The cycle of plants growth

A given species of plants may be thought of as having a definite cycle growth carrying it from seed stage to seed stage. In general, the phrases of this cycle are (1) germination, (2) seedling growth, (3) active or developmental growth, (4) reproduction, (5) maturation, and (6) dormancy. Each part of the cycle presents certain problems pertinent to crop production.

Germination. The ability of a seed to germinate is based upon both genetic and physiologic factors. Proper maturation and the storage of seeds under favourable environmental conditions contribute much to their ability to germinate. If it is assumed that the seed was stored properly, it may be expected to germinate when placed under the proper environmental conditions of heat, water, and aeration. For example, corn is not planted, until the ground is warm, while wheat, oats, barley and flax may be seeded in soil, which is rather cold. Usually in the spring of the year most small grains are planted, must be delayed until the excess water has been drained, or evaporated from the soil. The presence of an excess of water is closely allied to aeration, since a wet soil will not possess enough oxygen for optimum germination. This is one of the most common causes of poor germination of seeds, particularly of corn, during a period of cold, rainy weather. Other unfavourable environmental conditions, such as diseases, may also prevent normal germination.

Seedling growth. The cultivated crops such as corn and the sorghums respond to tillage in this early of growth and it is important that tillage be as deep and close to the plants as possible to provide good aeration for the developing roots. In the small-grain crop, the seedling stage is important because a favourable environment at this time may result in the development of many tillers or stools and increase the number of potential fruiting stems.

Упражнение 9. Ответьте на вопросы.

1. What are the phases of the cycle of plants growth?

2. What are the main factors of maturation?

3. Why is the seedling stage important for the plant growth?

Вариант 3

Упражнение 1. Заполните пропуски соответствующими личными или притяжательными местоимениями.

1. Hello, Ben! How are … ?

2. She likes … very much. She takes … photo with her.

3. … flat is not very large. But they like … flat.

4. The student lives in the big city. But … visits … parents every Saturday.

5. I like this writer. I read … books with pleasure.

Упражнение 2. Задайте пять вопросов к предложению.

There were many vegetables and fruits on that farm.

Упражнение 3. Напишите множественное число следующих существительных.

Region, man, climate, vegetable, speciality, harvest, branch, agriculture, type.

Упражнение 4. Переведите предложения на русский язык, Обращая внимание на степени сравнения прилагательных и наречий и на сравнительные конструкции.

1. Moscow is older than Novosibirsk.

2. The apple is as red as the tomato.

3. This is the most beautiful dress I have ever seen.

4. Summer is the hottest season.

5. This horse is the best of the three.

Упражнение 5. Заполните пропуски словами many, much, a lot of.

1. This lazy boy makes … mistakes.

2. He doesn’t spend … money on his clothes.

3. I love this music very ….

4. There are … children in the garden.

5. They have so … relatives in this village.

Упражнение 6. Переведите на русский язык следующие пары слов.

White-fleshed field carrots, costy to harvest, slow growing, selective weed killer, to deal with annuals, maincrop carrots, stiff day soils.

Упражнение 7. Раскройте скобки, обращая внимание на употребление глагола в Passive Voice.

1. An agricultural exhibition (to held) in Paris next year.

2. These beautiful flowers (to grow) in flower-beds.

3. The book (not to publish) yesterday.

4. Mickey Mouse (to create) by Walt Disney.

5. Charlie Chaplin (to be born) in London.

Упражнение 8. Прочитайте и переведите текст письменно.