Plant Disease

 1. Plant Disease

Plants can be infected by disease that are caused by microorganisms (viruses, fungi, and bacteria). Some examples of disease of plants are as follows :

a) Soft rot disease

Soft rot is a rotting that disease happens 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.

Symptoms of attack:

1. In general strike in the nursery, the seedlings notched base attack symptoms such as pinch, foul, brown, and finally collapsed seedlings.

2. Disease usually affects areas with a temperature of 240C, relative humidity above 85% of poor drainage and high rainfall the soil pH from 5.2 to 8.5.

control:

1. This disease can be overcome by setting the spacing of seedlings.

2. Disinfection of the soil before sowing the seed or seedling spraying.

3. Immersion of seeds before planting with a fungicide netalaksil 3 g / liter of water Mankozep (2-3 g / liter of water), Benomil 2-3 g / liter of water and Propanokrab

b) 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, which lead to desreased production.

c) CVPD disease

The citrus vein phloem degeration (CVPD) disease is a disease that attacks 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.

d) Disease in rice plants

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.

e) Tobacco mosaic disease

TMV (tobacco mosaic virus) virus caused white spots on tobacco’ leaves which lead to decrease in the quality of the leaves.

2. Plant Pets

Organs in plants can also be damage because of pets. Pets that attacks the organs of plants sre generally animals. The pets can be :

a) Mammals, such as mice, monkeys, and elephants

b) Insects, such as walang sangit, rice pets, grasshoppers, beetles, and aphids

c) Birds, such as sparrows, weaverbirds and finches.

A. Mammals

a) Mouse 

Rats invade a variety of plants. Disarang plant parts are not just seeds - grains but also the young plant stem. Which makes the strong eat the seeds rats - grain to the detriment of the farmers are a powerful incisors and sharp, so the mouse is easy to take seeds - grains. Rats make a hole - a hole in the rice field and often took refuge in the bush - bush. If the state of paddy fields were damaged then it means that the attacked mouse.

Symptoms of attack:

     Rats invade a variety of plants.

     Attack in the nursery, the vegetative, generative period, harvest, storage area.

     Disarang plant parts are not just seeds - grains but also the young plant stem.

     Rats make a hole - a hole in the rice field and often took refuge in the bush - bush.

b) Monkey

monkey, attacking crops of fruits and vegetables.

B. Insecta

a) Walang sangit 

Walang sangit (Leptocoria oratorius) attack young and soft grains. As a result, the grains becomes empty or incomplete.

b) Stemborers

A stemborer is the larva phase from the metamorphosis of Scirpophaga innotata butterfly. This caterpillar drills and destroys the grain’s stem and then attacks growth point of grain during sowing. A caterpillar can move from one stem to another. It attacks the tip of the grain and causes a new leaf to not be formed. The tip of leaf then turns yellow and finally dies.

Symptoms of attack:

1.Snorer leaves or white pests (Nymphola depunctalis) attack the leaves   of rice since dipesemaian to field.

2.cut rice leaf that has turned white, living skeleton leaves.

3. Larvae are semi-aquatic, utilizing water as a source of oxygen.

4. The larvae make rolls / bag of rice leaf and then dropped into the water. Larva green, to be pupal development 14-20 days. Stadia pupa 4-7 days.

c) Planthopper 

Planthopper is a kind of beetle that causes the leaves and stems of plants hole - a hole, then dried, and eventually die.

These tiny insects suck plant fluids and also to spread some viruses (especially reovirus) that cause tungro disease). Javelin beetle eat leafhoppers and their children while acting as a predator wasp eggs. These natural predators to control planthopper populations under

d) Aphids

Aphids are usually located in a lower leaf to suck the leaves. The pest is abundant in the dry season. In the leaf lice will arise spots - small spots and then the leaves will turn yellow and fall. These pests can be overcome by collecting leaves - leaves that are attacked by pests in some places and burnt.

Symptoms of attack:

1. Mites (tiny bugs) bisaanya located on a lower leaf to suck the leaves.

2. In the leaf lice will arise spots - small spots and then the leaves will turn yellow and fall.

e) Grasshopper

Grasshopper (Aularches miliaris) cause damage to major crops, such as various types of banana, coconut, areca nut, and orange.