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The field application of safe chemical inducers plays a vital role in the stimulation of systematic acquired resistance (SAR) of plants. In this study, the efficacy use of three and six field applications with chitosan, lithovit, and K-thiosulfate at 4 g L−1 and salicylic acid at 1.5 g L−1 in improving tomato productivity, quality, and modifying the defense signaling pathways to the Alternaria alternata infection was investigated. Salicylic acid was the most effective in vitro where it completely inhibited the growth of Alternaria alternata. The highest yield quantity was recorded with six applications with Chitosan followed by Salicylic acid; also, they were the most effective treatments in controlling the Alternaria alternata infection in tomato fruits. The maximum increase in chitinase and catalase activity of tomato fruits was observed at five days after inoculation, following treatment with six sprays of salicylic acid followed by chitosan. The transcript levels of seven defense-related genes: ethylene-responsive transcription factor 3 (RAP), xyloglucan endotransglucosylase 2 (XET-2), catalytic hydrolase -2 (ACS-2), proteinase inhibitor II (PINII), phenylalanine ammonia-lyase 5 (PAL5), lipoxygenase D (LOXD), and pathogenesis-related protein 1 (PR1) were upregulated in response to all treatments. The highest expression levels of the seven studied genes were recorded in response to six foliar applications with chitosan. Chitosan followed by salicylic acid was the most effective among the tested elicitors in controlling the black mold rot in tomato fruits. In conclusion, pre-harvest chitosan and salicylic acid in vivo application with six sprays could be recommended as effective safe alternatives to fungicides against black mold disease in tomato fruits.

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Two field experiments were conducted during two successive seasons of 2014/2015 and 2015/2016 at Vegetable Experimental Research Farm in Kaha, Kaliobia Governorate to study the effect of application method of safety compounds on growth and productivity of globe artichoke cv. "Concerto" used treatments included three different application method; i.e., soaking 20 min., spraying 6 times started after 70 days from planting date and repeated every 15 days through the growth season and soaking plus spraying in seven different safety compounds; i.e., Amino power (source of free amino acids) 0.5 cm 3 /l, Fruiting (source of gibberellins) 0.5 cm 3 /l, Mega humic acid (source of humic acid) 0.25 g/l, Cytojeep (source of gibberellins plus free amino acids) 0.5 cm 3 /l, Chitosan 1% and Garlic extract 50 cm 3 /l as well as tap water (control). A split plot design with four replicates was used in this experiment. Main plots were application method and sub-plots were safety compounds.The obtained results revealed that spraying Mega humic acid or soaking plus spraying significantly produced the highest leaves number/ plant, plant height, produced yield (early, late and total) expressed as heads weight / plant, head and edible part weight (early and late yield), dry matter percentage in late yield as well as the lowest total phenols in early yield comparing with the control. On the other hand, using Cytojeep significantly produced the highest offshoots number / plant and the least number of days to the anthesis. Also, spraying Fruiting significantly increased inuline percentage in early and late yield and decreased the fibers contents in late yield.