Two field experiments were conducted in a sandy soil at Um Saber village, Kom Hamada, (latitude of 30.52° N and longitude of 30.79° E), El-Beheira Governorate, Egypt, during 2017/2018 and 2018/2019 seasons to find out the optimal levels of phosphorus, boron and magnesium to get the highest yield and quality of sugar beet. Sugar beet variety "Hamza" was sown. RCBD in a split-plot arrangement was used to lay out 27 treatments, represented the combinations of three phosphorus (P) levels (15, 30 and 45 kg P2O5/fed), three foliar levels of boron "B" (zero, 75 and 150 ppm) and three magnesium "Mg" levels (zero, 5 and 10 g MgSO4.7H2O/l). Raising P-level to 30 kg P2O5/fed considerably increased sucrose%, extracted sugar% (ES%), quality index (QI), sugar yield/fed in the 2 nd season, as well as root diameter, root fresh weight/plant (RFW) and root yield/fed, while, sugar lost to molasses (SLM%) was markedly decreased. Increasing B-level to 150ppm appreciably increased RFW, sucrose%, ES%, QI, root and sugar yields/fed. Raising Mg-fertilizer level to 10 g/l sharply increased RFW, sucrose%, ES%, QI, root and sugar yields/fed in both seasons, while SLM% substantially reduced in the 2 nd one. Effects of the significant interactions among phosphorus, boron and magnesium levels on the studied traits were discussed. Under the environmental conditions of this study, adding 30 kg P2O5/fed to the soil + spraying 150 ppm boron + spraying 10 g MgSO4.7H2O/l could be recommended to attain economical root and sugar yields/fed, as well as the best quality of sugar beet.

In line with sustainable agriculture that depends on modern methods and new sources of nontraditional irrigation, a field experiment was conducted at a privet farm behind Cairo-Alexandria Desert Road, Giza, Egypt during two seasons to evaluate five sugar beet varieties under water salinity stress condition. The present work included 15 treatments; represent five sugar beet varieties: viz. Multi-germs (Amina, Farida, and Faten) and Mono-germs (Unners and Sharleston), in combinations with two salinity treatments (Magic-Sal (13% humic acid + 20% carboxylic acid) and Sal-Wax (50% carboxylic acid) components) compared to control application. Results indicated that salinity treatments help in early stages to increase the emergency percentage of sugar beet varieties under high salinity water stress. As compared to control treatment, salinity treatments significantly increase proline accumulation, leaf relative water content (LRWC %),and root yield, but, it caused a reduction in quality parameters (sucrose, purity, and extractable sugar percentages) in both seasons. On the other hand, variety (Amina) overpassed the other varieties under salinity water stress with respect to germination ratio, proline content, LRWC%,and root yield (ton/fed) in both seasons. While, Sharelston variety surpassed significantly the other studied varieties with respect to sucrose, purity, and extractable sugar percentage (ES%) in both seasons.The distribution of stomata density of leaf increased as salinity water stress level increased. Results also showed that five sugar beet varieties under two salinity treatments (Magic-Sal or Sal-Wax) had positive effects and increased stomata area, but stomata density and its index as well as stomata closure% decreased compared with nonuse.

Two field trials were carried out at Tamiya Agricultural Research Station, (latitude of 29.58°N and longitude of 30.96°E), Fayoum Governorate,Egypt, during 2018/2019 and 2019/2020 seasons to study the relative importance of nitrogen-fixing bacteria i.e. Bacillus polymyxa (BC)and Azospirillum brasilense(AZS) as a soil drench under mineral nitrogen fertilizer levels and their effects on some sugar beet varieties. A split-plot design was used. Four treatments of nitrogen fertilization (80 kg N/fed "control", 60 kg N/fed + soil drench with BC, 60 kg N/fed + soil drench with AZS and 60 kg N/fed + soil drench with a mixture of BC and AZS) were occupied the main plots, whereas, six varieties (Beta303, Sirona, Panther,Des9003, Athospoly and Maximus) were distributed randomly in the sub-plots. Adding 60 kg N/fed + soil drench with a mixture of AZS and BC was adequate to produce the economical values of extractable sugar%, root and sugar yields/fed. Varieties Sirona and Maximus had the highest values of root and sugar yields/fed. Significant interactions effects among nitrogen treatments and varieties on the studied traits were discussed. Root and sugar yields/fed were significantly and positively correlated with leaf area index and crop growth rate, root diameter and its fresh weight/plant, in both seasons. Under the environmental conditions of this study, it was found that sowing Sirona and/or Maximus varieties under fertilization of 60 kg N/fed in combination with a mixture of BC and AZS at 5L/fed twice as a soil drench could be recommended to achieve the economical root and sugar yields/fed.

