Agricultural producers lose valuable crops each year due to disease.
Every year, agricultural producers lose large amounts of crops due to various crop diseases. To understand how and why certain diseases affect certain crops, plant pathologists have classified all diseases into two general groups, infectious and non-infectious. Once segmented into one of the categories, diseases are described by the characteristic of the offending pathogen or the environmental cause, such as fungi, bacteria, extreme temperatures, or soil deficiency. Finally, horticulturists classify a disease based on what part of the crop is affected, such as leaf disease, root disease, and more. There are numerous different types of agricultural diseases, but all diseases basically fall into the category of infectious and non-infectious for further classification.
A fungal or bacterial infestation can be the kiss of death for a farmer’s crop.
Non-infectious or abiotic diseases are those caused by unfavorable environmental circumstances and that do not result from living organisms. Non-infectious diseases generally tend to weaken a plant, making it susceptible to more serious infectious diseases. Examples of non-infectious diseases include extreme temperatures, too much or too little water, insects, poor soil nutrition, and toxic chemicals. These factors can weaken the entire plant or a certain part of the plant, making it susceptible to infectious stem diseases, seed diseases, pod diseases, and more.
The science of treating and curing crop diseases is very important to the agricultural industry.
Infectious or biotic diseases make up the majority of the various agricultural diseases. They are caused by living organisms that infect the crop. Fungi, such as dirt, rust, mold and pests, are the most common cause of crop disease. Most fungi require very moist conditions to grow and reproduce. Some fungi develop pustules on cultures, while others produce a discolored, powdery sooty colony.
Non-infectious diseases are caused by unfavorable environmental conditions, such as poor soil nutrition and excessive lack of water.
Bacteria and viruses, which are other infectious hosts, are tiny organisms that infiltrate plant organs and reproduce. Some bacteria do not harm crops, but others can produce toxins or attack plant cells for food. Viruses are generally spread by insects when an insect chews through the plant’s protective outer layer and infiltrates the inner cells. Bacterial pests and wilt commonly affect wheat and barley crops, as well as vegetables such as cucumbers and beans. Crop diseases caused by viruses can cause considerable damage, such as wheat mosaic virus and potato virus, which can wipe out an entire crop very quickly.
Ringspot, which can cause circular lesions on plant leaves, is an example of a viral plant disease.
Nematodes and protozoa are also classified as infectious diseases. These tiny worm-like organisms reside in the soil, waiting for an opportunity to attack a crop weakened by non-infectious causes. They can carry viruses, causing further damage to crops and complicating disease treatment. Examples of such biotic diseases include potato cyst nematode, pine wilt and soybean cyst nematode. As their names verify, these crop diseases invade the sensitive roots or vascular systems of crops and cause cysts that slow plant growth and dramatically reduce crop yields.
Limiting or curing crop diseases is a big problem. Scientists and farmers have developed a wide variety of fungicides, insecticides, pesticides, and antibacterial solutions to control crop diseases. Although advances have been made, pathogens have shown a tenacious propensity to adapt to repellents. As the agricultural industry learns more about the various types and causes of crop diseases, it becomes better equipped to treat and prevent the many diseases that plague the world’s crops.