CBSE Class 5 Science Growing Plants and Agriculture Notes Set 01

New plants without seeds

Many plants can grow from parts other than seeds, such as roots, stems, leaves and spores. This is called vegetative reproduction. It is useful because the new plant is quick to grow and is a copy of the parent.

From roots

Plants such as carrot, beetroot and dahlia have roots that can grow into new plants. If we cut off the top of a carrot and keep it in a shallow dish with water, with the cut side down, a new shoot grows from it after a few days.

From stems

1. Underground stems: potato, ginger, onion and sugarcane have underground stems with buds. In potato these buds are called eyes, and a piece of potato with an eye can grow into a new plant. 2. Runners: doob grass has thin stems that spread along the ground, called runners. They form roots at regular points, and each point grows into a new plant.

From leaves

The edges of the leaves of bryophyllum and begonia have buds. When the leaf falls on moist soil, small plants grow from these buds.

From spores

Ferns and mosses make tiny powdery spores. Spores can stay alive for a long time even in poor conditions, and they grow into new plants when conditions are suitable.

Artificial methods of growing plants

1. Stem cutting: a slanting cut piece of stem is planted in soil, as in rose, bougainvillea and money plant. 2. Grafting: a piece of the shoot (the scion) from one plant is joined to the rooted stem (the stock) of another plant. It is used for rose, mango and apple. 3. Layering: a young branch of jasmine or raspberry is bent and pressed into moist soil. Roots form on the buried part, and then the branch is cut from the parent.

Agriculture

A crop is a plant grown in large numbers on a piece of land in a particular season. Growing crops on a large scale in fields is called agriculture. The steps are: 1. Ploughing: loosening the soil with bullocks or tractors. 2. Adding manure and fertilizers: to make the soil more fertile. 3. Sowing: planting good-quality seeds at proper distances by hand or with seed drills. 4. Irrigation: supplying water to the crop, by methods such as sprinklers. 5. Crop protection: using weedicides to remove weeds and pesticides to remove pests. 6. Harvesting: cutting and collecting the ripe crop. 7. Storage: keeping the grain safe from damage.

Kharif and rabi crops

Kharif crops are sown at the beginning of the rainy season in June, are harvested in September or October, and need plenty of water. Examples are cotton, maize, paddy and sunflower. Rabi crops are sown in November in the winter season, are harvested in March or April, and need little water. Examples are wheat, mustard, gram, beans and cauliflower.

Worked examples

Example 1. How can we grow a new potato plant? Answer: Cut a piece of potato that has an eye (bud) and plant it in soil.

Example 2. Name the plant that grows from buds on its leaves. Answer: Bryophyllum.

Example 3. Is wheat a kharif or a rabi crop? Answer: Rabi, because it is sown in winter and needs little water.

Quick Check Questions