A field experiment was conducted at privet farm of Demo (29° 17ˋ N, 30° 53ˋ E), Fayoum Governorate, Egypt, during 2018/2019 and 2019/2020 to study the effect of three humic acid treatments, i.e. (0 without humic acid as control, 3.5 and 7 Kg humic acid/fed) on quality and yield traits of eight sugar beet varieties (Santolhne, Pepite, Amina, Beta 401, Dina, Grinta, Sirona and Bts 302). Results indicated that root yield (ton/fed) was increased by increasing the rates of humic acid from 3.5 to 7kg per fed in the first season (27.02 and 29.11 ton/fed, respectively), corresponding (28.08 and 29.72 ton/fed in the second season respectively). Similarly, the content of molasses forming substances showed more reduction in 3.5 than in 7kg/fed treatment. Nevertheless, the trend of increasing content of sucrose and refined sugar was associated with humic acid rates. Results showed that varieties significantly differed among them where, Sirona variety show the superiority over the other seven tested varieties and recorded the highest values of root diameter (14.19 and 15.14 cm, respectively), fresh root weights/plant (1.41 and 1.47 kg, respectively), in both seasons, as well as root yield/fed (29.94) in 2 nd season. While, in first season variety (Bts 302) registered the highest values of root yield (29.42 ton/fed), also this variety recorded the highest sugar yield (4.62 and 5.23 ton/fed, respectively) in both seasons. Highly significant interaction effects between humic acid and varieties root yield and sugar yield and their related traits in both seasons. it could be concluded that fertilization with humic acid at a rate of 7kg /fed as a soil application to get the maximum of root and sugar yields/fed in sandy soil.

This work was investigated to study the combined effects of water stress levels [60%, 80%, and 100% of irrigation water requirements (IWR)] and different types of soil mulching [non-mulch, organic mulch (paddy straw and sawdust), inorganic mulch (black polyethylene film mulch (BPFM)] under drip irrigation system on growth, some physiological characteristics, yields and quality of sugar beet crop. The study was conducted at a private farm in the vicinity of Cairo-Alexandria Desert Road, Egypt (30° 14' 14.59˝ N latitude and 30° 46' 53.90˝ E longitude) during 2017/2018 and 2018/2019 seasons. The experimental design used was a split plot in a randomized complete blocks arrangement with three replications. The results revealed that most of growth, physiological and yield characteristics significantly increased by increasing irrigation levels from 60% up to 80 or 100% of irrigation water requirements (IWR) in both seasons. On the contrary, quality parameter of sugar beet decreased by increasing irrigation levels from 60% to 100% of IWR. Covering soil with inorganic mulch (black polyethylene film mulch (BPFM)) was significantly more efficient for the growth, physiological and yield parameters followed by organic cover (paddy straw and sawdust) compared to non-mulching in both seasons. The distribution of stomata density of the leaf increased as water stress level increased. There were slight differences between full the irrigation (100%) and moderate stress (80% of IWR) for stomata closure % but stomata closed under severe stress (60% of IWR). The results also showed that, all mulching types under the three water stress levels had positive effects and increased stomata area, but stomata density and its index as well as stomata closure% decreased compared with non-mulch. Finally, the highest sugar yield (ton fed -1 ) was observed under moderate stress (80% of IWR) and covering soil by BPFM.