Using multivariate analyses to evaluate the impact of proline on sugar and root yield traits in sugar beet under saline conditions

Two field experiments were conducted at the Agricultural Experimental Station, Faculty of Agriculture, Cairo University, Giza, Egypt during 2013/2014 and 2014/2015 seasons to study the agro-economic effect of three nitrogen fertilization rates (60, 80 and 100 kg N/fed), three cropping systems (sugar beet sole, sugar beet + canola and sugar beet + onion) and four multi-germ sugar beet varieties (Farida, Carola, Gloria and Demapoly). The experimental design was a split- split plot in randomized complete block arrangement with three replications. Results revealed that increased N rates, from 60 to 100 kg fed-1 and Growing sugar beet as a sole crop significantly increased root weight, root yield and sugar yield in both seasons. Sugar beet variety Carola was superior in root weight, root yield and sugar yield followed by the variety Farida in both seasons. The main effects of nitrogen, cropping systems and varieties had no significant effect on root quality traits in terms of total soluble solids%, sucrose%, purity% and extractable sucrose% during the two seasons. The highest significant values of mean root weight (1.019 and 1.109 kg), root number (28.69 and 28.21 thousand plants/fed), root yield (29.35 and 31.47 ton/fed) and sugar yield (3.72 and 3.75 ton/fed) resulted from fertilized sugar beet sole plants with 100 kg N/feddan in the 1st and 2nd seasons, respectively. Irrespective of cropping systems, fertilized sugar beet varieties Farida and Carola plants with 100 kg N/ feddan gave the highest mean values of root weight, root yield and sugar yield during the two seasons. The interaction of cropping systems x varieties had a significant effect on mean root weight, root number, root yield and sugar yield during the two seasons. Among the tested varieties, sole planting of Carola had maximum beet root weight (0.953 and 1.043 kg), beet root yield (28.65 and 31.07 ton/fed) and sugar yield (3.69 and 3.74 ton/fed.) in the 1st and 2nd seasons, respectively, followed by Farida when planted as a sole crop. The highest and significant root and sugar yields were obtained from the sugar beet variety Carola when planted as a sole crop and fertilized with 100 kg N/feddan during the two seasons. It was observed that irrespective of sugar beet varieties and cropping systems, the highest cost of production and gross revenue were recorded when plants received 100 kg N/feddan. The cost of sugar beet (sole) production was LE. 5350 fed-1 against the production costs of LE. 5650 and 6950 fed-1 when sugar beet was intercropped with canola and onion, respectively. The highest gross revenue (19002 and 17650 LE/fed) resulted from intercropping sugar beet varieties Carola and Gloria, respectively with onion under 100 kg N/feddan. The maximum net returns was obtained under combination of sugar beet variety Carola + onion (12052 LE/ fed), followed by sugar beet variety Gloria + onion (10700 LE/fed) when plants fertilized with 100 kg N/feddan. The maximum cost benefit ratios of 1.73 and 1.54 were obtained with nitrogen rate of 100 kg/feddan under combination of sugar beet variety Carola + onion and sugar beet variety Gloria + onion, respectively. The results showed that for obtaining higher net returns from the unit area, preference may be given to intercrop sugar beet variety Carola with onion and fertilized plants with 100 kg N feddan-1.

Soil salinity is affecting plant production, including sugar beet growing, especially in Al-Fayoum Governorate, Egypt. Screening for salinity tolerant varieties is one of the most often methods used by breeders in sugar beet. The present study was carried out at Al-Fayoum Governorate, (29°17ˋ N; 30°53ˋ E), Egypt, during 2017/2018 and 2018/2019 growing seasons. The objective was to evaluate the effect of saline soil of three locations (villages) S1, 3.57 dSm-1 (Monshat Sinnuris), S2, 8.6 dSm-1 (Monshat bani Othman), and S3, 11.84 dSm-1 (Monshat Tantawy) on plant growth, quality and yield traits of ten multigerm sugar beet varieties. The experimental design was a randomized complete block design with three replications. Results showed that root yield and sugar yield, as well as root dimensions were significantly decreased by increasing soil salinity levels as compared with the control treatment. Under severe soil salinity, Florima variety was superior in root and sugar yields [13.71 and 1.82 ton/fed (fed=0.42 ha)]; on the other hand, Euklid variety recorded the lowest values (11.38 and 1.39 ton/fed), respectively. As for the interaction between soil salinity levels and sugar beet varieties, the highest values for root and sugar yields were recorded by the varieties Florima, Toro, Cleopatra, and Tarbelli, under severe soil salinity (11.84 dSm-1). The results recommended the above four varieties to be cultivated by farmers under saline soil; these varieties are tolerant to soil salinity and they can produce stable root and sugar yields in the stressed soil. High broad-sense heritability estimates were obtained by extractable sugar (94.9%), root length (93.36%), and root weight (92.05 %). Heritability of metric traits is of great significance to the breeders as its magnitude indicates the accuracy with which a variety can be recognized by its phenotypic expression. Results showed that four varieties (Florima, Toro, Cleopatra and Tarbell (had a salinity susceptibility index (SSI) based on root and sugar yields of <1 and were relatively tolerant to salinity stress.

