Emergence Patterns of Rare Arable Plants and Conservation Implications.

Knowledge on the emergence patterns of rare arable plants (RAP) is essential to design their conservation in Europe. This study hypothesizes that is possible to find functional groups with similar emergence patterns within RAP with the aim of establishing management strategies. Seeds of 30 different species were collected from Spanish arable fields and sown under two tillage treatments: (a) 1 cm depth without soil disturbance to simulate no-till, and (b) 1-10 cm depth with soil disturbance every autumn to simulate tillage to 10 cm depth.

The Role of Light in the Emergence of Weeds: Using Camelina microcarpa as an Example.

When modelling the emergence of weeds, two main factors are considered that condition this process: temperature and soil moisture. Optimum temperature is necessary for metabolic processes that generate energy for growth, while turgor pressure is necessary for root and shoot elongation which eventually leads to seedling emergence from the soil. Most emergence models do not usually consider light as a residual factor, but it could have an important role as it can alter directly or indirectly the dormancy and germination of seeds.

Crop Species Diversity Changes in the United States: 1978-2012.

Anecdotal accounts regarding reduced US cropping system diversity have raised concerns about negative impacts of increasingly homogeneous cropping systems. However, formal analyses to document such changes are lacking. Using US Agriculture Census data, which are collected every five years, we quantified crop species diversity from 1978 to 2012, for the contiguous US on a county level basis.

Flowering dynamics and pollinator visitation of oilseed echium (Echium plantagineum).

Echium (Echium plantagineum L.) is an alternative oilseed crop in summer-wet temperate regions that provides floral resources to pollinators. Its seed oil is rich in omega-3 fatty acids, such as stearidonic acid, which is desired highly by the cosmetic industry.

United States Department of Agriculture-Agricultural Research Service research on pest biology: weeds.

Over 125 permanent full-time scientists conduct research within the USDA Agricultural Research Service (ARS) on issues related to weeds. The research emphasis of most of these scientists involves ecology and management or biological control of weeds. Many scientists perform research on weed biology as components of their primary projects on weed control and integrated crop and soil management.

Application of Weed Seedbank Ecology to Low-Input Crop Management.

Pesticide use in the United States is concentrated in the Corn Belt, mainly in the form of herbicides on corn (Zea mays) and soybean (Glycine max). If this chemical load to the environment is to be reduced, without appreciably affecting crop yields, an intimate understanding of weed ecology is necessary. For annual weeds in the U.

Relative abundance in an alien weed flora.

Both relative abundance and absolute abundance of alien weed species in a large geographic region increased from the year 1900 to 1980. The increase in relative abundance may have been due to competitive displacement among the weeds, patterns of landscape disturbance, or simply time. The increase in absolute abundance indicates the ineffectiveness of past weed control policies in stemming weed migration.