Pathological studies on some diseases of safflower plants

Safflower diseased plants, showing typical symptoms of damping-off, root and stem rot, wilt and/or rust diseases, were collected from Behera and Giza governorates for isolation the microorganisms associated with the disease(s).The isolated fungi were carefully purified and identified to the species or the generic level and the frequency of each was calculated. 85fungal isolates were obtained from Giza governorate, while 80 isolates were isolated from Wadi EI Notron, Behera governorate. Fusarium oxysporum, Pythium sp, Rhizoctonia solani. Sclerotinia sclerotiorum were isolated from Giza. but not from Behera.Meanwhile, Fusarium solani and Phytophthora sp. were isolated from Behera, but not from Giza. Macrophomina phaseolina was widespread and isolated from the two governorates with high frequency. Puccinia carthami, the causal of safflower rust was encountered elsewhere. Pathogenicity tests were performed to throw light on the relative importance of the tested fungi to cause the aforememioned diseases. All the tested fungi were able to cause the damping-off disease, but in diferent degrees. F. oxysporum caused damping-off and vascular wilt symptoms. P. carthami showed also damping-off and the seedling rust phase. The other fungi were able to colonize safflower roots and cause damping-off and root rot symptoms .The results showed that the amount of the disease was affected by the tested fungi and the sowing date(s). ln most cases, sowing at November 2nd recorded the intermediate amounts of infection and the best seed germination.One biocide, viz. Biocontrol: one resistance inducer, viz. Biomycin in addition to three fungicides, viz. Moncut, Vitvax - T, and Rizolex - T were tested in vivo for their ability to control safflower damping-off and root rot caused by the tested fungi. i.e. M, phaseolina. R. solani and F. solani. The obtained data revealed that none of the evaluated formulations was able to prevent entirely the infection with any of the tested fungi. The best control of M, phaseolina was given by seed treatment with Biomycin Vitavax - T and Rizolex - T, R. solani was controlled best by Biomycin and Rizolex - T. Meanwhile, Vitavax-T, Biomycin and Rizolex-T were the best treatments against F. solani.