Sugar beet is known globally as one of the most important sources of sucrose. Sugar beet, which provides raw materials to many industries, creating an important employment opportunity in the regions where it is cultivated. In this study, yield and quality parameters of eight different sugar beet varieties were determined by different analytical methods. The experiment was carried out in 2024 at the experimental field of the Faculty of Applied Sciences, Muş Alparslan University, utilizing a randomized block design with three replications. Following a seven-month vegetative period, yield and quality analysis of the harvested beets were carried out, allowing for the determination of relationships between variety and traits. Statistically significant and important differences were found among the sugar beet varieties in terms of the parameters analyzed. Notably, the Lamberta variety came to the forefront in terms of storage root yield parameters (root weight, root length, single plant weight). Consequently, this variety displayed the highest average root yield compared to other varieties. While the Agatella variety demonstrated high averages for dry matter content and polar sugar content, it exhibited lower storage root and sugar yields. These findings suggest a negative correlation between sugar content and storage root yield and sugar yield. Overall, the Lamberta variety stood out in terms of root yield, while the Annamira variety stood out in terms of sugar yield. As a result of the research, sugar beet varieties varied between root diameters of 9.11-15.41 cm, root lengths of 15.34-18.43 cm, root weights of 646-2892 g, dry matter content of 20.87-24.40%, polar sugar content of 16.68-19.41%, root yields of 5196-8229 kg/da, and sugar yields of 908-1348 kg/da. According to the “which-where-won” model of GGE biplot analysis, the studied traits were clustered under 3 mega environments.

A field experiment of drip-irrigated sugar beet (Beta vulgaris, L.)was conducted at the research field of the Nubaria Agricultural Research Station, Egypt at 30° 54' 21'' N, 29° 52' 15'' E and 11.0 m altitude above mean sea level during 2011/2012 growing season.The aim of the present study was to evaluate the impact of deficit irrigation on sugar beet productivity, and quantitative and qualitative characteristics of sugar beet root yield under drip irrigation. The sugar beet (Beta vulgaris, L) variety Gloria (polygerm) was planted on 13 October 2011. Sugar beet plants were thinned to one plant at distance of about 0.3 m on the rows at the 4th week after planting. After emergence, the plots were irrigated by the drip irrigation method.The present study consisted of 5 treatments. The irrigation treatments were based on replenishment of soil water depletion according to reference evapotranspiration (ET0). The irrigation treatments were: Irrigation at 40, 60, 80, 100 and 120% of ET0. Sugar beet vegetative growth, sugar beet yield and yield components, and juice quality and impurities content were determined. The results clearly indicated a significant effect of different irrigation regimes on all sugar beet growth characters except leaf area per plant and foliage water content as compared with control (100% of ET0). The results alsoclearly indicated a significant effect of irrigation regimes on sugar beet yield and yield components. Irrigation at 40% of ET0 gave a highest value of root length (32.7cm) and root diameter (13.0 cm), but 60 % of ET0 gave the highest values of average root fresh weight (1500 g/plant) and root gross yield (100.0 ton/ha). The highest value of root/top ratio (1.31) was attained at irrigation with 120% of ET0. The percent increase of root gross yield of sugar beet at 60% of ET0 was account as 49.99%, for gross sugar yield was 45.66% and for white sugar yield was 44.16% over the common treatment (100% of ET0). The different irrigation regimes significantly affected the juice quality and impurities contents of sugar beet. Irrigation at 40 and 60% of ET0 gave the highest value of TSS (total soluble solids), 23.0%, white sugar yield (13.71 ton/ha), gross sugar yield (16.97 ton/ha) and loss sugar yield (3.26 ton/ha) were attained at 60% of ET0. The highest values of polarity or sucrose content (17.76 %), effective polarimetric assay of sugar (15.46%),thick purity juice, TPJ (90.66%), white sugar content (14.94%) and juice purity (84.13%) were attained at 60% of ET0. The increase in sugar yield was due to both increase in sugar content and root yield in which sugar yield was adversely affected by water deficit. Increasing the impurities in the root of stressed plants decreased extraction of white sugar. So, deficit irrigation improved sugar beet quality by reducing these impurities. The findings in this study strongly recommend that up to 60% deficit irrigation of sugar beet would be advantage if the farmers target is to maximize root and white sugar yield. But if the target is to put more area into production under limited water supply, irrigation at 40% of reference evapotranspiration in sugar beet may be feasible.

