Web Blight Research Articles

Participatory variety selection for released white common bean varieties in South Gondar Zone, Ethiopia

Participatory variety selection plays a vital role in adopting improved crop varieties into a new growing area. Farmers' preferences across locations and growing seasons must be taken into account to introduce improved varieties that farmers will accept. Evaluating improved common bean varieties in specific agro-ecologies is a key activity to enhance the productivity of the crop. The purpose of this study was to identify adapted, high-yielding, disease-resistant, and farmers' preferred white common bean varieties in the south Gondar zone, Ethiopia. Seven released white common bean varieties were evaluated in the mother and baby trial system using Randomized Complete Block Design replicated three times during the 2019 cropping season at the farmers' field of Libokemkem and Simada districts. Seed shape, maturity days, disease reactivity, pod number/plant, and seed number/pod were utilized as variety selection criteria during field observation to determine varieties preferred by farmers. The results revealed that among the evaluated varieties, Awash-2 (1722.7 kg ha−1) and Awash-1 (1509.8 kg ha−1) produced considerably higher yield at Libokemkem whereas Awash-Melka (3888.1 kg ha−1), Batu (3697.6 kg ha−1), Awash-2 (3463.9 kg ha−1), Mexican-142 (3455.6 kg ha−1) and Awash-1 (3235.3 kg ha−1) were found as high-yielding varieties at Simada. When comparing grain yields at both locations, Awash-2 and Awash-1 are consistently good yielder varieties, which is one of the most important features for the farmers. Based on the farmers’ preference, Awash-2 was consistently preferred and selected by the farmers across the two locations. Awash-2 is consistent both in the amount of grain yield and its acceptance by the farmers across the two locations and is suggested as a promising variety that needs to be promoted, multiplied, and disseminated to the farmers of the study areas for cultivation. Assessment of the varieties for Anthracnose and web blight diseases showed no or little and insufficient economic injury and the varieties were generally categorized as less susceptible and intermediate in their response to the diseases.

Characterization of Cultural and Morphological Variability in Rhizoctonia solani Isolates Associated with Root Rot of Ajwain (Trachyspermum ammi L.)

Rhizoctonia solani (teleomorph: Thanatephorus spp.) is a plant pathogenic fungus which had a wide host range. It is best known to cause many diseases in plants such as collar rot, root rot, damping- off, sheath blight, stem canker, web blight and wire stem throughout the world. In vitro study of the various isolates of R. solani for morphological and cultural characters and results revealed that this experiment the various isolates of R. solani differed in colony characters and showed black brown colored cultures with 90.0 mm colony diameter on 7th day of incubation under uniform environmental condition. The highest growth reported was isolates CHIRs-5 and sclerotial formation was recorded in all the isolates of R. solani. Morphology of sclerotia varied from 1.9×1.5 mm of DCHIRs-1 and 1.8×1.5 mm of RUDPRs-2.

DNA barcode, multiplex PCR and qPCR assay for diagnosis of pathogens infecting pulse crops to facilitate safe exchange and healthy conservation of germplasm.

