolates, which previously had shown to cause mortality rates higher than 50%, was selected in the laboratory: Mt1, Bb cosmo, Mt2, Bb4 and Bb10. Isolates concentrations from 1x105 to 1x1010 spores/ml were tested. The cumulative mortality percentage (at 18 days after the inoculation) ranged from 100% with Bb cosmo, Mt1 and Mt2 at concentrations of 1x1010 spores/ml to 90% with Bb4 and Bb10 at concentrations of 1x109 spores/ml. Lethal doses 90 (LD90) of 1.1x1010, 7.3x109, 2.2x1010, 3.9x1010 and 4.3x1010 spores/ml were calculated for each isolate, respectively. An evaluation of the biocontrol activity of the isolates was carried out under greenhouse conditions. Mortality percentages obtained reached 76%, 67.5%, 63.5%, 59% and 53.5% for Mt1, Bb cosmo, Mt2, Bb4 and Bb10, respectively. These results suggest that the use of native biocontrolers is a promising alternative to be included in the integrated management for white grubs in Nariño.</p>

The tea mosquito bug,Helopeltis theivoraWaterhouse (Heteroptera: Miridae): its status, biology, ecology and management in tea plantations

2015 ◽  
Vol 61 (3) ◽  
pp. 179-197 ◽  
Author(s):  
Somnath Roy ◽  
Narayanannair Muraleedharan ◽  
Ananda Mukhapadhyay ◽  
Gautam Handique
Keyword(s):  
Tea Plantations ◽  
Tea Mosquito Bug

Dissipation rates of some selected pesticides from the soil of tea agroecosystem in Assam, India

2016 ◽  
Author(s):  
Yumnam Devashree ◽  
B. K. Dutta ◽  
S. B. Paul ◽  
Sudip Choudhury
Keyword(s):  
High Performance ◽  
Negative Impact ◽  
Degradation Kinetics ◽  
Cost Benefit ◽  
Sampling Period ◽  
Application Rate ◽  
Tea Plantations ◽  
Tea Plants ◽  
One Year ◽  
The Impact

An experiment was carried out in Rosekandy Tea Estate, Barak Valley, Assam to investigate the persistence of some selected pesticides (i.e Endosulfan, Fipronil, Paraquat and 2,4-D) on the soil. These pesticides were applied in the soil as per the application rate, where one year old tea plants were growing and the residue were analysed for a period of 50 days. Their degradation kinetics in soil was also studied and described. Soil samples were collected with the help of soil corer. The samples were brought to the laboratory, air dried in room temperature and extracted for analysis with high performance liquid chromatography (HPLC). Among the pesticides 2,4-D was highly persistent with half life of 57.75 days followed by Endosulfan which lost 42.64% of its initial concentration by the last sampling period (i.e 50 days) after the spraying. Fipronil and paraquat lost 65% and 70.32% of initial residue in soil making them the least persistent amongst these pesticides in the studied soil. Considering the impact of pesticide residues on human health, the less persistent pesticides may be used in tea plantations to minimize the potential negative impact of pesticides in the environment. The cost benefit ratios of the use of the pesticides should be also worked out.

scholarly journals Distribution, Severity, and Spread of Armillaria Root Disease in Kenya Tea Plantations

Plant Disease ◽  
1997 ◽  
Vol 81 (2) ◽  
pp. 133-137 ◽  
Author(s):  
J. M. Onsando ◽  
P. M. Wargo ◽  
S. W. Waudo
Keyword(s):  
Disease Severity ◽  
Management Practice ◽  
Woody Debris ◽  
Root Disease ◽  
Disease Spread ◽  
Tree Roots ◽  
Tea Plantations ◽  
Armillaria Root Disease ◽  
Residual Tree ◽  
Tea Plants

Surveys for Armillaria root disease severity were conducted over a 5-year period in small tea farms (0.5 to 1.0 ha) in the 12 tea-growing districts of Kenya. The disease occurred in all tea districts, but severity was greater in the districts east of the Rift Valley. Disease severity was associated with relative amounts of residual woody debris, especially roots, from trees and shrubs present when the land was converted to tea plantations. Excavation of tea bushes in disease centers showed that infection of tea bushes occurred primarily by mycelial growth from residual tree roots and from infected tea roots rather than from rhizomorphs. Rhizomorphs were scarce, and rarely involved in infection. They were confined mostly to the surface of the residual tree roots and were found growing freely in the soil in only one tea district. Rhizomorphs were more abundant in higher elevation plantations than in lower elevation plantations, where they occurred only on residual tree roots in the deeper, cooler, moister levels of the soil. Inoculum from residual tree debris in the soil was the most important source of infection in plantations of seed origin. Secondary spread from infected tea plants to healthy ones was limited and disease centers were small. In tea plantations derived from clonal cuttings, secondary disease spread from infected to healthy tea plants was more important resulting in large disease centers or gaps due to plant death and removal. Currently, soil sanitation by thorough removal of roots of forest trees and prompt removal of infected tea bushes is the best available management practice.

