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Annual decreases in soybean (Glycine max L. Merrill) yield caused by diseases were estimated by surveying university-affiliated plant pathologists in 28 soybean-producing states in the United States and in Ontario, Canada, from 2010 through 2014. Estimated yield losses from each disease varied greatly by state or province and year. Over the duration of this survey, soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) was estimated to have caused more than twice as much yield loss than any other disease. Seedling diseases (caused by various pathogens), charcoal rot (caused by Macrophomina phaseolina (Tassi) Goid), and sudden death syndrome (SDS) (caused by Fusarium virguliforme O’Donnell & T. Aoki) caused the next greatest estimated yield losses, in descending order. The estimated mean economic loss due to all soybean diseases, averaged across U.S. states and Ontario from 2010 to 2014, was $60.66 USD per acre. Results from this survey will provide scientists, breeders, governments, and educators with soybean yield-loss estimates to help inform and prioritize research, policy, and educational efforts in soybean pathology and disease management.

Since 1974, soybean disease loss estimates for the southern United States have been published in the Southern Soybean Disease Workers (SSDW) Proceedings, summaries of which were published in 1978 (6), 1988 (2,3), 1993 (4), and 1995 (8). A summary of the results from 1974 to 1994 has also been published (7), and the 1994 results were published as part of the disease loss estimate for the top 10 soybean producing countries (9). The loss estimates for 1994 to 1996 presented here were solicited from: Bill Gazaway, Alabama; Clifford Coker, Arkansas; Robert Mulrooney, Delaware; Tom Kucharek, Florida; Boyd Padgett, Georgia; Don Hershman, Kentucky; Ken Whitam, Louisiana; Arvydas Grybauskas, Maryland; Joe Fox, Mississippi; Allen Wrather, Missouri; Steve Koenning, North Carolina; Phil Pratt, Oklahoma; Charles Drye, South Carolina; Melvin Newman, Tennessee; Joseph Krausz, Texas; and Patrick Phipps, Virginia. Various methods were used to identify the diseases of soybeans and to obtain disease loss estimates, with most estimates derived by more than one method. The methods used to assist in disease identification were field surveys, plant disease diagnostic clinic samples, questionnaires to Cooperative Extension staff, and private crop consultant reports. Methods used to obtain disease loss estimates were grower demonstrations conducted by the Cooperative Extension Service, private crop consultant reports, variety trials, foliar fungicide trials, and research plots. Yield losses were based on estimates of yield in the absence of disease. The actual production figures for each state were supplied by the state crop reporting service. Dollars lost to disease were calculated by multiplying the estimated loss in metric tons by the average annual price of $222.67/t in 1994 ($6.68/bu), $208.33/t in 1995 ($6.25/bu), and $263.33/t in 1996 ($7.90/bu). Percentage of loss estimates from each state is specific for the causal organism or the common name of the disease. In 1995, the list of diseases was modified in order to obtain more specific information on the occurrence of diseases that in previous years had been placed together in general categories. For example, the category “root and lower stem rots” was separated into brown stem rot, Fusarium root rot, Sclerotinia stem rot, and southern blight. The category “foliar diseases (other)” was separated into aerial blight and frogeye leaf spot. The Diaporthe/Phomopsis complex was added to the list of diseases. Additional information on each disease can be found in the Compendium of Soybean Diseases (5). During 1994, 16.18 million metric tons (594.45 million bushels) were harvested from 7.11 million hectares (17.57 million acres) in the southern states. Disease losses were estimated at 9.29%, resulting in a production loss of 1.24 million metric tons (45.47 million bushels) valued at $303.74 million ($6.68/bu; Table 1). The greatest percentage of loss occurred in Florida (24.30%) and the least in Delaware (4.10%). The greatest financial loss occurred in Missouri ($67.33 million), followed by Arkansas ($57.31 million) and Louisiana ($32.00 million). During 1995, 12.43 million metric tons (456.70 million bushels) were harvested from 6.77 million hectares (16.73 million acres) in the southern states. Disease losses were estimated at 9.14%, resulting in a production loss of 1.18 million metric tons (39.52 million bushels), valued at $247.03 million ($6.25/bu; Table 2). The greatest percentage of loss occurred in Alabama (18.20%) and the least in Delaware (2.50%). The greatest financial loss occurred in Missouri ($76.29 million), followed by Arkansas ($50.26 million) and Mississippi ($27.87 million). During 1996, 15.67 million metric tons (575.8 million bushels) were harvested from 7.05 million hectares (17.42 million acres) in the southern states. Disease losses were estimated at 8.67%, resulting in a production loss of 1.58 million metric tons (58.22 million bushels) valued at $459.92 million ($7.90/bu; Table 3). The greatest percentage of loss occurred in Texas (14.70%) and the least in Virginia (1.30%). The greatest financial loss occurred in Missouri ($115.92 million), followed by Arkansas ($99.89 million) and Mississippi ($62.28 million). The greatest economic loss over the 3year period was caused by soybean cyst nematode ($275.38 million), followed by charcoal rot ($159.22 million), Phytophthora root rot and stem rot ($84.43 million), and root-knot and ectoparasitic nematodes ($79.50 million). Prior to 1995, Phytophthora root and stem rot was not identified as an individual disease in the SSDW disease loss estimates. It was included in the broad category of “root and stem rots.” Diseases have been reported to cause significant loss in soybean production in the United States and in other major soybean-producing countries (1-9). Since 1977, soybean diseases have been reported as causing significant yield reduction in the southern soybean producing states (2-8). It is essential that University Research and Cooperative Extension continue their efforts to discover methods to control these diseases and to educate soybean producers concerning the best methods to prevent yield loss due to soybean diseases.

