Phylogenetic distribution of Ralstonia solanacearum species complex populations in potato in Kenya

Plant Disease ◽  
2021 ◽  
Author(s):  
Lilian Auma Okiro ◽  
Richard Mbithi Mulwa ◽  
Maurice Edwards Oyoo ◽  
Eunice Machuka ◽  
Monica L. Parker ◽  
...  
Keyword(s):  
Disease Severity ◽  
Ralstonia Solanacearum ◽  
Species Complex ◽  
Block Design ◽  
Progression Rate ◽  
Pathogenicity Test ◽  
Solanacearum Strain ◽  
Progress Curve ◽  
Severity Scores ◽  
Significant Difference

Abstract Ralstonia solanacearum is a pathogen causing bacterial wilt disease of potato, resulting in 70% potato production losses in Kenya. A study was conducted to determine the diversity of Ralstonia solanacearum species complex strains within the main potato-growing regions of Kenya. Potato tubers were collected from different potato-growing regions of Kenya from visibly wilted potato plants, including tomato and irrigation water and cultured for pathogen isolation. Genomic DNA was isolated from 135 purified cultures of RSSC isolates and PCR amplified using multiplex and sequevar primers targeting the endoglucanase partial gene sequences. Pathogenicity test using R. solanacearum strain (phylotype II sequevar I) was done on Kenya Karibu, Shangi, Chulu, Wanjiku and Money Maker cultivars. Phylogenetic analysis of the partial endoglucanase gene identified two genospecies, R. pseudosolanacearum sp. nov (1.5%) and R. solanacearum (98.5%). All R. solanacearum strains clustered in sequevar I and were distributed in all the potato-growing regions surveyed. The cultivars were grown in a greenhouse for two cycles in a randomized complete block design and inoculated with R. solanacearum strain. The severity scores were assessed and the area under disease progress curve (AUDPC) was determined. All the cultivars tested for pathogenicity exhibited wilting symptoms at varying intervals after infection, with none showing complete resistance to R. solanacearum. Cultivar Shangi exhibited minimum disease severity and progression of 41.14% and AUDPC of 1041.7, respectively while Kenya Karibu was the most susceptible with a high progression rate of 68.24% and AUDPC of 1897.5, respectively. Money Maker, Chulu and Wanjiku showed no significant difference in disease severity depicting a simultaneous rate of infection among them. These findings provide valuable information to better understand the pathogen genetic diversity in Kenya and how it spreads.

Comparative Performance of Sanitizers in Managing Plant-to-plant Transfer and Postharvest Infection of Calonectria pseudonaviculata and Pseudonectria foliicola on Boxwood

Plant Disease ◽  
2021 ◽  
Author(s):  
Ravi Bika ◽  
Warren Copes ◽  
Fulya Baysal-Gurel
Keyword(s):  
Shelf Life ◽  
Disease Severity ◽  
Ammonium Compound ◽  
Conidial Suspension ◽  
Rooted Cuttings ◽  
Disease Progress ◽  
Progress Curve ◽  
Significant Difference ◽  
Plant Transfer ◽  
Blight Disease

