RESUMEN
Bacillus sp is one of the biocontrol agents are extensively used in management of fungal diseases of crop plants, exhibiting mycoparasitism against a wide range of plant pathogens. In the present investigation Efficacy of Bacillus subtilis was tested against Pythium aphanidermatum under glass house and field conditions. With regard to the germination and seedling growth parameters, the treatment T2 (liquid formulation of Bacillus subtilis @10 ml/L) recorded the highest germination percentage (92.59%), shoot length (59.3 cm), root length (24.3 cm), vigor index (7740.52) and yield (22.67 mt/ha). This was followed by the treatments T3, T1 and T4 in the decreasing order of merit. In the biometric observations also, 10 ml/L and 20 ml/L concentration of liquid formulation of Bacillus subtilis recorded statistically significant results. Observations on total protein content in brinjal plants treated with different concentrations of Bacillus subtilis revealed that treatment T2 was found best in both field and glass house conditions yielded highest protein as 0.44mg/ml and 0.30mg/ml respectively. The least values of germination, growth parameters, protein content and yield were observed in untreated control.
RESUMEN
This work aimed a survey on the biodiversity of maize endophytic actinomycete, and an evaluation of their potential to control the phytopathogenic fungi. From several regions of São Paulo state, 40 strains were isolated from the healthy maize plants. The identification of these strains, based on morphological properties and fatty acid methyl ester (FAME) profile showed that most of them belonged to the Streptomyces genus. These isolates were first screened for the growth inhibition of phytopathogenic fungi and results showed that all the isolate were able to inhibit the development of at least one tested pathogen. Two selected isolates were then evaluated for the control of P. aphanidermatum in cucumber (Cucumis sativa L.) under greenhouse conditions. Isolate 16R3B was able to reduce up to 71% damping-off incidence whereas isolate 14F1D/2 reduced the disease incidence by 36%. Damping- off control in cucumber, mainly for the isolate 16R3B, suggested for its use in greenhouse cucumber producing fields and to be tested in field trials.
RESUMEN
Four kinds of colophony were used to isolate the herbicidal substance from the toxin produced by isolate PAM1 of Pythium aphanidermatum, which had herbicidal activity to Digtaria sanguinealis L and the results showed X-5 was the best one for absorbing herbicidal substance among the four kinds of colophony used. Four solvents including 50% ethanol, 95% ethanol, ethyl acetate and acetone were used as eluting solvent and 2 procedures were tested, and the results of growth inhibition and seed germination indicated that the best eluting procedure was procedure 1.
RESUMEN
A severe damping-off disease of bush okra caused by Pythium aphanidermatum, was diagnosed in plastic houses in Der Attia village, 15 km southwest of El-Minia city, Egypt, during the winter of 2001. Bush okra seedlings showed low emergence with bare patches inside the plastic houses. Seedlings that escaped pre-emergence damping-off showed poor growth, stunting and eventually collapsed. Examination of the infected tissues confirmed only Pythium aphanidermatum, showing its typical intercalary antheridia, and lobulate zoosporangia. P. aphanidermatum was shown to be pathogenic on bush okra under pot and field experiments. Bacteria making inhibition zones against the damping-off fungus P. aphanidermatum were selected. Agar discs from rhizosphere soil of bush okra containing colonies were transferred onto agar plate culture of P. aphanidermatum. After 2 days of incubation, colonies producing clear zones of non-Pythium growth were readily detected. The two bacteria with the largest inhibition zones were identified as Pseudomonas fluorescens. Bush okra emergence(%) in both pot and plastic houses experiments indicated that disease control could be obtained by applying P. fluorescens to the soil or coating the bacteria to the bush okra seeds before sowing. In the plastic houses, application of the bacteria onto Pythium-infested soil and sowing bush okra seeds dressed with bacteria gave 100% emergence. In addition, This was the first reported disease of bush okra by this oomycete in Egypt.