Weed scientists generally have done an excellent job of documenting herbicideresistant weeds. Over 400 unique cases of herbicide resistance, involving over 200 weed species in 65 countries, have been reported (Heap 2014). Oftentimes, evolved resistance in weeds is due to a mutation in a gene encoding the herbicide target site, and weed scientists also have done a good job of identifying these m...

Nearly all weed control methods influence both the abiotic and biotic components of the ecosystem. These include the following: mechanical control techniques; cultural practices such as grazing, burning, flooding or revegetation, the introduction of biological weed control agents; and the use of chemicals. This paper reviews many of the risks of weed control and, in some cases, suggests prevent...

Herbicide safeners, formerly referred to as herbicide antidotes, are chemical agents that increase the tolerance of monocotyledonous cereal plants to herbicides without affecting the weed control effectiveness. The use of safeners offer several benefits to agricultural weed control. Safeners may allow: (1) the selective chemical control of weeds in botanically related crops; (2) the use of nons...

Blubaugh, Carmen K. Ph.D., Purdue University, May 2015. Undercover Predators: Vegetation Mediates Foraging, Trophic Cascades, and Biological Control by Omnivorous Weed Seed Predators. Major Professor: Ian Kaplan. Weed pressure is the most costly challenge that vegetable growers face, requiring more labor investment than other production inputs. Vertebrate and invertebrate seed predators destroy...

Increasing concerns about the environmental impacts of herbicides, the development of herbicide-resistant weeds, and the need to carefully weigh costs and benefits have led to greater interest in developing rational, economical, and sustainable approaches to weed management (O'Donovan 1996). In addition, greater emphasis on post-emergence applied herbicides such as glyphosate has allowed for mo...

An investigation was made to see the salt tolerance of 10 weed species of rice. Properly dried and treated seeds of weed species were placed on 9 cm diameter petridishes lined with Whatman No. 1 filter paper under 6 salinity regimes, viz. 0 (control), 4, 8, 16, 24 and 32 dS m(-1). The petri dishes were then kept in germinator at 25 +/- 1.0 degrees C and 12 hr light. The number of germinated see...

Historically, pasture breeders have not considered environmental weed risk in species selection and assessment. Consequently several pasture or former pasture species are now problematic environmental weeds in Australia. The CRC for Plant-Based Management of Dryland Salinity (CRC) has taken a pro-active approach to prevent further introduction or promotion of weedy pasture species by developing...

Weed pressure in 1995 was incredible! What happened to produce such a glorious crop of weeds? The answer: drought! The Drought of 1995 and Weeds and Weed Control in 1996 Weed pressure in 1995 was, in a word, incredible! I toured many areas — golf courses, lawns, athletic fields, and institutional grounds — that were solid crabgrass, knotweed, clover, etc. In many of these areas, if there weren’...

Weed control is generally the first major decision to be made once alfalfa has germinated. Managing weeds in a timely manner is necessary to provide maximum production of high quality alfalfa hay. A poor weed management decision can lead to stand loss, poor quality hay, unacceptable weed control, alfalfa injury and a loss of money. Herbicides are applied to 75% of newly planted alfalfa in Calif...

The genetic basis of weedy and invasive traits and their evolution remain poorly understood, but genomic approaches offer tremendous promise for elucidating these important features of weed biology. However, the genomic tools and resources available for weed research are currently meager compared with those available for many crops. Because genomic methodologies are becoming increasingly access...