Calonectria pseudonaviculata and Pseudonectria foliicola causing the infamous ‘boxwood blight’ and ‘Volutella blight’, respectively, are a constant threat to the boxwood production and cut boxwood greenery market. Both pathogens cause significant economic loss to all parties (growers, retailer, and customers) in the horticultural chain. The objective of this study was to evaluate efficacy of disinfesting chemicals [quaternary ammonium compound (QAC), peroxy, acid, alcohol, chlorine, cleaner] in preventing plant-to-plant transfer of C. pseudonaviculata and P. foliicola via cutting tools, as well as reduction of postharvest boxwood blight and Volutella blight disease severity in harvested boxwood greenery. First, an in vitro study was conducted to select products and doses that completely or near-completely inhibited conidial germination of C. pseudonaviculata and P. foliicola. The selected treatments were also tested for their ability to reduce plant-to-plant transfer of C. pseudonaviculata and P. foliicola and manage postharvest boxwood blight and Volutella blight in boxwood cuttings. For the plant-to-plant transfer study, Felco 19 shears were used as a tool for mechanical transfer of fungal conidia. The blades of Felco 19 shears were exposed to a conidial suspension of C. pseudonaviculata or P. foliicola by cutting a 1 cm diameter cotton roll that had been dipped into a fungal suspension. Disease-free boxwood rooted cuttings (10 cm height) were pruned with the contaminated shears. The Felco 19 shears were equipped with a mounted miniature sprayer connected to a pressurized reservoir of treatment solution that automatically sprayed the blade and plant surface while cutting. The influence of accumulated sap on the shear blade was studied through 1- or 10-cut pruning variable on test plants and screened for the efficacy of treatments. Then, the boxwood rooted cuttings were transplanted and incubated in room conditions (21 °C, 60% RH) with 12 h of fluorescent light; data evaluation on disease severity was done weekly for a month. Disease progress [area under disease progress curve (AUDPC)] was calculated. In another study, postharvest dip application treatments were used for the management of postharvest boxwood blight or Volutella blight on boxwood cuttings. The harvested boxwood cuttings were inoculated with a conidial suspension of C. pseudonaviculata or P. foliicola, then dipped into treatment solution 3 days afterwards. The treated boxwood cuttings were kept in room conditions, and boxwood blight or Volutella blight disease severity as well as marketability (postharvest shelf life) assessed every 2 days for 1 week. A significant difference between treatments was observed for reduction of boxwood blight or Volutella blight severity and AUDPC. The treatments (ODD + DoD + DdD + DB)AC [Simple Green D Pro 5], 2 propanol + DDAC (0.12%) [KleenGrow], and DBAC + DEAC [GreenShield] were the most effective in reducing the plant to plant transfer of boxwood blight and Volutella blight when pruned with contaminated Felco 19 shears. In addition to the three effective treatments above, acetic acid (2.5%) [Vinegar], 2-propanol + DDAC (0.06%), sodium hypochlorite (Clorox) and potassium peroxymonosulfate + NaCl (2%) [Virkon] were effective in reducing postharvest boxwood blight whereas DBAC + DBAC [Lysol all-purpose cleaner], ethanol [70% (Ethyl alcohol)] and DDAC +DBAC [Simple Green D Pro 3 plus] were effective in reducing Volutella blight disease severity and AUDPC, and also maintained better quality and longer postharvest shelf life of boxwood cuttings when applied as a dip treatment. The longer postharvest shelf life of boxwood cuttings noted may be attributed to reduced disease severity and AUDPC resulting in healthy boxwood cuttings.

scholarly journals Management of Anthracnose Disease of Aloe vera in Bangladesh

2021 ◽  
pp. 7-15
Author(s):  
Abu Noman Faruq Ahmmed ◽  
Md. Al-Amin Islam ◽  
Fatema Begum ◽  
Salma Sarker
Keyword(s):  
Disease Severity ◽  
Field Experiments ◽  
Bordeaux Mixture ◽  
Block Design ◽  
Aloe Vera ◽  
Pathogenicity Test ◽  
Traditional Use ◽  
Causal Organism ◽  
Anthracnose Disease ◽  
Garlic Bulb

Aims: To identify the causal organisms of anthracnose disease of Aloe vera in Bangladesh and to manage this disease in field condition. Study Design: The experiment was designed by Randomized Complete Block Design (RCBD) with three replications. Place and Duration of Study: The field experiments were conducted in Natore, Bangladesh and the laboratory experiments were carried out at the Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh from January, 2017 to December, 2018. Methodology: The causal organism Colletotrichum gloeosporioides was isolated by tissue plating method and identified based on morphological and cultural characteristics and that was confirmed by pathogenicity test. Infested farmer’s fields were selected in rainy season under natural epiphytic condition to evaluate the efficacy of eleven treatments. Results: Among the treatments, Bordeaux mixture gave best result against this disease. Moreover, Tilt 250 EC and Folicur 25 EC and Garlic bulb extract showed better effect against the disease than the other treatments. Lime also has moderate effect against anthracnose disease of A. vera. In 2017, after 4th spray, the lowest incidence was recorded in Bordeaux mixture (58.33%) which was statistically identical with Folicur (64.58%), Tilt (64.58%) and Garlic bulb extract (66.67%). Similarly, the lowest disease severity was found in Bordeaux mixture (3.55) followed by Folicur (5.67%), Tilt (6.67%) and Garlic bulb extract (7.67%). Similar result also found in 2018. After 4th spray, the lowest incidence was recorded in Bordeaux mixture (38.58%) which was statistically identical with Lime (41.66%) and Garlic bulb extract (45.83%). Similarly, the lowest disease severity was found in Bordeaux mixture (0.20%) followed by Lime (0.25%) and Garlic bulb extract (0.36%). Conclusion: Garlic bulb extract could be used as eco-friendly approach. Moreover, use of Bordeaux mixture is better than the traditional use of lime. From chemical pesticides, Tilt 250 EC and Folicur 25 EC could be used for controlling the disease as the last option.

