scholarly journals Influence of weather parameters on alternaria leaf blight severity of makhana under the agro-climate of Koshi region of Bihar

2021 ◽  
Vol 23 (1) ◽  
pp. 54-59
Author(s):  
SANTOSH KUMAR ◽  
MD. NADEEM AKHTAR ◽  
SANTOSH KUMAR ◽  
MAHESH KUMAR ◽  
TRIBHUWAN KUMAR
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Disease Severity ◽  
Infection Process ◽  
Leaf Blight ◽  
Alternaria Leaf Blight ◽  
Weather Parameters ◽  
Maximum Temperatures ◽  
Blight Disease ◽  
Cent Disease

Weather parameters play a pivotal role in the infection process and spread of pathogen. It also influences the expression of susceptibility/resistance of the host plant during post-infection phases. Therefore, an experiment was conducted for two consecutive cropping seasons (2018 &2019) to study the influence of weather parameters such as temperature, humidity, rainfall and wind direction on the emergence of alternaria leaf blight of makhana in Koshi region of Bihar. Maximum per cent disease severity of alternarialeaf blightwas observed during the peak monsoon months (June to August). Highest disease severity of leaf blight (14.80% & 15.7%) was observed in the mid June during crop season, 2018 and 2019. High temperature (36.9oC & 38.1oC), and relative humidity (94% & 96.4%) of both the year 2018 and 2019 were found correlated with higher severity to alternaria leaf blight. Similarly average HTR values (3.1) were also found correlated with the average high temperature and relative humidity of both years (2018 and 2019) in terms of severity of leaf blight disease. Maximum temperatures, relative humidity and rainfall exhibited strong positive linear relationship and influenced the occurrence of alternaria leaf blight disease significantly. We also developed a geo-phytopathological model for the prediction of alternaria leaf blight disease of makhana on the basis of congenial mean temperature and relative humidity.

scholarly journals Influence of weather parameters on progress of rust disease severity in pea (Pisum sativum L.)

2017 ◽  
Vol 9 (3) ◽  
pp. 1724-1728
Author(s):  
Vinod Upadhyay ◽  
K. P. S. Kushwaha ◽  
Puja Pandey
Keyword(s):  
Relative Humidity ◽  
Disease Severity ◽  
Wind Velocity ◽  
Minimum Temperature ◽  
Meteorological Parameters ◽  
Maximum Temperature ◽  
Rust Disease ◽  
Rust Severity ◽  
Weather Parameters ◽  
Cent Disease

Decision to apply one or more fungicide spray will depend on the risk of rust epidemic in a particular year. Rust epidemic is determined by interaction of three important factors namely, susceptible host, virulent pathogen and the most important i.e. favourable environment for a particular period of time. Therefore, it is necessary to study the correlation between different meteorological parameters and rust severity. Present study revealed that rust dis-ease generally appeared 60 days after sowing and was subsequently increased with a period of time till harvest (4.17 to 64.17 per cent). Disease was observed at a maximum temperature of 16.85 to 24.79ᵒC, 8.09 to 12.27ᵒC minimum temperature, 90.30 to 95.70 percent morning Relative Humidity (RH), 54.80 to 78.40 percent afternoons RH, 0.10 to 5.45mm rainfall and wind velocity of 3.93 to 4.23 km/hr. The correlation between different meteorological parameters and rust severity revealed that per cent disease severity showed highly positive correlation with maxi-mum temperature (r = 0.977), minimum temperature (r = 0.704), rainfall (r = 0.039) and wind velocity(r = 0.093) whereas disease severity show negative correlation with morning(r=-0.925) and afternoon RH (r = -0.926). It was observed that the rust severity is highly influenced by the different weather parameters such as temperature, relative humidity, rainfall and wind velocity. This information will help the researchers in formulating the forecasting model for the rust disease in pea and will also supports farmers in decision making regarding time of occurrence of rust epi-demic and thereby, allow timely scheduling and need based utilization of fungicides accordingly for the management of pea rust.

scholarly journals Response of cotton genotypes against the incidence of Alternaria leaf blight of cotton under field conditions

2021 ◽  
Vol 42 (4) ◽  
pp. 1002-1007
Author(s):  
G. Rajesha ◽  
◽  
S. Nakkeeran ◽  
T. Indumathi ◽  
P. Adhipathi ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Block Design ◽  
Disease Index ◽  
Leaf Blight ◽  
Field Conditions ◽  
Breeding Lines ◽  
Alternaria Leaf Blight ◽  
Resistant Reaction ◽  
Blight Disease ◽  
Cent Disease

