Download or read book Studies in the Management of Pythium Seed and Root Rot of Soybean written by Kelsey L. Scott and published by . This book was released on 2018 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Ohio, soybean seedling damping-off and seed rot are problems routinely encountered soon after planting. Reduced tillage systems that lead to inoculum build-up combined with saturated soil conditions are ideal environments for seedling diseases, which cause large losses of soybean stand and thus yield. Prior Ohio field surveys identified multiple species of Pythium and Phytophthora that contribute to soybean seedling damping-off. Among the most common and aggressive species are Phytophthora sojae, Pythium irregulare, Pythium ultimum var. ultimum, and Pythium ultimum var. sporangiiferum. Fungicide seed treatment and host resistance are two management strategies that are used to minimize yield loss caused by these pathogens. Thus, the objectives of these studies were to: i) evaluate new active ingredients for efficacy in the lab and field, and ii) identify and characterize new sources of resistance towards the most common seedling pathogens. These are key strategies for the development of effective strategies for the management of soybean seedling disease. During 2014-2015, at two environments, ethaboxam seed treatments combined with metalaxyl on a susceptible cultivar significantly increased yield compared to other fungicide treatments containing metalaxyl or mefenoxam alone. Soybeans treated with ethaboxam plus metalaxyl had significantly higher plant populations when compared to the nontreated control at all four 2016 field locations, while one environment had significantly higher yield. In laboratory seed plate and greenhouse cup assays, ethaboxam plus metalaxyl in a commercial formulation provided equal or better protection against multiple species of Pythium when compared with other seed treatments that contained metalaxyl or mefenoxam only. These results indicate that ethaboxam with metalaxyl is effective at managing seed and rot root caused by the diverse species of Pythium and Phytophthora and provides another seed treatment fungicide available to producers which can be used in an integrated disease management program. The parents that were used to develop six nested association mapping (NAM) populations were previously identified as segregating for resistance towards Phytophthora sojae, Pythium irregulare, Pythium ultimum var. ultimum, and Pythium ultimum var. sporangiiferum. Following inoculation in a cup assay, the resistance was quantitatively inherited in each of the NAM populations towards the four seedling pathogens. In total, 33 QDRL from the six populations surpassed the genome-wide logarithm of odds (LOD) threshold and there was a large number of suggestive QDRL that surpassed the chromosomal LOD threshold. Of these 33 significant QDRL, 10 explained more than 15% of the phenotypic variation. Only four QDRL conferred resistance to more than one of the oomycete pathogens; one on chromosome 3, one on chromosome 17, and two located at separate locations on chromosome 13. This indicates that there may be multiple mechanisms for resistance to these root pathogens. Further analyses are needed to precisely map these QDRL so they may be selectively bred into highly resistant germplasm in order to manage seed and seedling damping-off. These NAM populations will serve as a rich resource for breeders to incorporate resistance into adapted soybean cultivars.

