Disease severity

Blast disease development caused by the fungus Pyricularia oryzae Cavara was determined in leaf and panicle stages in some Iranian and Afghan rice varieties. For this purpose, Hashemi, Kazemi, Anam, Sadri, Surkha, Niloofar, Surkha Long, Shiroudi, Koli and Shola varieties were grown at the experimental field of the University of Guilan in 2021 and 2022 growth seasons as a randomized complete block design. As the first disease symptoms were observed in experimental plots, disease severity was assessed and continued at specific intervals until harvest time. The results indicated a significant difference between varieties in disease development at the leaf and panicle stages. The initial severity, progression over time and final severity of leaf blast varied among the studied varieties. In both years of the study, the Niloofar variety showed the highest susceptibility to leaf blast (69.16% in 2022). Surkha, Sadri and Shola varieties showed high susceptibility as 31.78%, 24.75% and 17.27 and Hashemi and Kazemi had less susceptibility as 6.68% and 5.95%, respectively. There was no significant increase in the severity of leaf blast in the Surkha Long, Anam, Koli and Shiroudi. Regarding panicle blast in both years, Niloofar variety showed the highest susceptibility based on the panicle blast severity (97.46%) and then, Surkha Long and Kazemi varieties had the highest severity of panicle infection (18.86% and 17.6%, respectively). Shola, Sadri, Surkha, Hashemi, and Anam varieties were less susceptible. Shiroudi and Koli varieties were the most resistant to the panicle blast infection.

Bean common mosaic virus and related races are one of the most important bean viral diseases and are present in almost all bean growing regions. In order to investigate the effects of salicylic acid treatment on the reaction of sensitive bean variety (Akhtar) to common bean mosaic virus (BCMV), an experiment was conducted in the form of a completely randomized design with 4 replications in greenhouse conditions. The experimental treatments included concentrations of zero, 200, 400 and 800 micromolar salicylic acid. The desired treatments were performed three days before inoculation with the respective virus agent. ELISA test using BCMV antiserum showed 83.3% of samples were infected with this virus. The results showed that different levels of salicylic acid could reduce the severity of the disease compared to the control infected with the virus.The lowest severity of the disease was obtained in the treatment of salicylic acid with a concentration of 800 micromolar (15.5%). The amount of phenol in the leaves in the treatment of salicylic acid with a concentration of 800 micromolar showed the highest value (92%), which did not show a statistically significant difference with the infected control, and this trait can be an indicator of the induction of resistance with the improvement of phenol levels due to the use of salicylic acid. Salicylic acid was effective in improving the morphological parameters such as the wet weight of the aerial parts of the plant and the dry weight of the root, and in disease conditions it prevented further damage during the experimental period to such an extent that this amount in the treatment of salicylic acid with a concentration of 800 µM in the conditions of the disease did not show any significant difference with the healthy control.

Fusarium wilt is one of the most important diseases of tomato seriously threatening the cultivation and development of this crop worldwide. In this study, the biocontrol potential of four basidiomycota fungal endophytes isolated from wheat and wild oat, namely Rhizoctonia endophytica M32, R. zeae M9, Fomes inzengae M40 and Coprinopsis urticicola M2, was evaluated against fusarium wilt of tomato under laboratory and greenhouse conditions. In lab, identity and race of the pathogen was first determined using phylogenetic inference and specific primers. In addition, antagonistic potential of fungal endophytes in inhibiting the pathogen and possible plant resistance induction was assessed through dual culture, volatile metabolite production, pot cultivation, split-root and root-cutting tests. Molecular evidence determined the identity of the pathogen as Fusarium oxysporum f. sp. lycopersici race 3. Lab tests showed that in duel culture test all four fungal endophytes were able to reduction of colony diameter of pathogen significantly five and seven days after inoculation compared to control. In volatile metabolite test all isolates could reduce mycelial growth of the pathogen significantly compared to control except R. zeae M9 in third and fifth day. Under greenhouse condition, only C. urticicola M2 isolate could significantly reduce the severity of fusarium wilt of tomato and increase plant growth factors compared to the control and other fungal endopytes. Through split-root and root-cutting tests, the possible mechanism of disease severity reduction caused by C. urticicola M2 was identified as stimulation and induction of resistance in tomato plant.

