Plants are living creatures just like animals. The only difference is that they are non-motile and unable to communicate. As they are made up of living cells, they too fall prey to diseases and pathogens. When a plant is healthy, it will develop normally and function to its optimum potential. However, if the plant is affected by a disease or is facing continuous stress and irritation, its development as well as functioning gets affected.
There are two types of diseases that affect plants, pathogenic and non pathogenic diseases. Pathogenic diseases are caused by infectious agents such as bacteria, viruses, fungi, parasites, nematodes, etc. Non pathogenic diseases are those that are not caused by living agents but by abiotic factors. We shall concentrate more on the non pathogenic diseases in plants in the following paragraphs.
What are Non Pathogenic Diseases?
Non pathogenic diseases are those that are caused by abiotic agents or environmental stress. This includes injury or damage to the plant like mechanical injury, hail damage, damage by insects, mites, deer, rodents, birds, lightning injury, etc. When a plant is damaged by these injuries, its absorption and translocation of nutrients and water from the soil and to other parts of the plants may get affected. This may affect photosynthesis and storage of energy. It may even cause decrease in fruit or flower production as well as formation of seeds. In case of crops and other economically important crops, it may lead to reduction in yield, loss of aesthetic value of the plants or even total loss of entire crop. Let us have a look at abiotic diseases in plants.
List of Non Pathogenic Diseases
There are different environmental as well as mechanical factors that may lead to disease in plants without the presence of a pathogen. The following list of non pathogenic plant diseases will help you recognize these diseases.
Plants are harmed when they are exposed to extremely high temperatures or low temperatures for a long period of time. This may lead to scorching leaves and sunscald fruits due to high temperatures or sunburn. Low temperatures may lead to damage to sensitive plant parts like leaves, buds, fruits, etc. Cold temperatures may also kill the entire plant.
If there is too much moisture content in water or too less water, it may lead to damage to the plant. Too much water in soil due to flooding, too much watering, poor drainage, etc. can lead to yellowing of leaves and stunted plant growth. Excessive moisture in soil may lead to lack of aeration. This causes damage to the root system leading to root rots and damping-off of seedlings. Sometimes, plants may develop 'edema' due to excessive soil moisture and high humidity in air. The plant develops wart-like bumps in edema. Low soil moisture content will lead to wilting and plant death.
If the plant receives low light intensity, it causes a number of problems like etiolation, etc. In etiolation, the plant growth is poor and lanky along with chlorotic foliage.
When the roots are oxygen deprived, it leads to poor growth and even death of the plant. Lack of oxygen may lead to potato tubers forming browning and necrosis of the internal tubers called 'black heart'.
Plants require many major and minor elements for growth. Major elements include phosphorus, calcium, magnesium, nitrogen, etc. while minor elements include iron, boron, copper and zinc. When the plant suffers from deficiencies of either of the minerals, it leads to interruption of essential plant functions, leading to death of the plant. Thus, one has to feed the plant with fertilizers and nutrients to prevent deficiencies.
Any change in soil pH will lead to growth problems, toxicity symptoms and even mineral deficiency. High pH or low pH are unfavorable for plant growth. If the soil pH is not corrected soon, it could lead to plant death.
These were some of the non pathogenic diseases that affect plants. Other abiotic diseases like air pollution, herbicide damage, packaging damage, etc. can also lead to plant growth disruption and death. The diseases can be prevented, if one takes good care of the plants. Hope the above information has broadened your knowingness about non pathogenic diseases so that it will help you keep your plants secure and disease free.