Studies on survivability of field pea rust caused by Uromyces viciae-fabae (Pers.) de Bary in Tarai region of Uttarakhand (India)

Pea rust, which is caused by Uromyces viciae-fabae (Pers.) de Bary has become the important pathogen since last decade and results in significant yield losses in India. The experiment was conducted during the 2006 to 2010 crop seasons on the survivability on rust of field pea under in vitro condition at Pantnagar, India. The results indicated that maximum urediospores germination was recorded from 2006 to 2010 in the month of April followed by May and June. However the number of uredinia on assayed plant indicated apparent survival of urediospores increased dramatically in the viable germination test of urediospore in June, July and August in the year 2008 to 2009. The urediospore survived at 10°C for four months in infected crop debris followed by 5 and 20°C, while failed to survive at temperature (30 to 40°C). Crop debris at different depths revealed that survivability of urediospore declined sharply over period of time as well as increased in the depth of placement. Maximum survivability of fungus was recorded in samples buried at 10 cm followed by 5, 15 and 20 cm deep, respectively. However, the urediospore failed to survive at any depth beyond 4 weeks in 2007 and 2008.   Key words: Uromyces viciae-fabae, survivability, urediospore, aeciospores.