scholarly journals What is Rose Rosette Disease?

HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 592-595 ◽  
Author(s):  
H. Brent Pemberton ◽  
Kevin Ong ◽  
Mark Windham ◽  
Jennifer Olson ◽  
David H. Byrne
Keyword(s):  
North America ◽  
Great Plains ◽  
Best Management Practices ◽  
Management Practices ◽  
Rna Virus ◽  
Sources Of Resistance ◽  
Transfer Resistance ◽  
Specialty Crops ◽  
Rose Rosette ◽  
Rose Rosette Disease

Rose rosette disease (RRD) is incited by a negative-sense RNA virus (genus Emaravirus), which is vectored by a wind-transported eriophyid mite (Phyllocoptes fructiphilus). Symptoms include witches broom/rosette-type growth, excessive prickles (thorns), discolored and distorted growth, and, unlike most other rose diseases, usually results in plant death. RRD is endemic to North America and was first described in Manitoba, Wyoming, and California in the 1940s. It has spread east with the aid of a naturalized rose species host and has become epidemic from the Great Plains to the East Coast of North America on garden roses in home and commercial landscapes where losses have been high. The disease was suggested to be incited by a virus from the beginning, but only recently has this been confirmed and the virus identified. The presence of the vector mite on roses has been associated with RRD since the first symptoms were described. However, more recently, the mite was demonstrated to be the vector of the disease and confirmed to transmit the virus itself. As a result of the RRD epidemic in North America and its effects on the national production and consumer markets for roses, a research team comprising five major universities (Texas, Florida, Tennessee, Oklahoma, and Delaware), a dozen growers and nurseries (all regions), six rose breeding programs (California, Wisconsin, Texas, and Pennsylvania), the major rose testing programs (Earth-Kind and AGRS), the major rose organization (American Rose Society), and the major trade organization AmericanHort has formed. This research project has been funded by the Specialty Crops Research Initiative through the U.S. Department of Agriculture (USDA) with the short-term objective of improving and disseminating best management practices (BMPs) and the long-term goal of identifying additional sources of resistance and developing the genetic tools to quickly transfer resistance into the elite commercial rose germplasm.

scholarly journals Combatting Rose Rosette Disease with Volunteer Involvement in the Monitoring Effort

HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 601-603 ◽  
Author(s):  
Kevin Ong ◽  
Madalyn Shires ◽  
Holly Jarvis Whitaker ◽  
Jennifer Olson ◽  
Joseph LaForest ◽  
...  
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Public Awareness ◽  
Scientific Work ◽  
Disease Spread ◽  
North American Continent ◽  
The North ◽  
Monitoring Effort ◽  
Rose Rosette ◽  
Rose Rosette Disease

Rose rosette disease (RRD) was first reported on the North American continent in the early 1940s. In 2011, the causal agent of this disease was identified and described—the Rose rosette virus (RRV). In the last 10 years, RRD has gained widespread notoriety because of disease symptoms appearing on many roses which are used frequently in landscape plantings, both commercial and residential. Much of the prior scientific work on this disease was carried out on the multiflora rose. Currently, the disease issues are on cultivated roses within which no cultivar has been confirmed to be resistant. There is an information gap in our knowledge of the pathogen, vector, and the disease on cultivated roses. Our goals for this project are to seek and identify potential disease tolerance or resistance in roses and increasing public awareness and knowledge of RRD with the purpose of reducing the disease spread with best management practices. Outreach and volunteer recruitment are key activities used to provide scientifically sound information, to establish the current disease range and to actively gather observational reports of RRD to identify resistant rose sources. Elements of these activities include educational meetings, factsheets, posters, and workshops where RRD symptoms recognition is emphasized. A web-based reporting tool was developed to capture observations from volunteers while continually keeping them engaged. It is hoped that through outreach and the collective monitoring effort, researchers will have access to information that contributes to a better understanding of RRD and will find disease-resistant roses that could be used in breeding programs for the continued enjoyment of roses.

scholarly journals Evaluation of Elite Wheat Germ Plasm for Resistance to Tan Spot

Plant Disease ◽  
2006 ◽  
Vol 90 (10) ◽  
pp. 1320-1325 ◽  
Author(s):  
P. K. Singh ◽  
M. Mergoum ◽  
S. Ali ◽  
T. B. Adhikari ◽  
E. M. Elias ◽  
...  
Keyword(s):  
North America ◽  
Great Plains ◽  
Wheat Germ ◽  
Management Practices ◽  
Germ Plasm ◽  
The United States ◽  
Tan Spot ◽  
Northern Great Plains ◽  
Breeding Lines ◽  
Resistant Varieties