scholarly journals Determination of the most susceptible phenological stage of rice panicles to infection by species of Fusarium graminearum

2019 ◽  
Vol 45 (3) ◽  
pp. 243-246
Author(s):  
Bruno Tabarelli Scheidt ◽  
Ricardo Trezzi Casa ◽  
Otávio Ajala Fiorentin ◽  
Flávio Chupel Martins ◽  
Paulo Kuhnem ◽  
...  
Keyword(s):  
Disease Severity ◽  
Fusarium Graminearum ◽  
Species Complex ◽  
Phenological Stage ◽  
Flowering Stage ◽  
Phenological Stages ◽  
Progress Curve ◽  
Rice Hybrid ◽  
Rice Panicles

ABSTRACT Occurrence of rice seeds infected by Fusarium graminearum has shown the importance of identifying the most favorable phenological stage of panicles to grain infection. The experiments were conducted in two crop seasons under greenhouse conditions, using the rice hybrid INOV CL. The phenological stages during inoculation were complete booting, full heading and flowering. All plots were inoculated using two isolates of Fusarium graminearium species complex 15A (F. graminearium - 15-ADON) and FmNiv (F. meridionale - Nivalenol). Disease severity was estimated at weekly intervals and was used to calculate the area under the disease progress curve (AUDPC), while panicles were collected to determine the percentage of spotted grains and Fusarium incidence. Percentage of spotted grains and incidence of F. graminearum and F. meridionale were greater when inoculation was made during flowering stage, significantly differing from heading and booting stages. Rice flowering stage is more susceptible to infection by F. graminearum and F. meridionale, inducing higher disease severity and incidence of spotted grains, as well as presence of fungi in the grains. Flowering was the most susceptible stage in the two crop seasons for both isolates, and the complete booting stage presented the lowest values of AUDPC.

scholarly journals Nitrogen Level and Irrigation Interval on Mitigating Stemphylium Blight and Downy Mildew in Onion

2018 ◽  
Vol 6 (1) ◽  
pp. 17-22
Author(s):  
Bibek Acharya ◽  
Ram Kumar Shrestha
Keyword(s):  
Downy Mildew ◽  
Disease Severity ◽  
Growth Stage ◽  
Block Design ◽  
Nitrogen Level ◽  
Yield Parameters ◽  
Progress Curve ◽  
Irrigation Interval ◽  
Randomized Block Design ◽  
Stemphylium Blight

Field trial was conducted on horticultural farm of Lamjung Agriculture Campus, Lamjung, Nepal between December-April 2016/17 on onion (Allium cepa), following two factorial Randomized Block Design with three replications and fifteen treatments to assess disease severity of Stemphylium blight (Stemphylium vesicarium) and Downy mildew (Peronospora destructor). The onion cultivar Red Creole, widely grown in this locality and susceptible to these diseases was used for trial. The disease intensity for Stemphylium leaf blight and Downy mildew was rated on weekly basis. Disease severity of both the disease significantly varied with nitrogen level and irrigation interval during initial and middle growth stage of onion, but in contrary, was found non-significant during later days as the plant approached harvesting stage. Area under Disease Progress Curve (AUDPC) also significantly varied in both treatments for both disease. Yield parameters recorded viz. bulb diameter and bulb yield significantly varied with nitrogen level and irrigation interval. The interaction effect of both the treatment was found non-significant for disease severity, AUDPC level and yield parameters during entire growth stage of onion. The results indicated that 7 days irrigation interval and government recommended dose of nitrogen i.e. 235 kg/ha were significantly better over other level of treatments in reducing Stemphylium blight and Downy mildew disease severity and also increasing yield parameters.Int. J. Appl. Sci. Biotechnol. Vol 6(1): 17-22

scholarly journals Evaluation of Resistance Sources of Tomato (Solanum lycopersicum L.) to Phylotype I Strains of Ralstonia solanacearum Species Complex in Benin