The seeds of common bean plants (Phaseolus vulgaris) are among the most important food sources worldwide. The plant pathogenic fungus Rhizoctonia solani causes seed rot and seedling damping-off of bean plants and is one of the most important soil-borne pathogens in most cultivation areas of this plant. R. solani plays an important role in reducing the yield and quality of this crop. Biological control is a promising, effective, and sustainable solution for managing soil-borne fungal diseases. The simultaneous use of biological control agents, especially agents with different mechanisms of action, might increases the chance of success in disease management. Indeed, two living agents can show different types of interactions based on their inherent characteristics and ecological conditions. In the current research, the potential of co-application of mycorrhizal fungi and bacterial strains from different taxonomic groups was evaluated on increasing the growth of beans and suppression of bean damping-off.

In this research, the effect of 14 different bacterial strains on the mycelial growth of R. solani was investigated by dual culture and by the volatile compound production tests in the laboratory. The list of bacterial strains included: Bacillus megaterium B15, Bacillus thuringiensis B48Pet, Bacillus subtilis BS (B.s), B. subtilis AS, Lysinibacillus boronitolerans RUPB71 (Lysin), Pseudomonas putida RUP1, Arthrobacter citreus B27Pet, Alcaligenes faecalis 1624, Bacillus pumilus INR7, Bacillus thuringiensis 32B (B.thur), Azotobacter vinelandii RUA1 (Azoto), Delftia tsuruhatensis PIIR (Delft), Stenotrophomonas maltophilia S37 and Bacillus velezensis JPS19 (B.vel). In the dual culture test, B.s, B.vel, Alca, Azoto, Lysin, and Delft strains significantly reduced the mycelial growth of the pathogen. In volatile compounds production test, three strains, Alca, Azoto, and B.thur, significantly reduced the mycelial growth of the pathogen. Four bacterial strains, including B.s, B.vel, Alca, and Azoto, were selected for greenhouse experiment. The selected bacterial strains as separate and combined application with two species of arbuscular mycorrhizal fungi (AMF), including Funneliformis mosseae (F.moss) and Glomus claroideum (G.cla) were investigated for inhibiting the disease caused by R. solani, and for their effect on the growth parameters of bean plants in the presence of the pathogen. The greenhouse experiment was conducted as a completely randomized design with 16 treatments and five replications.

Many of the greenhouse treatments that were applied in this study, significantly reduced the severity of the disease compared to the diseased control. They significantly increased the fresh and the dry weight of the shoots, root fresh weight and root dry weight. Four treatments (F.moss, B.s, Alca and Azoto) significantly enhanced the root length and four treatments (Alca, B.s, B.vel+G.cla and Alca+G.cla) increased the shoot length. In terms of the effect on the disease, the B.s strain was the best treatment, which reduced the disease severity by 36.5% and showed the greatest effect in promoting the vegetative characteristics of the plant. Although the bacterial and mycorrhizal strains showed compatibility in many combined treatments, G.cla+B.vel was the only double treatment that showed an increasing effect on the fresh weight and shoot length compared to the separate applications. The other double treatments did not have an additive or synergistic effect in reducing the disease and improving plant growth. Even in some double treatments, in terms of reducing disease and improving plant growth, a weaker effect was seen than their single treatments. Among different treatments, Alca+G.cla and Alca+F.moss showed the highest and B.s+G.cla showed the lowest mycorrhizal colonization.