Field experiment was carried out at Rashedia field, Ninavah during 2001—2002 and 2002-2003 with clay loam soil to study the effect of different level of potassium fertilizer (0.0,30,60 and 90kg ha-1) on growth and yield of three sugar beet varieties (Tenor, Tripel which are monogerm and Panama is multigerm ).Results indicated that root yield, sugar percentage and total sugar yield had significant effect over two 30 and 60kg ha-1 potassium fertilizer, while total soild soluble material and extractable sugar yield were significant under 30,60or 90kg ha-1of potassium. It had noted a reduction in juice purity percentage when it used 90kg ha-1 of potassium. Tenor and Panama varieties had to excel in root yield, sugar percentage and total sugar yield, also Panama variety had to surpass in total solid soluble material and extractable sugar yield. Significant result was obtained in extractable sugar yield when it used all the different level of potassium (30, 60 or 90kg ha-1) with Panama variety. There is a significant and positive correlation between total sugar yield with the sugar percentage and root yield. Also extractable sugar yield had correlation with the percentage of total solid soluble material and root yield.

Two field experiments were carried out during 2008/2009 and 2009/2010 seasons at Kafr El-Hammam village, Sharkia Governorate to study the effect of harvesting dates on productivity of some sugar beet varieties. Sugar beet varieties Gazella, Carola and Lola were planted on 1st October in both seasons. Harvesting dates were done at 180, 195 and 210 days from sowing. The experimental design was a split-plot design with four replication, harvesting dates were allocated in the main plots and varieties in the sub-plots. Results showed that: delaying harvesting dates from 180 to 210 days from sowing significantly increased root fresh weight (g/plant), sucrose%, as well as root and sugar yield (tons/fed). While, nitrogen%, sodium%, potassium% were decreased significantly in both seasons. Harvesting dates at 195 days from sowing gave the highest values. Sugar beet varieties gave significant increase for root fresh weight (g/plant), sucrose%, as well as, root yield and sugar yield (tons/fed) in both seasons. While, sodium%, potassium% decreased significantly in both seasons. However, root diameter in the 2nd season only. The interaction was significant in both seasons for root fresh weight (g/plant), sucrose%, root and sugar yield (tons/fed). However, root diameter in the 1st season and sodium and potassium% in the 2nd season., respectively. In general it can be concluded that harvesting Lola sugar beet variety at 195 days from sowing was the best treatment for maximizing sugar beet productivity in the newly reclaimed soils under the environment of this study.