Aim: To identify the resistant source present in the breeding materials against Alternaria leaf blight disease of cotton (Gossypium spp.). Methodology: Breeding entries were sown in a randomized complete block design in the experimental site. Disease intensity on each genotype at 45, 90, 135 and 180 days after sowing (DAS) were recorded from leaves of lower, middle and upper parts of plants and graded. According to 0 - 4 disease scoring scale, per cent disease index (PDI) was calculated and genotypes were categorized into different categories based on disease reaction Results: Development of Alternaria disease was noticed at early days of crop growth in few genotypes and the disease increased upto 135 days after sowing. The maximum mean per cent disease index of 41.17 and 40.06 were recorded in Br.14a (ZT)1333 and Br.14a (ZT)1332 respectively. The least PDI of 0.58 was recorded in Br.03a (ZT)1303. Disease incidence of <11.00% of was reported in 37 entries at 45 days after sowing. None of the genotypes showed apparently immune reaction, twenty-one genotypes showed resistant reaction, eleven genotypes were moderately resistant and five showed moderately susceptible reaction. Interpretation: Twenty-one breeding lines showed resistant reaction against Alternaria leaf blight disease under field conditions, however, further utilization of these lines may be carried out in breeding programmes for the development of resistant source against this disease.

scholarly journals Present status of Alternaria leaf blight disease of sunflower in north eastern Karnataka

2020 ◽  
Vol 8 (3) ◽  
pp. 2906-2908
Author(s):  
P Vidyashree ◽  
ST Yenjerappa ◽  
D Pramesh ◽  
Gururaj Sunkad ◽  
Vikas Kulkarni
Keyword(s):  
Present Status ◽  
Leaf Blight ◽  
Alternaria Leaf Blight ◽  
North Eastern ◽  
Blight Disease

scholarly journals Assessing Taro (Colocasia esculenta (L.) Schott) Leaf Blight Incidence, Severity, and Farmers’ Knowledge of the Disease in Fako Division of Cameroon

2020 ◽  
pp. 17-29
Author(s):  
Mandah Cicelia Takor ◽  
Ekwa Yawa Monono ◽  
Ojong Agbor Ntane ◽  
Jemimah Evenye Ngale ◽  
Lum A. Fontem
Keyword(s):  
Disease Severity ◽  
Disease Incidence ◽  
Management Strategies ◽  
Leaf Blight ◽  
Cultural Methods ◽  
Randomized Design ◽  
High Prevalence ◽  
Severity Of The Disease ◽  
Blight Disease ◽  
Taro Leaf Blight

Taro leaf blight (TLB), a major disease of taro plant caused by Phytophthora colocasiae, a pseudo-fungus, that occurs in many taro producing areas, especially in the South West of Cameroon. A Survey was conducted to assess farmers’ knowledge, as well as to determine the incidence and the severity of the disease in taro fields. Structured questionnaires were administered in selected locations (Bokova, Ekona, Muea, Mile 16, Mutengene, and Likomba) of taro production. Two farms were selected with two quadrats of 64 m2 each were carved to assess disease incidence and severity on taro. The number of plants infected with taro leaf blight were counted and the area of the affected leaves measured was used to evaluate the disease incidence and disease severity. Data collected were subjected to ANOVA for complete randomized design and the means were compared using Tukey test at 0.05 probability levels. The results revealed that most of the farmers could identify the disease while practicing cultural methods in controlling the disease. The results also revealed significant differences (p = 0.001) in disease incidence and disease severity in all the localities, with Mile 16 showing the highest percentage mean of 96.53% and 85.59%, respectively. The severity scored showed high infection range of 3 – 3.95 in all locations except in Likomba (2.60).  It could be concluded from the results that there were high prevalence of taro leaf blight disease in Fako Division. Good management strategies are therefore required to control Taro leaf blight and improve taro production in the area.

scholarly journals Effects of Nozzle Type and Spray Pressure on Control of Alternaria Leaf Blight of Muskmelon with Chlorothalonil

Plant Disease ◽  
2001 ◽  
Vol 85 (10) ◽  
pp. 1081-1084 ◽  
Author(s):  
Daniel S. Egel ◽  
Philip Harmon
Keyword(s):  
Disease Control ◽  
Disease Severity ◽  
Leaf Blight ◽  
Hollow Cone ◽  
Alternaria Leaf Blight ◽  
Progress Curve ◽  
Yield Responses ◽  
Similar Decrease ◽  
Affect Disease Severity ◽  
Nozzle Type

Methods of fungicide application were evaluated for their influence on the chemical control of Alternaria leaf blight of muskmelon in 1997, 1998, and 1999. Chlorothalonil was applied through either flat-fan or hollow-cone nozzles and with spray pressures ranging from 207 to 1,034 kPa. In all 3 years, unsprayed controls had significantly more disease than any of the sprayed treatments. There was no significant effect of nozzle type on disease severity or yield in any year. Spray pressures of 207, 414, or 620 kPa did not significantly affect disease severity or yield in 1997. In 1998, the 827-kPa pressure significantly lowered disease severity compared with the 207-kPa and 414-kPa pressures, but a similar decrease in the number of lesions per leaf did not occur. Yield responses in 1998 did not support a relationship between spray pressures and disease control. In 1999, spray pressure of 1,034 kPa did not significantly decrease the area under the disease progress curve as estimated from weekly ratings of the disease severity ratings or counts of lesions per leaf made on two dates. Results indicate no differences in disease control due to any of the application methods examined.

scholarly journals Management of Leaf Blight Disease Caused by Alternaria polianthi in Tuberose

