BACKGROUND The need to increase marketable tomato yields and decrease losses due to sunburn and disease during the summer motivates farmers to adopt additional cultural practices such as shading and grafting. To investigate complex interactions among grafting, shading, and tomato cultivar, grafted and ungrafted tomatoes (cv. 'Optima' F1 and cv. 'Big Beef' F1) were grown in the soil under net‐house cover, using pearl and red nets, and in unshaded conditions (open fields). Tomato fruit at the red stage of maturity were used for the analysis of quality traits, and total and marketable yields were recorded during the whole production season. RESULTS Grafting and shading in tomato production might be considered as cultivation practices to increase the marketable tomato yield. A decrease in sugar content increased the uptake of some micro elements (Fe and Zn) and macro elements (Ca). In some cases, firmer and less elastic skin may be expected due to grafting. Shading with pearl net might result in fruit with lower firmness and higher total, and particularly malic, acid content. CONCLUSION Shading with colored nets and grafting provide alternative strategies for achieving higher fruit yields and avoiding or reducing a decrease in tomato quality caused by environmental stresses such as excessive radiation and temperature in the summer cropping season. © 2019 Society of Chemical Industry

The antimicrobial activity of Allium ursinum aqueous extract prepared using high pressure extraction was evaluated. Minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) of A. ursinum extract for six bacterial pathogens were determined using the broth macrodilution method. Although the A. ursinum extract was shown to be effective toward all investigated foodborne bacteria, its antimicrobial activity depended on its concentration and bacterial strain. Listeria monocytogenes was the most sensitive to antimicrobial activity of A. ursinum extract among all tested pathogens. Accordingly, the lowest MIC and MBC of A. ursinum extract were determined for L. monocytogenes (28 and 29 mg/mL). The tested extract showed a similar antimicrobial potential to other examined bacterial strains (Salmonella Enteritidis, Proteus hauseri, Enterococcus faecalis and two strains of Escherichia coli) with MIC and MBC values at concentrations of 29 and 30 mg/mL, respectively. The dependence of the antimicrobial activity of the A. ursinum extract on the level of contamination of tested pathogens was also observed. The increase in the contamination level caused an intense reduction in antibacterial potential of the A. ursinum extract. The composition of the A. ursinum extract was analyzed and found to be a good source of polyphenols and sulfur compounds. However, considering the applied extraction method and the HPLC analysis of bioactive compounds, the antimicrobial potential may be attributed more to polyphenol content. The obtained results that the extracts have shown toward food pathogens open the possibility of using the tested extracts as natural additives in a variety of food products.

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Application of plant growth regulators (PGRs) in apricot orchards is a common practice with a goal of improving yield and/or quality of fruits at harvest. However, the question of whether such treatment alters postharvest properties is seldom answered. The effects of an early application of PGRs on postharvest changes on apricots were investigated on cultivar NS-4, grown on Myrobalan rootstock with blackthorn interstock in a 5-year-old orchard. PGR treatments included 50 and 100 ppm of benzyladenine (BA) and 200 ppm of gibberellic acid (GA3), which were applied when the green ovary was surrounded by dying a sepal crown, at the stage where sepals beginning to fall. Apricots at the stage of commercial ripeness were used for the postharvest experiments. Analysis was performed at harvest, after 21 days of cold storage (at 1 ± 1 °C and 80 ± 10% RH), and after 3 days of shelf life (24 ± 2 °C). At harvest, significant differences were observed between treated and untreated fruits regarding flesh firmness, color, ethylene production and respiration rate, flavonoid, carotenoid and citric acid content, while application of BA100 changed TA and TSS. Prolonged cold storage reduced the initial differences in firmness, respiration rate, flavonoid and carotenoid contents, but new differences in fructose, malic and succinic acid contents began to appear. Shelf life reduced the difference in citric acid, but differences in TA, TSS, phenol and flavonoid content appeared. There is no difference in the sensory properties of treated and non-treated fruit after cold storage and shelf life.

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