Effect of irrigation time and chemical controlling on the infection ratio with root rot caused by ( Pythium aphanidermatium ) and yield of cucumber

Abstract

A study was carried out in one of Ramadi fields, AL-Anbar province in the spring season of 2005. The aim was to study of effect of irrigation time and chemical controlling by use of fungicide (Ridomil MZ-72) on the infection ratio with root rot caused by the fungus (Pythium aphanidermatium) and yield of cucumber. Results showed that regular irrigation for four days led to decrease infection ratio significantly (24%), decreasing infection ratio resulted in significant elevation in yield (5633 kg/d). The infection ratio were increasing when used the irrigation for seven days and between days which were (54.3 and 45.3% , respectively), this elevation in infection ratio resulted in reducing yield significantly (1956 and 2766 kg/d , respectively). The chemical controlling by fungicide (Ridomil MZ-72) for twice led to decrease infection ratio significantly (20%) and the ratio increased (32.7%) when controlling only for once, while the low infection ratio at this treatments led to increasing yield significantly (4700 and 3933 kg/d , respectively). The infection ratio increasing significantly (71%) in control, un use fungicide leading to reduce yield significantly (1723 kg/d). The combination between time of irrigation and chemical controlling showed a significant decreasing in infection ratio to low level (12%) when used irrigation for four days and twice controlling, while yield in this combination increasing to high level (7300 kg/d). The highest increasing infection ratio was (87%) for the interaction between irrigation for seven days and un use of fungicide, while the combination irrigation between days and un use of fungicide significantly reduced yield to low level was (1200 kg/d).