Annual decreases in corn yield caused by diseases were estimated by surveying members of the Corn Disease Working Group in 22 corn-producing states in the United States and in Ontario, Canada, from 2012 through 2015. Estimated loss from each disease varied greatly by state and year. In general, foliar diseases such as northern corn leaf blight, gray leaf spot, and Goss's wilt commonly caused the largest estimated yield loss in the northern United States and Ontario during non-drought years. Fusarium stalk rot and plant-parasitic nematodes caused the most estimated loss in the southern-most United States. The estimated mean economic loss due to yield loss by corn diseases in the United States and Ontario from 2012 to 2015 was $76.51 USD per acre. The cost of disease-mitigating strategies is another potential source of profit loss. Results from this survey will provide scientists, breeders, government, and educators with data to help inform and prioritize research, policy, and educational efforts in corn pathology and disease management. Accepted for publication 26 August 2016.

Soybean (Glycine max (L.) Merr.) germplasm line S99-2281 (Reg. No. GP-361, PI 654356) was developed at the University of Missouri-Delta Center and released by the University of Missouri Agricultural Experiment Station. It is an F 4 plant selection composited in the F 5 generation from the cross of N90-516 × S92-1069. S99-2281 is a productive, early group V (relative maturity 5.2) soybean line with broad resistance to soybean cyst nematode (Heterodera glycines Ichinohe) HG types (races), southern root knot nematode (Meloidogyne incognita (Kofoid & White) Chitwood), and reniform nematode (Rotylenchulus reniformis (Linford and Oliveira)). It also carries the Rcs3 gene for resistance to all known races of frogeye leaf spot, caused by Cercospora sojina K. Hara. In combined analyses over 3 yr, S99-2281 yielded 3 and 7% more than 'Manokin' in southeast Missouri trials (15 tests) and in Uniform Group IVs Tests-Southern States (39 tests), respectively. It will be useful as an elite parent in soybean breeding programs to develop productive soybean cultivars with broad resistance to frogeye leaf spot and resistance to multiple nematode species.

The soybean cyst nematode, Heterodera glycines, is a serious economic threat to soybean producers in Missouri. Periodic monitoring for the presence, population densities, and virulence phenotypes of H. glycines is essential for determining crop losses and devising management strategies implementing the use of resistant cultivars. A survey using area-frame sampling was conducted to determine the distribution and virulence phenotypes of H. glycines in Missouri during 2005. Two samples from each of 125 fields representing eight geographical regions of Missouri were collected; 243 samples were processed for extraction of cysts and eggs. In all, 49% of samples had detectable cyst nematode populations, which ranged from 138 to 85,250 eggs per 250 cm3 of soil. Race and H. glycines type tests were conducted on populations from 45 samples. Nearly 80% of the populations that were tested, irrespective of the region, were virulent on the indicator line plant introduction (PI) 88788, which is the source of resistance for most H. glycines-resistant cultivars. More than 70% of populations could reproduce on the indicator lines PI 88788, PI 209332, and PI 548316 (Cloud), indicating that soybean cultivars with resistance derived from these sources need to be carefully monitored and used only in rotation with nonhost crops and soybean cultivars with resistance from other sources. Approximately one-third of the populations, primarily in the southern regions of Missouri, could reproduce on PI 548402 (Peking), another common source of resistance. Fewer than 10% of the populations could reproduce on PI 90763, PI 437654, PI 89772, or PI 438489B, suggesting that these sources of resistance should be used in soybean breeding programs to develop H. glycines-resistant soybean cultivars.

