Alfalfa Downy Mildew
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
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.
Aspen, Important Pests of Ornamental Aspen
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)
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 of Onion
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.
Candidatus Liberbacter of Pepper
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 or Shothole
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.
Curly Top of Tomato
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
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 of Pears and Apples
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.
Fire Blight Annual Management Guide for Utah
The popular Fuji, Gingergold, and Gala are more susceptible to fire blight. In addition,
fire blight spreads more rapidly in high-density orchards.
Intermountain Tree Fruit Production Guide
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 in Onions
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
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
Necrotic Ring Spot and Summer Patch of Turfgrasses
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
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.
Peach Leaf Curl
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
Pink Root Disease of Onions
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 Mold on Small Grains
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 Mold on Turfgrass
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.
Spruce Health in Utah Landscapes
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.
Streptomycin Resistance of Erwinia amylovora, Causal Agent of Fire Blight
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
Take-all Patch in Turf
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.
The Backyard Orchard - Apple Pests
The Backyard Orchard - Apricot Pests
The Backyard Orchard - Cherry Pests
The Backyard Orchard - Peach and Nectarine Pests
The Backyard Orchard - Pear Pests
The Backyard Orchard - Plum Pests
Thousand Cankers Disease of Walnut
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.
Utah Home Orchard Pest Management Guide
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.
Wheat Stripe Rust
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.
Zebra Chip Disease of Potato
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.