Download or read book Effect of Oxygen Concentration on Pythium Seed Rot of Soybean written by George Eldon Brown and published by . This book was released on 1965 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization and Interactions of Pythium and Fusarium Spp Associated with Soybean on Seed Decay and Root Rot written by Maria Valeria Avanzato and published by . This book was released on 2011 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Soybean Seedling Disease Complex written by Margaret Lee Ellis and published by . This book was released on 2011 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Seedling diseases in soybean fields in Ohio have increased over the past decade. This study was conducted to better characterize some of these seedling pathogens, specifically Fusarium graminearum and two new pathogenic species of Pythium, as well as evaluate management strategies, particularly host resistance, for F. graminearum and Pythium irregulare. A rolled towel assay was developed to understand the potential impact of F. graminearum as a soybean pathogen by evaluating the effect of inoculum density, temperature parameters, and fungicide seed treatments on disease development. Inoculum concentrations of 2.5 x 104 macroconidia/ml or higher were necessary for disease development at temperatures 18 to 25°C, indicating that high levels of inoculum may be necessary for disease to occur. Seed treated with captan at 61.9 g a.i. or fludioxonil at 2.5 or 5.0 g a.i. per 100 kg developed smaller lesions than other seed treatments and the non-treated control. The rolled towel assay was used to screen 24 soybean genotypes for resistance to F. graminearum. Five genotypes had high levels of resistance to F. graminearum, including the cultivar Conrad, a major source of partial resistance to Phytophthora sojae. A population of 262 F6:8 recombinant inbred lines (RIL) derived from a cross of Conrad x Sloan (Susceptible) was evaluated for resistance and segregated as a quantitative trait. Four putative quantitative trait loci (QTLs) were identified from Conrad on chromosomes 8, 13, 15, and 16, and one putative QTL from Sloan on chromosome 19. The putative QTLs identified in this population did not map to the same regions that confer resistance to Ph. sojae, suggesting different mechanisms are required for these two seedling pathogens. In this study, two new species of Pythium, P. schmitthenneri and, P. selbyi, were described using morphology and sequence analysis of the ITS1-5.8S-ITS2 region. These new species were recovered from 30% of fields surveyed which was focused on the identification of seedling pathogens; they are both pathogens to corn and soybean. Pythium irregulare is one of the most widespread Pythium species in Ohio soybean fields and has very high levels of pathogenicity. In a greenhouse assay, 105 soybean genotypes were evaluated for resistance to two isolates of P. irregulare. Isolate x genotype interaction for root weight and rot root score was not significant. The plant introduction (PI) 424354 had high levels of resistance to P. irregulare. Two BC1F2:3 populations were used to map the resistance including: 192 lines of OHS 303 (moderately susceptible) x (Williams (susceptible) x PI 424354) and 127 lines of Dennison (moderately susceptible) x (Williams x PI 424354). Both populations fit the model for quantitative resistance based on root weight and root rot score. Putative QTL were identified on chromosomes 1, 5, 6, 8, 10, 11, 13, 14, and 20. These results suggest PI 424354 can be an important source of partial resistance in developing germplasm for breeding new cultivars with more durable resistance to P. irregulare.

Download or read book Integrated Management of Phytophthora Stem and Root Rot of Soybean and the Effect of Soil applied Herbicides on Seedling Disease Incidence written by Vinicius Castelli Garnica and published by . This book was released on 2019 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soybean seedling diseases and Phytophthora stem and root rot (PSRR; caused by Phytophthora sojae) are two of the most economically important diseases in North Central U.S. Remarkable differences in disease incidence occur each year, which demonstrate that abiotic and biotic factors must interact for disease onset and development. During 2017 and 2018, field studies were conducted to (i) address the efficacy of seed treatment and genetic resistance for PSRR management on soybean population, canopy coverage (CC), and yield, and (ii) investigate potential interactions between pre-emergence (PRE) herbicides and the incidence of seedling diseases in alluvial soils in Nebraska. Despite field history, PSRR developed in only four of six environments studied. Commercial seed treatment had a positive effect on plant population density, CC, and yield in at least three environments. Compared to non-treated control, seed treatment increased emergence between 11,600 to 53,700 plants ha-1 and early-season CC between 0.7 to 1.2%. Under high disease pressure, management programs using moderately resistant cultivars improved yields when compared