The influence of salicylic acid (SA) on growth, yield, fruits’ quality and enzymes’ activities was monitored in strawberry plants cv. Camarosa grown under salinity stress via two pot experiments in two successive years of 2018 and 2019. The examined concentrations of SA were 30, 60, and 90 ppm, which foliary applied in addition to control (sprayed with water), while the used levels of salinity were 20, and 40 mM as NaCl as irrigation application in addition to control (without salinity). The results showed a significant effect of salinity at 40 mM where the mean values of shoot fresh and dry weights, chlorophyll, leaves’ NPK, yield plant⁻¹, yield ha⁻¹, and fruits’ ascorbic acid were significantly decreased. However, the 40 mM salinity resulted in a significant increase in leaves’ content of Na and proline as well as catalase (CAT) and peroxidase (POD) enzymes’ activity and the fruits’ TSS and acidity. The application with 90 ppm SA was found to be the most significant positive treatment for all of the studied characters except the Na leaves’ content. Regarding tolerance index percentages (STI%), the high values of CAT, POD, and proline referred to the ability to use them as indicators for strawberry salinity response in other physiological and plant breeding studies. The findings of this study suggest that the 90 ppm SA foliar application can ameliorate the negative effect of salinity on the growth of strawberry cv. Camarosa.

Two field experiments were carried out during the two successive seasons of 2015 and 2016 in a newly reclaimed private farm at Abu El-Matamer region, El-Beheira Governorate. The objective of this investigation was to study the main effects of four N-fertilizer levels (0, 20, 40, 60 kg N fad-1) in the form of ammonium nitrate (33%) and three different stimulator treatments; humic acid (1 and 2 gmL-1) fulvic acid (2.5 and 5 gmL-1) and tryptophan (0.5 and 1 gmL-1 ), as well as their interactions on vegetative growth, leaf chlorophyll, N, P and K contents and yield and its components characters of common bean cv. Nebraska. The obtained results indicated that application of mineral N, significantly increased all the studied growth, minerals and yield characters. The highest N rates (60 kg N fad-1) was remarkable and associated with the highest mean values of the most studied characters. Moreover, the biostimulator treatments application exhibited higher mean values of all studied growth, minerals and yield parameters compared to control. Tryptophan treatment was more pronounced in this concern. It could conclude that fertilization of common bean plants with 60 kg N fad-1 combined with tryptophan at 1 gmL-1 was the best interaction treatment for all the studied parameters.

Two field experiments were conducted to study the effect of foliar applications of salicylic acid (200 ppm), folic acid (100 ppm) and/or Mancozeb (50% and 100% of recommended dose) on the growth, yield, quality, enzymes activities related to stress, and disease severity% of tomato plants cv. “Fayrouz” grown under biotic stress conditions of early blight (A. solani) disease. The results showed significant effects of the applied treatments on all the studied characters with a noticeable superiority of the treatments of SA+FolA+50%Rec followed by 100%Rec without significant difference between them, which reflects on high mean values of growth, chlorophyll, yield, fruit quality, total phenol, and enzymes activities, in both seasons. Also, the best-applied treatments were related with the highest significant increases in leaves’ total phenol content in addition to enhancing the activity levels of POD, PPO, and CAT enzymes, which were found to significantly decrease the disease severity%, in both seasons. It could be suggested to reduce the recommended dose of mancozeb fungicide up to 50% by using 200 ppm of salicylic acid with 100 ppm of folic acid for ameliorating the deleterious effects of early blight and producing tomato safer for human consumption and eco-friendly.

Tow field experiments were conducted during the seasons of 2020/2021 and 2021/2022 at the experimental farm Etay El-Baroud research station to investigate the effect of foliar application with gibberellic acid (GA3) at 50 and 100 ppm and the chitosan (CS) at of 100 and 200 ppm, in addition, to control for each to Giza Red onion. The results showed significant and positive effects of the examined concentrations of GA3 or CS on all the studied characters except leaves number and shape index, in both seasons. Concerning the interaction effect, all of the studied characters were enhanced significantly in all treatment combinations between GA3 and CS levels. The treatments of GA3 (50 ppm) with CS (200 ppm), GA3 (100 ppm) with CS (100 ppm), and GA3 (100 ppm) with CS (200 ppm) were found to give the highest mean values for all characters, in both seasons without significant differences among them. Also, the results revealed some kind of synergistic effect between GA3 and CS where the combined application was found to be more effective in onion plants performance thane the single ones that gave the ability to reduce the used doses of GA3 by 50%, which, consequently, reduce the expected hazardous of using gibberellins.

The most dangerous biotic-stress impact in confronting the common bean was damping-off disease. This study aims to examine eco-friendly means instead of using traditional chemical fungicides. Pre-sowing seeds treatment with gradual doses of gamma irradiation (0, 20, 40, 60, 80, and 100 Gy) was chosen compared to Vitavax fungicide. Two germination tests and two open field experiments were conducted during summer seasons of 2021 and 2022 using common bean "Giza-7". Generally, all the treatments were affected significantly all of the studied characters, in both seasons. In particular, the treatments of 20 Gy or Vitavax were significantly enhancing the vigor of common bean plants in confronting the biotic stress of damping-off disease. They, significantly, increased the germination%, survival%, plant height, shoot fresh and dry weights, chlorophyll reading, 100-seed weight, seed yield fad-1, seeds content of N, P, and K%, seeds crude protein, enzymes activity of CAT, POD, and PPO, leaves total phenols and total soluble proteins without significant difference between them. While, the same two previous treatments shared their ability to significantly reduce pre-, post-, and total damping-off percentages, in both seasons. Concerning the cluster analysis of total soluble proteins, the results revealed that the closest treatments were 20 Gy and Vitavax. This study's findings suggest the capability of replacing the fungicide Vitavax with a low dose of gamma irradiation (20 Gy) as pre-sowing seeds treatment for enhancing the physiological status of common bean plants in addition to disease aspects when grown under the biotic stress of damping-off disease. gamma irradiation, biotic stress, damping-off disease, enzymes activity.

Two field experiments were conducted in the summer seasons of 2020 and 2021 to study the effect of potassium fertilization (0, 40, and 80 Kg K2O fad-1), foliar application of NAA (0, 5 and 10 ppm), and CKs as two types (BAP and TDZ at 0, 10 and 20 ppm) on yield and quality of potato tubers c.v. “Hermes”. Generally, the examined levels of each studied factor were affected significantly on all yield and tubers quality traits, in both seasons. Also, the best level of each factor was 80 Kg K2O fad-1, 5 ppm for NAA and 10 ppm TDZ for CKs. According to the first order interaction between the pairs of three main factors, the best treatment combinations were 80 Kg K2O+5 ppm NAA, 80 Kg K2O+10 ppm TDZ, and 5 ppm NAA+ 10 ppm TDZ, in both seasons. Moreover, the second order interaction among the three studied factors was found to affect significantly all the studied characters with superiority of treatment combination of 80 Kg K2O+5 ppm NAA+10 ppm TDZ, in both seasons. The treatment combination of 80 Kg K2O+5 ppm NAA+10 ppm TDZ could be a recommended for increasing potato yield with keeping high quality of potato tubers.