2020 ◽  
pp. 12-17
Author(s):  
M. R. Ravikumar ◽  
D. K. Harish ◽  
B. H. Kumara ◽  
Amarendra Kumar
Keyword(s):  
High Temperature ◽  
Yield Loss ◽  
Maximum Yield ◽  
Disease Index ◽  
Leaf Blight ◽  
Growth Reduction ◽  
Severe Problem ◽  
Tropical Areas ◽  
Percent Disease Index ◽  
Blight Disease

Tuberose is an ornamental crop which is growing under tropical and sub-tropical areas. Recently, the incidence of leaf blight disease caused by Alternaria polianthi a fungal disease of tuberose is considered as a severe problem causing growth reduction and yield loss triggered by high temperature and humidity. Hence an investigation was carried out in farmer fields at Tumnakatti, Ranebennurtq in Karnataka, to study the bio-efficacy of different fungicides against leaf blight of tuberose. There were six chemicals viz., Tebuconazole 250 EC @ 0.1%, Difenconazole – 25% EC @ 0.1%, Propinoconazole 25% EC @ 0.1%,  Hexaconazole  2% SC @ 0.1%, Mancozeb75 WP @ 0.25%, Chlorothalonil 75 WP @ 0.2%, were evaluated in tuberose cultivar Prajwal during kharif  2016 and 2017. Among the different fungicides, four sprays taken with Tebuconazole @ 0.1% at 15 days interval starting from onset of disease proved to be the most effective treatment and resulted in lowest percent disease index, PDI (10.80). Maximum yield and number of flower stalks per square meter area were recorded in Tebuconazole @ 0.1% (50.90). Tebuconazole @ 0.1% could be used for management of leaf blight and increase the yield of tuberose.

scholarly journals Field Performance of BAU-Biofungicaide for Management of Narrow Brown Leaf Spot and Bacterial Leaf Blight Disease of Rice CV. BRRI Dhan29

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Hyat Mahmud
Keyword(s):  
Disease Severity ◽  
Leaf Spot ◽  
Seed Quality ◽  
Field Performance ◽  
Leaf Blight ◽  
Bacterial Leaf Blight ◽  
Leaf Spot Disease ◽  
Brown Leaf Spot ◽  
Brown Leaf ◽  
Blight Disease

Potent (0.1%) and BAU-Biofungicide (2%) revealed the significant reduction both in disease severity and incidence of narrow brown leaf spot disease, and the lowest disease severity and incidence of bacterial leaf blight disease were 3.00% and 5.83%, respectively in BRRI dhan29 in 2012 year. BAU-Biofungicide (Trichoderma based preparation), extract of garlic (Allium sativum) and neem (Azadirachta indica), Bavistin DF (Carbandazim) and Potent 250 EC (Propiconazole) were evaluated in controlling narrow brown leaf spot and bacterial leaf blight disease (Xanthomonas oryzae pv. Oryzae) under field condition for producing seed quality and controlling seed borne pathogen of rice cv BRRI dhan29 during 2012 and 2013 years. Maximum normal seedling (87.67%) and 37.49% higher increase in vigour index on seed quality test of harvested seeds were observed with BAU-Biofungicide (3%) over control. BAU-Biofungicide (2 and 3%) and Potent 250 EC (0.1%) were found to be effective in controlling seed borne pathogens. BAU-Biofungicide has also been attributed as profound contribution on quality seed production of harvested seed of BAU-Biofungicide sprayed plot.

scholarly journals Identification of Salicylic Acid Mechanism against Leaf Blight Disease in Oryza sativa by SR-FTIR Microspectroscopic and Docking Studies

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 652
Author(s):  
Wannaporn Thepbandit ◽  
Narendra Kumar Papathoti ◽  
Jayasimha Rayalu Daddam ◽  
Kanjana Thumanu ◽  
Supatcharee Siriwong ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Disease Severity ◽  
Three Dimensional ◽  
Docking Studies ◽  
Leaf Blight ◽  
Dimensional Structure ◽  
Post Inoculation ◽  
Pathogenesis Related ◽  
Infra Red ◽  
Blight Disease

The present study was to investigate the application and mechanism of salicylic acid (SA) as SA-Ricemate for the control of leaf blight disease using a Synchrotron Radiation-based Fourier-Transform Infra-Red (SR-FTIR) microspectroscopy and docking studies. After treating rice plants cv. KDML 105 with SA-Ricemate, the leaves were inoculated with Xanthomonas oryzae pv. oryzae, the causal agent of leaf blight, and disease severity were assessed. The leaves were also used to detect changes in endogenous SA content. The results indicated that SA-Ricemate, as an activated compound, reduced disease severity by 60% at three weeks post-inoculation and increased endogenous content by 50%. The SR-FTIR analysis of changes in the mesophyll of leaves (treated and untreated) showed that the groups of lipids, pectins, and proteins amide I and amide II occurred at higher values, and polysaccharides were shown at lower values in treated compared to untreated. Besides, docking studies were used to model a three-dimensional structure for Pathogenesis-related (PR1b) protein and further identify its interaction with SA. The results showed that ASP28, ARG31, LEU32, GLN97, and ALA93 are important residues that have strong hydrogen bonds with SA. The docking results showed that SA has a good interaction, confirming its role in expression.

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