Evaluation of Foliar Fungicides at Different Growth Stages on Soybean Diseases and Yield

Soybean Sclerotinia stem rot (white mold) caused by Sclerotinia sclerotiorum is a major disease in commercial production, particularly in intensive production regions of the United States, Argentina, and northern China. The occurrence of white mold (Figure 1) depends on various seasonal factors like cool temperatures \u3c85°F, good soil moisture during flowering/early pod formation stage, canopy closure, narrow row spacing, and apothecia production (Figure 1a) at flowering. White mold management measures are preventative and include application of fungicides. Except for seed production, prior to 2005 foliar diseases were not a major concern to soybean production in Iowa and much of the north central region of the United States. Since the report of Asian soybean rust in South America in 2001, and then in the United States in 2004, attention on fungicide applications in soybean production has increased consistently over the years

Effect of Foliar Fungicides at R3 Growth Stage on Soybean Disease and Yield

The foliar, stem, and root diseases of soybeans are significant components of yield loss in soybean fields. Use of fungicides is one of the options in management of soybean diseases. According to USDA-NASS, fungicide use in soybean has increased from \u3c1 percent in 2002 to 11 percent of soybean planted acres in 2012 in 20 soybean producing states (Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, North Carolina, North Dakota, Ohio, South Dakota, Tennessee, Virginia, and Wisconsin). The objectives of these trials were to test efficacy of various foliar fungicides sprayed at R3 growth stage on disease control and yield response during 2012 and 2013 growing seasons

Efficacy Tests of Foliar Fungicides on Soybean Diseases and Yield during 2012 and 2013 Growing Seasons in Northeast Iowa

The foliar, stem and root diseases of soybean are significant components of yield loss for crop producers. Use of fungicides is one of the options in management of soybean diseases. Fungicide use in soybean has increased from \u3c1 percent in 2002 to 11 percent of soybean planted acres in 2012 in 20 soybean-producing states (Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, North Carolina, North Dakota, Ohio, South Dakota, Tennessee, Virginia and Wisconsin) (USDA-NASS). The objective of these trials was to test the efficacy of various foliar fungicides on disease control and yield during 2012 and 2013 growing seasons

Seedling Inoculation Screening Technique to Identify Resistance to Fusarium solani f. sp. glycines a Causal Agent of Soybean Sudden Death Syndrome

Sudden death syndrome (SDS) caused by Fusarium virguliforme (FV) formerly F. solani f. sp. glycines is one of the major yield reducing diseases of soybean (Glycine max). There is concern among producers due to noticeable expansion in geographical array of SDS and the associated potential yield losses. Yield loss due to SDS in the top 10 soybean producing countries varies from 2x103 in Canada to 0x105metric tons in the United States (Wrather et al., 2001). Techniques developed earlier for SDS resistance screening were inconsistent in foliar symptoms expression. Hence, objectives of the study during 2002–2005 were to develop a simple, rapid, repeatable, quantifiable and season independent resistance screening technique to measure relative tolerance of soybean varieties to SDS and understand infection process

More On Soybean White Mold This Year

Soybean white mold has been a production problem for soybean producers since early 1990s. White mold outbreaks often occur in even years due to crop rotations, with rare severe occurrences in odd years. Iowa’s cool, wet summer has increased the white mold risk for some growers in eastern Iowa – even though it is an odd year. Extension field agronomist Virgil Schmitt first reported the occurrence of white mold in east central Iowa and Jim Fawcett, northeast Iowa field agronomist, has received a report of severe white mold in a 60-acre field

Good Harvest in Corn Should Help Manage Soybean SDS

This year is one of the worst soybean sudden death syndrome (SDS) epidemics since the disease was found in Iowa in 1994. Preliminary research data suggest that corn has much to do with SDS pathogen and there are things we can do about the disease as we begin harvest. Management of SDS should start when we harvest corn fields

Note for fall soybean diseases

It is well established that outbreaks of plant diseases are associated with extreme weather. This year\u27s extreme weather created favorable conditions for several soybean diseases. Sudden death syndrome(SDS) was severe in southern Iowa, and severe outbreaks of white mold occurred in eastern Iowa. The two diseases also occurred in other parts of Iowa, and an article will address the management of the two diseases later this year

Charcoal rot -- a dry weather disease

In the last issue of the ICM Newsletter, we reported that charcoal rot, a drought-related soybean disease, was prevalent in Iowa late this summer, causing premature death of soybeans. We briefly discussed identification and scouting methods. In this article, we address management issues and provide more information on identifying this disease in fall

Effects of Fall Tillage on Soybean White Mold and Sudden Death Syndrome in 2011

Because of the summer flooding and outbreaks of soybean sudden death syndrome (SDS) this past growing season, more tillage has been made this fall in Iowa than the past few years. This can be seen while driving on Iowa highways, a similar situation we saw after 1993 floods. Fall tillage practices will impact two important soybean diseases, soybean white mold and sudden death syndrome. The former was wide spread during 2009 growing seasons and the later was prevalent in both 2009 and 2010. In this article, we will discuss the implications of tillage on these two diseases

Sudden death syndrome – A growing threat of losses in soybeans

Sudden death syndrome (SDS) caused by Fusarium virguliforme is one of the major yield-limiting soil borne diseases of soybean (Glycine max). The SDS has been reported from 21 U.S. states and is known to occur in Africa, North America, and South America. In the U.S. the losses due to SDS was estimated at $3.06 billion for a period from 1988 to 2010. Since 1983, several management approaches have been investigated to reduce SDS and yet, continued efforts are necessary to develop long term disease management programs and to sustain disease below economic threshold levels. Integrating available control measures is an option, but adaptability and real-world assessments are equally important. Support of several funding agencies to better understand the disease in identifying suitable control measures to reduce yield losses in commercial cultivations has been indispensable in accomplishing these goals. In spite of sustained efforts, SDS continued to spread within the U.S. and reported in seven other countries since its first report in 1971. Comprehensive reviews have previously been published on this disease by Roy et al. [98], Leandro et al. [58], and Hartman et al. [32]. In this review, updated information on geographic distribution and economic significance of SDS, epidemiology, factors affecting SDS, and management options for SDS including screening techniques have been compiled. Also, discussed significant gaps in use of plant, fungi and bacteria based biocontrol agents in addressing management of SDS