Solarization and natural heating of irrigated soil amended with cruciferous residues for improved control of Macrophomina phaseolina

The efficacy of summer irrigation and soil solarization combined with cruciferous residues was tested against the dry root rot pathogen Macrophomina phaseolina in an arid climate. In irrigated amended soil, polyethylene mulching during May increased the soil temperature to 57°C and 50°C at depths of 0–15 and 16–30 cm, respectively. As a result, within l5 days the population of M. phaseolina was almost eradicated (93–99%) at both soil depths. A considerable reduction (75–96%) was also achieved by natural heating of irrigated soil (46–53°C) for l5 days after amending with cruciferous residues. Mulching alone was only partially effective (69–89% reduction). These results suggest a new approach to controlling soil‐borne pathogens in hot, arid regions by combining summer irrigation with soil amendment. Amendment with residues alone or in conjunction with soil solarization also increased the population of lytic bacteria against M. phaseolina .