The effect of bacteria on mycorrhizal colonization was increasing, decreasing, or null depending on the combination of bacterial and mycorrhizal strains used. In many cases, there was no direct relationship between the amount of mycorrhizal colonization and disease control. Overall, before the commercial use of the combination of biological agents, it is necessary to check their interactions in greenhouse and field experiments and ensure their compatibility and lack of antagonistic effect on each other. If the biological agents present in a consortium are compatible, its biocontrol effect will be more stable, efficient and reliable, and it will be possible to use it in a wider range of variable soil ecological conditions. Moreover, the interaction of individuals within a given consortium is strain-specific, and the results of an experiment on specific strains cannot be generalized to other strains of the same species.

Scab disease caused by Venturia inaequalis is the most important diseases of apple in the world which causes serious damage, especially in areas with wet and moderate weather. In order to investigate the effect of fungicides on the time progression curve of apple scab disease in North Khorasan province, the experiment was conducted in the form of Randomized Complete Block Design with eight treatments and eight replications in Bojnord city. With the appearance of disease symptoms, samples were taken in a regular schedule every week until the disease progression was reduced in the control.  Disease Incidence and severity percentage of the disease in each tree were determined and statically analyzed. Using linear regression, disease progression curves were fitted with six growth models as conventional models including linear, exponential, monomolecular, logistic, log-logistic and Gompertz linearized. The results showed that the progression curves changes from the Gompertz model in the control samples by using of fungicides according to the efficiency of each treatment to the log-logistic model and finally to the monomolecular model.

Fusarium dry rot is one of potatoes' most significant postharvest fungal diseases, reducing crop yield and seed tuber quality. Utilizing certified seed tubers treated with chemical fungicides is the simplest and most cost-effective method for preventing dry rot disease damage to potatoes. Monitoring for diseases transmitted by tubers enhances the quality of seed tubers produced and reduces the risk of disease establishment and soil contamination. This study aimed to identify the causal fungal agents of potato seed tubers dry rot, determine the susceptibility of seed samples from potato seed farms to Fusarium dry rot agents, as well as to evaluate some of the effective factors in disease severity, particularly the levels of extracellular enzyme activity and fusaric acid production on the disease index and dry rot volume of potato tubers.

To identify Fusarium species responsible for dry rot disease in the seed tubers of Agria, Banba, Jelly, Challenger, Ramus, Sagitta, Sante, Sifra, Fabula, and Colomba cultivars of potato grown in Ardabil (Ardabil), Chaharmahal & Bakhtiari (Borujen), Razavi Khorasan (Fariman and Torbat-e Heydarieh), Zanjan (Khodabandeh), Fars (Abadeh and Eqlid), Lorestan (Khorramabad), Markazi (Arak) and Hamedan (Razan, Kabudarahang, and Bahar) provinces were sampled according to the standard guidelines of the National Seedling Health and Propagation Materials Laboratory. The pathogenicity test was carried out on artificially inoculated potato tubers tubers cv. Agria for determining the volume of dry rot caused by Fusarium isolates. Furthermore, spectrophotometry and high-performance liquid chromatography (HPLC) methods were used to evaluate in vitro activities of amylase and cellulase, as well as fusaric acid production.

The results indicated that approximately 18% of the seed tubers samples collected from different fields were infected with Fusarium dry rot disease in the 1 to 3% range. A total of 26 isolates were identified based on morphological and molecular characteristics belonging to F. solani sensu lato (13 isolates, 11%), F. oxysporum (8 isolates, 7%), and F. sambucinum (5 isolates, 5%). Analyzing the activity of extracellular enzymes revealed that all recovered Fusarium isolates were capable of producing amylase and cellulase enzymes but at varying levels. The maximum amount of extracellular enzymes produced by Fusarium spp. isolates ranged from 286 to 675 μg mL-1 for cellulase and from 103.5 to 317 μg mL-1 for amylase. According to the results, cellulase peaked sooner than amylase, but both enzymes contributed to the development of dry rot in potato tubers. The results revealed that approximately 38% of the isolates produced fusaric acid in the 13-32 μg kg-1 range. Moreover, the disease index level and the volume of dry rot caused by different Fusarium species isolates on potato tubers varied.