scholarly journals РЕАБИЛИТАЦИЯ НЕУХОЖЕННЫХ ЧАЙНЫХ ПЛАНТАЦИЙ И РАЗРАБОТКА ПОСЛЕДУЮЩЕЙ АГРОТЕХНОЛОГИИ НА ПРИМЕРЕ РЕГИОНА ИМЕРЕТИ

2019 ◽  
pp. 7-12
Author(s):  
Копалиани Р. Ш. ◽  
Джинчарадзе Н. И. ◽  
Капанадзе Ш. Ю.
Keyword(s):  
Root System ◽  
The State ◽  
Morphological Features ◽  
Extreme Conditions ◽  
Recent Past ◽  
Different Types ◽  
Tea Plantations ◽  
Long Time ◽  
Massive Scale ◽  
Tea Plants

Tea farming, in the recent past, was one of the leading branches of agriculture in Georgia. Since the 1990s of the last century this very important and leading branch of subtropical agriculture turned out to be bankrupt. On without well-groomed plantations, on a massive scale spread weeds, on the part of which, tea plants have undergone tough competition, it caused the weakness of tea culture function ability, in particular, in tea bushes were disturbed the function of physiological process, mainly the intensity of photosynthesis, increased breathing, etc. This article presents the results of a study of the state of tea plantations, who find themselves in extreme conditions unclean for a long time on the example of one of the tea producing regions of Georgia – Imereti, namely the degree of weed, morphological features of the aerial organs of tea plants, the root system, In this article it is discussed Some aspects of bushes caring process by applying different types of trimming and using the methods of mulching between rows. and also there is presented the development of practical measures for the rehabilitation of tea plantations.

scholarly journals The effect of root and shoot damage on the growth of tea plants.

1969 ◽  
Vol 17 (3) ◽  
pp. 234-240 ◽  
Author(s):  
T. Visser
Keyword(s):  
Root Growth ◽  
Apical Part ◽  
Tea Plant ◽  
Substantial Portion ◽  
Subsequent Reduction ◽  
Carbohydrate Reserves ◽  
Total Growth ◽  
Shoot Damage ◽  
Vegetatively Propagated Plants ◽  
Tea Plants

Experiments were carried out under various conditions of elevation and climate, in which young vegetatively propagated plants of selected tea clones were subjected to pruning operations at or after transplanting. Generally the removal of a substantial portion of shoot, root or both caused a temporary set back in growth and, in many instances, increased mortality. The subsequent reduction in total growth depended on the amount initially removed, except when only the immature apical part of the shoot was cut off, in which case the plants grew as well as the untreated ones. Retarded root growth and mortality as a consequence of pruning were associated with a marked depletion of the carbohydrate reserves of the roots, which was more serious when the original level (in Ceylon primarily determined by altitude) was low. Bringing a young tea plant into bearing as soon as possible requires the induction of lateral branching while avoiding growth restriction as far as possible; the practice of bending was found to be less detrimental to growth than other methods involving repeated pinching of apical shoots, cutting across at about two-thirds of the height of the plant, centering and modifications of these methods.-Inst. hort. Plant Breed., Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals The effects of tea plants-soybean intercropping on the secondary metabolites of tea plants by metabolomics analysis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yu Duan ◽  
Xiaowen Shang ◽  
Guodong Liu ◽  
Zhongwei Zou ◽  
Xujun Zhu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Secondary Metabolites ◽  
Growth Stages ◽  
Photosynthetic Parameters ◽  
Tea Quality ◽  
Tea Plantations ◽  
Sustainable System ◽  
Leguminous Crops ◽  
Tea Plants ◽  
Different Growth Stages

Abstract Background Intercropping, especially with legumes, as a productive and sustainable system, can promote plants growth and improves the soil quality than the sole crop, is an essential cultivation pattern in modern agricultural systems. However, the metabolic changes of secondary metabolites and the growth in tea plants during the processing of intercropping with soybean have not been fully analyzed. Results The secondary metabolomic of the tea plants were significant influence with intercropping soybean during the different growth stages. Especially in the profuse flowering stage of intercropping soybean, the biosynthesis of amino acids was significantly impacted, and the flavonoid biosynthesis, the flavone and flavonol biosynthesis also were changed. And the expression of metabolites associated with amino acids metabolism, particularly glutamate, glutamine, lysine and arginine were up-regulated, while the expression of the sucrose and D-Glucose-6P were down-regulated. Furthermore, the chlorophyll photosynthetic parameters and the photosynthetic activity of tea plants were higher in the tea plants-soybean intercropping system. Conclusions These results strengthen our understanding of the metabolic mechanisms in tea plant’s secondary metabolites under the tea plants-soybean intercropping system and demonstrate that the intercropping system of leguminous crops is greatly potential to improve tea quality. These may provide the basis for reducing the application of nitrogen fertilizer and improve the ecosystem in tea plantations.

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