College publications are given 2-part "pub numbers" that are used to identify them. The first part (the prefix) is a set of letters that indicates which series the document belongs to. A series is a grouping of documents that share similar content. The second part of the pub number is just a sequential number.
In descending order, by date published.
Curvularia leaf spot is a corn disease that was reported for the first time in the United States in Louisiana in 2017, and was confirmed in Kentucky in 2018. While the impact of Curvularia leaf spot in Kentucky is not yet known, this disease causes yield loss in tropical areas, and is considered to be one of the most important diseases of corn in China. This publication describes the symptoms and cause of disease, conditions that favor disease development, and foliar diseases that have similar symptoms.
Diplodia leaf streak of corn is a disease that has become more prevalent in Kentucky in recent years. It is commonly observed in fields in western Kentucky and is easily confused with other corn foliar diseases. Small, round, dark brown-to-tan lesions are first observed on leaves. Dark concentric rings may be observed in the center of early lesions at the infection site on the leaf. These lesions expand lengthwise in long streaks from the infection point and form elongated elliptical lesions. In severe cases, lesions can coalesce to blight large areas of affected leaves.
Physoderma brown spot can be a striking foliar disease that is periodically observed in field corn in Kentucky. This publication describes the symptoms and cause of disease, conditions that favor disease development, and options for disease management.
Holcus leaf spot, a bacterial disease, can be seen sporadically in Kentucky cornfields, and it is challenging to diagnose. This publication describes the disease symptoms, conditions that favor disease, and how to distinguish holcus spot from herbicide injury that can mimic this disease.
Diplodia ear rot can reduce yield and grain quality by damaging kernels, lowering grain test weight, and reducing grain fill. Incidence of affected ears in the field can vary from 1% or 2% to as high as 80%. Although mycotoxins have been associated with Diplodia ear rot in South America and South Africa, there have been no reports of livestock feeding issues due to mycotoxins linked to Diplodia ear rot in the United States.
Historically, Stewart's wilt of corn has resulted in losses for corn producers. Although this disease still occurs occasionally, it has become less prevalent in recent years in Kentucky and surrounding states. Stewart's wilt has been known by other names, such as bacterial leaf blight, Stewart's leaf blight, and maize bacteriosis.
10/1/2008 (minor revision)
Authors: Paul Vincelli
Corn seeds and seedlings are susceptible to infection by a number of soilborne fungi. When planted into cool, wet soils, seeds may decay before or after germination. Affected plants that survive past the seedling stage may go on to produce an ear if nodal roots develop normally, although stunting and reduced ear size can occur as a result of seedling diseases. Severely affected plants may die during stressful weather as the result of an inadequate root system.
Although most corn in Kentucky is planted following a rotation to other crops, individual producers are often interested in planting corn following corn. In these situations, one of the main concerns voiced by producers is increased pressure from diseases, and rightfully so. Crop rotation is one of the most fundamental disease control practices available. Rotating to other crops deprives pathogens (disease-causing microorganisms) of a food source and exposes them to "starvation." Furthermore, as infested crop residues decompose, pathogens are exposed to antagonism by native soil microbes. These mechanisms have the effect of naturally reducing the populations of many pathogens in the soil.