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WHAT ARE WEEDS?

NCERT

QUESTION: WHAT ARE WEEDS? HOW TO CONTROL THEM?

SUBJECT: SCIENCE

CLASS:8

WELCOME TO INTELLIFY INTERACTIVE VIDEO SERIES

What are weeds?

How do we control them?

There is a proverb — one rotten apple destroys other apples in the basket, and the same is true for weeds also.

If weeds start growing in your field, and do not get cut in time, it could destroy your healthy crop.

Why does this happen? What property of weed makes it so harmful for other plants?

Weeds are defined in numerous ways by different scientists but the one thing is common in all — it is an unwanted plant that grows itself and destroys other plants. Some few definitions of weeds are mentioned below:

• a plant out of place and not intentionally sown

• a plant growing where it is not wanted

• A plant whose virtues have not yet been discovered.

• plants that are competitive, harmful, and interfere negatively with human activity

What are the characters which make weeds different from other healthy plants?

These characteristics help you to remove weeds in time because weeds grow at a very fast pace.

a) Abundant seed production

b) rapid population establishment

c) seed dormancy

d) adaptation for spread

e) presence of vegetative reproductive structures

f) serve as hosts for crop diseases or provide shelter for insects to

overwinter.

g) Production of chemical substances which are toxic to crop plants

h) Limit the choice of crop rotation sequences and cultural

practices.

There are many species of these destructive plants. Every species is different from one another.

Now, what could a person do to avoid these weeds growing?

Let’s see different methods to protect our crops from these green evils (weeds).

• Mechanical control — In this method farmers simply use their hand or other farm equipment to pull out the weeds.

Over the years there are many improvements in agriculture tools which make this task super easy.

• Biological methods — this method include any living organisms which play the role of enemy for the particular type of weed species. For example grazing animals like goats and cows are used to graze the field so that they can eat weeds but one should be careful during this method because the chance of overgrazing is high.

Geese are used to control weeds in cotton plants.

• Chemical methods — In this method different types of chemicals (herbicides) are used which are harmful for the weed but not for the crop.

These chemicals slow the rate of germination of weeds.

• Cultural methods — this is the traditional method used by farmers for many years.

Farmers in this method try to keep their field in such a condition that the weeds are less likely to grow in the field.

Examples of cultural weed control would be crop rotation, avoiding overgrazing of pastures or range land, using well-adapted competitive forage species, and maintaining good soil fertility.

So next time, whenever you see any weed’s species growing in your field just opt one of the above methods to protect your crops.

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