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

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.

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Effects of Application Method and Rate on Control of Sclerotinia Blight of Peanut with Iprodione and Fluazinam1

Peanut Science ◽

10.3146/i0095-3679-28-1-8 ◽

2001 ◽

Vol 28 (1) ◽

pp. 28-33 ◽

Cited By ~ 8

Author(s):

J. P. Damicone ◽

K. E. Jackson

Keyword(s):

Disease Control ◽

Disease Incidence ◽

Maximum Yield ◽

Wide Band ◽

Yield Response ◽

Application Method ◽

Sclerotinia Blight ◽

Progress Curve ◽

Application Methods ◽

Yield Responses

Abstract Two trials with iprodione and three trials with fluazinam were conducted to assess the effects of application method and rate on the control of Sclerotinia blight of peanut with fungicide. In order to concentrate the fungicides near the crown area where the disease causes the most damage, applications were made through a canopy opener with a single nozzle centered over the row to achieve a 30.5-cm-wide band (canopy opener), and through a single nozzle centered over the row to achieve a 46-cm-wide band (band). Broadcast applications were compared to these methods at rates of 0, 0.28, 0.56, and 1.12 kg/ha on the susceptible cultivar Okrun. Sclerotinia blight was severe, with > 70% disease incidence and < 2000 kg/ha yield for the untreated controls in each trial. Linear reductions in area under the disease progress curve (AUDPC), but not final disease incidence, with iprodione rate were significant (P < 0.05) for all methods of application. However, the rate of decrease did not differ among application methods. Linear increases in yield with rate of iprodione were greater for canopy opener compared to the band or broadcast applications. Only a 50% reduction in AUDPC and a maximum yield of < 2700 kg/ha was achieved with iprodione using the best method. At the maximum rate of 1.12 kg/ha, fluazinam provided > 75% disease control and > 4000 kg/ha yield for all application methods. Differences in disease control and yield among application methods only occurred at the 0.28 and 0.56 kg/ha rates of fluazinam. Reductions in AUDPC with fluazinam rate were quadratic for all application methods, but AUDPC values were less for the canopy opener and band methods at 0.28 and 0.56 kg/ha compared to the broadcast methods. The yield response to rate for broadcast applications of fluazinam was linear. However, predicted yield responses to fluazinam rate were quadratic for the band and canopy opener methods and approached the maximum response at 0.84 kg/ha. Targeting fungicide applications using the band and/or canopy opener methods was beneficial for fluazinam at reduced rates. Disease control with iprodione was not adequate regardless of application method.

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

Journal of Agrometeorology ◽

10.54386/jam.v23i1.88 ◽

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.

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Effect of Protectant Fungicide Application Schedules on Gummy Stem Blight Epidemics and Marketable Yield of Watermelon

Plant Disease ◽

10.1094/pdis.2000.84.3.254 ◽

2000 ◽

Vol 84 (3) ◽

pp. 254-260 ◽

Cited By ~ 32

Author(s):

Anthony P. Keinath

Keyword(s):

Disease Control ◽

Leaf Area ◽

Disease Severity ◽

Spray Application ◽

Didymella Bryoniae ◽

Marketable Yield ◽

Stem Blight ◽

Gummy Stem Blight ◽

Progress Curve ◽

Marketable Fruit

The watermelon cultivar Royal Star was grown in fall 1996, spring and fall 1997, and spring 1998 and treated with 2.52 kg a.i./ha of the protectant fungicides mancozeb or chlorothalonil. Spray application schedules used in the experiments included two initiation times, sprays every 7, 10, or 14 days, and two termination times. Severity of gummy stem blight, caused by Didymella bryoniae, was high in fall 1996 and 1997, moderate in spring 1997, and low in spring 1998. In each experiment, fungicide applications reduced the area under the disease progress curve (AUDPC), percent leaf area diseased at the end of the season, time to reach 25% disease severity, or all three disease measurements relative to the nonsprayed control. In the 1996 and both 1997 experiments, 7-day spray intervals provided more effective disease control than 14-day intervals. In general, initiating sprays early reduced gummy stem blight compared with delayed sprays, but spray termination times did not affect AUDPC. In both fall experiments, fungicide applications increased yield of marketable fruit over the no-fungicide control. A 7-day spray interval increased marketable weight compared with a 14-day interval only in fall 1996. Weight of marketable fruit did not differ among treatments in either spring experiment. Differences in disease control among treatments often did not correspond to differences in marketable yields.

