Distribution of powdery mildew in field and waste land weeds in urban and sub-urban areas of Central Punjab

Weeds act as alternative host of many plant pathogens as they serve source of over-wintering for a wide
range of pathogens and effects on all aboveground parts of the plant. Perennials weeds play important role in the
spreading of obligate pathogens. Among the prevalent diseases caused by obligate fungal pathogens, powdery
mildew is counted in most common diseases especially for vegetables and ornamental plants in Pakistan. The
pathogens Erysiphe cichoracearum, Sphaerotheca fuliginia, and Leveillulata urica have been reported on
Convolvulus arvensis, Argemone mexicana, Rumex obtusifolious and Rumex dantatus, Euphorbia hirta, Conyza
ambigua, Cucumis melo var. Agrestis and Chenopodium murale in Lahore, Faisalabad, Gujranwala and
Sheikhupura districts of Central Punjab. Distribution assessment on a visual 0–5 visual rating scale was recorded
at 4 severity rating on C. arvensis, while other weeds showed intermediate reaction except C. melo proved highly
resistant against powdery mildew.