to moderately susceptible cultivars. By contrast, minimum yield differences were detected between Rps1k andRps1c genotypes, except in one environment. While a weak to moderate correlation was observed between CC and incidence of P. sojae symptomatic plants, a moderate to strong association was found between CC and yield. Across multiple environments, PRE herbicides chlorimuron-ethyl, metribuzin, saflufenacil, sulfentrazone, and flumioxazin had no impact on seedling root rot (disease severity index; DSI) when compared to the non-treated control. Similarly, no significant differences between PRE herbicides were detected on plant population, plant height, and yield. Community composition depicting primary pathogenic genera Fusarium, Phytophthora, Pythium, and Rhizoctonia did not occur at random but rather varied across environments and DSI classes. In two of the three environments, Phytophthorastructured approximately 22% of primary pathogenic genera, whereas, Rhizoctoniarecovery was low (

Download or read book Pythium written by Mahendra Rai and published by CRC Press. This book was released on 2020-01-28 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pythium is one of the most important phytopathogens causing significant damage to agriculture, forest, and nurseries, etc. It is an unseen enemy of the root zone of various plants and hence considered as "hidden terror" for a number of plants. An accurate diagnosis and identification of Pythium causing various infections in plants is very important because it is often confused with several other fungi. Pythium infections are difficult to control once they have set in. Therefore, its effective and ecofriendly management is of paramount importance. In addition, there are many reports on Pythium causing infections in human beings and animals. The present book on Pythium focuses on various aspects which mainly include pathogenesis, technological developments in detection and diagnosis, and its management. Key Features Includes identification of Pythium spp. by traditional and molecular methods Deals with different diseases caused by Pythium spp Describes the role of Pythium in mammalian diseases Incorporates various management strategies Discusses emerging role of nanotechnological tools for the management of Pythium diseases

Download or read book Compendium of Soybean Diseases written by James Burton Sinclair and published by . This book was released on 1989 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Production; Soybean diseases; Infectious diseases; Bacterial diseases; Bacterial blight; Bacterial pustule; Bacterial tan spot; Wildfire; Bacterial wilts; Crown gall; Other bacteria; Mycoplasmalike diseases; Machismo; Bud proliferation; Witches'-broom and phyllody; Beneficial bacteria; Fungal diseases; Fungal diseases of foliage, upper stems, pods, and seeds; Alternaria leaf spot and pod necrosis; Anthracnose; Brown spot; Cercospora blight and leaf spot; Choanephora leaf blight; Downy mildew; Frogeye leaf spot; Phyllosticta leaf spot; Powdery mildew; Red leaf blotch; Rhizoctonia aerial blight; Rust; Scab; Target spot; Fungal diseases of roots and lower stems; Brown stem rot; Charcoal rot; Fusarium blight or wilt, root rot, and pod and collar rot; Phytophthora rot; Pod and stem blight and Phomopsis seed decay; Stem canker; Pythium rot; Red crown rot; Rhizoctonia diseases; Sclerotinia stem rot; Sclerotium blight; Thielaviopsis root rot; Other fungi associated with root rots; Beneficial fungi; Virus diseases; Bean pod mottle virus; Cowpea chlorotic mottle virus; Peanut mottle virus; Soybean dwarf virus; Soybean mosaic virus; Tobacco ringspot virus; Tobacco streak virus; Bean yellow mosaic virus; Black gram mottle virus; Cowpea mild mottle virus; Cowpea severe mosaic virus; Indonesian soybean dwarf virus; Mung bean yellow mosaic virus; Peanut stripe virus; Soybean chlorotic mottle virus; Soybean Crinkle leaf virus; Soybean yellow vein virus; Tobacco mosaic virus; Other viruses; Nematode diseases; Soybean cyst nematode; Lance nematodes; Lesion nematodes; Reniform nematode; Root-knot nematodes; Sting nematodes; Other nematodes; Seed pathology; Detection of seedborne pathogens; Seedborne bacteria and bacterial diseases of seeds; Bacillus seed decay; Other seedborne bacteria; Seedborne fungi and fungal diseases of seeds; Alternaria pod and seed decay; Purple seed stain; Cercospora sojina; Chaetomium cupreum; Colletotrichum truncatum; Diaporthe-Phomopsis complex; Fusarium spp.; Macrophomina phaseolina; Yeast spot (Nematospora spot); Peronospora manshurica; Phomopsis seed decay; Other seedborne fungi; Postharvest pathology; Seedborne viruses; Other pathogens associated with seeds; Diseases of unknown or uncertain cause; Foliage blight; Sudden death syndrome; Yellow leaf spot; Noninfectious or stress diseases; Crusting and compaction; Frost; Hail; Heat canker; Lightning; Sunburn; Water stress; Mineral deficiencies and toxicities; Herbicide damage; Insecticide damage; Air pollutants; Soybean disease management strategies; Exclusion; Eradication; Protection; Disease resistance; Integrated pest management.

