HOW DISEASES DEVELOP AND THEIR TRANSMISSION

Stages of Diseases Development and Transmission

There are four major stages of disease development and transmission in crops.
These are:
1. Invasion: This is the stage where ‘the disease causing agent comes in contact with the host plant.
2. Establishment
At this stage the disease causing agent enters and establishes llfe in the crop tissues.
3. Injury
This is the stage where the disease pathogen multiplies itself leading to the actual attack of the host.

MCQ on Virus - Examsegg Biology
MCQ on Virus - Examsegg Biology

4. Mission/Spread
This is the stage where the disease organism spreads from one plant to a healthy one. The process is aided by wind, water, insects contact and others.

7.5 Prevention and Control of Crop Diseases
It is better and more economical to prevent a disease from, crops than to control it when it has occurred. The sure way luting diseases, in farms is to prevent the disease causing organism from reaching the crops.

This is possible through regular removal of rotten materials from the farm, routine spraying of crops planting resistant varieties and so on.

However, crop diseases can be controlled in the following ways:

1. Cultural Control
The techniques adopted in this control measure include:
(i) Proper care for plants such as regular weeding. This practice reduces the amount of disease attack on the crops.
(ii) Burning of farmland: This involves setting farmland on fire before cultivation. The fire helps to kill disease causing agent such as bacteria, fungi, virus and other organisms in the soil.
(iii) Karly Planting: Early planting enables the crops to escape the outbreak of some crop diseases.
(iv) Practicing Crop Rotation: This practice, ensures that crop which suffer from similar diseases do not follow each other in the same rotation. This is to make sure that the cycle of the disease development is disturbed.
(v) Removal of dead plants and other disease harbouring agents from the farm. The source of the disease is removed when this is done.

2. Biological Control
This involves the use of good ar.cl resistant crops varieties to plant. It is a very successful method of controlling most serious plant diseases. Over the years, scientists have developed crop types which have great resistance to some deadly crop diseases. The use of which helps to control most diseases of crops.

3. Chemical Control
This involves the use of chemicals to kill the disease organism affecting the crops. For example: (i) Fungicides such as perenox. Bordeaux mixture, and copper sulphate are used in the
control of fungus diseases.

(ii) Virus diseases can be controlled by using appropriate chemicals such as vetox 85 to kill the vectors e.g. aphids. mealy-bugs white flies, etc. that transmit the virus diseases.

(iii) Most bacterial diseases can now be treated using appropriatle chemicals (bacteriacides) such as Agrosan 5W mercurial duss and acid.
(iv) Nematodes can be controlled by using nematicides such a nemagoiu and DDT.

don’t forget to use the comment box and leave a message or suggestion and we will get back to you within seconds.

You can read some of most interesting topics below

PROTOZOAN DISEASES
155. TRYPONOSOMIASIS

159. TAPE WORM
160. ROUND WORM OF PIGS
161. LIVER FLUKE
162. ECTO PARASITES
163. TICK
check out these recent posts

  1. loans for businesses
  2. how to establish enterprises
  3. what is a firm
  4. price equilibrium
  5. scale of preference
  6. concept of economics
  7. economic tools for nation building
  8. budgeting
  9. factors affecting the expansion of industries
  10. mineral resources and the mining industries

Please feel free to share while using our comment box below.
Thanks for sharing

let us know what you think

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: