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.

Nano-fertilizers are effective substitutes for the traditional ones. However, to what extent can nano hydroxyapatite (NHA) and nano-boron oxide (NBO) be suitable substitutes for calcium superphosphate(CSP) and boric acid (BA)? The answer required conducting a field experiment on broccoli (Brassica oleraceavar. italica) cultivated on a heavy claysoil for two successive seasons of 2016/2017 and 2017/2018.The nano form of NHA surpassed CSP by 14.2 to 17.8 % for leaf area and 13.6 to 15.8% for total head yield. Foliar spray with NBO increased leaf area, head yield and vitamin C content in heads as compared with BA. P and B contents in broccoli shoots receiving the nano forms surpassed those of the conventional fertilizers. Combined application of the two nano-fertilizers surpassed the combined application of the two conventional fertilizers by 16.0 %. Values for yield and yield components were significantly positively correlated with P and B contents in plant shoots and heads.

Shortage of available water resources has become a critical problem facing vegetable production in Egypt. So, the aim of this study is to decrease the level of irrigation water: 85 and 70% of full irrigation requirements (FI), versus 100% FI in presence of four compost rates (0, 4.8, 9.6 and 14.4 m3 ha-1). Results show that, deficit irrigation levels caused considerable reductions in many growth parameters and the total yield. But we can save 15% of the water used with an average total yield of 39.15 Mgha-1 and a yield shortage of 14.1% in both seasons. This is an acceptable level of decrease in view of the 36.3 Mgha-1 national average according to the 2017 Egypt’s Agricultural Statistics. The application of compost at different rates increases the growth, quality and quantity ​​of cauliflower at different water deficiency levels. The highest application rate of compost + 100% of FI recorded the highest values ​​in the characteristics of vegetative growth, total yield and NPK content in curd. The treatment 85% of FI + 14.4 m3 compost / ha came in the second rank recording significant differences with all other treatments in both seasons. The results also indicate that the water productivity in the case of 85% FI is significantly equal to the water productivity in case of 100% of FI in both seasons. It is; therefore, concluded that compost applications minimized the negative implications of deficient irrigation on cauliflower production.

Increasing consumer awareness has contributed in establishing food safety issues and environmental concerns through introducing organic and bio-approaches as substitutes for the traditionally chemical fertilization. However, the efficiency of these fertilizers seemed to be relatively low when compared with the traditional mineral fertilizers. This study postulates that algae extracts of Chlorella sp. might stimulate the growth of plants. To examine this assumption, a field study was conducted for two successive seasons (2015/2016 and 2016/2017) using different N-sources e.g. organic (compost), bio (Azotobacter chroococcum and Azospirillium lipoferum) and mineral (ammonium nitrate) fertilizers with or without algeal extracts of Chlorella sp. to investigate their efficiency for improving the growth parameters and yield components of broccoli plants grown on a sandy loam soil. Results reveal that the highest increases in uptake of NPK were attained for the application of “compost + ammonium nitrate + biofertilizer”. Such improvements resulted in concurrent increases in plant height, number of leaves per plant, leaf area; shoot fresh weight, chlorophyll a and b, curd weight and diameter, vitamin C, TSS, total phenol and antioxidants content in broccoli heads and the outcome head yield. Moreover, the combination between different N-sources and foliar spray of alga extract resulted in further significant increases in NPK uptake by plants and this in turn improved significantly, the abovementioned growth parameters and yield components. Accordingly, our results support the hypothesis indicating that algae extracts improved significantly the growth parameters and yield components of broccoli plants grown on a sandy loam soil.

A field experiment was conducted on melon (Cucumis melo var. reticulatus Naud, cv. Rodin hybrid) grown in a sandy loam soil during the two successive seasons of 2015 and 2016 in a farm near EL-Sadat City, Minofia Governorate, Egypt to assess the response to foliar spray with four treatments i.e., distilled water (DW), yeast extract (YE), Lithovit® (micronized calcium carbonate) (LV) and Delfan® (amino acids) (DF), and two treatments of nitrogen application i.e., N1: 50% of the recommended N as mineral-N + 50% of the recommended N as organic manure (compost), and N2: 100% of the recommended rate as mineral-N. The recommended rate of N is 170 kg N ha-1. Lithovit gave the highest increase in plant length, weight of shoots, leaf area per plant, total chlorophyll, fresh yield, nutrient uptake, fruit diameter, total sugar, and total soluble solids. In some plant traits (fresh yield, nutrient uptake, fruit diameter, total sugar and total soluble solids) YE gave the second highest increase. N1 treatment was superior to N2 in nearly all traits. Spraying with both LV and YE gave the highest fresh yield and the best fruit quality. LV was highest either by using 50% mineral-N + 50% organic-N or 100% mineral-N, while YE was highest with 50% mineral-N + 50% organic-N. This increase for the above mentioned treatments reached 28.78, 27.27 and 26.30 % as an average in both seasons for total yield, as compared with plants supplied with 170 kg mineral-N and sprayed with distilled water (control).

Two field experiments were carried out at the experimental Farm of the Faculty of Agriculture, Moshtohor, Benha university, Qalubiya Governorate, Egypt during the two successive seasons of 2010/2011 and 2011/2012, to study the effect of foliar application with bulk or nano-titanium dioxide (TiO2 <10 nm) with three levels (0.01, 0.02 and 0.03 %) on the growth and nitrate content of lettuce (Lactuca sativa var. capitata cv. Great lakes) As a photocatalyst, nano-TiO2 under light could cause an oxidation–reduction reaction. The nano-TiO2 treatments have obvious effects on the improvement of growth and development in lettuce; however, bulk TiO2 treatments have only little effects. It was demonstrated that nanoanatase TiO2 (0.03%) could greatly improve growth (fresh and dry weight) and pigments of photosynthesis (β-carotene, chlorophyll a and b) of lettuce. The results also, showed that TiO2 nano particles (0.03%) recorded the highest total yield (16.434 ton fed-1) and the lowest content of nitrate in lettuce leaves (182.5 µg g-1 DW) as an average in both seasons. Nano-anatase TiO2 treatment could enhance growth, photosynthesis efficiency, activities of nitrate reductase and consequently decrease nitrate content in lettuce plants.