Weeds - Types and Symptoms of weeds - Class 9 Science

Types and Symptoms of Weeds 

Weeds are undesirable plants that grow alongside crops. These weeds provide nutrients to the crops while also reducing the number of nutrients available to the crops, hindering their growth. To promote plant growth, the growth of these weeds must be restricted.

What are the most common weed types?

Weeds are divided into two types: annual and perennial. Annual weeds are only spread by seeds. They normally have a brief growing season and produce a lot of seeds. Annual grasses (Pova anva), green foxtail (Cetaria viridis), and chickweed are the most common species (Stellaria media).

Perennial weeds are both prolific and spread vegetatively. Rhizomes, tubers, and stems are all used to disseminate them. As a result, avoiding this category is particularly tough. Even chemical control is frequently ineffective. Quackgrass (Elimus rippens), Johnson grass (Sorgam halfpens), dubery (Rubus cicius), and dandelion are all common perennial weeds (Taraxacum officinalis).

 Symptoms of weeds

Weeds can survive thanks to some traits that connect them. One or more of the following can be found in weeds:

seed dysfunction; long-term survival of buried seeds; adaptation to expansion; the presence of vegetative reproductive structures; abundant seed production;

 Rapid Population Institution; seed dysfunction; long-term survival of buried seeds; adaptation to expansion; the presence of vegetative reproductive structures; 

Also, the ability to capture areas that have been altered by human activity.

There are 250,000 species of plants on the planet; about 3%, or 8000, are weeds.

Weeds are aggravating in a variety of ways. It reduces crop yields by competing for water, light, soil nutrients, and space, among other things. Other weed-related challenges in agriculture include:

Interaction with the crop; lower the quality of the crop by contaminating it;

Serve as hosts for crop illnesses or give winter habitat for insects;

Limit crop rotation and cultural selection practises, as well as the production of hazardous compounds for agricultural plants, animals, or humans (Allelopathy).

Click to read the Benefits of weeds

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