Agriculture

Retroviral microRNAs
Eukaryotic cells and several DNA viruses encode miRNAs to regulate the expression of specific target genes. It has been controversial whether RNA viruses can encode such miRNAs as miRNA excision may lead to cleavage of the viral RNA genome. We will focus on the retrovirus family, HIV-1 in particular, and discuss the production of virus-encoded miRNAs and their putative function in the viral rep...


Systems biology and systems genetics—novel innovative approaches to study host–pathogen interactions during influenza infection
Influenza represents a serious threat to public health with thousands of deaths each year. A deeper understanding of the host–pathogen interactions is urgently needed to evaluate individual and population risks for severe influenza disease and to identify new therapeutic targets. Here, we review recent progress in large scale omics technologies, systems genetics as well as new mathematical an...
Cytomegalovirus microRNAs
The discovery that animals, plants and DNA viruses encode microRNAs (miRNAs) has transformed our understanding of the regulation of gene expression. miRNAs are ubiquitous small non-coding RNAs that regulate gene expression post-transcriptionally, generally by binding to sites within the 3′ untranslated regions (UTR) of messenger RNA (mRNA) transcripts. To date, over 250 viral miRNAs have been...


Environmental Implications of Herbicide Resistance: Soil Biology and Ecology
Soil microbial community structure and activity are linked to plant communities. Weeds may alter their soil environment, selecting for specific rhizosphere microbial communities. Rhizosphere modification occurs for many crop and horticultural plants. However, impacts of weeds in agroecosystems on soil biology and ecology have received less attention because effective weed management practices w...
Integrated Weed Management Using Planting Pattern, Cultivar, and Herbicide in Dry-Seeded Rice in Northwest India
Field experiments were conducted in Punjab, India, in 2011 and 2012 to study the integrated effect of planting pattern [uniform rows (20-cm spacing) and paired rows (15-, 25-, and 15-cm spacing)], cultivars (PR-115 and IET-21214), and weed control treatments (nontreated control, pendimethalin 750 g ai ha−1, bispyribac-sodium 25 g ai ha−1, and pendimethalin 750 g ha−1 followed by b...


In-Field Movement of Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) and Its Impact on Cotton Lint Yield: Evidence Supporting a Zero-Threshold Strategy
This research was aimed at understanding how far and how fast glyphosate-resistant (GR) Palmer amaranth will spread in cotton and the consequences associated with allowing a single plant to escape control. Specifically, research was conducted to determine the collective impact of seed dispersal agents on the in-field expansion of GR Palmer amaranth, and any resulting yield reductions in an enha...
Environmental Impact of Glyphosate-Resistant Weeds in Canada
Glyphosate-resistant (GR) giant ragweed, horseweed, and common ragweed were confirmed in southwestern Ontario, Canada in 2008, 2010, and 2011, respectively. In the western prairie provinces of Alberta and Saskatchewan, GR (plus acetolactate synthase inhibitor-resistant) kochia was discovered in 201This symposium paper estimates the environmental impact (EI) of the top herbicide treatments or pr...

Evaluation of Weed Emergence Model AlertInf for Maize in Soybean
AlertInf is a recently developed model to predict the daily emergence of three important weed species in maize cropped in northern Italy (common lambsquarters, johnsongrass, and velvetleaf). Its use can improve the effectiveness and sustainability of weed control, and there has been growing interest from farmers and advisors. However, there are two important limits to its use: the low number of...
Lessons Learned From the History of Herbicide Resistance
The selection of herbicide-resistant weed populations began with the introduction of synthetic herbicides in the late 1940s. For the first 20 years after introduction, there were limited reported cases of herbicide-resistant weeds. This changed in 1968 with the discovery of triazine-resistant common groundsel. Over the next 15 yr, the cases of herbicide-resistant weeds increased, primarily to...

Integrating Social Science into Managing Herbicide-Resistant Weeds and Associated Environmental Impacts
Controlling herbicide resistance (HR) and its associated environmental risks is impossible without integrating social and economic science with biophysical and technology aspects. Herbicide resistance is a dynamically complex and ill-structured problem involving coupled natural–human systems that defy management approaches based on simple scientific and technology applications. The existence ...
Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) Increases Herbicide Use, Tillage, and Hand-Weeding in Georgia Cotton
In 2005, the existence of glyphosate-resistance in Palmer amaranth was confirmed at a single 250 ha field site in Macon County, Georgia. Currently, all cotton producing counties in Georgia are infested, to some degree, with glyphosate-resistant Palmer amaranth. In 2010 and 2011, surveys were administered to Georgia growers and extension agents to determine how the development of glyphosate-res...

Rhizosphere Microbial Community Dynamics in Glyphosate-Treated Susceptible and Resistant Biotypes of Giant Ragweed (Ambrosia trifida)
In a previous study, glyphosate-susceptible and -resistant giant ragweed biotypes grown in sterile field soil survived a higher rate of glyphosate than those grown in unsterile field soil, and the roots of the susceptible biotype were colonized by a larger number of soil microorganisms than those of the resistant biotype when treated with 1.6 kg ae ha−1 glyphosate. Thus, we concluded that so...
Organic Farmer Knowledge and Perceptions are Associated with On-Farm Weed Seedbank Densities in Northern New England
Weed management remains a high priority for organic farmers, whose fields generally have higher weed density and species diversity than those of their conventional counterparts. We explored whether variability in farmer knowledge and perceptions of weeds and weed management practices were predictive of variability in on-farm weed seedbanks on 23 organic farms in northern New England. We intervi...
Crop Performance and Weed Suppression by Weed-Suppressive Rice Cultivars in Furrow- and Flood-Irrigated Systems under Reduced Herbicide Inputs
Weed control in rice is challenging, particularly in light of increased resistance to herbicides in weed populations and diminishing availability of irrigation water. Certain indica rice cultivars can produce high yields and suppress weeds in conventional flood-irrigated, drill-seeded systems in the southern United States under reduced herbicide inputs, but their response to reduced irrigation ...
Cover Crop Residues—Effects on Germination and Early Growth of Annual Weeds
There is an increasing interest in the use of cover crops in agriculture, in Sweden mainly for the use as catch crops to reduce nitrogen leakage. Some of these crops are known for their allelopathic abilities, which may play a role in the control of weeds and contribute to reduced herbicide use. This study aimed to explore the possible suppressive effect of the cover crop species white mustard,...