Effectiveness of Systemic Fungicides for Control of Phytophthora parasitica NK1 in Foot Rot of Piper betle

Abstract

Using a bio-asay technique, the effectiveness of fice systemic fungicides was assessed for the control of growth and development of the isolate NK1 of Phytophthora parasitica, the cause of foot rot of betel vine (Piper betle Linn.) in Nongkhai province of Thailand. The assessment was made by recording the radial growth of fungal colonies on fungicide treated potato dextrose agar. Growth and development of the fungal colonies was completely inhibited on media treated with chev. RE-20615 (15% WP) and benalaxyl (Galben 10% WP) at rates as low as 10 ppm a.i., by etridiazole (Terrazole 35% WP) at 50 ppm a.i., and metalaxyl (Ridomil 25% WP) at 500 ppm a.i. fosetyl aluminium (Aliette 80% WP) was unable to completely inhibit growth even at a rate of 500 ppm a.i.