Due to the expansion of strawberry nursery cultivation, transplant production has become an important industry in Egypt. Nitrogen and phosphorus are the most important nutrients affecting the number and quality of strawberry transplants. However, no empirical research exists addressing the optimal requirements of nitrogen and phosphorus fertilization rates for strawberry nurseries in Egypt, until now. This study was conducted at a private farm in Abo Ghalib, Giza Governorate, Egypt during the two successive summer seasons of 2015 and 2016 to determine the optimal requirements of nitrogen and phosphorus fertilizations for Festival strawberry cultivar nurseries via evaluating the influence of four nitrogen rates (83, 100, 117 or 134 kg N/feddan) and five phosphorus rates (38, 62, 74, 86 or 98 kg P2O5/feddan) in a factorial experiment. Results revealed that increasing the rates of nitrogen and phosphorus fertilizations increased the number of main runners/mother plant and number of marketable transplants/m2, and enhanced all vegetative growth parameters, leaf SPAD readings, leaf relative water content, crown diameter, crown carbohydrates, and leaf mineral content in both growing seasons. On the contrary, both elements had an inverse effect on leaf total soluble phenols. Thus, the study recommends to the nurserymen of Festival straw-berry cultivar to apply 117 or 134 kg N with 98 kg P2O5 per feddan under pure sandy soil condition which gave the highest number of transplants with high quality and subsequent high quality crop in the field.

This study was carried out during three successive seasons of 2010/2011, 2011/2012 and 2012/2013 in a private orchard at 76 km Cairo, Alex. Desert road  to investigate the effect of nitrogen and potassium fertilization treatments and shading with white net on yield, and fruit quality of three-years-old mango (Mangifica indica L.) cv. Keitt grafted on sucary seedling rootstocks planted at 2.5×2.5 meters apart grown in sandy soil under drip irrigation system with wells water .This experiment included nine treatments of fertilization: T1= N 80+ K2O 80 Kg/Fed., T2= N 80+ K2O 100 Kg/Fed., T3= N 100+ K2O 80 Kg/Fed., T4= N 100+ K2O 100 Kg/Fed., T5= N 120+ K2O 80 Kg/Fed., T6= N 120+ K2O 100 Kg/Fed.,T7= N 150+ K2O 80 Kg/Fed., T8= N 150+ K2O 100 Kg/Fed. and control (T9) = N 133+ K2O 90 Kg/Fed.. The results cleared that mango Keitt cv. trees grown under white net shading condition significantly increased yield (kg)/ tree, number of fruit set/ panicle, fruit weight, TSS and ascorbic acid content. Trees supplied with 150 Kg/Fed. nitrogen + 100 Kg/Fed. potassium exhibited the highest yield (kg)/tree, number of fruit set/panicle and  fruit weight under shade . Moreover, the best fruit peel color was achieved with trees received 100 kg/feddan of nitrogen +100 kg/feddan of potassium and grown under screenhouse conditions during the three studied seasons. The higher significant value of acidity and TSS were recorded in trees supplied by 120 units of nitrogen + 100 units of potassium during first and third season. Whereas, the control treatment attained a maximum ascorbic acid content.

Two field trials were conducted at Giza Research Station, with split plot design with three replicates during the two successive summer seasons in 2012 and 2013. The aim of this study was to find out the effect of cotingen for covering seed by four treatments (zero, 7.5, 15 and 22.5 g kg-1 grain) and six nitrogen fertilizer levels (control, 30, 60, 90, 120 and 150 kg fed.-1) on maize yield and yield attributes of single cross 10 cultivar. Stepwise multiple linear regression analysis was used to determine the importance of yield components and to predict the yield under different levels of nitrogen and cotingen rates. Nitrogen levels exhibited significant effect for all studied traits, while cotingen were significant for100-kernels weight; shelling% and grain yield traits only. The interaction between cotingen and Nitrogen was significant for row per ear, shelling% and grain yield. Meanwhile, stepwise linear regression analysis showed that 100-kernels weight, number of kernels per row and shelling% were the most important contributing traits to yield (R2 = 82.11%). The nitrogen rates for maximum yield derived from the four statistical models (linear, logarithmic, quadratic, and exponential) describing the response of yield, using the R2statistic to select a model, which shows how each of the models fits the data. The quadratic model best described the yield responses observed in this study. Further confirms the role of nitrogen and cotingen fertilizers in increasing yield production in maize. The 5th N rate under 3rdcotingen (120 Kg fed-1 + 22.5 and 15g kg-1 grain) produced the highest yield being 34.70 and 34.65 ard. fed-1 over all treatments. This is very close to recommendations. The 4th N (90Kg fed-1) rate under any cotingen level produced higher yield than any nitrogen rate only. Economically, considering optimum N fertilization rate, 105.18 Kg fed-1 nitrogen and 22.5 g kg-1 grain cotingen was the most reasonable level. This is considerably below the current recommendation. Therefore, results confirmed that higher cotingen treatment decreased the optimal nitrogen and increased the yield.

