Plant Diseases and Pathology Flashcards
7 cards from real CPH practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Plant Diseases and Pathology flashcards as text
Phytophthora root rot is most severe in landscapes when:
Answer: Soils are poorly drained with prolonged saturation
Phytophthora species are oomycetes (water molds) that produce motile zoospores requiring free water in saturated or flooded soils to infect plant roots.
Black spot (Diplocarpon rosae) on roses is best managed through a combination of which two strategies?
Answer: Removing infected leaves and applying fungicides preventively
Black spot is managed by removing and disposing of infected leaves to reduce inoculum and applying protectant or systemic fungicides before infection occurs.
Crown gall, which produces tumor-like growths at or near the soil line on woody plants, is caused by:
Answer: Agrobacterium tumefaciens (bacterium)
Crown gall is caused by Agrobacterium tumefaciens, a bacterium that transfers a segment of its Ti plasmid DNA into plant cells, triggering uncontrolled cell proliferation.
Anthracnose diseases of ornamental trees are primarily caused by which group of pathogens?
Answer: Coelomycetous and hyphomycetous fungi
Anthracnose diseases are caused by fungi such as Colletotrichum, Apiognomonia, and Discula species that produce acervuli and infect young leaves and shoots in wet spring weather.
Which of the following best describes a 'systemic' plant disease?
Answer: A disease that spreads throughout the entire plant via vascular tissue
Systemic diseases spread throughout the plant via xylem or phloem, meaning the pathogen or its products move beyond the initial infection site to affect the whole plant.
The term 'necrosis' in plant pathology refers to:
Answer: Localized or widespread death of plant tissue
Necrosis is the death of plant cells or tissues, which appears as brown, tan, or black dead areas on leaves, stems, or roots.
Copper-based fungicides and bactericides are commonly used in horticulture primarily because copper:
Answer: Is toxic to fungal and bacterial cells while having low mammalian toxicity at label rates
Copper ions denature proteins and disrupt enzyme function in fungal and bacterial cells, making copper-based products broad-spectrum protectants with a favorable safety profile at registered use rates.