M.Radha
Written by M.Radha . Posted in Nature on 28 November 2009.
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Different kinds of pests like insects, larva, rats etc. damaged the crops by eating away the roots, stem, leaves and fruits. Micro-organisms like bacteria and fungi cause diseases in plants.

Chemical substances used to destroy pests are called pesticides. It can be in liquid or power from. Dusters and sprayers are used in spraying them. Substances to control and destroy diseases are fungicides and bactericides.

Any disease caused to a plant is identified by its symptoms and proper chemical is selected to control the pest disease causing agent.

Fungal disease

Stem-root: decay and dampening of lower plants of the stems along with a white mould can be observed on the stem. The leaves become red and the entire plant is dried. This disease spreads quickly to the neighboring chilly plants.

Powder mildew: on the lower surface of the leaves, powdery patches appear. Leaves become yellow and fall down.

Fruit rot and die-back:

The fungus attacks at the time of flowering. Flowers become damp and brown. On the stem, long dots with white stripes and black borders are formed. The stem and the fruits also dry up. Black dots appear on the fruits.

Bacterial diseases of chili: leaf spot disease is caused by bacteria. On the leaves brown spots are farmed. They become black and the disease is spread to the fruits and stem. The leaves become yellow and are shade.

Control: Agrimycin and bhitox, mixed in water is sprayed.

Diseases caused by insect pest

Root-grubs: larva of an insect is called the grub. The roots of chili plants are cut and eaten away by the root grubs, which leads to the death on the plant.

Control: before transplantation on the soil spread the Margo oil cake.

Aphids: round and brown colored small insects in groups are found on the lower side of the leaves and young shoots. Aphids suck the sap or juice of the plant. As leaves are reduced in size, they become wrinkled. Reduction in flowering and yield is also observed.

Control: monocrotophos along with water is sprayed.

Pod- borers: the caterpillars which affect the pod are pale and greenish brown in color. They bore holes in the fruit at the stalk and eat away the seed. The fruit develop white coloration on drying or the drop off.

Control: endosulfan mixed in water is sprayed. The eggs can be collected and destroyed.

Plants and animals balance in nature

A balance between the number of plants and animals is also very important. What will happen if there is an increase in the number of animals?

Plants may not be able to supply enough food and oxygen to all the animals.

Or, if there is an increase in the number of plants, the carbon dioxide supplied by animals may not be enough for the plants.

To maintain the balance in nature, we have to protect both plant and animals life. Under wildlife protection programmed, wild animals are given special protection in forest reserves and sanctuaries. Program is like Vanamahotsava promote the planting of trees and make people aware of the harm caused by cutting them down senselessly.

Animals and plants depend on each other for survival. Animals need food to eat and oxygen to breathe. Plants give animals this food and oxygen. Plants need carbon dioxide to make food. Animals breathe out carbon dioxide. This is used by plants. This is why fish, live longer in an aquarium with water pants in it, than in one with out plants.

The food or sugar is made by the leaf, burnt to give energy, used by the plant to grow and stored as starch.

During photosynthesis, green plants trap the sun’s energy to make food. This energy is passed on to humans and animals when they eat food.

So plants and animals depend on each other. A balance between plant animal lives is needed if life on earth has to go on. The flow of energy from the sun to plants and then to animals helps them both to live.

 

 


M.Radha

Author: M.Radha

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