By :Aida Wulan Elmaghriba ( 02 )

Kartika Ningtyas ( 15 )Sita Puspitaningtyas ( 23 )

DISEASE IN PLANT ORGAN

What is Disease?

Disease is something that causes disturbance in plant so plant cannot make reproduction or dies slowly.

Characteristic of disease are as follows :1.The cause of disease is hardly seen by

naked eye2.The cause of disease are microorganism

( virus, bacteria, fungi, or mushroom ) and lack of certain substance in the soil

3.Disease attack commonly is in indirect so the plant dies slowly

Phytopathology

• Plant pathology (also phytopathology) is the scientific study of plant diseases caused by phatogens (infectious diseases) and environmental conditions (physiological factors).

• Disease in plant commonly cause by Microorganism that form of virus, bacteria, and fungi.

• Plant disease causes damage or abnormality in absorbing and transporting food, mineral, water, food synthesize, or other metabolic process disturbance that influence the appearance ( quality ) and the yield of crops ( quantity ).

• Agent that causes disease in plant can be in the form of biotic agent and abiotic agent.

BIOTIC AGEN

The biotic agent ( biology ) is pathogenic organism , especially bacteria, fungi, virus, parasitic plant, and nematode worm. Pathogenic organism causes disease by :

1.Absorbing food or cell content continuously that makes the host weak. Ex : bacteria, parasitic plant, nematode, virus.

2.Killing cell or causing damage on metabolic activity of host cell by secreting substance, such as enzyme or toxin into the host cell. Ex : Phytophthora infestans fungus, Ustilago maydis ( That cause corn seed smut.

3.Disturbing transportation of food, mineral, and water on host vascular tissue. Ex: Fusarium axysporum ( cause wither on tomato’ s leaf )

4.Preventing photosynthesis process.

abiotic agent

The followings are several factors considered as abiotic agent :

1.Extreme temperature, such as very hot and very cold; 2.Too much or too little water;3.Low or high light intensity;4.Insufficient oxygen;5.Air pollution;6.Insufficient amount of nutrients;7.Too acid or to alkaline soil and ;8.Poisonous chemical drugs, such as insecticide,

fungicide, nematicide, molusicide, and another perticide.

1. Virus

Viruses are very small organisms whose composition is very simple because it only contains the acid nuclei in the form of RNA and only a few DNA. Properties virus is different from other organisms can be crystallized without the loss of infection.

2. Bacteria

A bacterial single-celled prokaryotic microorganisms. There are about 200 species of bacteria that can cause plant diseases. This especially type of rod-shaped bacterium include Agrobacterium, Corynebacterium, Erwinia, Pseudomonas, and Xanthomonas Steptomyces.

3. fungi

Fungi reproduce by spores that spread expenditure through the medium of air, water, and soil. Fungus likes damp areas and can live to stay another organism. Most of fungi is the enemy of the plant because of the many plants that died due to fungi attack.

1. BLIGHT DISEASE OF POTATO LEAF

The first symptoms are the presence of pock on the edges and tip of the leaf, the pock widens and form a brown necrotic areas. pocks surrounded by white sporangium. The development of leaf pock disease is most rapidly occurring at a temperature of 18 ˚ C - 20˚ C. On the air temperature 30˚ C the development of spots hampered.

This disease is caused by Phytophthora infestans fungus.

The control to the disease is by :1. Cultivating potato that endures to disease2. Using healthy potato pest 3. Making spraying by using fungicide

pICTURE

BLIGHT DISEASE OF POTATO LEAF

Phytophthora infestans

2. CABBAGE WET ROTTEN DISEASE

Shows symptoms those are on its leaf found wet pock of irregular shape. The pock widens and folding, it has blackish brown colour. Secondary bacteria infection causes plant releases specific rotten smell.

This disease caused by Erwinia carotovora pv. Carotovora bacteria.

To control this disease by :1. Keeping cleanliness of garden from remain of sick plant

2. Keeping humidity of not too high by cultivation cabbage plant with cultivating distance not too dense

3. Always Wash the product by water that contains chlorine or borax of 7.5%

4. Stored in warehouse that has enough of ventilation

picture

CABBAGE WET ROTTEN DISEASE

Erwinia carotovora

3. DISEASE IN CABBAGE POUNDER ROOT

Shows symptoms those are its root gets fission reaction and cell enlargement. Then formed lump or irregular gland, the lump unite to be enlengthen swollen like pounder. The leaf becomes grey green and faster withered because its transporter tissue is broken.

This disease caused by Plasmodiophora brassicae fungus.

To control this disease by :1.Preventing the entering of fungus of disease to the lands that free from fungi infect

2.Seeding in land of pathogenic free3.Liming

picture

CABBAGE POUNDER ROOTPlasmodiophora brassicae

4. CHILI WITHERED DISEASE

Show symptoms those are young leaf is withered followed by yellowing of old leaves. If the tip of stem is cut and pressed, from surrounding of vascular bundles will quit mucilage of grayish colorThis disease caused by Pseudomonas solonacearum

bacteria. To control this disease by :

1.Decreasing bacteria population in soil by covering soil with transparent plastic for one month2.Making plant rotation3.Regulating irrigation 4.Chemically by using bactericide also soil

sterilization

PICTURE

.CHILI WITHEREDPseudomonas solonacearum

5. VIOLET SPOTS DISEASE IN GARLIC

Shows symptoms those are in its leaf appears small spots, folding of white colored until grey. If its size enlarges, spots are seen “ringed” and its color rather purplish and surrounded by yellow color.

This disease caused by Altenaria porri fungus. To control the disease is done by :

1.Cultivating garlic in land that has good water conduct

2.Making plant rotation 3.Making fungicide spraying

picture

VIOLET SPOTS DISEASE IN GARLIC

Altenaria porri

6. LEAF ROTTEN DISEASE OF ONION

Shows symptoms those are near its leaf appears pale green spots. If condition of surrounding is humid, on the leaf develops violet white colored fungus and leaf becomes turn yellow, withered, and dried. This disease caused by Peronospora destructor

fungus. To control by :

1.Using healthy seed or free from disease2.Burning leaf of harvest remain3.Spraying fungicide

picture

LEAF ROTTEN DISEASE OF ONION

Peronospora destructor

7. LEAF SPOTS DISEASE IN ASPARAGUS BRANCH

Shows symptoms those are there are found enlengthen spot of brown until grey colored with wide edge of reddish brown in its leaf and branch.

This disease caused by : Cercospora asparagi fungus.

To control this disease by spraying contact fungicide.

picture

LEAF SPOTS DISEASE IN ASPARAGUS BRANCH

Cercospora asparagi

8. Soft rot disease

Soft rot is a rotting that disease happen at the neck newly grown plant roots ( during germination ).This disease is caused by an infection of

the fungi Phythium sp. or Rhizoctonia solani. The neck of the root will become smaller so the root can no longer support the stem. As a result, the new plant will collapse.

PICTURE

Soft root diseasePhythium sp

9. POWDERY MILDEW DISEASE

This disease attacks a growing seed, so the seed becomes spongy and finally dies. The cause is the fungi Peronospora parasitica. This fungus sometimes also attacks seeds that already have their first leaves. The plant becomes short with black spots on the leaves, which lead to decreased production.

PICTURE

Peronospora parasitica. POWDERY MILDEW DISEASE

Peronospora parasitica

10. CVPD DISEASE

The Citrus Vein Phloem Degeneration ( CVPD ) disease is a disease that attacks the phloem of an orange’s stem. The symptoms are that the leaf buds become small, and turn yellow so they become yellow colored fruit. This disease is caused by bacteria.

CVPD Disease

This disease attacks the internodes of the stem and grains. It is caused by the fungus Pyricularia oryzae. Thus, the internodes of the stem are easily broken and crops finally die.