Download or read book Soybean Diseases written by Denis C. McGee and published by American Phytopathological Society. This book was released on 1992 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diseases that are seedborne and seed transmitted; Fungi; Ascochyta leaf spot; Anthracnose; Curvularia cotyledon spot; Downy mildew; Frogeye leaf spot; Phomopsis seed decay; Purple seed stain; Sclerotinia stem rot; Bacteria; Bacterial blight; Bacterial pustule; Bacterial tan spot; Bacterial wilt; Corynebacterium wilt; Wildfire; Viruses; Alfalfa mosaic; Bean pod mottle; Brazilian bud blight; Bud blight; Cowpea mild mottle; Cucumber mosaic; Peanut stunt; Peanut stripe; Soybean mild mosaic; Soybean mosaic; Soybean stunt; Tomato ringspot; Diseases that are seedborne but not seed transmitted; Fungi; Altenaria leaf spot; Botrytis stem rot; Brown spot; Brown stem rot; Charcoal rot; Drechslera blight; Fusarium pod and collar rot; Fusarium root rot; Fusarium wilt; Myrothecium leaf spot; Phyllosticta leaf spot; Phytophthora root rot; Pythium root rot; Rhizoctonia aerial blight; Rhizoctonia root rot; Stem canker; Southern blight; Storage rot; Target spot, Thielaviopsis root rot; Verticillium stem rot; Yeast spot; Bacteria; Bacillus seed decay; Chocolate spot; Viruses; Southern bean mosaic; Diseases that are not seedborne or seed transmitted; Fungi; Choanephora leaf blight; Leptosphaerulina leaf spot; Mycoleptodiscus root rot; Neocosmospora stem rot; Powdery mildew; Red crown rot; Red leaf blotch; Scab; Soybean rust; Stemphylium leaf blight; Sudden death syndrome; Bacteria; Bacterial crinkle leaf spot; Pseudomonas andropogonis leaf spot; Mycoplasmas; Bud proliferation; Machismo; Witches' broom; Viruses; Abutilion mosaic; African soybean dwarf; Azuki mosaic; bean chlorotic ringspot; Bean common mosaic; Bean yellow mosaic; Black gram mottle; Blackeye cowpea mosaic; Cowpea aphid-borne mosaic; Cowpea chlorotic mottle; Cowpea mosaic; Cowpea severe mosaic; Crinkle leaf; Indonesian soybean dwarf; Mung bean yellow mosaic; Peanut mottle; Rhyncosia mosaic; Rosette; Soybean chlorotic mottle; Soybean dwraf; Soybean severe stunt; Soybean yellow vein; Tobacco mosaic; Tomato spotted wilt.

Download or read book Management of Sclerotinia Stem Rot of Soybean and Diversity of Pythium Irregulare in Ohio written by Jaqueline Huzar Novakowiski and published by . This book was released on 2017 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: An unexpected increase in incidence and severity of SSR was observed following application of pyraclostrobin, a strobilurin fungicide, compared to the untreated check in several field trials. There are numerous studies indicating that strobilurin fungicides can affect plant physiology, and one of the most common effects reported is delay in senescence, which is attributed to reduction in ethylene synthesis. Ethylene can either be directly or indirectly involved in plant defense response to necrotrophic pathogens. Therefore, the patterns of expression of defense-related genes were studied in three soybean cultivars inoculated with S. sclerotiorum following application of pyraclostrobin under controlled conditions. A great variability in disease development was observed among the three experiments. The pattern and magnitude of gene expression varied among the cultivars and the sampling times. Overall, upregulation of ET-related genes was observed following inoculation of S. sclerotiorum, whereas the pattern of expression of SA and JA-related genes varied. The results from this study offered some insights that require further study about the underlying mechanisms of enhanced susceptibility towards S. sclerotiorum following treatments with pyraclostrobin observed under field conditions.

