by Judy Siegal-Itzkovitch

A novel, environmentally friendly agent that naturally controls fungus and bacteria in agriculture has been developed by the Yissum Research and Development Company at the Hebrew University in Jerusalem. The new biocontrol method for protecting plants from pathogens uses yeast isolated from strawberry leaves, is non-toxic and effective for a large variety of plants.

Agriculture depends heavily on the use of pesticides to increase crop yield. But the widespread use of chemical pesticides has resulted in severe environmental pollution, and many pathogens are developing resistance to the chemicals. In addition, many pesticides are now banned for use, and organic farming may not rely on such substances at all. A major goal, therefore, is to develop new, environmentally- friendly tools to control pathogens.

Now, Yissum’s new biocontrol agent, based on naturally-occurring fungi, not only boosts the plant’s resistance to infestations but also enhances growth. The HU company is now looking for an appropriate partner for the further development and commercialization of the product.

The agent was developed by Dr. Maggie Levy from the university’s department of plant pathology and microbiology in the faculty of agriculture, food and environment.

It is based on a species of the epiphytic yeast called Pseudozyma, which derives moisture and nutrients from the air and rain. It usually grows on another plant but is not parasitic.

Levy and her team showed that the yeast secretes substances that inhibit several fungal and bacterial pathogens. Application of the yeast spores significantly diminished the growth of different fungal causal agents of plant diseases such as powdery mildews, the gray mold that has more than 400 different hosts, crown rust, the black spot disease of cultivated Brassicas and late wilt disease in corn. Pathogenic bacteria such as Clavibacter michiganensis, the causative agent of bacterial canker of tomato, were also inhibited by the yeast.

Levy’s novel biocontrol agent is easy to produce, nontoxic and effective at low concentrations and will reduce the amount of chemicals required for pathogen control.

This, in turn, would genuinely benefit farmers, consumers and the environment.

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