Lesson Notes By Weeks and Term - Senior Secondary School 2

Term: 2^nd Term

Week: 6

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 2 periods each

Date:       

Subject:    Agriculture

Topic:-      Diseases of crops

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Explain the meaning of crop diseases
2. State the causes of crop diseases
3. Highlight the symptoms, signs, prevention and control measures for each diseases

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION	TEACHER’S ACTIVITY	STUDENT’S ACTIVITY
STEP 1 INTRODUCTION	The teacher reviews the previous lesson on ornamental plants	Students pay attention
STEP 2 EXPLANATION	She explains the meaning of crop diseases She states the causes of crop diseases	Students pay attention and participates
STEP 3 DEMONSTRATION	She highlights the symptoms, signs, prevention and control measures for each disease	Students pay attention and participate
STEP 4 NOTE TAKING	The teacher writes a summarized note on the board	The students copy the note in their books

 

NOTE

PLANT DISEASES

A plant disease may be defined as a departure or deviation of the plant from the normal state of health, presenting marked symptoms or outward visible signs.

 

Causes of Diseases

Diseases are caused by the following agents:

(i)  Viruses 

(ii) Bacteria 

(iii) Fungi 

(iv) Nematode 

(v) Nutrient deficiency

 

SIGNS AND SYMPTOMS OF PLANT DISEASES

1. Fungal disease signs:

A fungal infection is frequently manifested as local or general necrosis. Crop diseases caused by fungi can also interfere with normal growth or contribute to an abnormal burst of growth known as hypertrophy.

Other symptoms of crop diseases include:

• Leaf spots.
• Exfoliation.
• Rot.
• Anthracnose.
• Leaf ulcers.
• Curls of warts and leaves.

 Fungal disease symptoms:

• Leaf rust (common in corn).
• Birds-eye spot on berries (anthracnose).
• Seedlings damping off (Phytophthora).
• Chlorosis (yellowing of leaves).
• Stem rust (wheat stem rust).
• Leaf spot (septoria brown spot).
• Sclerotinia (white mold).
• Powdery mildew.

 

3. Bacterial disease signs (difficult to observe, but can include):

As previously stated, there are numerous disease types due to a large number of bacteria. The most common crop plant diseases are listed below:

• Bacterial ooze.
• Water-soaked lesions.
• Bacterial streaming in water from a cut stem.

 

Bacterial disease symptoms:

• Fruit spot.
• Crown gall.
• Leaf spot with a yellow halo.
• Canker.
• Shepperd’s crook stem ends on woody plants.

 

4. Viral disease signs:
   
   Crop diseases symptoms caused by viruses are typically classified into four types:
   malformations, such as abnormal shoot growth and leaf and flower distortion;
   necrosis, wilting, and the appearance of annular stripes and spots;
   dwarfism, growth retardation of both individual parts and the entire plant; and
   discoloration, such as yellowing and vein clearing.

Root crop diseases, which manifest as rotting, are a telltale sign of the presence of a virus. Some plants, however, may not show symptoms and may be latent carriers of disease. As a result, extreme vigilance is required in the fight against this type of infection.

PREVENTIVE MEASURES/CONTROL OF PLANT DISEASES

1. Planting of resistant or tolerant varieties.
2. Managing optimal planting and harvesting times.
3. Plant quality and healthy material.
4. Disinfestation of equipment.
5. Rotating crops.
6. Plant nutrient management based on crop need

EVALUATION:   1. Explain the meaning of plant disease

2. State the causes of plant disease
3. Outline the symptoms and signs of
4. fungal disease
5. bacterial disease
6. viral disease
7. Highlight some prevention and control measures                              against plant diseases

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively