Use of liohumus extract for ecological control of potato late blight

Summary

Ecological control of potato late blight caused by the fungus Phytophthora infestans (Μοnt) de Bary is based on forecasting programs, cultural practices (Shea and Broadbent, 1983), use of resistant cultivars (Umareus et al., 1983; Williams and Williams, 1994; Bradshaw et al., 1995) and application of suggested plant protective products.
Copper products are used only as preventatives and in limited quantities in order to avoid accumulation in the soil. Control of the pathogen has been reported with the use of Fusarium sambucinum (Klukov et al., 1983) and Pythium ultimum (Kuznetsova et al., 1995) extracts. Bacteria of Bacillus genus were successfully used in tomato plants in vivo (Sadlers, 1996). Pseudomonas fluorescens strain ΑP33 and other bacteria isolated from the phylloplane and rhizosphere of potato and canola plants significantly controlled pathogen (Daayf et al., 2003). Skytalidine, antibiotic from Skytalidium pesante fungus, restricted pathogen development (Cook and Baker, 1983). Patatin that codifies resistance to Phytophthora infestans, inhibited spore germination by 70% (Sharma et al., 2004), while similar effects were reported for the alkaloid derivatives pipernonaline and piperidine from Piper longus (Lee et al., 2001).
The purpose of this work was to study the possibility of controlling potato late blight with the use of a compost extract made from olive mill waste water, olive pomace and olive leaves, known by the Greek term “liohumus”.