It appears that the amount of dry rot caused by Fusarium spp. isolates on potato tubers are affected by the production of fusaric acid and the activity levels of cellulose and amylase. This research provides new insights into the health status of potato seed tubers, the predominant Fusarium species causing dry rot disease, and the effect of the level of extracellular enzymes and fusaric acid secreted by fungal isolates on the disease progress in potato tubers, which can be applied to the revision of the national standard for seed tuber health and effective disease management during storage. The dry rot disease and its detrimental impact on tubers significantly threaten the official seed tubers certification system, production, and storage procedures. The current study is the first report on identifying the Fusarium dry rot disease agents from potato seed tubers in Iran and investigating the relationship between the disease severity of isolates and their extracellular enzyme activity, and fusaric acid production.

Fusarium head blight disease of wheat causes economic damage on this strategic crop. This disease reduces crop yield and quality by lowering the grain yield and pose health risks to consumers via production of fungal toxins such as nivalenol and deoxynivalenol on the seeds. In this study the reaction of 25 commonly cultivated wheat genotypes were evaluated to Fusarium head blight disease under greenhouse conditions.The genotypes were inoculated twice at the time of spike formation and flowering, and after ten days, the disease incidence and the disease severity were calculated. Analytical results of data related to disease incidence, disease severity and seed contamination rate (thousand seed weight and number of seeds per spike) in greenhouse conditions showed that there is a significant difference between genotypes regarding the mentioned characteristics. Also, Irana, Niknejad, Gahar, Morvarid and Zagros were resistant genotypes, Wa-82-9 and Akbari genotypes were semi-resistant, Chamran, Karvan, Pastor, Chamran 2, Chenab, weebile 264 and Spring BC Roushan were semi-susceptible genotypes, S-90-5, Mehregan, Sholah, Flat, Hirmand, Alvand, Darab, Sistan, Zarin and Star genotypes were sensitive and also Bazh was recognized as very sensitive genotype. With the evaluation of resistance and semi resistance genotypes designated in this study, against this disease under field conditions, it will possible to recommend these genotypes for wheat production programs in different parts of Iran.

In this study, the effect of two fungal species and also a strigolacton phytohormone was evaluated on inducing resistance in two tomato cultivars infected with fusarium wilt disease. In this greenhouse experiment, two cultivars of tomato namely, Captain and 4129 and Trichoderma reesei, Rhizophagus irregularis and GR24 phytohormone (106µM) were used. For this purpose, a factorial experiment was used in a completely randomized design with three replications in different time periods after inoculation of the pathogen (0, 7, 15, 35 days). The effect of biocontrol treatments on changes of some antioxidant enzymes, phenol, total protein and disease severity was assayed. Data analysis showed that the highest activity of all three enzymes with different values for both cultivars occurred during 35 days after inoculation. Among combined and single treatments, application of a combination of three biocontrol factors (T. reesei, R. irregularis and GR24 phytohormone), respectively showed significant effect on increase of measured parameters compared with other treatments. Based on the results of this study it is suggested that application of all three agents in liquid form can be considered as a limiting factor for the growth of the pathogen on the seed surface besides inducing resistance against disease.

Rhizoctonia root rot is a widespread and destructive disease that affects sugar beet yield in Iran and worldwide. In this study, we investigated integrated disease management methods, including the use of resistant cultivars and fungicides, to prevent the development of the disease. The present study focused on the Shokoufa susceptible cultivar and the Novodoro resistant cultivar, and tested three fungicides of Celeste, Uniform, and Maxim. The experiment was conducted under natural and artificial contamination conditions during 2022. The results showed that the Uniform fungicide effectively prevented the development of the disease on the resistant cultivar, resulting in a harvest index of 70.59%. Although this fungicide did not work as effectively on the susceptible cultivar, it still showed better performance compared to other experimental treatments. The Celeste fungicide had a disease index of 3.29 on the resistant cultivar, with 5% of the root surface having ulcers. However, it did not have a significant effect on disease control in the susceptible cultivar, which showed a sensitivity reaction. The harvest index of the resistant cultivar in this treatment was 76.47%, while the susceptible cultivar had a harvest index of 11.76%. The Maxim fungicide and control treatments had similar effects on both the resistant and susceptible cultivars in terms of disease and harvest indexes. Although the severity of the disease was lower in the resistant cultivar compared to the susceptible cultivar, both cultivars showed a low harvest index and were in the sensitive range..

