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Common Diseases in your Garden – Plant Pathogens

Being able to diagnose a disease in a plant can be a very difficult task. Many of the symptoms exhibited by an afflicted plant may lead you to believe that some other problem is present, such as a nutrient deficiency or weather issues. Keeping your plants disease free is best prevented by providing your plants with optimum growing conditions at all time. This article is designed to help gardeners better understand how disease can affect their plants.

Types of Plant Pathogens – Bacteria, Viruses, Fungi and Nematodes

Bacteria is present wherever life is present. The vast majority of bacteria on plants is beneficial and maintains a symbiotic relationship that essential to the health of your garden. Some bacteria can cause unique defects in plants, making it much easier to identify. For example, Agrobacterium tumefaciens is a well known, but poorly understood pathogenic plant bacteria. It creates tumor-like lumps on plants ranging from tomatoes to roses.

Viruses work on plants in a similar manner to humans by hijacking the genetic material in the nucleus of a cell. They often produce symptoms in plants that mimic other common problems, such as yellowing of leaves and deformed growth. It is not often that a virus will cause a plant to die, so gardeners will put an unnecessary effort towards fixing the problem, such as adjusting the soil. Viruses in plants can be tricky to diagnose and are one of the most frustrating garden pathogens.

Fungal infections in plants are common and can be difficult to treat. Fungal spores are present in both the air and soil and it will colonize the plant to obtain nutrients from its living cells. Plants that suffering from a fungal infection will usually show signed of blotchy brown leaves or contain a powdery white material on the leaves and stems. Each species of fungus has a different affect on plants.

Nematodes are microscopic wormlike organisms that live in the soil. Some nematodes are beneficial and some are bad. They are a common problem in commercial agriculture and often affect root crops, such as carrots and potatoes. They are not limited to root crops and also damage citrus crops and corn, among others. When a plant is infected with nematodes it will show symptoms on virtually all parts of the plant.

Learn more at http://www.nda.agric.za/docs/ET/plant_pathology.htm