In the period of 2016–2018, two series of field studies on organic sugar beet growing (Beta vulgaris L.) were carried out in northern Poland on Luvisol loamy soil (medium–heavy) soil in Bałcyny and Płonne. The aim of this study was to decrease the yield gap between organic and conventional beets. Factors to increase the yield of organic beet were differentiated fertilization (cattle farmyard manure (FYM), compost, and Bioilsa) and choice of varieties (Eliska, Jampol, and Sobieski). The reference point was the conventional cultivation of the same sugar beet varieties, fertilized with manure and NPK mineral fertilizers, the prevailing standard of sugar beet cultivation in Poland. High sugar beet root yields exceeding the average yield in Poland by 25–30% were obtained in both studies, both in conventional and organic cultivation. Higher root and white sugar yields were obtained in the study conducted at Płonne (with similar soil conditions to those at Bałcyny), but they were characterized by higher temperatures during the growing season. The lowest root yields in both experiments were obtained by fertilizing the organic beet with compost (66.1 t per ha in Bałcyny and 78.13 t per ha in Płonne), which were 10.8% and 8.5% lower than the conventional crop, respectively. Higher root yields in organic cultivation were obtained by fertilizing the sugar beet with FYM, which reduced the differences from conventional beet to 7.7% in the study in Bałcyny and 2.1% in the study in Płonne. Thus, the results showed no need to convert cattle FYM to compost. The highest root yields in organic cultivation were obtained by fertilizing the sugar beet with Bioilsa N 12.5 supplemented with mineral fertilization of K, Mg, and S (Patentkali). This fertilization provided a yield of 78.1 t of roots per ha in Bałcyny, which is a reduction in the yield gap to 1.4%, a statistically insignificant value. Moreover, in the study at Płonne, organic sugar beet fertilized with Bioilsa and Patentkali yielded 86.7 t of roots per ha, compared to 85.6 t per ha of conventional beet, so a yield gap was not seen here. The choice of varieties was also of great importance for root and pure sugar yields in both farming systems. The lowest yields were obtained from the Eliska variety, and at Bałcyny, a change of beet cultivar to Jampol increased the organic root yield from 68.8 t per ha to 76.0 t per ha, while reducing the yield gap from 10.1% to 2.2%. At Płonne, replacing the Eliska variety with Jampol reduced the yield gap between organic and conventional roots from 6.6% to 0.3%.

Two field experiments were conducted at Gelbana district Sahl–El Tina plain (North Sinai) laying between longitudes 32 o 20 and 32o 33 east and latitudes 30 0 57 and 310 04 North during two successive seasons 2011/2012 and 2012/2013 to study the effect of soil application of inorganic nitrogen fertilization at rates of 50, 75 and 100 kg N fed -1 and organic humic acid fertilizer at rates of (0- 10 kg fed-1)and its impact on some chemical soil properties, growth, chemical composition, yield and quality of some sugar beet varieties (Mirador, Panther and Athospoly). A split- split plot design with three replicates was used in the two seasons. The highest values of available K content in soil in both seasons and available N content in the 1st season were recorded by Panther variety. Panther variety occurred a significant superiority over the other varieties in vegetative traits i.e. diameter, weight, dry matter %, of root, photosynthetic pigments i.e. chlorophyll a, b and carotenoides and proline as will as root and sugar yields in the two season. All quality parameters (total soluble solids %, sucrose% and juice purity %) were insignificantly affected by the tested varieties in the two seasons. Soil application of humic acid exhibited significant increase in available K-content in the soil in both seasons and available N in the 2nd season as will as N, P and K- percentages in sugar beet root in both seasons. Also application of humic acid significantly increased proline concentration in leaves beet by (15.73 and 13.97%), sucrose% by (0.41 and 0.61%), as will as root yield by (22.80 and 28.38 %) and sugaryield by (26.56 and 32.44%) in the 1st and 2nd seasons compare with untreated one. Increasing mineral N-rate significantly increased root and sugar yields/fed in both seasons. Also application of 100 kg N fed -1 recorded the highest values of root yield ( 29.91 and 27.27 ton fed -1) and sugar yield ( 5.53 and 4.71 ton fed -1) in the 1st and 2nd seasons. The interaction between mineral nitrogen fertilizer rates and humic acid (NXH) had a significant effect on root and sugar yields, sucrose%, and proline concentration in both seasons as will as on available K in the soil in the 1st season. However, the interaction between sugar beet varieties and nitrogen fertilizer (VxN) and between sugar beet varieties and humic acid (VxH) had a significant effect on root length, LA, chlorophyll a and carotenoides, proline concentration and root and sugar yields in both season. Meantime, the interactions effects between the three variables under study (sugar beet varieties, humic acid and mineral nitrogen fertilizer rates) insignificantly effected on all traits under studies.