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Effect Of NPK On The Incidence Of Alternaria Leaf Blight Of Mustard

Bangladesh Journal of Agricultural Research ◽

10.3329/bjar.v36i3.9269 ◽

1970 ◽

Vol 36 (3) ◽

pp. 407-413 ◽

Cited By ~ 1

Author(s):

F Khatun ◽

MS Alam ◽

MA Hossain ◽

S Alam ◽

PK Malaker

Keyword(s):

Field Study ◽

Disease Severity ◽

Seed Yield ◽

Nutrient Management ◽

Disease Incidence ◽

Leaf Blight ◽

Recommended Dose ◽

Soil Test ◽

Alternaria Leaf Blight ◽

Macro Nutrients

A 2-year field study was carried out to find out the effect of three macro nutrients NPK on the severity of Alternaria leaf blight and yield of mustard. Nitrogen @ 80, 100, 120, 140, and 160, phosphorus @ 15, 30, and 45, and potassium @ 30, 60, and 90 kg/ha were applied. Among the nutrients, 120-30- 60 kg NPK/ha was considered as recommended dose on the basis of soil test. Fertilizer dose 120-30-90 kg/ha appeared to be the best combination of N, P, and K in reducing the disease incidence and to increase seed yield of mustard. Higher dose of K (90 kg/ha) decreased the incidence of Alternaria leaf blight but higher dose of nitrogen (140 and 160 kg N/ha) increased the disease incidence. The highest seed yield of 1718 kg/ha was obtained with 120-30-90 kg of NPK/ha which was statistically similar to the doses of 120-30-60 and 120-45- 60 kg of NPK/ha. Higher seed yield and lower disease severity was also observed under these three treatments as compared to other treatments. Keywords: Mustard; Alternaria leaf blight; nutrient management. DOI: http://dx.doi.org/10.3329/bjar.v36i3.9269 BJAR 2011; 36(3): 407-413

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Ginger Essential Oils-Loaded Nanoemulsions: Potential Strategy to Manage Bacterial Leaf Blight Disease and Enhanced Rice Yield

Molecules ◽

10.3390/molecules26133902 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3902

Author(s):

Abdullahi Adamu ◽

Khairulmazmi Ahmad ◽

Yasmeen Siddiqui ◽

Intan Safinar Ismail ◽

Norhayu Asib ◽

...

Keyword(s):

Antibacterial Activity ◽

Electron Microscope ◽

Essential Oils ◽

Disease Severity ◽

Rice Yield ◽

Cell Structure ◽

Leaf Blight ◽

Bacterial Leaf Blight ◽

Control Treatment ◽

Promising Alternative

The bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious rice diseases, causing huge yield losses worldwide. Several technologies and approaches have been opted to reduce the damage; however, these have had limited success. Recently, scientists have been focusing their efforts on developing efficient and environmentally friendly nanobactericides for controlling bacterial diseases in rice fields. In the present study, a scanning electron microscope (SEM), transmission electron microscope (TEM), and a confocal laser scanning microscope (CLSM) were utilized to investigate the mode of actions of ginger EOs on the cell structure of Xoo. The ginger EOs caused the cells to grow abnormally, resulting in an irregular form with hollow layers, whereas the dimethylsulfoxide (DMSO) treatment showed a typical rod shape for the Xoo cell. Ginger EOs restricted the growth and production of biofilms by reducing the number of biofilms generated as indicated by CLSM. Due to the instability, poor solubility, and durability of ginger EOs, a nanoemulsions approach was used, and a glasshouse trial was performed to assess their efficacy on BLB disease control. The in vitro antibacterial activity of the developed nanobactericides was promising at different concentration (50–125 µL/mL) tested. The efficacy was concentration-dependent. There was significant antibacterial activity recorded at higher concentrations. A glasshouse trial revealed that developed nanobactericides managed to suppress BLB disease severity effectively. Treatment at a concentration of 125 μL/mL was the best based on the suppression of disease severity index, AUDPC value, disease reduction (DR), and protection index (PI). Furthermore, findings on plant growth, physiological features, and yield parameters were significantly enhanced compared to the positive control treatment. In conclusion, the results indicated that ginger essential oils loaded-nanoemulsions are a promising alternative to synthetic antibiotics in suppressing Xoo growth, regulating the BLB disease, and enhancing rice yield under a glasshouse trial.

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Epidemiology and management of bacterial leaf spot on watermelon caused byPseudomonas syringae

Plant Disease ◽

10.1094/pdis-11-16-1628-re ◽

2017 ◽

Vol 101 (7) ◽

pp. 1222-1229 ◽

Cited By ~ 4

Author(s):

E. A. Newberry ◽

L. Ritchie ◽

B. Babu ◽

T. Sanchez ◽

K. A. Beckham ◽

...

Keyword(s):

Disease Severity ◽

Pseudomonas Syringae ◽

Leaf Spot ◽

Negative Relationship ◽

Disease Outbreaks ◽

Field Trials ◽

Multiple Regression Model ◽

Bacterial Leaf Spot ◽

Progress Curve ◽

Cool Conditions

Bacterial leaf spot of watermelon caused by Pseudomonas syringae has been an emerging disease in the southeastern United States in recent years. Disease outbreaks in Florida were widespread from 2013 to 2014 and resulted in foliar blighting at the early stages of the crop and transplant losses. We conducted a series of field trials at two locations over the course of two years to examine the chemical control options that may be effective in management of this disease, and to investigate the environmental conditions conducive for bacterial leaf spot development. Weekly applications of acibenzolar-S-methyl (ASM) foliar, ASM drip, or copper hydroxide mixed with ethylene bis-dithiocarbamate were effective in reducing the standardized area under the disease progress curve (P < 0.05). Pearson’s correlation test demonstrated a negative relationship between the average weekly temperature and disease severity (–0.77, P = 0.0002). When incorporated into a multiple regression model with the square root transformed average weekly rainfall, these two variables accounted for 71% of the variability observed in the weekly disease severity (P < 0.0001). This information should be considered when choosing the planting date for watermelon seedlings as the cool conditions often encountered early in the spring season are conducive for bacterial leaf spot development.

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Impact of weather parameters on alternaria blight of Indian mustard [(Brassica juncea (L.) Czern. & Coss.)]

Bangladesh Journal of Botany ◽

10.3329/bjb.v50i1.52663 ◽

2021 ◽

Vol 50 (1) ◽

pp. 15-19

Author(s):

Rakesh Punia ◽

Pavitra Kumari ◽

Anil Kumar ◽

AS Rathi ◽

Ram Avtar

Keyword(s):

Wind Speed ◽

Relative Humidity ◽

Disease Severity ◽

Vapour Pressure ◽

Minimum Temperature ◽

Indian Mustard ◽

Maximum Increase ◽

Alternaria Blight ◽

Progress Curve ◽

Sunshine Hours

Progression of Alternaria blight disease was measured on two susceptible Indian mustard varieties viz., RH 30 and RH 0749 sown at three different dates. The maximum increase in disease severity was recorded between first weeks of February and last week of February. During this period, the maximum and minimum temperature, relative humidity at morning and evening, average vapour pressure of morning and evening, maximum and bright sunshine hours and wind speed were higher, which resulted in congenial conditions for severe infection by the pathogen. The disease severity was positively correlated with maximum and minimum temperature, average vapour pressure, wind speed, sunshine hours and evaporation, while relative humidity and rainfall negatively correlated with Alternaria blight on both the varieties. A maximum value of area under disease progress curve was observed on cultivar RH 30 (651.1 cm2) as compared to RH 0749 (578.9 cm2), when crop was sown on 9th November.

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Improving Soybean Production Using Light Supplementation at Field-Scale: A Case Study

Journal of Agricultural Studies ◽

10.5296/jas.v9i3.18890 ◽

2021 ◽

Vol 9 (3) ◽

pp. 259

Author(s):

Ernane M Lemes ◽

Breno N R Azevedo ◽

Matheus F I Domiciano ◽

Samuel L Andrade

Keyword(s):

Grain Yield ◽

Plant Height ◽

Crop Production ◽

High Efficiency ◽

Field Scale ◽

Soybean Crop ◽

Illumination System ◽

Progress Curve ◽

Commercial Area ◽

Yield Responses

In modern agriculture, there is a growing need for increasing crop efficiency while minimizing environmental impacts. The use of high-efficiency light supplementation to enhance plant development is limited for high-productive crops at field conditions (outdoor). This study evaluated the soybean plant’s yield responses in an open commercial area (field scale) cultivated under conditions of artificial light supplementation. A commercial irrigated (pivot) area received an illumination system for light supplementation (LS) in its inner pivot spans. About 40 hours of LS were applied to the plants during the soybean crop cycle. The area’s outer pivot spans did not receive light supplementation (nLS). The internode number, the plant height, the pods per plant were evaluated weekly to compute the area under the progress curve (AUPC). The grain yield at harvest was also assessed. The AUPC of the internode number, plant height and pods per plant were positively affected by the LS treatment. The regular soybean cycle (nLS) is about 17 weeks; however, the LS harvest occurred three weeks later. Light supplementation increased soybean grain yield by 57.3% and profitability by 180% when compared to nLS. Although light supplementation at field scale poses a challenge, it is now affordable since sustainable field resistant technologies are now available. The present study is the first known report of light supplementation used to improve soybean crop production at field scale.

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Management of Daylily Rust With Different Fungicides and Fungicide Combinations

Plant Health Progress ◽

10.1094/php-03-17-0021-rs ◽

2017 ◽

Vol 18 (3) ◽

pp. 162-165 ◽

Cited By ~ 1

Author(s):

Robert S. Emmitt ◽

James W. Buck

Keyword(s):

United States ◽

Disease Management ◽

Disease Severity ◽

Low Cost ◽

Single Application ◽

Southeast United States ◽

Disease Progress Curve ◽

Disease Progress ◽

Progress Curve ◽

Disease Pressure

Production nurseries and daylily hybridizers in the southeast United States rely on the use of fungicides to manage daylily rust, caused by the fungus Puccinia hemerocallidis. Foliar sprays of pyraclostrobin, flutolanil, tebuconazole, myclobutanil, chlorothalonil, mancozeb, pyraclostrobin + boscalid, flutolanil + tebuconazole, flutolanil + myclobutanil, flutolanil + chlorothalonil, and flutolanil + mancozeb applied on 14-day intervals, and a nontreated control, were evaluated under high disease pressure at three locations in Griffin, GA, in 2015. Tebuconazole or the tebuconazole + flutolanil treatment consistently had the lowest area under the disease progress curve (AUDPC) of the treatments. The addition of flutolanil to chlorothalonil or mancozeb did not improve rust control and no difference in disease severity was observed in any treatment containing contact fungicides on all assessment dates. Single application costs ranged from $10.21 to $95.96 with tebuconazole providing excellent disease management at a relatively low cost per application ($13.90).

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