Fact Sheets - Plant Diseases
Downy mildew is an obligated parasite. Even though they look like fungi they are not. They belong to the Oomycota and are more closely realted to algae than true fungi.
Alfalfa stem nematode, Ditylenchus dipsaci, belongs to a diverse species of nematode often referred to as stem and bulb nematodes. Within this species are a number of races or strains of the nematode.
Aspens are one of the more popular forest trees in the Intermountain West. In an attempt to enjoy these beautiful trees around the home environment, many well-intentioned homeowners purchase or otherwise acquire aspens and transplant them into their landscapes.
Barley yellow dwarf virus (BYDV) is found worldwide. It infects small grains like barley, wheat, oats and rice as well as many wild grass species. There are two strains of the barley yellow dwarf virus: BYDV-MAV and BYDV-PAV.
Botrytis neck rot is a post-harvest storage disease. It is caused by the fungi Botrytis aclada and B. allii. Infections occur in the field mainly through uncured necks but pathogen remains inactive until weeks later.
The non-culturable bacterium Candidatus Liberibacter solanacearum infects peppers. Bacteria are transmitted by potato psyllids, (Bactericera cockerelli). Bacteria are transmitted throughout the lifetime of the insect and can also infect tomatoes and potatoes.
Coryneum blight, also called shothole blight, is a fungal disease of stone fruit trees including peach, nectarine, apricot, cherry, and almond (ornamental as well as nut-bearing); however, the most commonly affected are apricot, peach, and nectarine.
Beet Curly Top Virus (BCTV) is taxonomically a Curtovirus in the Geminiviridae family of plant pathogenic viruses. It is vectored, or carried, by the beet leafhopper (BLH) insect. BCTV causes curly top of tomato, a comon disease in Utah and the western U.S.
Damping-off is caused by several soilborne fungi. The fungi thrive in wet conditions. Some have motile spores that can swim in water from root to root. It can easily be prevented by good sanitation and good cultural practices.
Dothistroma needle blight is a fungal disease that occurs on a variety of coniferous trees. It is also known as "red band disease" in the western United States because of the distinct red banding symptoms that are produced.
Fire blight is a bacterial disease of rosaceous plants. Economically, it is most serious on pears and apples. The bacterium that causes fire blight can be spread by insects, contaminated pruning or grafting tools, infected grafts, and any manner that carries the bacterial pathogen from an infected plant to one that is not.
The popular Fuji, Gingergold, and Gala are more susceptible to fire blight. In addition, fire blight spreads more rapidly in high-density orchards.
Integrated pest management (IPM) involves collecting information about a pest and crop to ensure that you administer the most economical, effective, and environmentally and socially sound pest management decision.
Iris Yellow Spot Virus (IYSV) is a damaging viral pathogen of onions. The disease can devestate an onion field by destroying the photosynthetic area of the leaves of infected plants, thus reducing the ability of the plant to develop bulb size and directly affecting yield and grade of onions at harvest.
Necrotic Ring Spot (NRS) is a fungal disease that primarily affects the roots of turfgrasses. The disease occurs on turfgrasses worldwide. Many turf species can serve as host to the disease.
Necrotic ring spot and summer patch are two fungal diseases with similar above ground symptoms. Both pathogens mainly affect the root system and stolons of Kentucky bluegrass, annual bluegrass and tall fescue.
Onion powdery mildew is caused by Leveillula taurica, a fungal pathogen that has the ability to parasitize a very broad range of plant species. The pathogen can only grow on living host tissues and is thought to carry over from one season to the next on infected plant residue.
The disease is caused by the fungus Taphrina deformans. Disease is most severe during cool wet conditions. Foliage is susceptible until it is fully expanded. Infected leaves are distorted and discolored (yellow, red or sometimes purple).
The disease is caused by the fungus Phoma terrestris. Fungus is commonly found in soil. Infects roots but not basal plate or fleshy scales. Disease can get worse when onions are planted after cereals or in very short rotation with onion.
Snow molds are diseases caused by fungi that attack small grain crops under snow cover or in cool, wet weather. There are three important types of snow mold fungi that can infect small grains in Utah and they can occur together on the same plant.
Snow molds are fungi that attack turfgrass under snow cover or in cool, wet weather. There are two different types of snow mold fungi that can infect grass and they can occur together on a plant.
Spruces tend to prefer abundant moisture and may not do well on droughty sites. Water stress caused by too little soil moisture or too much heat can predispose spruces to insect attack. 80% of spruce trees submitted to the UPPDL are diagnosed with stress due to abiotic conditions such as drought stress and deep planting.
Fire blight is an important disease of apple and pear in Utah. Antibiotic streptomycin frequently used to control fire blight. Resistance to streptomycin first detected in 2006.
Take-all patch is a fungal disease of turfgrasses that primarily affects the roots of certain grass species. It has become a major disease of cool-season turfgrasses and can be found in many parts of the United States
A short summary of the main diseases of apples and how they are managed by the backyard fruit grower.
A short summary of the main diseases of apricots and how they are managed by the backyard fruit grower.
A short summary of the main diseases of cherries and how they are managed by the backyard fruit grower.
A short summary of the main diseases of peaches and nectarines and how they are managed by the backyard fruit grower.
A short summary of the main diseases of pears and how they are managed by the backyard fruit grower.
A short summary of the main diseases of plums and how they are managed by the backyard fruit grower.
Thousand cankers disease is caused by the fungus Geosmithia morbida. It is transmitted by the walnut twig beetle (Pityophthorus juglandis). Once symptoms are visible, trees can die within 2 to 3 years.
Tomato spotted wilt virus (TSWV) most commonly affects tomatoes, peppers and tomatillos. It has also been found in ornamental plants such as blanket fl ower (Gaillardia sp.), and zinnia and weeds. TSWV has become more prevalent in Utah in recent years. This virus is transmitted by western flower thrips (Frankliniella occidentalis), which are very small yellow/brown insects measuring less than 1 millimeter in size. TSWV can also be spread by onion thrips.
Integrated pest management (IPM) is the practice of combining knowledge of the pest and host plant with multiple tactics for long-term, safe pest control. The goal of IPM is pesticide reduction by using cultural, mechanical, and biological controls before the last option, pesticides.
Stripe rust, or yellow rust, is primarily a foliar fungal disease of wheat, although it can infect spike and stem tissues. If the pathogen infect the spike (head) it causes extensive quality and grain yield loss.
The non-culturable bacterium Candidatus Liberibacter solanacearum causes zebra chip disease of potatoes. Bacteria are transmitted by potato psyllids. Bacteria are transmitted throughout the lifetime of the insect and can also infect tomatoes and peppers.