The DNA barcodes were developed from ITS region for the identification of fungal plant pathogens namely, Alternaria alternata and A. tenuissima both causing leaf spots, Ascochyta rabiei causing Ascochyta blight, Fusarium oxysporum f. sp. ciceris causing wilt, Macrophomina phaseolina causing dry root rot, Rhizoctonia solani causing web blight and wet root rot, Sclerotium (Athelia) rolfsii causing collar rot, Sclerotinia sclerotiorum causing stem rot and Cercospora canescens and Pseudocercospora cruenta both causing leaf spots in pulse crops. Barcode compliance for A. alternata (DBTPQ001-18), A. tenuissima (DBTPQ002-18), A. rabiei (DBTPQ003-18), F. oxysporum f. sp. ciceris (DBTPQ004-18), M. phaseolina (DBTPQ005-18), R. solani (DBTPQ006-18), S. rolfsii (DBTPQ007-18), S. sclerotiorum (DBTPQ008-18), C. canescens (DBTPQ009-18) and P. cruenta (DBTPQ029-20) have been generated based on the Barcode of Life Data System (BOLD) system. In addition to ITS, other genomic regions were also explored and on the basis of sequence variation they were ranked as TEF-α > SSU > LSU > β-tubulin. These genes could be considered for secondary barcode and phylogenetic relatedness. ITS-based markers for the detection of A. alternata (BAA2aF and BAA2aR) and R. solani (BRS17cF and BRS17cR) were developed which provided 400bp and 220bp amplicons, respectively. While, for F. oxysporum f. sp. ciceris, COX1-based marker (FOCox1F and FOCox3R) was developed which amplified 150bp. The markers proved highly specific and sensitive with detection limit of 0.0001ng of template DNA using qPCR and simultaneously detected these three pathogens. The DNA barcodes and diagnostics developed are suitable for quick and reliable detection of these pathogens during quarantine processing and field diagnostics.

Participatory Variety Selection for Released White Common Bean Varieties in South Gondar Zone, Ethiopia

Participatory variety selection plays a vital role in adopting improved crop varieties into a new growing area. Farmers' preferences across locations and growing seasons must be taken into account to introduce improved varieties that farmers will accept. Evaluating improved common bean varieties in specific agro-ecologies is a key activity to enhance the productivity of the crop. The purpose of this study was to identify adapted, high-yielding, disease-resistant, and farmers’ preferred white common bean varieties in the south Gondar zone, Ethiopia. Seven released white common bean varieties were evaluated in the mother and baby trial system using Randomized Complete Block Design replicated three times during the 2019 cropping season at the farmers' field of Libokemkem and Simada districts. Seed shape, maturity days, disease reactivity, pod number/plant, and seed number/pod were utilized as variety selection criteria during field observation to determine varieties preferred by farmers. The results revealed that among the evaluated varieties, Awash-2 (1722.7 kg ha-1) and Awash-1 (1509.8 kg ha-1) produced considerably higher yield at Libokemkem whereas Awash-Melka (3888.1 kg ha-1), Batu (3697.6 kg ha-1), Awash-2 (3463.9 kg ha-1), Mexican-142 (3455.6 kg ha-1) and Awash-1 (3235.3 kg ha-1) were found as high-yielding varieties at Simada. When comparing grain yields at both locations, Awash-2 and Awash-1 are consistently good yielder varieties, which is one of the most important features for the farmers. Based on the farmers’ preference, Awash-2 was consistently preferred and selected by the farmers across the two locations. Awash-2 is consistent both in the amount of grain yield and its acceptance by the farmers across the two locations and is suggested as a promising variety that needs to be promoted, multiplied, and disseminated to the farmers of the study areas for cultivation. Assessment of the varieties for Anthracnose and web blight diseases showed no or little and insufficient economic injury and the varieties were generally categorized as less susceptible and intermediate in their response to the diseases.

Diagnosis of Neem Leaf Diseases Using Fuzzy-HOBINM and ANFIS Algorithms

This paper proposes an approach to detecting diseases in neem leaf that uses a Fuzzy-Higher Order Biologically Inspired Neuron Model (F-HOBINM) and adaptive neuro classifier (ANFIS). India exports USD 0.28-million worth of neem leaf to the UK, USA, UAE, and Europe in the form of dried leaves and powder, both of which help reduce diabetes-related issues, cardiovascular problems, and eye disorders. Diagnosing neem leaf disease is difficult through visual interpretation, owing to similarity in their color and texture patterns. The most common diseases include bacterial blight, Colletotrichum and Alternaria leaf spot, blight, damping-off, powdery mildew, Pseudocercospora leaf spot, leaf web blight, and seedling wilt. However, traditional color and texture algorithms fail to identify leaf diseases due to irregular lumps and surfaces, and rough ridges, as the classification time involved takes as long as a week. The proposed F-HOBINM algorithm recognizes the leaf intensity through the leaky capacitor, and uses subjective intensity and physical stimulus to interpret the diagnosis. Further, the processed leaf images from the HOBINM algorithm are applied to the ANFIS classifier to identify neem leaf diseases. The experimental results show 92.18% accuracy from a database of 1,462 neem leaves.

