In descending order, by date published.
9/11/2020 (minor revision)
Authors: Paul Vincelli
Necrotic ring spot and summer patch are two patch diseases that can be very destructive when Kentucky bluegrass is grown under intensive management. In addition to bluegrass, certain fine-leaved fescues are susceptible.
Species of both warm- and cool-season turfgrasses are grown in Kentucky. Identification of these grasses is critical for implementation of proper management practices. Grass identification is commonly performed by observing specific parts of the plant. For a review of the parts of the grass plant, see AGR-216: 'Turfgrasses of Kentucky'. The objective of this extension publication is to provide concise identification tips to properly identify Kentucky turfgrasses.
Nitrogen (N) fertilizer is required by turfgrass in larger quantities than any other mineral nutrient because the plant demand for N is high and the supply of N from the natural environment is normally low. In instances where N is not applied according to the University of Kentucky recommendations, applied N can increase the risk of surface and ground water contamination. The objective of this document is to describe the function of N in turfgrass, explain how soil and tissue tests can be used to manage N applications, and to describe the various N fertilizer sources available for application to turfgrass.
2/13/2020 (minor revision)
Authors: Paul Vincelli
Anthracnose is primarily a disease of intensely managed turfgrass, such as creeping bentgrass and annual bluegrass, on golf course putting greens. Outbreaks are generally induced by environmental conditions or cultural practices that result in stress to the turf. The anthracnose pathogen can incite a foliar blight phase or the more destructive basal rot phase.
Iron (Fe) is commonly applied using granular or foliar sources to enhance turfgrass color. Iron applications can result in darker green turfgrass as a result of increased Fe uptake or Fe oxidation on the leaf surface. In many cases, Fe results in no turfgrass response at all. Understanding the dynamics of Fe both in the plant and in the soil can enhance your nutrient management programs. The objective of this publication is to explain the function of Fe within the plant, describe the Fe sources available for turfgrasses, and identify which Fe fertilizers are most effective.
Calcium (Ca) is the dominant cation in all soils of agronomic importance and Kentucky soils are no different. Kentucky soils are naturally high in Ca. Consequently, Ca deficiency in Kentucky turfgrasses is extremely rare, and the probability of observing a Ca response on golf courses, home lawns, sod production, or sports fields is very low. Applying Ca fertilizers to artificially increase soil Ca above the level necessary for proper plant growth normally does not result in an increase in plant uptake because Ca uptake is genetically controlled. Regardless, Ca is commonly applied in both granular and liquid forms.
Magnesium is an essential element for all plants. Soluble magnesium (Mg) exists in soils primarily as Mg2+, a positively charged divalent cation. Kentucky soils are naturally high in Mg and, thus, Mg applications to turfgrass are normally unnecessary. However, turfgrasses grown in sand-based rootzones, such as golf course putting greens and sand-based sports fields, are prone to Mg deficiency. When Mg is necessary, it is essential to understand the function of Mg in the plant, the dynamics of Mg in the soil, and the forms of Mg fertilizers.
Phosphorus (P) is an essential plant nutrient and a common component of many turfgrass nutrition programs. Although P application can improve turfgrass quality in some soils, most soils of Kentucky already have adequate plant-available P to support healthy turfgrass growth. What is the function of P within the plant, and how much P is required to sustain acceptable turfgrass in Kentucky? Also, if P applications are necessary, when and how should P be applied?
Turgrasses under intensive management are often subject to outbreaks of infectious diseases. Good turf management practices often greatly reduce the impact of disease by promoting healthy plants that are better able to resist infections. Even under good management, however, diseases sometimes cause excessive damage to highly managed turfgrasses. The proper use of fungicides in these instances, in conjunction with good cultural practices that promote quality turf, can be an important part of an overall disease-management program.
Brown patch, also known as Rhizoctonia blight, is a common disease of turfgrass. All cultivated grasses grown in Kentucky can be affected; however, this disease is usually only destructive in tall fescue and perennial ryegrass. Fine fescues (hard fescue, creeping red fescue, chewings fescue, and sheep fescue) are all moderately susceptible to the disease. Occasionally, Kentucky bluegrass lawns can be affected by brown patch, although this grass is less susceptible than others.
Turfgrasses have many benefits, but oftentimes people question if pesticides, fertilizers, and water are justified to sustain a quality turfed area. Although these inputs have long been required to produce thick and dark green turfgrass, some turfgrass breeders have focused on improving the genetics of turfgrasses to produce high quality turf with fewer inputs. Improved turfgrass varieties with increased density, better color, deeper rooting, and improved disease resistance through improved breeding can reduce the overall environmental footprint. Many people select a turfgrass species and variety based on cost, but choosing an improved variety can reduce environment risk and overall maintenance costs in the long-run.