Fusarium wilt on cucumber caused by Fusarium oxysporum f. sp. radicis-cucumerinum is an important and common disease of cucumber in Iran. In this study, differences of pathogenicity between several isolates and their impact were assessed on the plant growth parameters. The pathogenicity of 50 isolates collected from cucumber plants with wilting and yellowing symptoms from different geographic areas of Iran, were examined on cucumber, Negin cultivar. The inoculated and control plants were placed at 25°C for 14 days. Disease severity and the weight of root and crown were measured 10 days post-inoculation. Studied factors showed significant difference at 1% level among isolates of F. oxysporum f. sp. radicis-cucumerinum. The maximum percentage of disease was observed in plants treated by F-111-2, F-133-2 and H8; while the highest disease severity induced in plants treated by F-111-2, F-160-12 and F-111-5. F-111-5, F-160-12 and F-121-4 incited the most decrease in root weight. The crown weight decrease in the presence of F-160-12, F-121-4 and F-111-10 isolates of Fusarium oxysporum f. sp. radicis-cucumerinum correspondingly. Totally, due to the results, it could be concluded that f-160-12 can be considered as the most severe pathogenic isolate.

Black dot disease triggered by Dilophospora alopecuri causes considerable damage in some fields in Golestan province, North of Iran. D. alopecuri is its causal agent and carried in to wheat by wheat gall nematode. Extracellular appendages on the conidia adhere to the cuticule of the nematode juveniles. The disease was reported in united state of America, Canada, Germany, Ugoslavia, India and Pakistan.The fungi is classDothideomycetes and order Dothideales. The geographical distribution of disease was studied in South-Eastern Australia in the summer 1995.The disease in Iran has been reported by Bamdadian since 1973 from Baluchistan, Isfahan, Golestan, Khorasan, Kerman and Khuzestan. The disease agent causes considerable damage in some fields in Golestan province, North of Iran. Symptoms have been found during a survey of foliar disease of wheat in Golestan province. The disease incidence was very low but fungus interaction with seed gall nematode causes considerable damage. The symptoms start with yellow spindle-shaped flecks which develop and become tan brown with black border. This spots may occur on peduncle and heads. The pathogen survives as mycelium in host debris or as conidia on seeds. The purpose of this study was determining the geographical distribution, disease incidence (DI) and disease severity (DS). Then molecular identification of isolates with ITS rDNA in North of Iran, Golestan province.

 Wheat fields infected with the disease in the cities of Golestan province were visited and subjected to sampling during spring 2017-2018. 42 samples suspected to infection with the twist disease were gathered from seven cities of Golestan province. The rate of disease distribution from seven cities farms with disease symptoms, three farms were selected in each crop year and their geographical coordinates were recorded. In this research mapping the geographical distribution of disease was prepared by ArcGIS10.2 software. During 2018 and 2019, a survey was conducted to characterize the disease incidence (DI) and disease severity (DS). The D. alpoecuri leaf spot reading scales rate carried out in this study. No visible symptoms are observed and the leaf remain a health 0; A few chlorotic lesions are present and the infection site is a tan-spot colored 1: Necrosis and chlorosis both exist on the leaf 2: A few pycnidia are visible on the infected site and less than 30% of the leaf is occupied by pycnidia 3: The entire leaf is covered by pycnidial lesions scored 4. A significant difference was observed between the disease rates in the two cropping years. Seven D. alopecuri isolates were identified on the based on morphological and molecular parameters. After purification of fungal isolates, 50 conidia and pycnidia were selected in each isolate and the length and width of pycnidia, conidia cell number, conidia size (length and width), colony shape on the culture medium were also measured in the laboratory. After that identifying of the fungus isolates pathogenicity test was performed in the greenhouse. The D. alopecuri spore suspension with 1.75× 106 CFU concentration and for nematode population with 25000 larvae (L2) were used for inoculation to plants. After three months symptoms of leaf spot (twist) disease was appeared in tillering stage. Fungal DNA extraction from mycelium mass of selected isolates was performed by Murray and Thompson (1980) method and part of ITS region was amplified using ITS4 and ITS5 primers by polymerase chain reaction (PCR). The amplified PCR products of fragments were purified and sequenced at sequencing Microsense Company in Switzerland.

