Assessment of synthetic chemicals for disruption of Rhynchophorus ferrugineus response to attractant-baited traps in an urban environment

The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier (Coleoptera, Curculionidae), is one of the most severe pests of ornamental palm species in urban areas of Mediterranean countries. Aiming to discover inhibitory semiochemicals for RPW population management in urban environments, we conducted electroantennographic (EAG) screenings of 17 commercially available synthetic compounds, representing three groups of plant volatiles (isoprenoids, phenyl propanoid derivatives and fatty acid derivatives) known for their repellent effects toward insects. These tests were followed by trap-based screenings of EAG-active menthone, α-pinene and methyl salicylate, singly and in combination, under urban conditions. In EAG bioassays, RPW antennae of both sexes showed positive dose-dependent responses to 13 of the 17 synthetic chemicals with significant differences among them. In field trapping experiments, conducted in the city of Palermo, Italy, from weeks 31 to 38 in 2010 and 2011, α-pinene, tested singly or in combination with methyl salicylate (2010) or menthone (2011), reduced trap catches by about 30% to 40%. Methyl salicylate and menthone alone were inactive. In conclusion, RPW is significantly affected by α-pinene. This isoprenoid is a promising disruptant for semiochemical-based management of this pest. In addition, identification of a large number of EAG-active chemicals could serve as a database for future design of active repellents or attractants of RPW adults.     

Management of downy mildew of sweet basil (Ocimum basilicum) caused by Peronospora belbahrii by means of resistance inducers, fungicides, biocontrol agents and natural products

To control downy mildew of sweet basil (Ocimum basilicum L.), incited by Peronospora belbahrii Thines, a number of compounds were tested in 2011 and 2012 under glasshouse conditions. These included copper-based fungicides, biocontrol agents, and compounds previously reported to induce resistance in plants to pathogens. Results were compared with those provided by fungicides registered for downy mildew control in Italy. The tested compounds were used alone or applied in rotation in spray programs. In all trials, the greatest reduction in disease incidence and severity was found with treatments that included metalaxyl-M?+?copper hydroxide, a mineral fertilizer ‘Alexin’, mandipropanid, and azoxystrobin. The glucohumates activator complex and acibenzolar-S-methyl also provided significant disease control (P?<?0.05). The mineral fertilizer Alexin, the glucohumates activator complex and acibenzolar-S significantly reduced disease incidence and severity 20 days after the last treatment compared with the untreated control (P?<?0.05). Among the copper-based products, the greatest reductions in disease incidence and severity were provided by copper hydroxide with terpenic alcohols and copper oxychloride?+?copper hydroxide. The mineral fertilizer Kendal and prohexadione-Ca, as well as mustard oil, partially reduced disease incidence and severity compared with the untreated control (P?<?0.05), whereas the biocontrol agent Bacillus subtilis QST 713 and thyme oil extract were not effective in two out of three trials. When different combinations of various products used in rotation were tested, effective control was found either using a rotation of fungicides with compounds that can induce resistance, as well as by using rotation with different resistance-inducing compounds on their own.     

Evaluation of Physicochemical,Microbiological and Sensory Stability of Frozen Stored Vacuum-Packed Lamb Meat

Nowadays, lamb meat represents only 7% of all meat produced in the world. In recent years the demand for standardized lamb meat cuts has been considered of great importance and the marketing occurs predominantly in the form of frozen cuts. Herewith, the main of this work was to evaluate the stability and safety of lamb meat during frozen storage. Meats were vacuum packed in high barrier multilayer plastic iflms and stored during 12 mon at （-18±1）℃. The meat stability was assessed by physical and chemical （lipid oxidation, objective color, pH value, cooking losses and instrumental texture）, microbiological （total count of psychrotrophic, coliform count at 45℃, coagulase-positive staphylococci and the presence of Salmonella） and sensory analysis （acceptance test and visual evaluation）. The vacuum packed lamb meat remained stable as to most physical and chemical indexes. Microbiological indexes showed good stability throughout the storage period according to Brazilian legislation standards to pathogenic microorganisms. Although a signiifcant reduction in tenderness （shear force increase from 3 to 8 kg）, it showed a good sensorial acceptance for all attributes tested, including texture, with scores of around 7 （like moderately） during the 12 mon of storage. Therefore, it can be concluded that, under the conditions applied in this study, lamb meat presents a shelf life of at least 12 mon when stored at-18℃.     

Male performance in pistachio (Pistacia vera)

Pollinator performance was evaluated in a collection of 17 male and 37 female pistachio clones from Cyprus, Greece, Iran, Israel, Syria, Tunisia and USA. Flowering time, pollen quantity and pollen quality were evaluated. The flowering dates of the clones spanned one month and covered the flowering time of the main female cultivars. Pollen quality, evaluated as in vitro pollen germination, was high in all the studied clones, averaging 85 %. However, big differences existed in pollen quantity, measured both as inflorescence density and as pollen per inflorescence. Thus, the amount of pollen per inflorescence averaged 173 mg and ranged from 73 mg to 252 mg. The fact that flowering time and pollen quantity were the two most variable characters between clones, but were constant over years, together with the fact that they are two characteristics easily measured in the nursery makes them good criteria for pollinator selection in this species.     

The effect of pre-planting desiccation stress and root pruning on the physiological condition and subsequent field performance of one year old Prunus avium and P. cerasifera seedlings

Summary

Severe desiccation of dormant seedlings of wild cherry (Prunus avium) and cherry plum (P. cerasifera) did not affect their immediate survival, but caused significant reductions in subsequent shoot growth and root volume which were not recovered in a single growing season. Damage to the fine roots, as indicated by the physiological plant quality measures of tetrazolium absorbance and root electrolyte leakage, increased rapidly over drying periods of ca. 6 h, further damage requiring progressively longer periods of desiccation. Root pruning prior to planting did not mitigate desiccation damage and severe pruning was highly injurious to subsequent growth. Generally the removal of the fine roots was equivalent to a relatively short desiccation period, but pruning of fine roots prior to, instead of after, desiccation in P. cerasifera resulted in more lateral shoots, possibly indicating the production of growth retardant substances by the dried root systems. All measures of physiological plant quality at the beginning of the growing season were effective as predictors of plant performance at the end. In the species tested, the most cost-effective routines are likely to be fine root electrolyte leakage and root moisture content, with tetrazolium testing and stem water potential measurements requiring both greater reproducibility and more sophisticated equipment.     

Plasticity and stability in the major fatty acid content of almond kernels grown under two Mediterranean climates

Summary

Oil contents and fatty acid compositions were determined in 17 almond cultivars growing under two different Mediterranean conditions, in northeast Spain and in central Morocco. The major differences were irrigation management in Spain and higher temperatures in Morocco. Although a cultivar effect was observed for some compounds, the general trend was for an increase in total oil content [58.65% vs. 55.58% (w/w)] and in the percentage of oleic acid [71.1% vs. 68.62% (w/w)] in those kernels harvested in Spain, probably due to having lower temperatures and better water status. As the total oil content and level of oleic acid in almond oil are the major parameters for higher quality almond kernels, these results emphasise the need to optimise the management of almond orchards to improve kernel quality, not only from the commercial and industrial points of view, but also because of their healthgiving properties.