Download or read book Evaluation of Pythium Root Rot and Damping Off Resistance in the Ancestral Lines of North American Soybean Cultivars and Chemical Control of the Active Ingredient Ethaboxam in Seed Treatments written by Katherine Susan McLachlan and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biological Seed Treatment to Control Phytophthora Root Rot of Soybeans written by Gusti Sarbini and published by . This book was released on 1976 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Soil applied Protoporphyrinogen Oxidase Inhibitor Herbicides on Soybean Seedling Disease written by Nicholas J. Arneson and published by . This book was released on 2019 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seedling disease is one the most economically important diseases of soybean in the United States. It is commonly caused by Fusarium spp., Rhizoctonia solani, Pythium spp., and Phytophthora sojae, alone, or together as a disease complex. Fungicide seed treatments continue to provide the most consistent management of seedling diseases. Soil-applied protoporphyrinogen oxidase (PPO) inhibitor herbicides are used preemergence in soybean production to manage several broadleaf weeds. Applications of PPO-inhibitors can result in phytotoxic injury to soybean when environmental conditions are not favorable for soybean growth. These environmental conditions can favor seedling disease development as well. In this thesis, two studies were conducted to determine the effect of soil-applied PPO-inhibitors on soybean seedling disease development in Nebraska under field and controlled conditions. The first study assessed the effect of two PPO-inhibitors and a fungicide seed treatment on seedling disease and yield in 9 soybean fields in Nebraska. PPO-inhibitor injury occurred at 7 of 9 locations with inconsistent effects on seedling disease, where increases in root rot severity of 6.6-28.1% were observed at 5 of 9 locations, decreases of 4.7-10.9% at two locations, and no effect at three locations. None of these effects impacted yield at any of the locations. Fungicide seed treatment did not reduce root rot severity at any location; however, it increased yield at two locations. The second study investigated the effect of PPO-inhibitors on seedling disease caused by Fusarium solani under controlled conditions. Disease pressure was consistent throughout this study, with root rot severities ranging 32.1-38.9%. PPO-inhibitor injury occurred in all experiments with severities ranging 7.0-33.0%. Sulfentrazone alone increased root rot severity 9-12%. There was an effect of PPO-inhibitors on seedling disease development, although results were inconsistent, indicating a need for further research. PPO-inhibitors should continue to be used in part of an integrated weed management program and fungicide seed treatments should be used in fields that have a history of seedling disease.

Download or read book Compendium of Soybean Diseases and Pests written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fusarium Root Rot of Soybean written by Curtlin Gregg Bender and published by . This book was released on 1976 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies on the Parasitism of Rhizoctonia Solani Kuhn on Soybeans written by Michael G. Boosalis and published by . This book was released on 1948 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Factors Affecting Pythium Root Rot of Soybean and Germination of Oospores of Pythium Ultimum written by Liu-Gei Chou and published by . This book was released on 1973 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oomycete Community Diversity and Pathogenicity Associated with Soybean in Ohio written by Krystel A. Navarro-Acevedo and published by . This book was released on 2019 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: The oomycetes, Phytophthora (Ph.), Phytopythium (Pp.), and Pythium (Py.) cause detrimental effects to soybean yields when susceptible cultivars are planted, and conducive conditions occur. Soils with high clay content found in many soybean production areas of Ohio paired with heavy rainfall, allows for water retention for longer periods of time. This enables the germination of oospores and mobility of zoospores towards soybean roots. Subsequently, infections occur and early symptoms include pre-and post- emergence damping-off of soybean seed and seedlings. In addition, mid-season infections lead to root rots but one species, Phytophthora sojae causes stem rot which results in plant death. Within the genus Phytophthora, only Ph. sojae and Ph. sansomeana have been recovered from soybean seedlings and reported as pathogens. In contrast, a vast diversity of Pythium species have been recovered from soybean seedlings across major soybean producing states in the U.S. and Canada. Pythium sylvaticum, Py. irregulare, Py. ultimum var. ultimum, Py. ultimum var. sporangiiferum and Py. heterothallicum are among the most frequently recovered species. More importantly, more than one species has been recovered from symptomatic seedlings or roots, suggesting that these occur as species complexes. To better manage this root pathogen complex, an integrated disease management approach is recommended. This includes a combination of fungicide seed treatments paired with host resistance. Fungicide efficacy is variable among species and host resistance has shown to be the best means of management