Field studies were conducted to determine the selectivity and efficacy of pronamide alone or with sethoxydim and trifluralin, in Belgian endive. Pronamide at 1.68 with sethoxydim or alone or at 2.24 kg ai ha−1 controlled weeds better than trifluralin at 0.6 or 1.0 kg ai ha−1 in the field. Pronamide at 2.24 kg ha−1 was the best at controlling grass and broadleaf weeds season-long. In nutrient culture studies, Belgian endive roots were injured at 5 mg L−1 of pronamide, whereas redroot pigweed and green foxtail were inhibited at 0.5 and 0.1 mg L−1, respectively. Shoot weights showed similar differences but were less sensitive than roots.

The tolerance of two proso millet cultivars to atrazine preemergence and postemergence applications of bromoxynil, clopyralid, dicamba, or metsulfuron plus amine formulations of 2,4-D was studied in the field. Proso millet grain yield, test weight, seed weight, moisture content, and plant height at harvest were not affected by any of the herbicide treatments, despite some early-season injury observed in 1990.

Rapid germination and root growth have been identified as important plant characteristics for establishment in arid environments. This study evaluates germination, radicle elongation, and root growth rates of two annual grasses, two forage species, and yellow starthistle. Yellow starthistle germination, radicle elongation, and root growth were faster than those of medusahead and hedgehog dogtailgrass. Subterranean clover possessed rapid seedling growth characteristics similar to those of yellow starthistle, whereas Palestine orchardgrass was most delayed.

Growing public concern for pesticide residues in drinking water has resulted in tighter federal and state regulations to prevent ground-water contamination. There are many uncertainties in estimating human exposure risk, yet standards are being set to protect human health. In the last several years, drinking water health standards have been developed for a number of pesticides, often at levels of a few μg L−1 or less. Ground-water monitoring studies, first required by the U.S. Environmental Protection Agency in 1984, have now become an integral requirement to support registration of pesticides shown to have leaching potential. Regulators are now faced with deciding the extent to which pesticides can still be used while continuing to meet legal requirements to protect the public and preserve ground-water resources. The implications are that pesticide use may be severely limited in regions with ground-water resources considered especially vulnerable to contamination, dramatically affecting the type of agricultural practices and crops grown in these regions.

Global positioning systems (GPS) technology, developed by the Department of Defense, enable accurate documentation of Cartesian coordinates anywhere on the earth's surface. Surveying, mapping, positioning, and subsequent management of weed infestations can be expedited with this technology. Positions and boundaries of infestation may be located with 10-m or better accuracy while the GPS receiver is continuously moving, and with 2-m or better accuracy with brief stops for repeated sampling. GPS data agreed closely with U.S. Geological Survey data. Coordinates for a weed infestation may be relocated for treatment, evaluation or other purposes. Basic geographic information systems (GIS) map features from Digital Line Graph (DLG), Topologically Integrated Encoding and Reference Systems (TIGER) and other sources of information may be used to fully integrate delimiting survey results from GPS readings in order to develop weed management plans.

The Chemical Movement through Layered Soils (CMLS) model was modified and combined with the USDA-SCS State Soil Geographic Data Base (STATSGO) and Montana Agricultural Potentials System (MAPS) digital databases to assess the likelihood of groundwater contamination from selected herbicides in Teton County, MT. The STATSGO and MAPS databases were overlaid to produce polygons with unique soil and climate characteristics and attribute tables containing only those data needed by the CMLS model. The Weather Generator (WGEN) computer simulation model was modified and used to generate daily precipitation and evapotranspiration values. A new algorithm was developed to estimate soil carbon as a function of soil depth. The depth of movement of the applied chemicals at the end of the growing season was estimated with CMLS for each of the soil series in the STATSGO soil mapping units and the results were entered into ARC/INFO to produce the final hazard maps showing best, weighted average, and worst case results for every unique combination (polygon) of soil mapping unit and climate. County weed infestation maps for leafy spurge and spotted knapweed were digitized and overlaid in ARC/INFO with the CMLS model results for picloram to illustrate how the results might be used to evaluate the threat to groundwater posed by current herbicide applications.

A Geographic Information System (GIS) was developed to evaluate its utility in an eradication program of common crupina. Infested areas were recorded in the GIS along with information normally found on United States Geological Survey topographic maps. Infested areas were separated into management areas according to possible treatment method and special environmental or health requirements such as proximity to streams or inhabited buildings. The location, size, and type of each management area were recorded in the database. The database was constructed to maintain treatment and efficacy data for tracking the process of eradication for each infestation. Areas were identified for detection surveying, including coordinates for navigating with a global positioning system (GPS).

Chicory (Cichorium intybus L. # CICIN), succory, blueweed, coffee-weed, blue sailors, bunk, or blue daisy, is familiar to many of us as an erect weed along roadsides or in fields, displaying small, startlingly bright blue flowers. Others of us may only have tasted its roots—roasted and ground into a bittersweet coffee substitute or additive: an essential component of the New Orleans brew served blacker than a hundred midnights in a cypress swamp. Along with its close relative endive (Cichorium endivia L.), chicory also has an important place in the salads of Europe and, increasingly, the United States. Both chicory and endive were indispensable in ancient and medieval herbal pharmacies and are still used medicinally today.