The best grass for your lawn is not necessarily the one you like the best, but the one that is best adapted to where you live and will take less work and fewer inputs (water, fertilizer, pesticides). Many people think that since Kentucky is the "Bluegrass State," it's best to grow Kentucky bluegrass across our state. Actually, Kentucky bluegrass is only marginally adapted to our climate and can require more inputs to keep an appealing lawn than some other choices. In general, Kentucky bluegrass can be an option for parts of central and eastern Kentucky, while zoysiagrass may be a better option in western Kentucky. Tall fescue is adapted to the entire state so is a good choice for most locations. Perennial ryegrasses and fine fescues are occasionally useful in different areas of the state, depending on specific conditions.
Calibrating application equipment is something many people avoid because they believe it is too time consuming or that the math involved is too confusing. Calibration, however, is critical. Applying too little can result in poor pest control and can lead to pesticide resistance. Whereas, over applying can be bad for the environment, damage the grass, and wastes money. There are several methods for calibrating sprayers. Choose the one that makes the most sense to you. Three different methods are described below. All these methods are reliable and will provide very similar application accuracy.
Bermudagrasses have been successfully grown on athletic fields and golf courses in the transition zone for many years. Although each year some level of winterkill threat exists, bermudagrass remains an excellent surface for golf and sports. Seeded varieties of bermudagrasses have been the most common choices in Kentucky due to the availability of seed of good varieties as well as the ease of planting seed versus living plant material. There are, however, several outstanding vegetative bermudagrass cultivars that are adapted to the transition zone.
Turf is the foundation of a quality landscape. It improves the beauty of other ornamentals and provides a safe recreational surface. Quality lawns greatly increase the economic and sociological value of urban homes. They beautify and reduce the often harsh urban environment by decreasing noise, glare, heat, dust, and mud. Lawns and other recreational turf areas are an integral part of our daily activities.
Authors: Nicole Mundell
There are several grasses that will grow in the transition zone, but none all that well. Our summers are often too hot for cool-season grasses like Kentucky bluegrass and our winters are often too cold for warm-season grasses like bermudagrass. Keep in mind, however, that the problem with most poor athletic fields is not grass selection, but rather over use, lack of maintenance, and/or use when field is wet or cannot recover.
Authors: Gregg Munshaw
Bermudagrass is an excellent choice for use on athletic fields throughout the transition zone (which includes Virginia, Kentucky, southern Indiana, and Missouri) because of its tolerance to close cutting heights, summer vigor, positive traction characteristics for athletes, resistance to divoting and ability to withstand and recover from significant traffic during active growth. The major limitation to successful bermudagrass persistence in transition zone locations is a general lack of cold tolerance and susceptibility to winterkill.
Authors: Gregg Munshaw
This newly expanded guide provides weed identification and control information that turfgrass professionals can use to develop effective weed control programs for golf courses, athletic fields, sod farms, lawns, and other turfgrass systems. The recommendations apply to the majority of the United States, with input from experts in Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, New York, Ohio, and Wisconsin. Available for purchase from Purdue University.
Authors: Gregg Munshaw
Roughly 7,500 grass species are grown around the world, but only 14 species are adapted as turfgrasses that have been used extensively. Kentucky is situated in the transitional climatic zone of the United States, the middle point between the cool north and the warm south, with warm summers and cool winters. Because of its unusual climate, no single grass is suitable for all situations and locations. The majority of the turfgrasses that are appropriate for use in Kentucky are known as C3 grasses, or cool-season grasses. Cool-season grasses differ from warm-season grasses (C4) in many ways, but most notably in their photosynthetic pathways. Warm-season grasses can tolerate and even thrive during the warm summers while cool-season grasses may become heat-stressed. Conversely, winters in Kentucky may be too cool for warm-season grasses and greenup in the spring may be long and arduous. Warm-season grasses enter a dormancy period during the fall and winter and may stay in this state as long as six or seven months.
The best method to control weeds is to grow a dense and healthy lawn. This objective should be primary for turf professionals. Lawn weed control is facilitated by identification of the turfgrass and weed species present. Not all herbicides will control all weeds, and not all herbicides are safe on all lawn grasses. This publication contains herbicide recommendations for licensed professionals. For information on weed control for non-professionals, see AGR 208: Weed Control for Kentucky Home Lawns.