If the fungus infests a cutting bed or if contaminated water is used in propagation, large losses usually occur. Almost all plants are susceptible to Pythium root rot. Root tips which are very important in taking up nutrients and water are attacked and killed. Pythium also can rot the base of unrooted cuttings. Symptoms Plants are stunted .
Root tips are brown and dead.
Plants wilt at mid-day and may recover at night. Plants yellow and die. Rot may proceed up the stem . Brown tissue on the outer portion of the root easily pulls off leaving a bare strand of vascular tissue exposed. The cells of roots contain many microscopic thick-walled spores .