تأثير بعض العوامل الأحيائية و الكيميائية في السيطرة على مرض تعفن جذور نبات البيتونيا Petunia Hybrida المتسبب عن الفطر Rhizoctonia solani

Abstract EN

This study was conducted to evaluate the efficiency of some biological and chemical agents in controlling petunia root-rot caused by Rhizoctonia solani.

Results showed that R.

solani has high pathogenicity on petunia seeds in Petri dishes that resulted in 100% seed decay.

The effect of some biological and chemical agents and the interaction between each other in controlling R.

solani were studied.

Trichoderma harzianum had inhibited the pathogenic fungus with 2 cm inhibition zone while Pseudomonas fluorescens completely inhibited R.

solani compared to 94.44% inhibition rate resulted from Bacillus subtilis.

The fungicide Topsin-M on the other hand resulted in complete inhibition when used at recommended dose.

The pathogenic R.

solani and its isolates were diagnosed using polymerase chain reaction PCR.

However, the diagnosis showed that R.

solani record for the first time in Iraq on petunia.