in regions with high levels of inoculum and conducive environments. The distribution and species diversity of Phytophthora, Phytopythium and Pythium among soybean and corn producing states have been documented in several previous surveys that used different isolation techniques. These surveys suggested that soil edaphic factors may play a role in species distribution and diversity. However, how community composition and species diversity change when soil edaphic factors remain constant was unexplored. Thus, the first objective of this study was to test the effects of temperature and agronomic practices on the community composition and species diversity of Phytophthora, Phytopythium and Pythium. A soil baiting technique was used to identify the pathogen complex in soils from five fields with different A soil baiting technique was used to identify the pathogen complex in soils from five fields with different rotation schemes and tillage practices but with similar soil edaphic factors. Soils were incubated at 15 and 25oC and seed of the susceptible cultivar Sloan was used as bait. Symptomatic seedlings were collected for direct isolation of pathogens onto oomycete selective media. Additionally, rhizosphere soil was collected for metabarcoding approach in which DNA was extracted, followed by amplification with oomycete primers of the ITS1 region and sequencing. Regardless of temperature or agronomic practice, Py. sylvaticum, and Py. ultimum were isolated through the baiting procedure and these along with Py. acrogynum, Py. attrantheridium, and Py. heterothallicum were detected with amplicon sequencing at all temperatures and all fields and were considered as the core species associated with soybean. More importantly, there were distinct communities between fields with different agronomic practices. Pythium arrhenomanes and Py. inflatum, were found in greater abundance in soil from the field under continuous corn while Ph. sojae was higher in soils from fields planted to a soybean corn rotation. There were also differences in community composition due to temperature, six Pythium species were abundant at 15oC while another six were favored by 25oC. These findings demonstrated that the diversity of Phytophthora, Phytopythium, and Pythium, associated with soybean roots can be influenced by temperature and potentially production practices which may explain in part the differences in species composition among the many surveys that have taken place as well as the importance previous production practices may be having on the community composition within a field. The second objective was to evaluate if soybean genotype could impact the abundance of Phytophthora, Phytopythium, and Pythium. Here, three cultivars (Kottman, Lorain, and Sloan) with different levels and types of resistance towards these three genera were planted across eleven environments with high disease pressure in Ohio over a two-year period. At soybean growth stage V1-V3, seedlings from each environment were collected for direct isolation, and rhizosphere soil used for a metabarcoding approach. In addition, data for early plant population and yield was collected from each environment to determine the performance of the cultivars under natural field conditions. Based on both a metabarcoding approach and direct isolation, the environment played a significant role on the Phytophthora, Phytopythium, and Pythium communities and these were also influenced by different soybean growth stages. In addition, cultivar significantly affected the abundance of Phytophthora species in the rhizosphere of soybean seedlings. Here the greater number of Ph. sojae reads were recovered from rhizosphere soil and symptomatic seedlings of the moderately susceptible cultivar Sloan compared to Kottman with race-specific resistance towards Ph. sojae. Two species, Py. periilum and Pythium sp. CAL, not reported previously in Ohio, were detected in the soybean rhizosphere using a metabarcoding approach. Pythium periilum was only detected in the rhizosphere while the undescribed Pythium sp. CAL. was only recovered from seedlings retrieved from one environment although it was detected in 9 environments. When tested against different soybean cultivars this species was highly pathogenic and optimal growth was approximately 25oC. In culture, oospores and sporangia were observed however, zoospores were not produced. This species was highly abundant across soybean fields in Ohio and further studies should be conducted to classify this species among the Pythium clades. Furthermore, Py. periilum was not isolated from seedlings suggesting that temperature during isolation or type of media should be modified to recover this species from the field. The seresults provide evidence that disease, when observed in the field, is often caused by more than one pathogen. In addition, the effect of cultivar was observed for Ph. sojae providing further evidence that host resistance is still an effective management strategy in environments conducive for disease development. These results will also allow for the development of targeted disease management approaches for fields in which conducive conditions for disease development are often encountered. Finally, species of Phytophthora, Phytopythium, and Pythium should be continuously monitored since populations can change and novel species can emerge that can be detrimental to soybean production.