VI. Look back at the text and choose the correct words to go together.

1. to interact on/with this environment;

2. to compare the clones with/in the special genotype;

3. As described on/above;

4. with/in order from/for evolution;

5. effects up/on plant processes;

6. in/on relation from/to;

7. on/at the hierarchical levels;

8. to act to/on plant phenotype;

9. to occur due on/to natural selection;

10. to think from/of genotype;

11. do not differ among/between the two environments.

VIII. Name each paragraph of the text Plant Ecology .

IX. Name a word or a word combination, which is not a part of the logical group.

1. Plant and its environment, growing season, plant population ecology, plant community ecology, ecosystem ecology.

2. Population dynamics, growth, reproduction, oilseed production, dispersal, and recruitment.

3. Natural selection, plant phenotype, foodstuff, plant genotypes.

4. Phenotypic variation, plants having more leaves, deeper red flowers, faster growth rates, garden ornament, more root differentiation, earlier onset of flowering.



I. Put up four questions of different types (general, special, disjunctive, alternative) to each sentence.


Model: Plant ecology is the study of organisms in relation to their environment.

1) Is plant ecology the study of organisms in relation to their environment?

2) What is plant ecology?

3) Plant ecology is the study of organisms in relation to their environment, isnt it?

4) Is plant ecology the study of organisms in relation to their environment or to each other?


1. Plant ecology can be divided in the following four sections.

2. The first section will describe environmental factors and their effects on plant processes.

3. The second section will focus on biological processes regulating population dynamics

4. The third section on community ecology will study patterns of multiple species coexisting in ecological habitats.

5. The last section on ecosystem ecology provides the information about the cycling of carbon, water, and nutrients in an ecosystem.

II. Put the verbs in brackets into the appropriate form and explain the usage of that form in the sentence.

1.Plants (to have) genes that (to code) for flower color, leaf differentiation, growth rate etc. 2. Phenotypic variation (to be) the variation in some plant trait. 3. Evolution in plants oftentimes (to result) from natural selectiondifferential fitness of individual plants. 4. Natural selection (to act) on plant phenotype. 5. Different plants may (to have) different alleles.

III. Make the sentences of the exercise II negative.



disease pathogens


thread-like appendices

cilia ⳿ () ()




decay , ,

water ducts


sap flow







copper sulphate



blight , ,

, ,

carbon disulphide



I. Read the text and answer the following questions:


1. What is a decisive factor for securing yields?

2. How do pests influence the health of man?

3. What does bacteria consist of?

4. How are so-called bacterioses usually caused by?

5. What are the symptoms of wet rot?

6. Where does the infection of the plants with bacteria primarily take place?

7. Why do the plant pathologists concentrate their efforts on the prevention of disease rather than its cure?

8. How are fungicides often applied?





A decisive factor for securing yields is the protection of agricultural cultures.

Day by day1 cultivated plants and supplies in store rooms2 are threatened by thousands of pests and disease pathogens. Every year millions of tons of produce are lost and plants and animals retarded in growth and development or the products derived from these organisms affected both quantitatively and qualitatively. Control of these pests and disease pathogens must become the greatest command for all scientists, technical engineers and farmers responsible for the production of agricultural products.

What is meant by a pest or disease pathogen? They are animal or plant organisms, which damage either cultivated plants or the products derived there from. They directly or indirectly influence the health of man and domestic and useful animals.

Bacteria as Disease Pathogens. Bacteria, unlike higher organisms, consist of a single cell only. Some of the bacteria possess thread-like appendices, so-called cilia, for purpose of locomotion. These cilia are fixed either at one end of the cell or are arranged over the whole surface of the cell. The size of the cells is microscopic, the pathogen thus being visible with the aid of a microscope only. Bacteria multiply by simple fission.

Bacterial diseases, so-called bacterioses, are usually caused by the penetration of bacteria into injured plant parts.

By excreting certain chemical agents bacteria break up cell unions, loosenthem or kill part of the cells.

This is followed by decay of plant parts, the infected plant tissue turning into a soft pulpy mass. Such disease symptoms are termed "wet rot."3

Some bacteria penetrate deeper into the tissue, reaching the water ducts within the plant and plant vessels and destroy this tissue.

This leads to blocking of the vascular system.

The exhibited disease symptoms, known as "vessel bacteriosis"4 lead to an interruption of the sap flow within the plant, followed by wilting and death. The infection of the plants with bacteria primarily takes place at plant wounds. Insects also act as carriers of bacteria.

Control of plant diseases. Plant diseases establish in such a manner that they are often well developed before they can be detected. By the time the disease is evident it is rarely possible to cure it.

The plant pathologists, therefore, concentrate their efforts on the prevention of disease rather than its cure.5The use of disease-resistant varieties is one of the most effective means of reducing disease in cultivated plants. It is also very important to destroy the sources of infection. Fire is the most effective way in this case.

The elimination of host plants6 plays an important part in the control of some diseases caused by rust fungi.7Efficient drainage of the soil helps in checking diseases which attack the tissues at ground level.

Fungicides now play a very important part in the control of plant diseases.

They are often applied in liquid or powder form. Spray mixtures are used for the control of some diseases especially those that attack orchards. Copper sulphate, lime, sulphur and Bordeaux mixture are used to control some of the rots, blights and mildew diseases. Carbon disulphide and chloropicrin are used for treating soil against nematodes. By planting at particular times some crops can be grown and mature before the disease germs become active.


1. day by day

2. store rooms

3. "wet rot"

4. "vessel bacteriosis"

5.concentrate their efforts on the prevention of disease rather than its cure , , ...

6.the elimination of host plants -

7.rust fungi

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