Tan spot, caused by Pyrenophora tritici-repentis, is a serious foliar disease of wheat (Triticum aestivum) in North America. Control of tan spot through management practices and fungicide application is possible; however, the use of resistant varieties is the most effective and economical means of controlling tan spot. This study was conducted to determine the disease reaction of 126 elite hard red spring, white, and durum wheat varieties and advanced breeding lines collected from the northern Great Plains of the United States and Canada to individual races/toxins of P. tritici-repentis. Seedling evaluation of the 126 genotypes was done under controlled environmental conditions with virulent races 2, 3, and 5 of P. tritici-repentis and toxins Ptr ToxA and Ptr ToxB. Based on disease reactions, two resistant varieties and two advanced breeding lines adapted to the northern Great Plains were found to be resistant to all the races and insensitive to the toxins tested. Additionally, six genetically diverse lines/varieties were identified to be resistant to tan spot; however, these sources may not be well adapted to the northern Great Plains. These results suggest that the wheat germ plasm contains a broad genetic base for resistance to the most prevalent races of P. tritici-repentis in North America, and the resistant sources identified in this study may be utilized in wheat breeding programs to develop tan spot resistant varieties.

Confirmation of Glyphosate-Resistant Horseweed (Conyza canadensis) in Montana Cereal Production and Response to POST Herbicides

2017 ◽  
Vol 31 (6) ◽  
pp. 799-810 ◽  
Author(s):  
Vipan Kumar ◽  
Prashant Jha ◽  
Amit J. Jhala
Keyword(s):  
Great Plains ◽  
Dose Response ◽  
Best Management Practices ◽  
Management Practices ◽  
Dry Weight ◽  
Shoot Dry Weight ◽  
Greenhouse Study ◽  
Whole Plant ◽  
Cereal Production ◽  
Sites Of Action

In recent years, horseweed has become an increasing problem in Montana. To confirm and characterize the level of glyphosate resistance, seeds were collected from putative glyphosate-resistant (GR) horseweed (GR-MT) plants in a wheat–fallow field in McCone County, MT. Known GR (GR-NE) and glyphosate-susceptible (GS-NE) horseweed accessions from Lincoln, NE, were included for comparison in dose–response and shikimate accumulation studies. Whole-plant glyphosate dose–response experiments conducted at the early- (5- to 8-cm diameter) and late- (12- to 15-cm diameter) rosette stages of horseweed indicated that GR-MT accessions had a 2.5- to 4.0-fold level of resistance to glyphosate relative to the GS-NE accession, on the basis of shoot dry weight (GR50values). The level of resistance was 3.1- to 7.9-fold on the basis of visually assessed injury estimates (I50values). At the whole-plant level, about 2.1- to 4.5-fold higher shikimate accumulation was observed in the GS-NE accession compared with the GR-MT and GR-NE accessions over a 10-d period after glyphosate was applied at 1,260 g ae ha−1. In a separate greenhouse study, all three horseweed accessions were also screened with alternate POST herbicides registered for use in wheat–fallow rotations. The majority of the tested herbicides provided ≥90% injury at the field-use rates for all three horseweed accessions 3 wk after treatment. This is the first published report on the occurrence of GR horseweed in Montana cereal production. Increased awareness and adoption of best management practices, including the use of diversified (based on multiple sites of action) herbicide programs highlighted in this study, would aid in mitigating the further spread of GR horseweed in the cereal production fields of the U.S. Great Plains.

Optimizing soil and plant responses to land-applied manure nutrients in the Great Plains of North America

2006 ◽  
Vol 86 (4) ◽  
pp. 587-595 ◽  
Author(s):  
J J Schoenau ◽  
J G Davis
Keyword(s):  
North America ◽  
Great Plains ◽  
Management Practices ◽  
Nutrient Loading ◽  
Nutrient Balance ◽  
Nutrient Content ◽  
Unit Weight ◽  
Available N ◽  
Animal Manures ◽  
Beneficial Management Practices

