Effect of Biofumigation with selected Brassicaceae plants on the count and diversity of soil-borne fungi in Arish city, Egypt,

Abstract

Biofumigation is a pest control strategy that involves the use of glucosinolate-producing plants, usually from the Brassica family. When these plants' tissues are damaged, an enzyme breaks down the glucosinolates, releasing a variety of chemicals that are known to be plant pathogen suppressors. In this study, applying this technique using Brassicaceae species such as cauliflower (Brassica oleracea, var. botrytis L.), radish (Raphanus sativus), watercress (Eruca sativa), canola (Brassica napus), cabbage (Brassica oleracea var. capitata L.), and turnip (Brassica rapa) was successful in lowering the count of soil-borne fungi compared to control. In meantime, it increased the water holding capacity of soil. As a result, the percentage of organic matter (OM%) and organic carbon (OC%) increased. The highest percentage of OM (2.03 and 2.45 %) and OC (1.19% and 1.42%) were recorded when applying canola and cauliflower plants, respectively. The average colony forming unit (CFU) for soil-borne fungus following biofumigation (211.6 X 10 3 /ml of soil extract) was lowered compared to those obtained before and during plant growth treatment (810.9 x 10 3 and 1533.2 X 10 3 /ml, respectively). For the most common plant pathogen like Fusarium lateritium, biofumigation recorded a significant reduction in colony number/ml of soil extract compared to those recoded during plant growth and the control soil without treatment (30.0, 48.0 X 10 3 and 128.4 and CFU ml -1 , respectively). Among genera of Brassica family used, canola, radish and cabbage were significantly the highest in reduction of fungal count. In general, biofumigation changed the measured soil properties as well as the composition of the soil-borne fungus community, causing the extinction of some genera and the emergence of others.