Soilborne fungi

Soilborne fungi are the most difficult to control. If possible, dig up and dispose of the infected soil. Or try solarizing your soil by laying a sheet of clear plastic over the moistened area and letting the sun cook the soil for a few weeks. For more details on soil solarization, see page 424. 

BIOACTIVE METABOLITES FROM SOILBORNE FUNGI NATURAL FUNGICIDES AND BIOCONTROL AGENTS... 

The articles contained in this volume include the interaction of alkaloids with neuroreceptors and ion channels, anthracyclines suited for antibody-directed enzyme prodrug therapy and metabolites from soilborne fungi. Several articles are concerned with bioactive natural products from marine sources. The other areas covered include natural products with polyene amide structures, potential hypoglycemic agents, biological activity of essential oils, bioactive saponins and biologically active diterpenoids. 

A list of soilborne phytopathogens which have been studied as mycoherbicides is found in Table I. With the exception of Sclerotinia sclerotiorwn (Lib.) de Bary, tested for control of Canada thistle [Cirsium arvense (L.) Scop.](5), and P. palmivora, the only soilborne plant pathogenic fungi currently being studied as mycoherbicides in crops belong to the genus Fusarium. 

Table I. Soilborne Phytopathogenic Fungi Studied as Mycoherbicides...

Leaves wilt and yeUow on an entire branch. Cause Vertieillium wilt. A soilborne fungus causes this disease, and there is no way to save a tree once it has this problem. Don t plant avocados in soil that has sustained other Verticillium-susceptible crops such as tomatoes, peppers, and eggplants. If you suspect Vertieillium fungi may be in your soil, solarize... 

Many species of plants, including some fungi, bacteria, algae, and higher plants, produce cyanide as a metabolic product. Some species of soil bacteria suppress plant diseases caused by soilborne pathogens by producing metabolites with antibiotic activity. Certain strains of Pseudomonas fluorescens, a soil bacterium, suppress black root rot of tobacco... 

Lee, S.O., G.J. Choi, K.S. Jang et al., 2007. Antifungal activity of ve plant essential oils as fumigant against postharvest and soilborne plant pathogenic fungi. Plant Pathol. J., 23 97-102. 

Adding S. fruticosa Mill. (Lamiaceae) compost to soil decreases the high C/N rates and raises the pH of the soil. Moreover, it increases the number of microbes in the soil, such as bacteria and fungi (Chalkos et al, 2010). S. sclarea (Lamiaceae) volatile oil s compounds are linalyl acetate, linalool, geranyl acetate, and a-terpineol. The essential oil is able to cause fungicidal activity on S. sclerotiorum, a soilborne pathogen. It also inhibits growth of Sclerotium cepivorum and Fusarium oxysporum f.sp. Dianthi (Pitarokili et al., 2002). 

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