Virus-induced soybean seed problems

Soybean growers this fall may have problems with green stem and mottled seed. Many of the problems may be caused by bean pod mottle virus (BPMV) or soybean mosaic virus (SMV). Both viruses cause the same leaf symptoms, green stem in the fall, and mottled seed coats. BPMV is transmitted primarily by bean leaf beetle; SMV is transmitted by at least 30 aphid species, including the newly introduced soybean aphid. Many soybean cultivars do not display obvious symptoms, and there is no positive correlation between severity of leaf symptoms and amount of seed coat mottling on fall-harvested seed

Electricity deregulation and the valuation of visibility loss in wilderness areas: A research note.

Visibility in most wilderness areas in the northeastern United States has declined substantially since the 1970s. As noted by Hill et al. (2000), despite the 1977 Clean Air Act and subsequent amendments, human induced smog conditions are becoming increasingly worse. Average visibility in class I airsheds, such as the Great Gulf Wilderness in New Hampshire’s White Mountains, is now about one-third of natural conditions. A particular concern is that deregulation of electricity production could result in further degradation because consumers may switch to lower cost fossil fuel generation (Harper 2000). To the extent that this system reduces electricity costs, it may also affect firm location decisions (Halstead and Deller 1997). Yet, little is known about the extent to which consumers are likely to make tradeoffs between electric bills and reduced visibility in nearby wilderness areas. This applied research uses a contingent valuation approach in an empirical case study of consumers’ tradeoffs between cheaper electric bills and reduced visibility in New Hampshire’s White Mountains. We also examine some of the problems associated with uncertainty with this type of analysis; that is, how confident respondents are in their answers to the valuation questions. Finally, policy implications of decreased visibility due to electricity deregulation are discussed

Spacelab 3 Mission Science Review

Papers and abstracts of the presentations made at the symposium are given as the scientific report for the Spacelab 3 mission. Spacelab 3, the second flight of the National Aeronautics and Space Administration's (NASA) orbital laboratory, signified a new era of research in space. The primary objective of the mission was to conduct applications, science, and technology experiments requiring the low-gravity environment of Earth orbit and stable vehicle attitude over an extended period (e.g., 6 days) with emphasis on materials processing. The mission was launched on April 29, 1985, aboard the Space Shuttle Challenger which landed a week later on May 6. The multidisciplinary payload included 15 investigations in five scientific fields: material science, fluid dynamics, life sciences, astrophysics, and atmospheric science

Identification and characterization of the Rose Rosette disease causal agent

Rose rosette disease is lethal to multiflora rose, a noxious weed occurring in pastureland in most of Iowa. The potential use of rose rosette disease as a biocontrol agent can be enhanced by grafting infected shoots onto plants in established stands (i.e., augmentation). However, questions arose about whether the disease could be spread to ornamental roses. This study probes the identity of the causal agent for the disease in hopes of determining whether fears of transmission to ornamental roses were valid

Characterization of the Rose Rosette Disease causal agent: potential for biological control and multiflora rose

Rosa multiflora (multiflora rose), introduced to America from Japan for ornamental pur­poses 200 years ago, was promoted in Iowa during the mid-1930s as a living fence that would help to conserve soil and provide cover for wildlife. Multiflora rose has since natural­ized, and today some two million acres of Iowa land are infested with this pest, which renders pastures unusable (dense stands exist in coun­ ties south of a line from West Pottawattamie through Winneshiek, affecting the southeast­ern two-thirds of the state). Cattle avoid the prickly stems, and grass dies beneath its thick growth. Although tillage can control the weed, land in permanent pasture or under the Conser­vation Reserve Program is at risk for the spread of multiflora rose

A step toward control of bean pod mottle virus: Identifying field tolerance

So, have you been wondering what to do about all those soybean plants that have mottled leaves? Populations of bean leaf beetles, the insect that efficiently transmits bean pod mottle virus, have been very high. The last issue of the ICM newsletter told you to expect potential yield reductions this fall and reduced seed quality evidenced by seeds that are stained (hilum bleeding). But there may be some soybean cultivars/accessions that are not so bad. We have known for some time that soybean cultivars can vary significantly in response to disease caused by the virus

Improved Disease Resistance on the Way – One Key to Soybean Improvement

As spring planting season begins, it is difficult to predict those diseases that may be most problematic during the growing season of 2008. So much depends upon rainfall, temperature and a myriad of other factors that can affect crops and pathogens. This includes potential for resistance to various pathogens. Despite all the management practices we talk about, disease resistance remains one of the most practical and economic ways to control plant disease. But, sometimes the genes that confer that resistance are not so easy to find. Iowa State University scientists, in research that would not have been possible without support by soybean check-off dollars, have recently been working to develop a means to find and characterize resistance genes to pathogens when resistance has been difficult to find