Animal manures are recognized as valuable sources of plant nutrients in cropping systems and also play a role in soil improvement through the input of organic matter. Using recent research examples from Saskatchewan and Colorado, this paper covers beneficial management practices for effective recycling of manure nutrients applicable to the Great Plains region of North America. Challenges in using animal manures as fertilizers include low nutrient content per unit weight, variability and availability of nutrient content, and a balance of available nutrients that often does not meet the relative nutrient requirements of the crop. Examples of imbalances that may arise requiring special management considerations include low available N content relative to available P for many solid manures, and low available S relative to N for some liquid manures. Application decisions are best supported by manure and soil analyses, with nutrient balance issues addressed by rate adjustments and the addition of supplemental commercial fertilizer to avoid deficiency or loading of specific nutrients. Placement of manure into the soil by injection or incorporation is desirable in that nutrient losses by volatilization and runoff are reduced and crop recovery is increased. Balancing the rate of nutrient application with crop requirement and removal over time is key to avoiding nutrient loading on soils receiving repeated applications of manure. Key words: Manure management, nutrient cycling, beneficial management practices, Great Plains

scholarly journals Challenges of Breeding Rose Rosette–resistant Roses

HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 604-608 ◽  
Author(s):  
David H. Byrne ◽  
Patricia Klein ◽  
Muqing Yan ◽  
Ellen Young ◽  
Jeekin Lau ◽  
...  
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Selection Procedure ◽  
The United States ◽  
Breeding Cycle ◽  
Viral Agent ◽  
Mass Propagation ◽  
Best Management ◽  
Commercial Trial ◽  
Rose Rosette

Rose rosette disease (RRD) whose causal agent, the Emaravirus Rose rosette virus (RRV), was only recently identified has caused widespread death of roses in the midwestern and eastern sections of the United States. A national research team is working on the detection and best management practices for this highly damaging disease. Unfortunately, little is known about the host plant resistance to either the causal viral agent or its vector, the eriophyid mite Phyllocoptes fructiphilus. Thus far, the only confirmed resistance is among Rosa species. Of the over 600 rose cultivars observed, only 7% have not exhibited symptoms of RRD. Replicated trials are in progress to confirm resistance and/or susceptibility of ≈300 rose accessions in Tennessee and Delaware. Rose is a multispecies cultivated complex that consists of diploid, triploid, and tetraploid cultivars. The basic breeding cycle is 4 years with a 3-year commercial trial coupled with mass propagation before release. Thus, if only one breeding cycle is needed, a new cultivar could be produced in 7 years. Unfortunately, for the introgression of a new trait such as disease resistance from a related species into the commercial rose germplasm, multiple generations are required which can easily take two decades from the first cross to cultivar release. Research is ongoing to develop a rapid selection procedure for resistance to RRD with the aid of molecular markers associated with the resistance. Such an approach has the potential of reducing the breeding cycle time by 50% and increasing the efficiency of seedling and parental selection manifold, leading to commercially acceptable rose cultivars with high RRD resistance in less time and with less expense.

Multispecies and Watershed Approaches to Freshwater Fish Conservation

2019 ◽  
Keyword(s):  
Great Plains ◽  
Best Management Practices ◽  
Life Histories ◽  
Management Practices ◽  
Fish Passage ◽  
Brazos River ◽  
Best Management ◽  
Short Life Span ◽  
Successful Recruitment ◽  
Viable Population

<em>Abstract</em>.—The Brazos River crosses eight ecoregions on its journey from New Mexico through the heart of Texas to the Gulf of Mexico. This diverse stream ecosystem supports at least 85 fish species, many of which—including two endangered, migratory, pelagic broadcast-spawning cyprinids, Smalleye Shiner <em>Notropis buccula </em>and Sharpnose Shiner <em>N. oxyrhynchus</em>—have life histories that track the natural flow regime. These two shiners were listed as endangered in part because of severe range reductions that left each with one viable population in the upper Brazos River. Given their short life span, a single adverse event, such as a persistent drought of two consecutive years, could lead to extinction. This concern was nearly realized in 2011 when a record drought and heatwave resulted in complete reproductive failure of these species, which led to rescue efforts for imperiled shiners confined to drying pools. Seventeen major reservoirs control streamflow and create distinct, disconnected fragments in the Brazos River basin. Long-term ecological studies have provided a strong science foundation for guiding water and environmental flow management and watershed conservation. Implementation of both upland and riparian best management practices in the upper Brazos River watershed, including management of invasive saltcedar <em>Tamarix </em>spp., seeks to improve habitat for fish and wildlife. Hydrological monitoring and modeling is being conducted to evaluate the potential for saltcedar control to improve base flows. Identification of stream reaches most threatened by drying and where aquifer pumping may reduce groundwater inflows to streams is the focus of ongoing research on groundwater–surface water relationships. Fish passage barriers hinder successful recruitment, migration, and recolonization of prairie fishes. Removal and mitigation of barriers, as appropriate, will be critical to restoring ecological functions and connectivity required for migratory fishes. Research on propagation and repatriation of prairie fishes is needed to inform conservation and recovery efforts. A watershed-scale, multidisciplinary approach coordinated across borders and among entities is critical to ensure conservation efforts result in the persistence of native fishes in the Great Plains, including the Brazos River.

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