This study was carried out at the nursery of Horticulture Department, Faculty of Agriculture, Ain Shames University during two seasons of 2015 and 2016 to study the effect of sowing medium and fertilization rates on vegetative growth and chemical composition of Swietenia macrophylla seedlings. Three different sowing media were used i.e., S M1= perlite: peat moss: compost (1:1:1), SM2 = perlite: peat moss: compost (1:2:1) and SM3 = perlite: peat moss: compost (1:1:2) (v/v). Also, four fertilization rates were used as follow: without fertilizer (control), 5, 10 and 15 g /plant of hydrocomplex fertilizer .The following data were recorded, stem length (cm), stem diameter (cm), number of leaves / plant, leaf area (cm2) and total fresh and dry biomass (gm). Moreover, chlorophyll a & b leaves contents (mg/g FW.), total carbohydrate content (mg/g DW), nitrogen, phosphorus and potassium content in leaves (% D.W.) were determined. Regarding the effect of sowing medium, the obtained results showed that, using sowing medium which content the highest percentage of compost (1:1:2) significantly increased stem length, stem diameter, number of leaves/ plant, leaf area, total fresh and dry biomass, total carbohydrate content and potassium leaves content in comparison the other growing medium while, the differences were insignificant in chlorophyll a & b, nitrogen and phosphorus leaves content. Concerning the effect of fertilization rates, using fertilization at the rate of 15g/plant caused significantly increased stem length, stem diameter , number of leaves / plant, leaf area, total fresh and dry biomass, chlorophyll a & b content, total carbohydrate  content, nitrogen, phosphorus and potassium leaves content in comparison the other fertilization rates with the exception of leaf area, chlorophyll  a , phosphorus  and  potassium leaves content at the rate of 10g/plant in the second seasons only. As for the interaction between sowing medium and fertilization rates, In general, application of growing medium which contain thehigh ratio of compost (1:1:2) was superior in all  tested characteristics followed by which contain the high ratio of peat moss (1:2:1)at 15 gm fertilizationas compared to the other treatments.

The beneficial effects of boron, zinc and active dry yeast on yield and fruit quality of Zaghloul date palm grown at the Experimental Orchard, Faculty of Agriculture, Assiut University, Egypt was studied during 2011, 2012 and 2013 seasons. The experiment was set up in a complete randomized block design with ten replicates each of one bunch. All treatments were sprayed two times after fruit set and one month later. The obtained results could be summarized as follow: -       Boron, zinc and active dry yeast sprays significantly increased the fruit retention percentage and bunch weight compared to the untreated ones. Yeast application was more effective compared with boron or zinc application. -       Spraying either yeast, boron or zinc at any studied concentration was accompanied with improving fruit quality in terms of significant increase in fruit weight, total soluble solids and sugar contents. No significant differences were detected between spraying with yeast at 250 or 500 ppm, 500 or 1000 ppm zinc, as well as, boron at 1000 or 2000 ppm. Moreover, active dry yeast spraying revealed the highest improvement in palm yield and fruit quality. However, it can be concluded that spraying either boric acid, zinc sulphate or active dry yeast twice after fruit set and one month later increased the palm yield and improved the fruit quality of Zaghloul date palm. Meanwhile, using dry yeast as more effective than both boric acid and zinc sulphate.

This investigation was conducted at Hada Elsham Experimental Research Station, King Abdul- Aziz University during 2007/2008 and 2008/2009 seasons, to study the effects of two irrigation water salinity levels (1200 mg/L and 10000 mg/L), three irrigation water intervals (3, 6 and 9 days) and three sulphur fertilizer rates (0.0, 4.0 and 6.0 t/ha) on seed yield, yield components and seed quality of canola, Pactole cv. The obtained results showed that seed yield kg/ha was significantly increased under the 1200mg/L irrigation water and 6t/ha of sulphur more than the seed yield/ha under the effect of 1200 mg/L irrigation water with 4 t/ha sulphur or 10,000 mg/L irrigation water with 6t/ha sulphur with no significant differences between the two later treatments. Irrigation every 3 days significantly dominated over the irrigation every 6 or 9 days on seed yield and yield components. Irrigation with 10.000 mg/L salinity water significantly decreased No. of branches /plant, No. of fruit/plant and seed weight/ plant. Besides, Protein content of the seed as well as oil content increased as water salinity increased in both seasons. As sulphur fertilizer rate increased seed yield, yield components protein and oil contents of seed significantly increased, in the two studied seasons.

This study was conducted for comparing three slow release N fertilizers namely, sulphur-coated urea (SCU), phosphorus – coated urea (PCU) and Enciabene with the conventional fast release N fertilizer namely ammonium nitrate each at the recommended rate of N i.e., 1000 g N/tree/year for growth characters on the three growth flushes, percentages of leaf N, P and K in the Spring growth cycle, date of first bloom, number of panicles/tree, fruit retention %, yield as well as physical and chemical characters of fruits in two mango cvs Figri Kelan and Keitt during 2004 and 2005 seasons. Results showed that suppling the trees of both mango cvs with the three slow release N fertilizers were superior to the application of the fast one in improving shoot length, number of leaves / shoot and leaf area in the three growth cycles, percentages of leaf N, number of panicles / tree as well as physical and chemical properies of the fruits. The slow release N fertilizers slightly advanced first bloom date. Application of sulphur-coated urea (SCU), phosphorus-coated urea (PCU) and Enciabene (ENC) in a descending order, was very favorable in this connection. These results were true for both mango cvs. It is suggested to fertilize the trees of both mango cvs Figri Kelan and Keitt with N at 1000g/tree/year as sulphur-coated urea fertilizer (2.4 Kg/tree/year) for obtaining an economical yield with fairly good fruit quality