Congratulations, you have made it to the final week of PLPA 200. PODCAST: pppodcastweek14.mp3
This Week's Major Concept is non-living disease agents. Although we have focused on plant diseases caused by pathogenic organisms, many plant diseases are caused by non-living factors. These abiotic diseases are non-infectious, not able to spread from one plant to another, and probably occur more often than do biotic diseases.

This Week's Point of Confusion is the difference between a disease and an injury. PODCAST: pppodcastweek13.mp3
This Week's Major Concept is VIRUSES. Viruses are the smallest pathogens that we study in Plant Pathology 200. These particles are measured in nanometers, or billionths of a meter. Some scientists consider viruses to be the smallest living pathogens, while others do not think of them as alive, but rather as complex macromolecules.

This Week's Point of Confusion is the difference between symptoms and signs of plant disease. PODCAST: pppodcastweek12.mp3
This Week's Major Concept is VECTORS. Any living organism - including insects, animals, fungi, nematodes, and human beings - that is able to transmit a pathogen and disseminate a disease is called a vector.

This Week's Point of Confusion is management strategies for Dutch elm disease and chestnut blight. PODCAST: pppodcastweek11.mp3
Dhuha Maki created this podcast as part of an honors project for PLPA 200.

The major concepts for this podcast are pumpkins and pumpkin infecting viruses. PODCAST: pumpkin viruses.mp3
The Major Concept for this week is the difference between autoecious and heteroecious rust life cycles. Of all the plant pathogenic organisms, the rust fungi have some of the most complex and interesting disease cycles.

This Week's Point of Confusion is the difference between primary and secondary inoculum. PODCAST: pppodcastweek10.mp3
The Major Issue for this week is mycotoxins. Chemicals produced by fungi that are harmful to humans and other animals are called mycotoxins. Mycotoxins can be present in our food without us knowing it because many of them are colorless, odorless and tasteless, yet the presence of these substances can make those who consume them very ill.

This Week's Point of Confusion is the difference between mycotoxins and the fungi that produce them. PODCAST: pppodcastweek9.mp3
The Major Concept for this week is NEMATODES. Nematodes are non-segmented roundworms, most of them so slender that they are typically invisible to the naked eye. Being members of the animal kingdom, nematodes are eukaryotic, multicellular, and heterotrophic.

This Week's Point of Confusion is the difference between the terms genetic diversity and monoculture. PODCAST: pppodcastweek8.mp3
The Major Issue for this week is human use of pesticides. A pesticide is a chemical or mixture of chemicals used to prevent, eliminate or control unwanted animals, plants or microorganisms. Fungicides are one class of pesticides used to manage plant diseases.

This Week's Point of Confusion is the various ways in which fungicides can be categorized. PODCAST: pppodcastweek7.mp3
The Major Issue for this week is exotic vs. endemic pathogens. Many of the plant disease epidemics that we have studied so far have been the result of introducing a new pathogen into an area where it did not exist before. We call these exotic diseases. However, not all plant diseases are the result of a new pathogen or new host being introduced to an area. Endemic plants are infected by endemic pathogens all of the time.

This Week's Point of Confusion is the difference between monocyclic and polycyclic disease cycles. PODCAST: pppodcastweek6.mp3
Joe Raab created this podcast as part of an honors project for PLPA 200.

The major concept for this podcast is DNA mutation. The term DNA mutation carries a very negative stigma in the minds of many people. However, it turns out that DNA mutation is actually the spice of life. PODCAST: pppodcast - mutations.mp3
Bryan Anderson created this podcast for PLPA 200 as part of a James Scholar Project

The Major Concept for this podcast is the CENTRAL DOGMA of genetics. Genetics is the study of how traits are passed down from one generation to the next. The basis of genetics is the macromolecule called deoxyribonucleic acid, or DNA. PODCAST: pppodcast - the central dogma.mp3
The Major Concept for this week is genetically modified organisms or GMOs. A genetically modified organism is any organism whose genetic material has been altered using enzymes and laboratory techniques that are generally known as recombinant DNA technology. Animals, plants, and microbes that are GMOs have been developed and are being used in many applications around the world.

This Week's Point of Confusion is the central dogma. The central dogma of biology describes the processes by which information is both maintained and expressed in a cell. PODCAST: pppodcastweek5.mp3
PLPA 200 student Jackie Rutter created this podcast as part of an honors project for PLPA 200.

The Major Concept for this podcast is binary fission. Binary fission is the process by which bacterial cells reproduce. The process of binary fission has some similarities and some differences with the reproduction processes used by eukaryotic organisms.

The point of confusion for this podcast is the difference between signs and symptoms of plant diseases. PODCAST: pppodcast - binary fission.mp3

The Major Concept for this week is the bacteria. Bacteria are tiny, single-celled organisms, in contrast to fungi, plants and animals, which are all multicellular. A single bacterium is smaller than the spores produced by fungi.

This Week's Point of Confusion is the term inoculum. For any plant disease, inoculum must be present to initiate the first, or primary, disease cycle as well as any subsequent, or secondary, disease cycles. PODCAST: pppodcastweek4.mp3