SPOT BLOTCH OF WHEAT IN DIFFERENT AGRO- ECOLOGICAL ZONES OF PAKISTAN

Surveys for foliar blight with special reference to spot blotch caused by Bipolaris sorokiniana were conducted to monitor the disease situation during 2005, 2006 and 2008 in different wheat growing zones across Pakistan. Among 8 different agro-ecological zones, the maximum disease (26.8) with highest incidence (84%) and severity (2.5) has been observed in zone 6 (Punjab area) during 2005 which was adjoining the zone 5 in geographic location. The disease situation decreased in the coming seasons and even in 2008 similar disease levels were not observed in these zones (5 and 6). Similar picture was found in other zones (3, 4, 7 and 9) except zone 10 and 11 (Northern Area) where disease was increased in 2008 as compared to the previous years. The situation was just because of the abnormal weather conditions prevailed in different years in different zones of Pakistan and replacement of commercial variety during the course of the time.