Weed Management in Alfalfa

Weeds compete with alfalfa for water, nutrients, light, and space. This competition can decrease yields, lower forage quality, increase disease and insect problems, create harvesting problems, and initiate or poison the animals which will consume the forage. Premature loss of alfalfa stands is usually the result of the interaction of the pest complex - diseases, insects, and weeds

Herbicides for Alfalfa Weed Control

Numerous herbicides are available for controlling weeds in pure or mixed stands of alfalfa. In addition, these herbicides can be applied at different times and stages of alfalfa growth -from prior to planting to actively growing alfalfa to dormant applications during the winter. To be confident of achieving the desired weed control, it is important to apply alfalfa herbicides at the proper growth stage and rate. The following tables contain information pertinent to proper utilization of the herbicides to obtain maximum weed control

New Developments in Pasture Weed Control

Weeds in pastures continue to offer challenges to the producer for controlling these unwanted plants. The combination of forage grasses grown in pastures and the climate of Kentucky provides an environment that is conducive for having numerous weedy species. Most pastures have a combination of cool season (those that begin growth in fall and mature in spring or early summer) and warm season (those that begin growth in spring and mature in late summer or fall) weeds. Additionally, some weeds such as thistles severely restrict grazing while other weeds do not. The decision to apply a weed management strategy is often difficult because of the wide array of weedy species and because some weeds cause little forage reduction

Potential for Crop Residue to Restrict Herbicide Movement in Surface from Water Corn and Soybean Fields

As no-tillage and other conservation tillage practices continue to increase, it is important to have knowledge of herbicide adsorption on crop residue with regard to the potential for the herbicide to be removed from the residue and move with runoff water from the field into nearby surface waters. Previous research had compared herbicide adsorption to various residues, but it was difficult to make comparisons among these studies because the residues were from different crops or the amount of residue decomposition was different. The amount of weathering or aging of the residue at the time of herbicide treatment could alter the amount initially adsorbed and subsequent desorption by rainfall. The amount of herbicide adsorbed varied greatly among the herbicides evaluated. Of the triazine herbicides, AAtrex had the least amount adsorbed (5%) and Princep was adsorbed the most (32%) with Bladex (15%) having an intermediate amount of adsorption. The two acetochlor formulations had a similar amount of adsorption with Surpass being 57% adsorbed and Harness being 61% adsorbed. Dual (44%) and Frontier (38%) had lesser amounts adsorbed compared to Surpass and Harness. A calculated Herbicide Contamination Potential (HCP) more accurately reflected potential contamination of surface water than did herbicide adsorption

Movement of Triazine Herbicides in Conventional, Reduced Tillage, and No-Tillage Corn Production

Herbicides are applied to over 90 percent of the corn acreage in Kentucky and triazine herbicides are used the most. Conservation tillage methods are often used to prevent soil erosion and to conserve soil water. However, as tillage is decreased the dependence on herbicides for weed control often increases. Minimizing herbicide movement from the application sites to non-target areas, such as ground and surface waters, is necessary to maintain optimum water quality

Potential of Surface Water Contamination from Three Triazine Herbicides

The movement of atrazine, cyanazine, and simazine from the site of application was monitored under conventional, reduced, and no-tillage conditions. Less water and soil was lost from the no-tillage and reduced tillage conditions. Conventional tillage conditions had about 66,000 L/ha runoff in 1986-87 and about 123,000 L/ha runoff in 1987-88. Seasonal rainfall was 885 mm in 1986-87 and 397 mm in 1987-88. The rainfall intensity was greater during the first two events in 1987 than the corresponding events in 1986. The first rainfall event in 1986 accounted for 91, 89, and 78% of the total seasonal loss of atrazine, cyanazine, and simazine, respectively. More simazine was found in the surface runoff water than was atrazine or cyanazine

Common Pokeweed Management in Corn and Soybeans with a Conservation Tillage Cultivator and Herbicides

Common pokeweed (Phytolacca americana L.) is a warm-season perennial that grows well in nondisturbed areas such as fence rows and woodland borders. In recent years it has begun spreading to com and soybean fields where no-tillage practices are used. The deep taproot that is characteristic of common pokeweed, makes this weed difficult to manage, particularly in no-till plantings. The green leaves, fleshy stems, and purple berries of common pokeweed can inhibit the harvesting process and lead to discounts at the elevator for high moisture and stained seed. The equipment industry has developed cultivators with large sweeps capable of operating in no-till plantings with minimal disturbance to stubble and plant residue at the soil surface. These cultivators are called conservation tillage cultivators and are intended to operate at shallow depths to cut plants below the soil surface. The fact that plants with deep taproots generally do not tolerate tillage may make the conservation tillage cultivator a valuable tool for managing common pokeweed in no-till plantings. The objective of this research was to evaluate the effectiveness of a conservation-till cultivator with and without herbicide treatments for common pokeweed control in corn and soybean

Weed and Feed

Fertilizer and herbicide combinations are often applied prior to planting, at planting, or after crop emergence, a procedure sometimes called weed and feed . The opportunities for utilizing this system are numerous with the major advantage being saving an extra trip across the field. In order for the system to work, it must ensure that both fertilizer and herbicide are present when needed. When both the crop plant and weedy plant are at growth stages which allow for compatible applications with a single treatment, this can be highly successful. Conversely, when these two plant systems are not at compatible growth stages, severe crop injury and/or a lack of weed control can result. There are several methods of applying herbicides and fertilizers together, but regardless, always follow directions on the pesticide label for specific instructions and/or restrictions

Letter from William De Witt Snodgrass to Louis Untermeyer, September 29, 1962

Letter from William De Witt Snodgrass to Louis Untermeyer concerning edits to his poem Meat Boy.https://scholars.unh.edu/snodgrass/1006/thumbnail.jp

ALS Resistant Smooth Pigweed in Western Kentucky

Pigweeds The pigweed, or Amaranthus, family contains some of the most commonly occurring weeds of midwest agriculture. Species from this family that occur in Kentucky include smooth pigweed (Amaranthus hybridus, most common), tumble pigweed, prostrate pigweed, spiny amaranth,Palmer amaranth,common waterhemp, and tall waterhemp. Research has shown that some pigweed species respond differently to various herbicides, therefore, proper identification is necessary to achieve acceptable control. Pigweed identification in early stages of seedling growth can be difficult because the distinguishing physical characteristics do not appear until plants are mature or have produced seed. Also, some pigweed species may cross-pollinate to produce hybrid plants that exhibit characteristics of both parents