Cotton is the most important fiber crop in the world, and current U.S. lint production accounts for nearly one quarter of the world supply. The unique role of cotton in world and American history is profound. Primitive cottons have been used in Africa, Asia, and the Americas for millennia. Domestic and international demand for cotton fiber contributed greatly to the westward expansion of the United States, the American Civil War, and the industrial revolution (81). The land area devoted to cotton production in the United States peaked in 1926 with approximately 18 million hectares (Fig. 1). The advent of mechanized farming equipment and the availability of effective, relatively low-cost fertilizers, pesticides, and improved cotton cultivars after World War II allowed the production of significantly greater yields per unit of land area, and hectarage declined. U.S. production of cotton lint in the past 5 years has varied from 3.0 × 10 to 4.4 × 10 kg produced on about 5 million hectares (147). Additionally, cotton seed is a valuable source of vegetable oil and protein used in animal feed, with production of 4.9 × 10 to 5.9 × 10 kg of cotton seed annually. Since World War II, cotton cultivation was increasingly dependent on inputs of chemical pesticides for weed and insect control. Historically, the cotton boll weevil, Anthonomus grandis Boheman, was the most costly pest of cotton in the United States. The combination of crop loss due to this insect directly and the expense for insecticides that was incurred by cotton growers attempting to control it amounted to several billion dollars annually until recently (130). The successful establishment of the Boll Weevil Eradication Program coordinated by the U.S. Department of Agriculture in many states in the eastern half of the country has resulted in a reduction in insecticide usage, improved profitability for growers, and has led to a resurgence of cotton production in the Southeast (37). In addition, the current widespread use of transgenic cotton cultivars with resistance to herbicides and/or insects also has greatly reduced the need for inputs of pesticides. Currently, 71% of cotton grown in the United States is herbicide resistant, resistant to lepidopteran insects, or has resistance to both (3). Reductions in pest pressure from weeds and insects as a result of the deployment of transgenic resistance and the boll weevil eradication program have

The clover stem borer, Languria mozardi Latreille (Coleoptera: Languriidae), is a widespread, native North American beetle (Wildermuth & Gates 1920; Vaurie 1948). The adult feeds primarily on pollen and foliage of its host plant but has been observed feeding on corn silks (Zea mays L.) and wheat heads (Triticum sp. L.) (Wildermuth & Gates 1920). Larvae tunnel inside the stem of host plants, feeding on the pith and softer inner portions of stem. Stem tunnels can be 75 cm in alfalfa, Medicago sativa L. (Wildermuth & Gates 1920). Economic injury to forage crops can result from the tunneling activity of larvae (Wildermuth & Gates 1920) but Folsom (1909) viewed L. mozardi as being of secondary importance, if at all, in clover. Languria mozardi is uni voltine in the Eastern United States and trivoltine in the South-western United States (Wildermuth & Gates 1920). Overwintering is typically as adults under leaf litter and debris, but overwintering of larvae in stems has been reported (Wildermuth & Gates 1920). Larvae mature within the host stem; pupate in the stem, and adults eclose and spend the first 23 d of adult life within the stem (Wildermuth & Gates 1920). Languria mozardi has a wide host range including plants in the families: Asteraceae, Brassicaceae, Campanulaceae, Fabaceae, Malvaceae, Poaceae, and Urticaceae (Folsom 1909; Wildermuth & Gates 1920; Vaurie 1948; Ward et al. 2007). Vaurie (1948) reported a dead adult in the erect stem of a soybean in South Carolina in Nov (no year or date mentioned), but did not list soybean as a larval host plant. Below we present documentation of L. mozardi utilizing soybean, Glycine max (L.) Merr. as a host plant. During soybean stem dissection to detect Dectes texanus LeConte in Tennessee, Missouri, and Arkansas, we found L. mozardi within stems (Table 1). The larva and pupae were reared to adulthood and adults are housed as specimens in the University of Missouri Delta Research Center collection with the exception of record 1 which was documented photographically (Fig. 1). Vaurie (1948) was used to key all adult specimens to L. mozardi.

Research must focus on management of diseases that cause extensive losses, especially when funds for research are limited. Knowledge of the losses caused by various soybean diseases is essential when prioritizing research budgets. The objective of this project was to compile estimates of soybean yield potential losses caused by diseases for each soybean producing state in the United States from 2006 to 2009. This data is of special interest since the 4-year period summarized in this report, permits an examination of the impact of soybean rust that was first reported in the United States in 2004. Thus, in addition to the goal of providing this information to aid funding agencies and scientists in prioritizing research objectives and budgets, an examination of the impact of soybean rust on soybean yield losses relative to other diseases is warranted. Yield losses caused by individual diseases varied among states and years. Soybean cyst nematode caused more yield losses than any other disease during 2006 to 2009. Seedling diseases, Phytophthora root and stem rot, sudden death syndrome, Sclerotinia stem rot, and charcoal rot ranked in the top six of diseases that caused yield loss during these years. Soybean yield losses due to soybean rust and Sclerotinia stem rot varied greatly over years, especially when compared to other diseases. Accepted for publication 21 October 2010. Published 22 November 2010.

Research must focus on management of diseases that cause extensive losses, especially when funds for research are limited. Knowledge of the losses caused by various soybean diseases is essential when prioritizing research budgets. The objective of this project was to compile estimates of soybean yields suppressed due to diseases for each soybean-producing state in the US from 2003 to 2005. The goal was to provide this information to help funding agencies and scientists prioritize research objectives and budgets. Yield suppression due to individual diseases varied among regions in the US, and the total of soybean yields suppressed due to diseases in the US varied among years. Soybean cyst nematode suppressed US soybean yield more during 2003 to 2005 than any other disease. Phytophthora root and stem rot, sudden death syndrome, and seedling diseases ranked in the top four on the list of diseases that suppressed soybean yield during these years. This is the first report of soybean yield suppression due to Asian soybean rust in the United States.