Two field experiments were carried out in the Experimental Station, Faculty of Agriculture, Mansoura University in the two summer seasons of 2014 and 2015 to study the effect irrigation water quantity and foliar application with salicylic acid on growth and yield of potato cv. Spunta grown under clay loamy soil conditions using drip irrigation system. The experiment layout was split plot in based on complete randomized block design with three replications. Quantity of irrigation water (700, 1000 and 1300 m 3 / fed.) were present in the main plots, while foliar application with salicylic acid (0.0, 0.1, 0.2 and 0.3 g /litter.) were assigned in the sub plots. The results indicated that increasing water quantity up to1300 m 3 / fed. led to a significant increase of vegetative growth parameters (Plant height, leaves number, leaves area, number of main stem and foliage fresh weight per plant), leaves chemical composition (N, P, K, chlorophyll a, chlorophyll b and carotenoids), Tubers yield and its physical quality (tubers weight and number per plant, marketable and total yield), Tubers chemical quality (Vit. C, TSS, N, P and K) and plant water relations (Relative water content). On contrary, foliage dry matter percentage, tuber dry matter percentage, hardness, density, electrolyte leakage and water use efficiency were decreased. With respect to the effect of foliar application of salicylic acid, the data exhibited that, the mentioned characters were increased compared to untreated plants except electrolyte leakage. The interaction between irrigation water quantity and spraying salicylic acid showed that the combination which consist of 1300 m 3 / fed. and 0.2 g/l salicylic acid gave the highest values for most effective previous parameters.

No abstract

No abstract

The experiment was performed to assess the possibility of overcoming NaCl salinity stress by foliar sprays of summer squash ‘Eskandrani’ with salicylic acid (SA) at the concentration of 10-6 M. NaCl treatment caused reduction of shoot fresh weight, leaf number per plant, fruit yield, concentrations of potassium in aerial parts, and the concentration of chlorophyll in leaves. Plants grown under salt stress conditions had higher shoot sodium concentrations than plants untreated with NaCl. Foliar application of SA ameliorated partly the negative effect of NaCl treatment. The beneficial effect of SA was also observed in non-stressed plants, increasing the shoot potassium accumulation and leaf photosynthetic pigments status, and decreasing sodium accumulation in shoots.

Nitrogen (N) fertilization plays a central role for improving yield in different vegetable crops and high N assimilation is desired to produce higher fruit yield. Several studies showed that salicylic acid (SA) application increases plant growth and productivity, but no attempts have been made to investigate the interaction effects of SA and N-nutrition. The aim of this study was to analyze the effects of different Nrates and SA concentrations, and their interaction on plant growth, photosynthetic pigments and fruit yield. Field experiments were carried out during two consecutive growing seasons under Egyptian conditions using different combinations of N and SA rates. Plant biomass and fruit yield were increased linearly in response to N addition from 0.0 to 90 kg/fed. in both years, however, this effect was true for photosynthetic pigments, especially chlorophyll a, b and total chlorophyll, in the second year of cultivation. Salicylic acid application showed mostly a significant increase in the previous traits under all N-rates. Carotenoids content in leaves was not affected significantly by N and SA in the first sampling date, however, in the second date it affected negatively by N fertilizer. The above mentioned results revealed a synergism between N fertilizer and SA application. This study showed that SA addition increased plant growth and yield mainly by increasing the N recovery from the soil.