Plant disease

[9] They include some of the most destructive plant pathogens, such as the causal agents of potato late blight[9] root rot,[10] and sudden oak death.

[11][12] Despite not being closely related to the fungi, the oomycetes have developed similar infection strategies, using effector proteins to turn off a plant's defenses.

[13] Some slime molds in Phytomyxea cause important diseases, including clubroot in cabbage and its relatives and powdery scab in potatoes.

[citation needed] Plant viruses are generally transmitted by a vector, but mechanical and seed transmission also occur.

Root knot nematodes have quite a large host range, they parasitize plant root systems and thus directly affect the uptake of water and nutrients needed for normal plant growth and reproduction,[21] whereas cyst nematodes tend to be able to infect only a few species.

Abiotic causes include natural processes such as drought, frost, snow and hail; flooding and poor drainage; nutrient deficiency; deposition of mineral salts such as sodium chloride and gypsum; windburn and breakage by storms; and wildfires.

The introduction of harmful non native organisms into a country can be reduced by controlling human traffic (e.g., the Australian Quarantine and Inspection Service).

[BH 1] X-ray and electron-beam/E-beam irradiation of food has been trialed as a quarantine treatment for fruit commodities originating from Hawaii.

The US FDA (Food and Drug Administration), USDA APHIS (Animal and Plant Health Inspection Service), producers, and consumers were all accepting of the results - more thorough pest eradication and lesser taste degradation than heat treatment.

[25] The International Plant Protection Convention (IPPC) anticipates that molecular diagnostics for inspections will continue to improve.

This method works by directly eliminating disease-causing organisms or curbing their spread; however, it has been shown to have too broad an effect, typically, to be good for the local ecosystem.

From an economic standpoint, all but the simplest natural additives may disqualify a product from "organic" status, potentially reducing the value of the yield.

Crop rotation is a traditional and sometimes effective means of preventing pests and diseases from becoming well-established, alongside other benefits.