Some economically important plant diseases are caused by pathogens that are present in soil. Many of these organisms have developed specialized survival structures such as hardened mycelial packs (sclerotia) or thick-walled spores (chlamydospores or oospores). These specialized structures assist their survival in harsh soil environment. Others remain as saprophytes, making their living by decaying dead plant tissues. Many of these so-called soilborne pathogens persist in soil over long period of time, from growing season to another, even if environmental conditions don’t support disease development. When optimal conditions (right moisture, temperature, and presence of a host plant) arise, these soil-borne pathogen structures often serve as source of inoculum for disease development. Whether the aim is to determine the causal agent of a disease problem or enumeration of the levels of soil-pathogen population before planting, our testing services are designed for your needs. AL&L offers testing for the most important soilborne fungal pathogens including:
- Fusarium
- Macrophomina
- Phoma terrestris
- Phytophthora
- Pythium
- Rhizoctonia
- Sclerotinia
- Sclerotium
- Verticillium
See the proper sampling collection protocol here. Contact us for further instructions about the sampling procedures for specific pathogens.
Additional Soil Information
Fusarium species cause root rot, wilt and yellows disease on many agronomic crops including onions, tomatoes, strawberries, Hemp/Cannabis, Cole crops and Cucurbits.
Phoma terrestris is a causal agent of onion pink root disease. It is also wide spread pathogen affecting several other crops such as cereals.
Macrophomina phaeseolina is a causal agent of charcoal rot disease. This fungus has a wide host range, more than 500 species. It causes variety of symptoms, including seedling rots, root and stem rots and wilts. Hot weather promotes the disease development.
Phytophthora genus includes several economically important plant pathogens that cause blights, cankers and rots in various plant species. Production of vegetables, fruit trees and nursery industry are most commonly affected by these diseases.
Pythium species such as its relatives, Phytophthora spp., are water-loving organisms, many of which are plant pathogens. Pythium species commonly cause seed rots and damping-off of young seedlings. Mature plants are also affected; Pythium-root rots of established plantings lead to poor growth and yield losses. Pythium diseases commonly affect nursery and greenhouse production.
Rhizoctonia solani is a common soil pathogen causing damping off, root and stem rots of variety of plant species.
Sclerotinia species, most commonly S. sclerotiorum and S. minor are causal agents of stem and soft rots of many agronomic crops such as celery (pink rot), lettuce (lettuce drop), tomatoes (white mold) and ornamentals (cottony rot).
Sclerotium species cause damping-off, stem canker, crown blight, root, crown, bulb and tuber rots on wide variety of plants, including vegetables, legumes, and cereals. Diseases caused by these species are often called Southern blights or wilts.
Verticillium dahliae, a causal agent of Verticillium wilt is a true soil-borne pathogen that can survive in soil for up to 15 years as microsclerotia. Another Verticillium species, V. albo-atrum also causes wilts but is differentiated from V. dahliae in that it does not produce sclerotia. Verticillium species attack over 200 plant species including vegetables, flowers, strawberries, fruit trees, field crops and shade and forest trees.