bacterial and viral diseases

Question 1

one sign of bacterial disease of cereals?

Answer 1

bacterial blight- bacterial ooze

Question 2

disease that is spread by six spotted leaf hoppers?

Answer 2

aster yellows

Question 3

3 methods of transmission of viral diseases in cereal crops and give one example of the disease for each?

Answer 3

vectors- aphids- yellow dwarf

Rub- inoculation of infected plant- leaves- necrotic mottle

mites- yellow dwarf

Don’t spread spring wheat or barley near infected inter wheat

Question 4

how does phytoplasm differ from bacteria and virus?

give one difference for each comparison.

Answer 4

Difference is that viruses rely on a host and have a protein capsule. Bacteria doesn’t.

phytoplasm doesn’t contain cell wall
bacteria contains a cell wall and cell membrane

Question 5

Disease caused by bacteria and phytoplasmas in barley

Answer 5

aster yellows

bacterial blight

Question 6

Disease caused by viruses in barley

Answer 6

barley stripe mosaic

yellow dwarf

Question 7

Symptoms of aster yellows

Answer 7

blotched on older leaves and later the entire leaf
distorted awn
dwarf bushy plants
**no control measures

Question 8

Symptoms of bacterial blight

Answer 8

pale green leaf sport or streaks which then enlarge to form translucent stripes
affected areas turn yellow and later light brown
bacterial ooze can occur

Question 9

Aster yellow scientific name

Answer 9

macro steles fascifrons

Question 10

bacterial blight scientific name

Answer 10

Xanthomonas translucens

Question 11

barley stripe mosaic

Answer 11

seed borne virus
yellow blotches or streaks on leaves
later turn in to sea brown tissue
plants may be stunted

Question 12

Do viruses or bacteria have scientific name

Answer 12

Viruses dont bacteria does

Question 13

Yellow dwarf in barley is ….

Hosts?

Answer 13

the most important virus for cereal crops in the whole world

barley, wheat, rye, corn, brass families

Question 14

Yellow dwarf in barley symptoms

Answer 14

yellow near tips of leaves then towards base

results in stunted plants, less tillers, sterile seeds

Question 15

Diseases that are caused by bacteria in Corn

Answer 15

holcus

bacterial leaf blight

Question 16

Diseases caused by viruses in corn

Answer 16

maize dwarf mosaic

Question 17

Holcus spot scientific name

Answer 17

pseudomonas syingae

Question 18

holcus symptoms in corn

Answer 18

leaf spot begins as dark green lesions and progressive into round oval shaped brown to white spots
relish brown margins surrounded by yellow halo

Question 19

Bacterial leaf blight scientific name

Answer 19

Erwinia stewartia

Question 20

bacterial leaf blight symptoms in corn

Answer 20

long pale green to tan streaks on leaves that turn brown 
stalk decays 
wilting of plant 
early infection causes stunted plants 
vector is flea beetle

Question 21

Maize dwarf mosaic symptoms

Answer 21

mosaic or mottled dark green spots
develop into yellow veins
later streaks turn red
stunted plant with poor seed set

Question 22

diseases caused by bacteria in oats

Answer 22

aster yellow

bacterial blight / halo blight

Question 23

diseases caused by viruses in oats

Answer 23

necrotic mottle 
yellow dwarf (red leaf)

Question 24

Bacterial blight in oats symptoms

Answer 24

light green oval spots with water soaked centres

heavily infected leaves turn brown and die

Question 25

necrotic mottle in oats symptoms

Answer 25

transmitted by rub
narrow pale green lines
stunted plants and reduced yield
no control measures

Question 26

yellow dwarf red leaf in oats symptoms

Answer 26

second to rust in terms of economic loss
chlorosis
blasting of florets
stunted plants

Question 27

Diseases caused by bacteria in wheat

Answer 27

aster yellow

bacterial blight

Question 28

diseases caused by viruses in wheat

Answer 28

streak mosaic

yellow dwarf

Question 29

aster yellow in wheat symptoms

Answer 29

early symptoms are similar to herbicide injury
losses not significant in wheat
develops with time

Question 30

bacterial blight in wheat symptoms

Answer 30

bacterial ooze

spots that expand and form greyish green or whitish tan spots which enlarge into golden streaks

Question 31

bacterial blight pathogen name in wheat

Answer 31

Psudomonas syingae

Question 32

Streak mosaic in wheat symptoms

Answer 32

vector- mite
light green/ yellow streaks on leaves
stunted plants
levelly shrivelled

Question 33

yellow dwarf in wheat

Answer 33

turns leaves yellow

stunted plants