Biological control of Citrus brown spot pathogen, "Alternaria alternata" by different essential oils.

The antifungal effects of laurel, myrtle and peppermint essential oils and their combinations were investigated in vitro on two strains of Alternaria alternata mycelial growth and in vivo on detached Citrus leaf disease incidence. Myrtle essential oil was rich in α-pinene and 1,8-cineole while peppermint essential oil in menthol and menthone. 1,8-Cineole was the main component of the essential oils from laurel, laurel + myrtle and peppermint + laurel. The combined peppermint and myrtle essential oil was characterized by the predominance of menthol and 1,8-cineole. All tested essential oils, incorporated in potato-dextrose agar, inhibited A. alternata mycelial growth and had a fungistatic effect at concentration 3 mg/mL of medium. A great synergism was detected between peppermint and laurel essential oils against the two strains of A. alternata. The combined laurel and peppermint essential oil reduced mycelial growth rates of inoculated detached leaves at concentration above 1.5 mg/mL.

Composition of Citrus sinensis (L.) Osbeck cv «Maltaise demi-sanguine¼ juice. A comparison between organic and conventional farming.

Juices from conventionally and organically grown Citrus sinensis (L.) Osbeck cv. Maltaise demi-sanguine blood orange were investigated for quality parameters and antioxidant capacity. This blood orange variety is particularly rich in linoleic, linolenic acids, vitamin C and phenolic compounds. The quantitative determination of these compounds in cv. Maltaise demi-sanguine juice produced under conventional and organic agricultural practices revealed significant differences. The organically grown fruits contained more hesperidin and total fatty acids amounts as well as a higher sugar content and a lower acidity. Conventionally-grown fruit was found to have an increase in antioxidant capacity. In addition to having higher antioxidant activity conventionally-grown fruit had an observed increase in the concentration of phenolic acids and most flavonoids. The results of this study indicated that organically-grown Maltaise demi-sanguine juice contained an increased concentration of hesperidin which has been observed to possess biological activities associated with a healthy life.