Occurrence of apical bud rot disease on ornamental palm [Pritchardia filifera] in Egypt and its control

Thirteen bacterial isolates were isolated from collected ornamental palm samples showing apical bud rot symptoms. Only three isolates were able to cause identical bacterial rot on palm leaf rachides tissues in vitro. These isolates were identified as Pseudomonas solanacearum. It is believed that the present study is the first report that P. solanacearum cause apical bud rot infection to the ornamental palm [Prichardia filifera] in Egypt. In vitro tests, Acetylsalicylic acid; Salicylic acid; Streptomycin sulphate; Copper sulphate and Kocide 101 showed high inhibitory effect on the growth of the highly patholggenic bacterial isolate. Moderate inhibitory effect on bacterial growth was observed with Tetracycline and phenicol, while Borax had no inhibiting effect. Mixing Aceplaslicylic acid with Stgreptomycin sulphate Strepto-Acetyle] inhibited bacterial rot developmentg on palm leaf rachides slices in vitro. Sterepto-Acetyle mixtures were more effective than each compound alone. In greenhouse experiment, application of these mixtures at the same time of bacterial inoculation gave complete reduction [100%] of rot development when compared with their application before [8%] and/or after [60%] bacterial inoculation. It is recommended that the application of Strepto-Acetyle mixture [800 ppm + 60 mM] at the appeaance of first sign of disease symptoms might be useful as control measure for apical bud rot of ornamental palm caused by P. solanacearum

Inhibitory effect of some essential oils and food additives on aflatoxins production by Aspergillus parasiticus on yellow corn during storage

Nine essential oils, two food additives and salicylic acid were evaluated for their inhibitory effect against activity of Aspergillus parasiticus. In vitro studies, the highest growth reduction of A. parasiticus was recorded when oils of geranium, lemon grass and rose added to the growth medium at concentrations above 0.5%, while the same effect was noticed at 2% of lime shell oil and 3% of peppermint, garlic and onion oils. Also, potassium sorbate [0.07%], sodium benzoate [0.09%] and salicylic acid [0.8%] were able to cause 100% growth reduction of A. parasiticus on growth medium. In vivo studies, the highest inhibition of fungal growth [9624%, 93.98%, 94.73%, 54.28% and 67.42%] and aflatoxins production [100%] were recorded on inoculated stored grains of yellow corn, treated with potassium sorbate, sodium benzoate and salicylic acid as well as geranium and rose oils at concentrations as 0.28, 0.36, 3.2,6 and 6%, respectively. Obtained results in the present study led to conclude that essential oils of germinum, rose and flood additives as potassium sorbate and sodium benzoate in addition to salaicylic acid could be used as preventing and inhibiting factors against mould contamination and aflatoxins production in food and foodstuffs during storage. These agents are considered inexpensive, safe, easily applied and not hazard to human health and environment