Gardeners, farmers and nursery plant owners often want to know about the various types of plant diseases. Plant diseases can be grouped into two categories - parasitic and non-parasitic diseases. The non pathogenic diseases in plants can occur due to changes in the soil pH, humidity, moisture in soil, etc. However, parasitic diseases are caused by contagious pathogens. These pathogens easily pass on from plant to plant, through air, soil, water, use of tools, insects, etc. In this Gardenerdy article, we shall have a look at a list of common plant diseases that are encountered in gardens and farms.
List of Common Plant Pathogens
Before going through the list of plant diseases, let us have a look at the pathogens causing them. These biological agents that affect plants are as follows: Fungi (that include saprophytic fungi and parasitic fungi) Bacteria Viruses Nematodes Mycoplasmas
List of Common Plant Diseases
As you have seen, there are 5 biological agents that cause plant diseases. The following list contains names of plant diseases that commonly trouble gardeners as well as farmers alike.
List of Plant Diseases Caused by Fungi
Fungi are known to cause extensive damage to the plants, especially the crops. Fungal parasites can either be saprophytic, that is feeding on dead or decaying organic matter or parasitic fungi that live on or within a host plant as an obligate or non-obligate parasite. They cause the following diseases:
Name of Disease
Plants Affected
Cankers
Woody plants
Damping off
All types of plants
Downy mildew
Grains, alfalfa, onions, cucumbers
Ergot
Rye, barley, wheat and other grasses
Powdery mildew
Grains, legumes
Root rots
All types of plants
Rusts
Wheat, oats, barley, rye
Scab
Wheat, rye, barley, potatoes
Seed decay
All types of plants
Smuts
Oats, barley, grasses, corn, wheat
Soft rots, dry rots
Potatoes, onions, carrots, fleshy organs, etc.
Wilts
Potatoes, alfalfa, trees
List of Plant Diseases Caused by Bacteria
Bacterial infection is very destructive to plants. There are over 50 species of bacteria that cause plant diseases. These bacteria enter the plant cells by pruning, cracks, stomata opening, cuts and wounds. Some of the bacterial diseases in plants are as follows:
Name of Disease
Plants Affected
Bacterial wilts
Corn, alfalfa, tomatoes, tobacco, potatoes
Blights
Fruit trees, vegetable crops
Cankers
Woody plants
Bacterial speck
Fruits and leaves of different plants
Crown gall
Many crops, trees
Leaf spot
Beans, peas, trees, cotton
Pith necrosis
Greenhouse tomatoes
Soft rots
Fleshy or succulent plant parts
List of Plant Diseases Caused by Viruses
Viruses can spread to plants when they invade the cellulose barriers of the cells. They spread with the help of infected seeds, grafting, pollination, dripping sap, etc. Once a plant is infected by a virus, it will surely die.
Name of Disease
Plants Affected
Mosaic leaf
Tobacco, corn, small grains, forage, legumes, tomatoes, potatoes, peas, sugar beets, cucumber, beans, maize, cauliflower, sugarcane
Curly top
Beans, sugar beets, tomato
Yellowing of leaf
Barley, potato, sugar beet
Bud Blight
Soy beans
List of Plant Diseases Caused by Nematodes
Nematodes are tiny animals that are adapted to all types of ecosystems. They are found in fresh waters, polar regions, tropics, marine environment, etc. They may be helpful or destructive to a plant depending on the species. The predatory ones then attack plants and act as viral vectors spreading diseases.
Name of Disease
Plants Affected
Hairy root
Sugarbeets, soybeans, potatoes
Root-knot
Tomatoes, peanuts and other crop plants
Root lesions
More than 2000 plant hosts
Necrosis and stunting by foliar nematodes
Alfalfa, clover, onions
List of Plant Diseases Caused by Mycoplasmas
Mycoplasmas are a genre of bacteria that lack a cell wall. They are transmitted from an infected plant through sap sucking plants. They make home in the phloem of the plant and reproduce. Diseases caused by mycoplasmas in plants are as follows:
Name of Disease
Plants Affected
Aster yellows
Many plant species
Pear decline
Pears
Western X
Stone fruit trees
This was a list of common plant diseases that many agriculturists and gardeners come across. If one has doubts about diseases or infections affecting their plants, one should go and speak to the experts in their area. There are treatments available to get rid of these plant diseases and save your plants or crops from destruction.