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1513
Author(s):  
Herbaud Zohoungbogbo ◽  
Adonis Quenum ◽  
Judith Honfoga ◽  
Jaw-Rong Chen ◽  
Enoch Achigan-Dako ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Species Complex ◽  
Block Design ◽  
Agricultural System ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Solanum Lycopersicum L ◽  
The University ◽  
Phylotype I

Finding sources of resistance to bacterial wilt (BW) caused by Ralstonia solanacearum species complex is a crucial step toward the development of improved bacterial wilt-resistant tomato varieties. Here, we evaluated new sources of bacterial wilt-tolerant/resistant tomato lines and identified associated phylotype/sequevar of R. solanacearum strains in Benin. Eighteen F5 lines and five checks were evaluated in two hotspots: the experimental site of the World Vegetable Center, Cotonou Benin, and the Laboratory of Genetics, Biotechnology and Seed Science of the University of Abomey-Calavi. Experiments were laid out in a randomized complete block design with four replicates. Data were collected on bacterial wilt incidence, horticultural and fruit traits and yield components. Across the two experiments, the F5 lines showed no wilting, while the local variety ‘Tounvi’ used as susceptible check showed 57.64% wilting. The wilting was due to BW and was associated with sequevars I-14, I-18 and I-31 of phylotype I. AVTO1803, AVTO1955-6 and H7996 were the highest yielding lines with 20.29 t·ha−1, 17.66 t·ha−1 and 17.07 t/ha, respectively. The sources of resistance to BW can be recommended to national agricultural system for dissemination or used in tomato breeding programs.

scholarly journals Resistance response of fifteen sweet potato genotypes to scab disease (Sphaceloma batatas) in two growing sites in East Nusa Tenggara, Indonesia

2018 ◽  
Vol 2 (1) ◽  
pp. 5-11 ◽  
Author(s):  
YOSEP SERAN MAU
Keyword(s):  
Disease Severity ◽  
Sweet Potato ◽  
Field Experiments ◽  
Block Design ◽  
Scab Resistance ◽  
Resistance Level ◽  
Resistance Response ◽  
Progress Curve ◽  
Randomized Block Design ◽  
Study Results

Mau YS. 2018. Resistance response of fifteen sweet potato genotypes to scab disease (Sphaceloma batatas) in two growing sites in East Nusa Tenggara, Indonesia. Trop Drylands 2: 5-11. Field experiments were carried out in two growing locations involving potential sweet potato clones from East Nusa Tenggara Province, Indonesia to: (i) evaluate scab resistance levels of the sweet potato clones, and (ii) identify sweet potato clones with good resistance level to scab disease. The experiment was carried out in the fields employing a Randomized Block Design with a mono-factorial treatment design in each location. The treatment assigned was sweet potato genotype, each consisted of two replicates. The variables observed were disease severity that was assessed at 2, 4, 6, and 8 weeks after inoculation (WAI), which then was used to calculate the Area Under the Disease Progress Curve (AUDPC) of the disease severity. The ANOVA of AUDPC was used to determine the treatment effect, and the disease severity at 8 WAI was used to assess scab resistance level of the sweet potato genotypes tested. The study results showed highly significant differences of disease severities among the tested sweet potato genotypes within each trial location. The majority of the genotypes tested were classified "resistant" or "moderately resistant" to scab disease, except the check clone SLM-01 and KRA-01 that were, respectively, "susceptible" and "moderately susceptible" to scab disease. The majority of sweet potato genotypes evaluated were consistent in their resistance performance in the two trial locations.

scholarly journals Serum Cystatin C as a Potential Predictor of the Severity of Multiple System Atrophy With Predominant Cerebellar Ataxia: A Case-Control Study in Chinese Population

2021 ◽  
Vol 15 ◽  
Author(s):  
Fei Ye ◽  
Tianzhu Wang ◽  
Huan Li ◽  
Jie Liang ◽  
Xiaoxin Wu ◽  
...  
Keyword(s):  
Multiple System Atrophy ◽  
Disease Severity ◽  
Cerebellar Ataxia ◽  
Cystatin C ◽  
Rating Scale ◽  
Pearson Correlation ◽  
Serum Levels ◽  
Severe Disability ◽  
Progression Rate ◽  
Significant Difference

