Antifungal activity of citrus essential oil components in vitro and in vivo against penicillium digitatum pers. (sacc.)

Proceedings of the International Conference “Environmentally friendly and safe technologies for quality of fruit and vegetables”, held in Universidade do Algarve, Faro, Portugal, on January 14-16, 2009. This Conference was a join activity with COST Action 924.In vitro studies were conducted on 37 compounds present in citrus essential oil, to test their activity against Penicillium digitatum by three methods: agar diffusion, amended growth medium and vapor assay. The aliphatic alcohols 1-nonanol, 1-decanol and especially 1-octanol exhibited the highest activities, as assayed by all the methods used. The terpenoid compounds perillalcohol, perillaldehyde, citral, terpineol, carveol and citronellol, as well as the reference aromatic compound cinnamaldehyde also exhibited high activity against P. digitatum. Neither hydrocarbons nor esters inhibited this fungus. The mode of action of 1-octanol, perillaldehyde, citral, perillalcohol and terpineol against P. digitatum was fungicidal, whereas 1-decanol, 1-nonanol, carveol and citronellol were only fungistatic. Application of biocidal formulations comprising 1-octanol and citral either separately or together inhibited decay of P. digitatum-inoculated lemons for three weeks after inoculation

Masarykova univerzita v Brn e

This thesis deals with the problem of deciding the existence of codings (injective morphisms) between trace monoids. We introduce the notion of weak morphisms of trace monoids and show that the problem of existence of weak codings is even more complex than the original problem for general morphisms. Further we investigate properties of weak morphisms and use them to prove the decidability of this problem for some classes of instances, which entails positive answers for the corresponding cases of the original problem. In particular, we show the decidability for instances whose domain monoids are defined by acyclic dependence graphs. We also partially answer the question of Diekert from 1990 about the number of free monoids needed for encoding a given trace monoid into their direct product. On the other hand, we prove that in general the problem of existence of codings from any given family of trace morphisms containing all weak codings is not recursively enumerable, which answers the question raised by Ochmanski in 1988

Effect of combined application of heat treatments and plastic packaging on keeping quality of 'Oroblanco' fruit (Citrus grandis L. x C. paradisi Macf.)

Combinations of various heat treatments with individual fruit sealing, packaging in polyethylene liners or waxing were tested as means to control pathological and physiological spoilage of 'Oroblanco' fruit (Citrus grandis L. x C. paradisi Macf.). The following heat treatments were used: curing at 36°C for 72 h, hot water dip at 52°C for 2 min or 'hot drench brushing' at 52, 56 or 60°C for 10 s. The standard packinghouse treatment included waxing with addition of thiabendazole (TBZ) and 2,4-D isopropyl ester. The fruit was stored for 2 weeks at 1°C (simulated low-temperature quarantine treatment), followed by 12-13 weeks at 11°C (simulated sea transportation to Japan) and 1 additional week at 20°C (simulated retail shelf-life period). The lowest weight loss and the highest firmness were observed with individually sealed fruit. Polyethylene liners were usually more efficient for weight loss control than waxing. However, the liner packaging enhanced the risk of postharvest disease development, if not accompanied by appropriate decay-controlling measures. Applying TBZ, hot water dip or curing controlled the development of postharvest pathogens, especially that of Penicillium molds. In another trial, both hot drench brushing at 56 or 60°C and hot water dip reduced decay incidence. Hot drench brushing at 60°C and hot water dip slowed fruit softening and reduced buttons abscission. In addition, the hot drench brushing at 60°C significantly delayed the loss of 'Oroblanco' green rind color, especially at the stylar and stem ends of the fruit. The hot dip at 52°C inhibited yellowing only when combined with individual seal-packaging. (C) 2000 Elsevier Science B.V.Contribution No 422/99 from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. This work was partially supported by the Citrus Marketing Board of Israel and by the scholarship of the Department of International Cooperation of the Ministry of Foreign Affairs of Israel given to Tayfun Agar. We are grateful to the authors of hot drench brushing technique (E. Fallik, O. Yekutieli, A. Wiseblum and R. Regev) for providing the opportunity to test the performance of this method with ‘Oroblanco’ fruit