Cereal Crops

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Slide 1

Cereal Crops

Rice, Maize and Sorghum

Slide 2

Cereals- the worlds staple foods

Cereals are all members of the grass family

Examples include rice, wheat, maize and sorghum

They are grown for their seeds (grains) which are high in carbohydrates and protein

The water content of the grains is low compared to other vegetables

Slide 3

Other benefits of cereals

Easy to store because the low water content helps prevent mould growth

Easy to transport because there is not a lot of wet bulk

There is a suitable cereal for each type of climate

Slide 4

Rice

Slide 5

Rice

Grown in areas of high temperature and high humidity

Small plants are planted out in flooded fields

Rice can grow in normal soil

Flooded fields reduce competition from weeds

Nitrogen fixing bacteria live on flooded rice roots providing nitrate. This reduces need for fertiliser

Slide 6

Adaptions of rice to waterlogging

Roots contain air spaces to conduct oxygen from the air down into the roots. This tissue is called aerenchyma

Root cells are tolerant of ethanol which is the waste product from anaerobic respiration by root cells when oxygen is lacking

Slide 7

Sorghum

This is a cereal which is adapted to grow in arid (dry) regions and tolerate high temperatures and light intensities

Uses a quarter of the water needed by rice

Has a lower grain yield than cereals grown in areas where water is abundant but is often the only crop that will grow

Slide 8

Adaptions of sorghum to drought

Extensive root system

Thick cuticle (waxy layer covering leaves) reduces evaporation of water from leaves

Sunken stomata reduce water loss by evaporation

Stomata close during drought and reopen very quickly afterwards

Slide 9

Adaptions of Sorghum to heat

Sorghum plants can synthesis heat shock proteins rapidly when temperatures rise

These heat shock proteins prevent enzymes being denatured and make them more thermostable

Slide 10

Adaptions of sorghum to high light intensity