Objective: Multiple system atrophy (MSA) is a serious neurodegenerative disease that is charactered by progressive neurological disability. The aim of this study was to investigate the correlation of serum oxidant factors with the severity of MSA.Methods: A total of 52 MSA patients and 52 age- and gender- matched healthy subjects were retrospectively enrolled in this study. Enzymatic colorimetric methods were used to assay the concentrations of uric acid (UA), serum creatinine (Scr), blood urea nitrogen (BUN), and cystatin C (Cys-C). Disease severity was evaluated by the Unified Multiple System Atrophy Rating Scale (UMSARS). The disease progression rate was defined by the change in UMSARS-IV (global disability score, GDS) over a 1-year period.Results: Comparisons between the two groups revealed that there were no significant differences in terms of serum Scr (70.81 ± 13.88 vs. 70.92 ± 14.19 μmol/L, p = 0.967). However, the serum levels of the other three biomarkers were significantly higher in the MSA patients (UA: 325.31 ± 84.92 vs. 291.19 ± 64.14 μmol/L, p = 0.023; BUN: 5.68 ± 1.67 vs. 4.60 ± 1.24 mmol/L, p < 0.001; Cys-C: 0.96 ± 0.15 vs. 0.89 ± 0.14 mg/L, p = 0.024). In addition, Pearson correlation analyses revealed that only serum Cys-C was significantly correlated to GDS (r = 0.281, p = 0.044). Subgroup analysis further demonstrated that serum Cys-C was the only factor that was positively associated with the disease severity in patients with MSA and predominant cerebellar ataxia (MSA-C) (r = 0.444, p = 0.018); there was no significant association in MSA patients with predominant Parkinsonism (MSA-P) (r = 0.118, p = 0.582). MSA-C patients with severe disability were shown to express higher serum levels of Cys-C than patients with mild disability (1.03 ± 0.13 vs. 0.88 ± 0.12 mg/L, p = 0.009). Finally, Kaplan-Meier plots revealed a significant difference in the 5-year probability of survival from severe disability between MSA-C patients with high- and low-concentrations of serum Cys-C (Log-rank test: X2 = 4.154, p = 0.042). ROC curve analysis confirmed that serum Cys-C exhibits good performance as a biomarker (AUC = 0.847).Conclusion: Our research indicated that oxidative stress plays a vital role in MSA. Serum Cys-C represents a potential prognostic biomarker to evaluate the severity of disease in patients with MSA-C.

Faba bean gall (Olipidium viciae Kusano) disease management using fungicides in North Shewa, Highlands of Ethiopia

2021 ◽  
Vol 1 (1) ◽  
pp. 001-005
Author(s):  
Belachew Bekele Tiruneh ◽  
Sisay Argaye Bereda
Keyword(s):  
Disease Management ◽  
Grain Yield ◽  
Disease Severity ◽  
Faba Bean ◽  
Hot Spot ◽  
Block Design ◽  
Rate Of Return ◽  
Marginal Rate ◽  
Significant Difference ◽  
Marginal Rate Of Return

Faba bean gall becomes the worst problem for the crop production. The diseases can cause up to complete crop failure. Studies showed that, applications of some fungicides and seed dressings have certain effects of reducing faba bean gall diseases and increases yield. Thus, the study aims to select best effective and economical fungicide for faba bean gall disease management. The experiment was conducted at farmers’ field on hot spot areas to manage the disease using fungicides in 2019/20 cropping season. Randomized complete block design with three replications was used. Nativo SC 300, Eminant star, Rex-Dou and Mancozeb 80 WP fungicides were applied as manufacturers’ recommendations. Significant difference between plots in plant height, disease severity, area under disease progress curve, grain yield and thousand kernel weights were recorded. The highest (46.67%) disease score were recorded in control plots followed by Rex-Dou (40.0%) sprayed plots. Whereas the lowest, disease severity (15.11%) were recorded from Eminant star sprayed plots. The highest grain yield was recorded in Eminant star (3.08 ton ha-1) sprayed plot followed by Nativo Sc 300 (3.01 ton ha-1) and Mancozeb 80 WP (2.54 ton ha-1) sprayed plots respectively. Eminant star sprayed plots also gave the highest economic benefit ETB (102770.0) and marginal rate of return (1678.46) followed by Nativo Sc 300 with net benefit of ETB (99190.0) and a marginal rate of return (925.40) were received. Pod per plant was not showed significant difference between plots.

scholarly journals Economic Management of Late Blight (Phytophthora infestans L.) of Potato in Eastern Tarai of Nepal

