In order for a plant disease to be present in desert plants, three legs of a triangle, called the disease triangle, must be met.
Plants succumb to diseases. The same is true for desert plants.
Nevertheless, understanding the plant disease triangle may help you save some plants and some produce this year.
A plant disease triangle consists of a susceptible host, a favorable environment and a pathogen (disease-causing organisms).
Any one of the above three factors cannot begin the disease alone. It requires all three factors, working in unison, for plants to contact a disease.
Conditions favoring pathogens could be too much water, too little water, high heat and poor drainage.
The host could be a variety particularly susceptible to the disease, or the plant could be weakened by other stresses.
Pathogens could include fungi, bacteria, phytoplasms, viruses, nematodes and other elements.
Here are some common diseases in plants and symptoms you can look for:
- Leaf spot: dead, discolored, or injured areas of tissue which usually have distinct margins; spots often appear on leaves or fruit.
- Blight: rapid yellowing, browning, collapse, and death of leaves, shoots, stems, flowers, or the entire plant.
- Chlorosis: yellowing of leaves and stems which are normally green.
- Necrosis: browning or blackening of areas on a plant indicative of the death of plant cells.
- Wilt: loss of turgor or drooping of leaves, shoots, or the entire plant due to lack of water.
- Distortion: twisting or other abnormal traits of leaves, stems, and shoots.
- Mosaic: uneven pattern of yellow, light green, or dark green, usually on leaves.
- Canker: dead area on a stem or branch; can be sunken, swollen, or discolored and are usually distinguished from adjacent healthy tissues by color.
- Rot: breakdown and decay of plant tissue; often used to describe conditions in roots and fruit.
- Dieback: death of the tips of leaves, shoots, and stems; failure of branches to develop, especially in the spring.
- Witches’ broom: abnormal proliferation of shoots from the same point on a plant resulting in a bushy, broom-like appearance.
- Gall: a swelling or abnormal growth of plant tissues; can develop on leaves, stems, and roots.
- Stunt: abnormally small-sized plant parts due to the failure of those plant parts to grow to full size; often used to describe an entire plant.