Current Status and Prospect of Web Blight of Cowpea: A Review

Pulses in India have been considered as the poor man’s only source of protein. Among them Cowpea (Vigna unguiculata) is an important food legume which is also known as vegetable meat due to high amount of protein in the grain with better biological value on dry weight basis. Various factors viz., diseases and insect pests are mostly responsible for its low production. Among diseases, web blight caused by Rhizoctonia solani is one of the most important disease of cowpea. The web blight appears every year at varying intensity and causes heavy losses in yield. Web blight disease is most severe at seedling and vegetative stage. The disease is characterized by oval or spindle shaped brown black lesions having length ranging from 0.2-8 cm at soil level near collar region and girdling the basal portion of the stem and lesions developed by basidiospores of Thanatephorus cucumeris which are 2-4 mm in diameter, circular and appear as brown necrotic spots with light brown centre. Cob web like symptoms also noticed hence, the name web blight.

Influence of Temperature on the Pathogenesis and Gene Expression of Rhizoctonia solani Causing Web Blight/Wet Root Rot Disease in Mungbean

Background: Mungbean (Vigna radiata L. Wilzeck) is one of the most important pulse crops and grown in almost all parts of the India. Web blight/wet root rot disease of mungbean is caused by Rhizoctonia solani Kühn. Crop environmental factors plays a vital role in the development of web blight disease caused by R. solani. An understanding of the role of environmental factors on the infection and survival of the pathogen is necessary to develop disease management practices. Methods: The effect of different temperatures (4oC, 20oC, 25oC, 30oC and 35oC) on mycelial growth of seven different R. solani isolates belonging to different anastomosis group were evaluated under in vitro conditions. Effect of different temperatures on the development of root rot/web blight disease of mungbean was also evaluated under phytotron conditions at various temperatures with constant relative humidity (85%) and illumination (alternate dark and light period of 12 h). Effect of temperatures on the expression of selected pathogenicity related genes was evaluated through real time PCR. Result: Maximum radial growth in R. solani isolates was observed at 25 and 30oC after 48 hrs of incubation. Maximum disease incidence was observed with R. solani isolate RUPU-18 (73.11%) followed by R-17 (68.75%), RDLM-1 (63.45%) at 25oC on mungbean genotype Pusa Vishal. Expression of genes like ABC transporter was observed only at 35oC, while other genes like 1, 3 glucan hydrolase expressed maximum at 25oC after 24, 48 and 72 hrs post inoculation. Present study suggested that the expression of pathogenicity related genes in mungbean-R. solani system is dependent on the temperature and time interval post pathogen inoculation.

Evaluation of botanicals against growth of Rhizoctonia solani under in vitro condition

Rhizoctonia solaniis a multiphagous widely distributed plant pathogen. Web blight caused by Rhizoctonia solani causes huge yield loses in urdbean (Vigna mungo). All the commercially grown varieties are susceptible. Being a typical soil borne fungus, its management through chemicals is expensive and not feasible, because of the physiological heterogeneity of the soil and other edaphic factors etc. Integrated approaches of the disease management are paying more attentiveness in terms of sustainability. The study was conducted at Department of Plant Pathology, College of Agriculture, Jabalpur, Jawaharlal Nehru Krishi Vishwavidyalaya (M.P) during 2018-19. It was carried out to know the efficacy of different botanicals on the mycelial growth of Rhizoctonia solani under in vitro condition. From the present study it could be concluded that all eight tested phytoextracts evaluated for their efficacy inhibiting R. solaniat different concentration of 10% and 20% under in vitro conditions using poisoned food technique significantly inhibited the growth of R. solani. The maximum percent inhibition in growth was recorded by onion and garlic bulb extracts.

First Report of Web Blight on Lavender Caused by Rhizoctonia solani AG-1-IB in Korea

Lavender (Lavandula officinalis L.) is an annual or short-lived perennial herb belonging to the mint family (Lamiaceae) that originates from eastern Africa, the Mediterranean, southwest Asia, to southeast India. Lavenders are cultivated extensively as ornamental plants for garden and landscape uses, for usage as culinary herbs, and commercially for the extraction of essential oils. In June 2017, approximately 5 to 10% of plants showed web blight symptoms in a private garden located near Gangneung, Gangwon Province, Korea. Specifically, leaf tissues were blighted, and white mycelial growth was seen on the stems. Symptomatic tissues were surface sterilized with 1% NaOCl, washed twice in sterilized water, blotted on sterile filter paper, and plated on 2% water agar at 25°C. After 2 days, hyphal tips were transferred to potato dextrose agar (PDA) to obtain pure cultures. A total of five morphologically similar fungal isolates (LWB001 to LWB005) were obtained from diseased samples; isolate LWB002 was selected for identification. The fungus produced a white mycelium when young but produced a brown mycelium with dark brown sclerotia on PDA at 20 ± 2°C for 10 days. Mature sclerotia (n = 20) were dark, spheroidal, with diameters ranging from 0.2 to 2.2 mm (average 0.7 mm). The young hyphae had acute angular branching near the distal septum of the multinucleated cells, and mature hyphal branches showed approximately 90° angles. Morphological characteristics were consistent with those of Rhizoctonia solani (Sneh et al. 1991). A representative isolate (LWB002) was deposited in the Korean Agricultural Culture Collection (KACC), National Institute of Agricultural Science, Rural Development Administration, Wanju, South Korea (KACC48671), to be used for further studies. The identification of the anastomosis group of the R. solani isolate was carried out on sterilized glass slides coated with 2% water agar medium placed on Petri dishes. The representative isolate was paired with tester strains of R. solani (AG-1-IA, AG-1-IB, AG-1-IC, AG 2-2-IIIB, AG 4, AG 7, and AG 11), which were collected from KACC (Ogoshi 1987) and examined microscopically. The fungal isolate anastomized only with tester strain AG-1-IB. To obtain a DNA sequence-based identification, a total DNA was extracted directly from the mycelium with a DNeasy Plant Mini Kit (Qiagen, Hilden, Germany). Following DNA extraction, the internal transcribed spacer (ITS) region of rDNA was amplified with primers ITS1/ITS4 and sequenced (White et al. 1990). BLASTn analysis of the 706 bp showed a 100, 99.71, and 99.86% similarity with sequences of R. solani AG-1-IB (teleomorph Thanatephorus cucumeris) in GenBank (JQ692293.1, GU585667.1, and KF907717.1, respectively). The nucleotide sequence has been assigned GenBank number MH122653. To confirm pathogenicity, three fungal mycelial discs (14 days old, 6.5 mm) were placed onto three wounded young plant stems on the soil line. Another three plants served as controls, for which only an agar plug was used on wounded plant stems. Then all the plants were incubated in a growth chamber (at 28 ± 2°C, 90% relative humidity, with 12/12-h light/dark). After 10 days, blight symptoms were similar to the original symptoms developed on inoculated plant leaves and stems, whereas no symptoms were observed on control plants. Five fungal isolates were reisolated from disease lesions of inoculated plants on PDA with the same morphological characters as before, and the identity was confirmed by microscopic studies, which fulfilled Koch’s postulates. Lavender web blight caused by R. solani AG-1-IB has been recorded in Italy (Garibaldi et al. 2013). To our knowledge, this is the first disease report of web blight on lavender caused by R. solani AG-1-IB in Korea, which poses a potential threat to lavender production, and our findings will be useful for the development of effective control strategies and further research.

Screening of antagonistic fungi against web blight disease and identification of volatile metabolites produced by Trichoderma

Aerial web blight caused by Rhizoctonia solani is one of the main soil borne pathogens which infects soybean crops. Biological control using antagonistic fungi has been reported promising to reduce the incidence of this disease. This study aimed to determine antagonistic activity of Trichoderma virens and T. asperellum against R. solani and to investigate total phenolic changes in soybean plants which interact with those Trichoderma in infected soil. Volatile metabolites produced by Trichoderma were also detected and identified. Antagonistic activity of five isolates of T. virens and five isolates of T. asperellum were comparable; the ranges of in vitro antagonistic activities were 88.7-99.6% and 85.7-91.3%, respectively. Both Trichoderma were able to reduce R. solani infection. Disease intensities of 22-40% and 24-40% for T. virens and T. asperellum were observed lower than that of control (> 50%). The increase of total phenolic and flavonoid contents depended on Trichoderma isolates. Volatile compounds were detected in both Trichoderma. Isolates of T. asperellum (F isolate) and T. virens (E isolate) triggered the increase of total phenolic contents which could be potential for biological control agents to induce systemic resistance in soybean.

A broad diversity survey of Rhizoctonia species from the Brazilian Amazon reveals the prevalence of R. solani AG‐1 IA on signal grass and the new record of AG‐1 IF on cowpea and soybeans

AbstractLeaf blight, sheath blight, and web blight are major diseases caused by Rhizoctonia species on both Fabaceae and Poaceae plant hosts in the Brazilian Amazon agroecosystem. To determine the diversity of Rhizoctonia species associated with foliar diseases on fabaceous (cowpea and soybean) and poaceous (rice and signal grass [Urochloa brizantha]) hosts, a broad survey was conducted in Pará, Rondônia, Roraima, and Mato Grosso, in the Amazon, from 2012 to 2013. We extended our survey to Cerrado areas of Mato Grosso, and the lowlands of Paraíba Valley, in São Paulo, where these Rhizoctonia foliar diseases have not been reported so far. Our findings revealed that these diseases are caused by a diversity of Rhizoctonia solani AG‐1 complex. We detected that R. solani AG‐1 IA (sexual phase Thanatephorus cucumeris) was the predominant pathogen associated with signal grass leaf blight and collar rot diseases in the Amazon, especially in Rondônia and northern Mato Grosso. In addition, a subgroup of R. solani (AG‐1 IF), not previously reported in Brazil, was associated with leaf blight on cowpea and soybean, in Roraima. Another subgroup (AG‐1 ID) was also detected in Roraima. In Mato Grosso Cerrados we did not find any of the major Rhizoctonia foliar pathogens. Instead, R. oryzae (Waitea circinata) was the predominant species associated with a collar rot on U. brizantha. In the lowlands of São Paulo, R. oryzae‐sativae (Ceratobasidium oryzae‐sativae) was the predominant pathogen detected causing the rice sheath spot disease.

Status of Common Bean (Phaseolus vulgaris L.) Diseases in Metekel Zone, North West Ethiopia

Common bean has versatile benefits such as nutritional, environmental and economic benefits for the producers and consumers. However, its production has been affected and threatened by a number of biotic factors. Survey was conducted in 2018/19 cropping season within three woredas of Metekel Zone, Benshangul-Gumz region, Ethiopia, with the objective of identifying and prioritizing haricot bean diseases.The result revealed that haricot bean production in the Zone is affected by eleven diseases which are caused by fungi, bacteria and virus. Based on the disease severity, incidence and prevalence scores, the diseases are categorized in to Major, intermediate and Minor disease. Angular Leaf Spot (Pseudocercospora griseola), Anthracnose (Colletotrichum lindemuthianum), Floury leaf spot (Mycovellosiella phaseoli), and Cercospora leaf spot (Cercospora cruenta are grouped in to major diseases. Rust (i), Web blight Rhizoctonia solani Kuhn (teleomorph Thanatephorus cucumeris (Frank) Donk), Ascochyta blight (Phomaexigua var. exigua/Ascochyta phaseolorum acc) and Bean common mosaic virus (potyvirus) are categorized as Intermediate and the remaining three diseases: Halo blight (Pseudomonas syringaepv. phaseolicola), Common Bacterial Blight (Xanthomonas axonopodis pv phaseoli) and Downy Mildew (Phytophthora phaseoli Thaxt) are grouped under minor diseases. The survey revealed, the common bean production and disease management practices and variety development efforts for the Zone, onwards, should focus on those major disease (such as Angular Leaf Spot, Anthracnose, Floury leaf spot, and Frog Eye leaf spot) in order to sustain production and productivity of common bean cultivars.