Tobacco Mosaic Virus ( TMV ) virus causes white spots on tobacco’ leaves which lead to decrease in the quality of the leaves

12. Tobacco mosaic disease

11. Disease in rice plants

pICTURE

Tobacco mosaic diseaseTobacco Mosaic Virus

pICTURE

Pyricularia oryzae Disease in rice plants

No. The name of disease

The name of microorganism

the parts that is attacked

The effort

1. BLIGHT DISEASE OF POTATO LEAF

Phytophthora infestans

The leaf 1. Cultivating potato that endures to disease

2. Using healthy potato pest

3. Making spraying by using fungicide

2. CABBAGE WET ROTTEN DISEASE

Erwinia carotovora pv. Carotovora bacteria.

The root 1. Keeping cleanliness of garden from remain of sick plant

2. Keeping humidity of not too high by cultivation cabbage plant with cultivating distance not too dense

3. Always Wash the product by water that contains chlorine or borax of 7.5%

4. Stored in warehouse that has enough of ventilation

3. DISEASE IN CABBAGE POUNDER ROOT

Plasmodiophora brassicae

The root 1. Preventing the entering of fungus of disease to the lands that free from fungi infect

2. Seeding in land of pathogenic free

3. Liming

4. CHILI WITHERED DISEASE

Pseudomonas solonacearum

The leaf 1. Decreasing bacteria population in soil by covering soil with transparent plastic for one month

2. Making plant rotation3. Regulating irrigation 4. Chemically by using

bactericide also soil sterilization

5. VIOLET SPOTS DISEASE IN GARLIC

Altenaria porri The leaf 1. Cultivating garlic in land that has good water conduct

2. Making plant rotation 3. Making fungicide spraying

6. LEAF ROTTEN DISEASE OF ONION

Peronospora destructor

The leaf 1. Using healthy seed or free from disease

2. Burning leaf of harvest remain

3. Spraying fungicide

7. LEAF SPOTS DISEASE IN ASPARAGUS BRANCH

Cercospora asparagi The branches spraying contact fungicide.

8. Soft rot disease Phythium sp. or Rhizoctonia solani.

The root

9. POWDERY MILDEW DISEASE

Peronospora parasitica.

Growing seed

10. CVPD DISEASE bacteria phloem

11. Disease in rice plants Pyricularia oryzae the stem and grains

12. Tobacco mosaic disease virus The leaf

QUESTION

1. A plant disease that attacks leaves is ……

a. Powdery mildew diseaseb. Soft rot diseasec. Tobacco mosaic diseased. CVPD disease

2. Blight disease of potato leaf is caused by fungi ……

a. Phytophthora infestansb. Peronospora parasiticac. Rhizoctonia solanid. Pyriculuria oryzae

3. Shows symptoms of disease in cabbage pounder root is ……

a. The young leaf is withered followed by yellowing of old leaves

b. Near its leaf appears pale green spotsc. Root gets fision reaction and cell enlargementd. In its leaf appears small spots

4. To control disease leaf spots disease in asparagus branch by ……

a. Making plant rotationb. Burning leaf of harvest remainc. Chemically by using bactericide also soil

sterilizationd. Spraying contact fungicide

5. Soft root is …..

a. Seed becomes spongy and finally diesb. A rotting that disease happens at the neck

newly grown plant roots (during germination)c. Citrus vein phloem degenerationd. Tobacco mosaic virus

1.

What are the characteristics of disease?

2.

Write down the organism that often causes plant infected by disease!

3.

Write down the symptom of plant that infected by disease

1. Blight disease of potato leaf2. Chili withered disease3. Violet spots disease in garlic

4.

Write down the effort that can be done to destroy disease in the violet spots disease in garlic!

5.

Write down the causes of the following disease!

1. Cabbage wet rotten disease2. Leaf rotten disease of onion3. Leaf spots disease in asparagus branch