1970 ◽  
Vol 6 ◽  
pp. 57-61 ◽  
Author(s):  
Prem CP Chaurasia
Keyword(s):  
Late Blight ◽  
Disease Severity ◽  
Field Experiments ◽  
Tuber Yield ◽  
Block Design ◽  
Winter Season ◽  
Cost Ratio ◽  
Research Station ◽  
Terminal Disease ◽  
Progress Curve

Field experiments were carried out at Regional Agriculture Research Station, Tarahara in threeconsecutive years (1997-2000) during winter season to know the economic sprays of differentfungicides to manage late blight disease of potato. Late blight susceptible cultivar of potatoKufri Sindhuri was used for the experiment. Krinoxyl gold (metalaxyl 8% and mancozeb 64%)at the rate of 1.5 g/l, Dithane M- 45 (mancozeb 75%) @ 0.3% and Bordeaux mixture @ 10 gcopper sulfate and 10 g lime/l of water and their different combinations were tested inrandomized complete block design with three replications. Terminal disease severity was thehighest (7.9) on 0-9 scale disease rating in unsprayed check and it was significantly higher thanthose of other fungicides sprays. Plots with three sprays of Dithane M- 45 @ 0.3% recorded thelowest (2.4) terminal disease severity. Disease development was the fastest in the unsprayed plotcompared to all other treatments. Similarly apparent infection rate was the highest in unsprayedtreatment. Area Under the Disease Progress Curve was also the highest in unsprayed plot and itwas significantly higher than those of other treatments. Tuber yield was the lowest (3.93 kg/4.5m2 plot in unsprayed and the highest (6.08 kg), in the plot receiving four sprays of Dithane M-45@ 0.3 % and this was at par with the tuber yield of plots receiving two and three sprays ofDithane M-45. Benefit cost ratio was the highest (1.54) in case of two sprays of Dithane M-45@ 0.3% at 10 days intervals. All others fungicide spays were uneconomical under Eastern Taraicondition.Key words: Eastern Tarai; economic spray; Dithane M-45; late blight management; potatoDOI: 10.3126/narj.v6i0.3365Nepal Agriculture Research Journal Vol.6 2005 pp.57-61

scholarly journals Management of Powdery Mildew on Ninebark Using Sanitizers, Biorational Products, and Fungicides

HortScience ◽  
2021 ◽  
pp. 1-6
Author(s):  
Fulya Baysal-Gurel ◽  
Ravi Bika
Keyword(s):  
Powdery Mildew ◽  
Disease Severity ◽  
Growth Parameters ◽  
Block Design ◽  
Experimental Period ◽  
Disease Progress ◽  
Progress Curve ◽  
Powdery Mildew Disease ◽  
Giant Knotweed ◽  
Reynoutria Sachalinensis

Ninebark (Physocarpus opulifolius) is a popular ornamental shrub and considered a hardy and tough plant that can thrive in different environmental conditions and resist diseases. However, powdery mildew, caused by Podosphaera physocarpi, can severelyaffect ninebark, deteriorating the ornamental value and making them unmarketable. Only a few studies have been done in managing powdery mildew of ninebark. The current study focuses on evaluating and identifying effective products (sanitizers, biorational products, and fungicides) for the management of powdery mildew disease of ninebark. A total of 12 treatments, including nontreated control, were studied. The experiment was arranged in randomized complete block design with four-single ‘Mindia Coppertina®’ ninebark plant per treatment and repeated twice. Powdery mildew disease severity, growth parameters, and phytotoxicity were assessed in the study. All treatments significantly reduced the powdery mildew disease severity and disease progress [area under disease progress curve (AUDPC)] compared with the nontreated control. The treatments, such as azoxystrobin + benzovindiflupyr at 0.17 and 0.23 g·L–1 total active ingredients (a.i.) applied, chlorothalonil + propiconazole at 1.12 mL·L–1 total a.i. applied, azoxystrobin + tebuconazole at 0.11 and 0.16 g·L–1 total a.i. applied, and giant knotweed extract [Reynoutria sachalinensis (0.5 mL·L–1 total a.i. applied)] were the most effective treatments in reducing disease severity and disease progress in both trials. The treatments had no significant effects on the plant growth parameters such as height and width. In Expt. 2, azoxystrobin + benzovindiflupyr and hydrogen peroxide + peroxyacetic acid treated plants showed the low level of phytotoxic symptoms. The phytotoxicity of these two treatments in Expt. 2 could be related to higher environmental temperature during the experimental period.

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