First Report of Web Blight on Swiss Chard Caused by Rhizoctonia solani AG2-2 IV in Korea

First Report of Web Blight on Swiss Chard Caused by <i>Rhizoctonia solani</i> AG2-2 IV in Korea

Key Plant, Key Pest: Juniper (Juniperus sp.)

This series of Key Plant, Key Pests publications is designed for Florida gardeners, horticulturalists, and landscape professionals to help identify common pests associated with common Florida flora. This seven-page publication, the ninth in the Key Plant, Key Pests series, helps identify the most common pests found on Juniper, with information and general management recommendations for bagworms, eriophyid mites, scale, spider mites, webworm, mushroom root rot, needle blight, Rhizoctonia web blight, tip blight, and wet root rot diseases. Written by Juanita Popenoe, Jacqueline Bourdon, Caroline R. Warwick, and Alfred Huo and published by the UF/IFAS Environmental Horticulture Department. http://edis.ifas.ufl.edu/ep570

Evaluation of Cowpea (Vigna unguiculata) Genotypes for Resistance to Web Blight Caused by Rhizoctonia solani

Evaluation of Cowpea (Vigna unguiculata) Genotypes for Resistance to Web Blight Caused by Rhizoctonia solani

First report of web blight on toothache plant caused by Rhizoctonia solani AG-4 HG-I in Italy

First report of web blight on toothache plant caused by Rhizoctonia solani AG-4 HG-I in Italy

Perspectives and Challenges for Sustainable Management of Fungal Diseases of Mungbean [Vigna radiata (L.) R. Wilczek var. radiata]: A Review

Mungbean (Vigna radiata var. radiata) is a key legume crop grown predominantly in South and Southeast Asia. Biotic and abiotic stresses cause significant yield reduction in mungbean, and among these, fungal diseases are particularly important. Although disease management practices, including physical, chemical, and biological methods have been researched and described in the literature, few of these are available or have been used by growers. Here we review the economic impact, pathogen characterization, and sustainable management options for the soil-borne and foliar fungal diseases of mungbean as well as major challenges to manage these diseases. Potential use of all possible components of integrated management practices including host resistance, fungicides, biocontrol agents, natural plant products, and cultural practices etc. are discussed. Major diseases include powdery mildew, anthracnose, Cercospora leaf spot, Fusarium wilt, Rhizoctonia root rot and web blight, Macrophomina charcoal rot/dry root rot and blight. Review of the literature indicated an absence of resistance to Rhizoctonia root rot, little sources of resistance for dry root rot and anthracnose. Major resistant genes (R genes) and quantitative trait loci (QTL) were identified for powdery mildew and Cercospora leaf spot, which may be potentially used in Marker assisted selection (MAS). has been used in resistance breeding for both of the latter. Although the mechanisms of induced systemic resistance (ISR) by biocontrol agents have been studied with Macrophomina blight, there is little information on the mechanisms and use of systemic acquired resistance (SAR) in managing fungal diseases of mungbean. Several studies targeted exploiting biological control for soil-borne root rot diseases. Botanical products, such as plant extracts, are also found effective to manage root and foliar diseases. However, many of these studies were limited to laboratory and/or green house experiments. Thus, long-term field studies are required for further exploitation of biological methods and commercial applications.

