1) Which of the following causes a plant disorder?
3) _________ reproduce by spores.
4) _________ reproduce by simple cell division.
5) _________ is an example of a fungal disease.
6) ________ diseases are commonly spread by aphids or leafhoppers.
7) Wilting is an example of a disease sign.
8) Infection begins when the pathogen ___________.
9) _________ move from plant to plant on in water droplets, rain splash, or being carried by insects.
10) Powdery mildew, root rots, and stem rots are examples of diseases caused by __________.
11) Most problems with dead and dying turfgrass grass are due to diseases.
12) From a distance, areas of turfgrass affected by ____________ appear chlorotic or yellowed; individual spots on the leaves have dark margins with tan centers.
13) __________ is characterized by small white patches, 1 to 3 inches in diameter that may join to form larger dead areas of turfgrass.
14) ___________ appears during hot weather in mid- to late-summer as circular to irregular patches of dead turf 1 to 2 feet in diameter.
15) _________ diseases usually produce pustules on plant leaves.
16) Leaf rust is rarely is an explosive problem because it develops so slowly.
17) _________ is the first step in disease management.
18) Many different plant diseases cause similar symptoms.