Chapter 10 Diagnosis and plant disorders Flashcards
T/f information about a trees history and symptoms gained from a home owner can always be considered accurate
False
If a tree is not well suited for the site in which it has been planted, it may become ________ predisposing it to other problems.
Stressed
A common mistake in diagnosis is to carefully examine the above ground portion of the tree, while ignoring the __________
Roots
T/f if a tree declines or dies within the first year following installation, a likely cause is excess or insufficient water.
True
Leaf scorch, girdling roots and mineral deficiencies are examples of __________ disorders.
Abiotic
Name 5 causes of physical or mechanical injuries to trees.
Lawn mower/ string trimmer Vandalism Construction Rodents Guy wires
Insect damage to trees is usually the result of feeding or _____ ______
Egg laying
Name 5 insect pests of trees with chewing mouthparts. Name 5 with piercing or sucking mouth parts
Chewing Beetles Caterpillar Weevils Leaf miners Borers
Piercing/sucking Aphids Scales Leafhoppers Mealybugs Psyllids
Insects that carry plant pathogens are said to be
Vectors
T/f mites are not actually insects
True
Microscopic worms that sometimes feed on trees and may carry diseases are called
Nematodes
Name the 4 factors required for a tree disease
Susceptible host
Pathogenic organism
Suitable environment
Proper timing
T/f vascular diseases of trees are rarely fatal
False
T/f diseases that affect only the foliage of a tree may not be a serious problem unless defoliation occurs in several consecutive yrs
True
Most fungi cause plant disease
False
The pathogens that cause plant diseases are primarily fungi
True
Fire blight is an example of a disease caused by a _________
Bacterium
__________ is the chemical inhibition of growth and development of one plant by another
Alleopathy
Pollution damage is often difficult to diagnose because the symptoms may mimic other problems such as insect injury and mineral deficiencies
True
Curling and cupping of the foliage and parallel venation are common symptoms of _________ damage
Herbicide
Biotic disorders
Abiotic disorders
Fungi, bacteria, virus, phytoplasmas, parasitic plants, nematodes, insect, mites.
Non infectious and include environmental issues such as temperatures, moisture extremes, mechanical injuries, soil compaction, mineral deficiencies.
Leaf blotch
Dead areas of tissue on the foliage
Necrosis
Death of tissue
Phytotoxicity
Ability to kill plants
Frass
Insect poop
Leaf blotch
Dead areas of tissue on leaves. Larger.
Leaf spot
Spot of dead tissue on leaves. Smaller than blotch
Canker
Localized dead stem tissue. Shrunk and discolored.