Urdbean web blight and its management strategies- A review

The production and productivity of urdbean ranks lower in India as compared to the that of world average due to the biotic and abiotic constraints. Web blight of Urdbean is caused by Rhizoctonia solani Kuhn and is a soil borne pathogen and initial inoculums come mainly from soil splashes which fall on leaves during heavy rains. Respective optimum temperature and relative humidity i.e. 26–28oC and 90–100% favours disease development chronically. The pathogen can survive very longer in the absence of a host either as sclerotia or thick walled brown hyphae in plants debris. Currently the disease is prevalent in many countries across the globe. The pathogen is highly variable in terms of its pathogenicity, culture, morphology, biochemical and molecular characteristics. The severity of this disease is directly linked with the population of viable sclerotia in the soil. Yield losses due to this disease vary in between 20-30% depending upon prevailing conditions.

Common bean (Phaseolus vulgaris L.) growth promotion and biocontrol by rhizobacteria under Rhizoctonia solani suppressive and conducive soils

Rhizobacteria promote plant growth and disease control. However, in crop management practices cultivar and environmental conditions may also interfere with diseases outcome. This study aimed to evaluate the effect of common bean seed treatment with isolates ALB629 and UFLA285 of Bacillus amyloliquefaciens, combined or not with metalaxyl + fludioxonil, the control of Rhizoctonia solani damping-off and web blight (WB), plant growth parameters and common bean yield. Field and greenhouse trials were carried out in two different locations in Brazil – Lavras, MG (Southeast) with suppressive soil conditions and Boa Vista, RR (North) with a conducive WB condition, using two cultivars of common bean – Pérola and BRS Agreste. The treatments responded differently to either the locations and the cultivars regarding the disease development or plant growth parameters. In Lavras the suppressive conditions did not allow R. solani establishment and promoted higher seed germination and emergency when soils were kept in natural conditions compared to sterile soils. In Boa Vista with conducive conditions, treatments with rhizobacteria associated with fungicide reduced by up to 164% the WB incidence in both cultivars, but the treatment with only ALB629 or UFLA285 also reduced the disease severity. The combination of rhizobacteria with fungicide ensured consistency and stability of results. The common bean yield was higher than the control in 23% and about 500% in Lavras (cv. Perola) and Boa Vista (cv. BRS Agreste), respectively when seeds were treated with ALB629. The use of ALB629 is a plausible strategy for bean seed treatment to control disease and increase bean yield, and therefore an important tool to improve common bean production.

English

Common bean is very important in the daily diet of Ecuadorians. Web blight (Rhizoctonia solani (Kuhn) is the major constraint faced by common bean farmers in Ecuador and everywhere in the world, causing high losses of yield grain every year. A constant selection of genotypes with excellent productive and resilience to disease features in each region is presented as a potential solution to these problems. The present study aimed to evaluate the phenology, web blight resilience and grain yield production of 17 common bean genotypes in field conditions, in the Guayas River Basin, Ecuador. Three commercial varieties (two belonging to determined feature and one to undetermined feature) and 14 more promising genotypes were evaluated. Day period for phenological stage R6 (full bloom) and R9 (flowering maturity), web blight resilience, number of harvested pods, number of grains per pod per plant, 1000-seed weight, grain yield and later yield per hectare were measured. Scott Knott test (p ≤ 0.05) was executed for mean comparisons and principal component analysis (PCA) statistical test was performed using the productive and agronomical variables, successfully distinguishing two group of genotypes according to their types of growth (determined and undetermined), highlighting the genotypes EVG-6-103, EVG-6, CAL-96, INIAP-473, AFR-619, INIAP-474, AFR-298, SER-29, SER-35, EVG-16-08 which showed the higher agronomic, sanitary, and productively averages in approximately all the studied variables. Key words: Phaseolus vulgaris L., Rhizoctonia solani (Kuhn), yield.