FIRST RECORD OF CHARCOAL DISEASE IN HIBISCUS SABDARIFFA L. A' TD ITS BIOLOGICAL CONROL

Salman Juber, Karnil

	FIRST RECORD OF CHARCOAL DISEASE IN HIBISCUS SABDARIFFA L. A' TD ITS BIOLOGICAL CONROL
The Iraqi Journal of Agricultural Science
Article 1, Volume 38, Issue 2, 2007, Pages 52-59
Author
Karnil Salman Juber
Abstract
The results of isolation and indentificatlon of samples of Hibiscus sahdurif]« L. plants revealed wilt and death xympto rns taken from three regions in Anbar.Baghdad and Al-Qndysia governol'ates showed that the disease caused by the fungus Mocrophomina p//{/solina(Maubl.)Ashby which isolated in 100% frum all the samples. This is regarded as the first record of the disease in roselle plants in Iraq. The isolates of the fungus showc.t variation in the daily growth rate and in the dimcntions and morphology of sclerotia in PTA. Sclerotia dimentious for the three isolates M P I ,1'1 1'2 and iVIP3 where 106-131, 112-131 and 116-134 ,II respectively. The three isolates don't produce pycnidia in culture media, while it produce morphologically identical pycnidia in the infected plants. The pathogenicity tests showed that fungus isolates MPI,MP2 and iIP3 caused significant reduction in seed germination and significant increase in disease severity whereas, the percentagcof seed germination and disease severity, in the treatments of fungnal isolates ranged 19%-85% and 30%-700/0, respectively while it was 90% and 0 in control treatment, respectively. The isolates showed differences in their effects in seed germination. The two isolates iIP2 and M 1'3 r;1I1SPlI hi~h rlisf'aSI' ,('verity in 30 rlavs old Roselle plants while the disease sen'dty in their' treatm cnts we re 85°Ir, and 100'1.." respectively after 15 days of inoculation, anrl without infection in the contr» treatment. The two biocontrol agents, Tricoderma hurzianum and Bacillus subtilis showed efficiency in the protection of roselle plants from the infection by the panthogenic fungus. they decreased the disease severity to 25% and 40% respectively compared with the lOO''o in the treatment of pathogenic fungus only. They also caused increase in shoot and root dry weight, since th e shoot dry weight in the treatments of the two biocontrol agents (T./lllrzilll1/1Jl1 and B.sllhtilis) in the presence of pathogenic fungus reached 5.50 and 3.07 g/planl, respectively and for the root dry weight 1.42 and 0.97 g/plant, respectively. The shoot and root dry weights in the control treatment inoculated with pathogenic fungus only were 1.37 and 0.47 g/plant, respectively,

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