Irrigation with high salinity water influences plant growth, production of photosynthetic pigments and total phenols, leading to reduction in crop yield and quality. The objective of this study was to investigate the effects of potassium (K) foliar application in mitigating the negative effects of salt stress on pepper plants. A greenhouse experiment was conducted to investigate the effects of foliar application of potassium (K) on pepper plants grown with different salinity water irrigation (3000 and 6000 ppm as compared to tap water with salinity level of 300 ppm). Irrigation using high salinity water decreased plant height, biomass production, and fruit yield as compared to those of the plants irrigated by tap water. Photosynthetic pigments and total phenols increased in the former as compared to those of the latter plants. The most serious affect was for the plants under highest salinity irrigation (6000 ppm) as compared to that of the plants under moderate salinity irrigation (3000 ppm). Foliar application of potassium mono phosphate (KMP) at 200ppm concentration increased the plant growth, biomass production, and fruit yield. Chlorophyll_a content and total phenols increased significantly with foliar application of 100 ppm KMP. Further increase in foliar KMP concentration to 200 ppm had no significant benefits on photosynthetic pigments and total phenols content. This study demonstrated that foliar application of KMP, to some extent, mitigated the negative effects of high salinity water irrigation on pepper plant growth and fruit yield

No abstract

Inroduction Onion (Allium cepa L.) is considered among the most important vegetable and food crops in Egypt. It is ranked the third in cultivated areas, after potatoes and tomato and also for production and trade in the world and in Egypt. In spite of the production amounts that covers the national consumption needs, but the demand for exportation nowadays grows continuously. Such as interactions between genotype and environment, epistasis and strong environmental affects make difficult to develope workings to promote salinity tolerance of a number of crops. In addition, to understand studies and the high yielding varieties, optimal cultural practices and its responses to moisture and salt stress would lead to qualitative and quantitative improvements in productivity and quality of bulb and seed (Mangal et al., 1989; Rouamba et al., 2001 and Galdón et at., 2008). Renu & Rashid (2001) noticed that flax plants exhibited enhancement of shoot bud formation after exposure to salt treatment.

A pot experiment was conducted in the greenhouse of the National Research Centre at Dokki, Cairo Egypt during 2010 -2011 winter seasons to evaluate the effect of different salt stress degrees on the growth and yield characters. The salinity treatments were: Irrigation by three concentrations of diluted seawater (2000, 4000 and 6000 ppm) more than the control treatment (irrigated by tap water 250 ppm) and spraying ascorbic acid (AsA) with two concentrations (100, and 200 ppm). Salinity depressed the pods, straw, straw+ pods and seeds weight relative to the control plants but the depression of these traits showed its maximum values when plants subjected to the higher level of salinity (6000 ppm) markedly more than that with the other two levels of salinity. Slight differences in the mentioned characters of plants irrigated by solution contained 2000 or 4000 ppm. Gradual depressions in pods/straw, seeds/pods and seeds/straw ratios were detected with the increase in salt concentration in water of irrigation. Ascorbic acid application led to increase the pod, straw, total and seeds yields. The high increment in pods weight and seeds to straw ratio wereshown by using 100 ppm ascorbic acid but the increment in straw, totalseeds weight and seeds/pods and pods/straw ratios.Furthermore, the absorption rate of N, K, P, Ca, and Mg ions from the growth medium significantly inhibited as a result of treatment with diluted sea water. Meanwhile, significant increases in the uptake of these ions were obtained in response to ascorbic acid application.

T HIS investigation was carried out to study the preserving of Egyptian pomegranate aril with different thermal and chemical pre-treatments to increase shelf life and maintain quality of Arils. TSS, pH, acidity, vitamin C, T. Phenol, antioxidant activity color characteristics, microbiological and sensory evaluation were determined for the different thermal and chemical pre-treatments of on Egyptian pomegranate aril for 21 days. All untreated and treated samples were storage at 4 o C for 21 days and the previous parameters were analyzed after zero, 7, 14 and 21 days. Results evidenced that it was found that the Total soluble solids (TSS) content, titratable acidity and pH decreased during storage of pomegranate arils in pre-treated samples through 21 days storage at 4 o C. During successive storage period the Hunter color Lab* value and parameters (L*, a*, b*, ΔE, C*, H* and BI) of arils decreased, showing a decrease in brightness (L*), redness (a*) & yellowness (b*). On 21 th day of storage the least microbial count was observed for samples thermal pre-treated with SB and WB, then chemical pre-treated with SO 2 and PS. The results showed that the non-enzymatic browning and the concentration of total anthocyanine (TACN) were low in SO 2 and PS pre-treatment pomegranate arils samples compared with un-treatment samples. However, all pretreatments did not effect on total phenol contents. The sensory score revealed that there was not much variation in color scores over the storage period. On 21 th day of storage highest sensory score was observed for arils treated with SO 2 and PS pre-treated pomegranate arils. The present study exposed that the thermal and chemical pre-treatments such as water blanching (WB), steam blanching (SB), sodium metabisulfite (SO2) and potassium sorbate (PS) can be applied for increasing shelf life of pomegranate arils maintaining the functional compounds during storage at 4 o C.

No abstract