  Comparing of harvested fungal isolates which have been grown on PDA medium showed some variation in different characteristics such as the number of conidia walls, conidia appendages and pycnidia size. In both subsequent years, maximum disease incidence (DI) and disease severity (DS) was measured in Kalaleh by 3.6% to 3.9%, while for Bandar-Torkaman, the city with the lowest DS, were1.3% to 1.65%. The average size of conidia length was 4-8×1 μm in diameters.The pathogenicity test showed that the D.alopecuri is capable to produce twist  disease symptoms only  in the presence with seed gall nematode in the host. The nucleic acid sequences of Internal Spacer Transcribed (ITS) regions for Golestan isolates showed 100% similarity and had small genetic similarity with D. alopecuri MH859142.1 deposited in NCBI Genbank. The sequences belong to D.alopecuri from Gonbad, Aqala, Azadshahr, Maravehtapeh, Kalaleh, Minodasht cities were registered in NCBI Genbank with MW302360, MW291507, MW291561, MW303438, MW303517, MW303518 accession number, respectively.

This is the first study carried out on the morphological and molecular characteristics of twist disease agent isolates, disease severity and its distribution in Golestan province as a major wheat production area of Iran. Many of results especially molecular data and submitted sequences form Iranian isolates of D.alopecuri to databanks are new for Iran.

Powdery mildew of wheat caused by Blumeria graminis f.sp. tritici, is one of the most important and common wheat disease in humid, semi-humid and semi-arid regions of the world, including Iran. At present, one of the important aspects of the management of this disease is its chemical control. In this study, the efficacy of the Pilartep (Tebuconazole +Pyraclostrobin) SC 30% was evaluated in controlling the powdery mildew of wheat in three regions of Qarakheil and Bayekola (Mazandaran) and Kohnekand (North Khorasan province) regions based on randomized complete block design with six treatments and four replications. Experimental treatments included Pilartep (SC 30%) 0.4, 0.5, 0.6 and 0.7 l/h, Tilt (EC 25%) 1 l/h, Folicur (EW 25%) 1 l/h and control. Spraying operation was performed in the growing stage of stem emergence with the emergence of flag leaves. The plots were evaluated for disease incidence and severity percentage using double digit scale and at the end of the season, wheat yields were recorded for each plot. In evaluating the effect of fungicides on incidence, disease severity percentage and crop yield, Pilartep fungicide at the rate of 0.6 and 0.7 l/h was placed in the first statistical group (the highest group). In general, according to the results obtained in order to use the fungicide optimally, Pilartep (SC 30%) at the rate of 0.6 l/h is recommended in the control of powdery mildew of wheat.

In this study, the effect of Rhizophagus irregulariss mycorrhiza and nitroxin bio-fertilizers alone and in combination form was evaluated on control of chickpea wilt disease caused by Fusarium oxysporum f. sp. ciceris. Evaluation of effectiveness of these treatments was done through measurement of chlorophyll and carotenoid pigments, and disease severity. A factorial experiment based on randomized complete block design by eight treatments with three replications was conducted under greenhouse condition. Our results showed that the amount of chlorophyll and carotenoid pigments were significantly decreased in infected plants without biofertilizer treatment while disease severity was increased. The highest increase in  chlorophyll a and carotenoid pigments was observed in nitroxin treatment while the highest increase in  chlorophyll b and ab was recorded in mycorrhizae treatment. Approximately, the maximum change in measured parameters was related to mycorrhiza treatment while all treatments were able to increase yield components compared to control plant. The results of disease severity assessment in infected plant inoculated with bio-fertilizers showed that application of these bio-fertilizers in combination form caused a significant reduction in disease severity. Based on these results, use of both bio-fertilizers combined with soil could increase plant resistance to disease stress by the  increase of yield components

White stem rot caused by Sclerotium rolfsii is a soilborne disease which is extensively common across the groundnut farms of Guilan province, especially during the harvest period. Using the beneficial microbial agents is an alternative method for applying the chemical fungicides.

