Cereal growth staging scales facts for kids
Cereal plants like wheat, corn, and rice grow through different stages, just like kids do! To help farmers and scientists understand and talk about these stages, they use special measuring systems called cereal growth staging scales. These scales help them know exactly how far along a plant is in its life, which is super important for taking care of the crops.
BBCH-scale: How Cereals Grow
The BBCH-scale is a detailed way to describe how cereals develop. It uses numbers to mark each step, from a tiny seed to a fully grown plant ready for harvest. Think of it like a plant's growth diary!
Here are some of the main growth stages in the BBCH-scale:
| Growth Stage | Code | What's Happening |
|---|---|---|
| 0: Getting Started (Germination) | 00 | The seed is dry. |
| 05 | A tiny root (radicle) pops out of the seed. | |
| 09 | The first shoot (coleoptile) pushes through the soil. | |
| 1: Leafing Out (Leaf Development) | 10 | The first leaf appears. |
| 11 | The first leaf fully opens. | |
| 19 | Nine or more leaves have opened. | |
| 2: Growing Side Shoots (Tillering) | 20 | No side shoots (tillers) yet. |
| 21 | The first side shoot appears. | |
| 29 | The plant has grown its maximum number of side shoots. | |
| 3: Stem Getting Taller (Stem Elongation) | 30 | The stem starts to grow taller. |
| 31 | The first "node" (a joint on the stem) is visible. | |
| 39 | The "flag leaf" (the last leaf to grow) is fully open. | |
| 4: Booting (Before the Head Appears) | 45 | The flag leaf sheath (the part that wraps around the stem) is swollen, meaning the head is growing inside. |
| 49 | The first "awns" (bristle-like parts on the grain head) can be seen. | |
| 5: Head Coming Out (Inflorescence Emergence, Heading) | 51 | The tip of the grain head starts to emerge from its sheath. |
| 55 | Half of the grain head has emerged. | |
| 59 | The entire grain head is out. | |
| 6: Flowering (Anthesis) | 61 | The plant starts to flower, with the first anthers (pollen parts) visible. |
| 69 | Flowering is finished for all parts of the head. | |
| 7: Grain Filling (Development of Fruit) | 71 | The first grains are watery and about half their final size. |
| 75 | The grains are milky inside and have reached their full size, but are still green. | |
| 8: Getting Ripe (Ripening) | 85 | The grains are soft but dry, like soft dough. |
| 89 | The grains are fully ripe and hard. | |
| 9: End of Life (Senescence) | 97 | The plant is dead and falling over. |
| 99 | The crop has been harvested. |
- Note 1: A leaf is "unfolded" when you can see its small, clear flap (ligule) or the tip of the next leaf.
- Note 2: Sometimes, tillering (side shoot growth) or stem elongation (stem getting taller) happens earlier than expected. If this happens, you just move to the next relevant stage number.
Feekes Scale: A Simpler Way to Track Growth
The Feekes scale is another system used to identify how cereal crops like wheat are growing. It was created by a Dutch scientist named Willem Feekes in 1941. This scale is very popular in the United States.
Knowing these growth stages is super helpful for farmers. It helps them decide when to use pesticides (to protect plants from bugs or diseases) and fertilizers (to help plants grow strong). Using these at the right time helps the crop grow its best and avoids harming the plants.
Here are the main stages in the Feekes scale:
| Cereal Growth Stages Using the Feekes Scale | |
|---|---|
| Stage | What's Happening |
| Tillering (Side Shoots Growing) | |
| 1 | The plant has one main shoot. |
| 2 | The first side shoot appears. |
| 3 | Many side shoots have formed. |
| 4 | The stem starts to get taller. |
| 5 | The stem is standing up straight. |
| Stem Extension (Stem Getting Taller) | |
| 6 | The first joint (node) on the stem can be seen. |
| 7 | The second joint is visible, and the next-to-last leaf is just appearing. |
| 8 | The "flag leaf" (the last leaf) is visible but still rolled up. The grain head inside is starting to swell. |
| 9 | The small flap (ligule) of the flag leaf is visible. |
| 10 | The flag leaf sheath is fully grown, and the grain head is swollen but not yet visible. |
| Heading (Grain Head Coming Out) | |
| 10.1 | The first tiny part of the grain head is visible. |
| 10.3 | Half of the grain head has emerged. |
| 10.5 | All grain heads are out of their protective sheaths. |
| Flowering | |
| 10.51 | The plant starts to flower. |
| 10.54 | Flowering is finished, and the kernels (grains) are watery inside. |
| Ripening | |
| 11.1 | The kernels are milky inside. |
| 11.2 | The kernels are soft but dry, like soft dough. |
| 11.3 | The kernels are hard, difficult to break with a thumbnail. |
| 11.4 | The crop is fully ripe and ready for harvest. The plant's straw is dead. |
Zadoks Scale: Important for Farmers
The Zadoks scale is another important system for tracking cereal development. It was created by a Dutch plant scientist named Jan Zadoks. This scale is widely used in farming and research.
Knowing the exact stage of a crop's growth is super important for farmers to make smart decisions. For example:
- Farmers might apply nitrogen (a type of fertilizer) or herbicides (to kill weeds) during the tillering stage.
- Special growth regulators for wheat are often used around stage Z30.
- Controlling plant diseases is most important when the stem is getting taller and the grain head is emerging (stages Z31, Z32, Z35), especially when the flag leaf appears (Z37).
- Crops can be more sensitive to hot or cold weather at certain stages. For instance, during a stage called "meiosis" (when cells are dividing), the crop is very sensitive to low temperatures.
Knowing the growth stage helps farmers decide what to do if they see problems with their crops.
Here are some examples of typical stages in the Zadoks scale:
- During tillering (side shoots growing):
- Z10: The plant has one leaf.
- Z21: Side shoots (tillers) start to grow.
- During stem extension (stem getting taller):
- Z30: The grain head inside the stem is about one centimeter long (in wheat).
- Z31: The first joint (node) on the stem is visible.
- Z37: The flag leaf (the last leaf) is fully out.
- During heading (grain head coming out):
- Z55: Half of the grain head has emerged.
- During ripening:
- Z92: The grains are fully ripe and hard.
These scales, like BBCH, Feekes, and Zadoks, help everyone involved in growing cereals speak the same language about plant growth. This makes it easier to share information and grow healthy, strong crops!