To find the appropriate fungal antagonistic isolates for the biological control of peanut white stem rot, the effect of three isolates of Trichoderma spp., three isolates of Penicillium spp., two isolates of Aspergillus spp. and one isolate of Cladosporium cladosporioides were studied on S. rolfsii in vitro using dual culture, slide culture, volatile metabolites and non-volatile metabolites. Peanut plants were inoculated with these fungal isolates as well as S. rolfsii in greenhouse experiments, and parameters including disease severity, height, fresh weight, and dry weight of the plant were measured.

The results showed that in the dual culture method, T. harzianum and T. virens were most capable of suppressing the mycelial growth of S. rolfsii with a suppression capability of 93.58% and 92.94%, respectively. In the slide culture method, all isolates turned out to be effective in suppressing the mycelia growth of S. rolfsii, except for T. virens and T. viride. In the volatile metabolite assay, P. glabrum and A. flavus with 81.25% and 75%, respectively and in the non-volatile metabolite method, T. harzianum and T. viride with 93.75% and 97.5% respectively showed the greatest ability to inhibit S. rolfsii mycelial growth. Moreover, the effects of these fungi on the control of S. rolfsii pathogen were explored in greenhouse trials. The results revealed that P. glabrum was 39.4% effective and T. viride was 38.8% effective in reducing the extent and intensity of the disease. Under the presence of the pathogen, the treatment of these antagonistic fungi in greenhouse conditions enhanced plant height, shoot and root fresh and dry weight. In the in vitro and greenhouse approaches, an analysis of variance and a comparison of means of the attributes using the least significant difference (LSD) indicated significant differences (P ≤0.01 and P≤ 0.05) among the examined fungi.

The results of the in vitro and greenhouse trials showed that T. viride, T. harzianum, P. glabrum, A. flavus, and C. cladosporioides, which are present in the natural flora of groundnuts, have the potential capability of the biological control of S. rolfsii as the pathogen of groundnut stem white rot.

Grape powdery mildew caused by Erysiphe necator is one of the most important diseases of vine in Iran. In this study, the efficacy of new fungicide, Sercadis® (Fluxapyroxad 26.5%), at doses of 0.1, 0.15 and 0.3 ml L-1 was compared with the registered fungicides Belkute® (Iminoctadine Tris 40%), Topas® (Penconazole 20%), Stroby® (Kresoxim-methyl 50%) and sulfur 80% to control grape powdery mildew. The experiment was carried out in Razavi Khorasan and Fars provinces in 2019. In each region, a vineyard with Asgari cultivar with a history of disease was chosen and the experiment was performed using randomized complete block design with nine treatments and four replications. Each replication contained a six-year-old fertile grapevine tree. Spraying was done four times. The first spraying was performed just as the buds started to swell, the second, third and fourth spraying were performed after petal fall, just as sour berries formation, and when the fruits were sweet and sour respectively. For data collection, in each treatment, 15 days after the fourth spraying, symptoms of 100 randomly chosen leaves and 8 Bunches of grapes were recorded. The disease incidence and disease severity were calculated for all the samples. The data were then analyzed using SAS software. The results show that, there is a significant difference between treatments and controls at 1% probability level and Sercadis® at the dose of 0.15 ml L-1 reduced disease severity on grape leaves and fruits at least by 72.79% and 82.91% respectively, which makes it an effective treatment in management of grapevine powdery mildew in Iran.