BackgroundSugar beet is considered a very important strategic economic crop, as it comes at the second place for white sugar production in Egypt after sugar cane and the sugar percentage in its roots is 20%. This work was conducted in Egypt as a direct response to bridge the gap which began to expand significantly between the production and consumption of white sugar and the desire for the genetic improvement process to increase the productivity of this crop. Further, as serious attempt to understand the nature of the genetic diversity among a group of sugar beet accessions with different origins, it constitutes an important source for establishing a program of breeding and improving sugar beet crop under Egyptian conditions.ResultsThe process of verifying the existence of significant genetic variation between the eight sugar beet varieties with various origins was carried out through a set of genetic parameters through two growing seasons besides, the data of ISSR markers profile. Further, all the sugar beet varieties were superior in all the studied traits during their evaluation over two agricultural years, where the two sugar beet accessions Oscar Poly and Rass Poly are superior in TSS % and sucrose % traits, Mont Bianco and Sultan in apparent purity % trait, Blino and Sultan in root yield and top yield traits and Rass Poly and Blino in sugar yield trait, respectively. In addition, the values of heritability in broad sense were high in all studied traits except the two traits; sucrose % and sugar yield where their results were appeared medium during both growing seasons. In the same regard, expected genetic advance values showed significant genetic progress in all studied traits during the two growing seasons. As well, highly genetic diversity was obtained between the eight sugar beet accessions through generated 169 amplified fragments from the twelve ISSR primers, 122 of them were polymorphic with 72.18% polymorphism.ConclusionsThe eight sugar beet varieties achieved remarkable and distinctive results for all traits under study during two agricultural years. However, they were differentiated and various from each other. As they differed in their superiority in all estimated traits and they proved to be fertile material for studying in this investigation and very suitable for enriching the breeding and genetic improvement program to promote the sugar beet yield in order to increase the productivity of white sugar in Egypt.

Two field experiments were conducted during 2008/2009 and 2009/2010 seasons at Sakha Research Station, Kafr EL-Shaikh Governorate to study the influence of three nitrogen rates (75, 100 and 125%) of recommended rate (RR=80Kg N/fed), sprayed with Zn, Mn and Fe individually or in mixture, on some chemical composition, juice quality and yield of sugar beet plants. Decreasing N dressing up to 60 Kg N/fed (75% of RR) significantly decreased photosynthetic pigments (chlorophyll a, b and carotenoids) at the age of 120 days from sowing in the two seasons, also a reduction in sucrose% and some technological parameters such as sugar extractable (SEX), sugar losses to molasses (SLM) and sugar coefficient (Sco), yield component (root length, diameter and fresh weight of tops in the two seasons have been recorded. Yields of roots and sugar, uptake of N, Mn and Zn had the same trend. On the other hand, increasing N dressing up to 100 Kg N /fed (125% of RR) significantly increased photosynthetic pigments i.e. chlorophyll a,b and carotenoids at the age 120 days from sowing in the two seasons, Na, K and α- amino N as impurities, sugar loss to molasses (SLM), yields of roots and sugar but juice purity was significantly decreased. Foliar spray with Mn, Zn and Fe individually or in mixture significantly increased chlorophyll a, b and carotenoids in both samples in the two seasons. Sucrose% and impurities as K and αamino N were significantly increased but juice purity was significantly decreased. Root length, diameter, fresh weight of roots and tops, sugar yield were significantly affected. Foliar spray with Zn, Mn and Fe significantly increased their uptake and N uptake. Foliar spray with the mixture of Zn, Mn and Fe exhibited the best treatment, where it gave the highest values of most traits under study. The interaction between N at the high rate and the mixture of Zn, Mn and Fe was the superior treatment where, it gave the highest values for chl a, b and carotenoids, K, α- amino N, juice purity and N uptake.

Ashwagandha (Withania somnifera) is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes) and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant) and crude fiber content exhibited strong association among them and showed significant positive genotypic correlation with yield. Starch-fiber ratio (SFR), determinant of brittle root texture showed strong negative association with root yield. The total alkaloid content had positive genotypic correlation with root yield. So genetic upgradation should aim at optimum balance between two divergent groups of traits i.e. root yield traits (root morphometric traits and crude fiber content) and root textural quality traits (starch content and SFR) to develop superior genotypes with better yield and quality.

Purpose. To investigate the influence of mineral, traditional and alternative organic-mineral fertilization systems on productivity and technological quality of sugar beet roots. Меthods. Long-term field and analytical. Results. Research data on the effectiveness of traditional and alternative fertilization systems in increasing the productivity and technological quality of sugar beet roots are given. The perspective of using straw, green mass of white mustard and mineral fertilizers to obtain high yield and technological quality of sugar beet roots under conditions of sufficient moisture on leached chernozem has been established. Conclusions. The mineral fertilizer system was inferior to the organic-mineral fertilization in terms of efficiency. The maximum dose of mineral fertilizers N120P80K120 ensured roots yield – 67.5 t/ha, sugar content – 17.9 %, sugar yield – 12.1 t/ha. The highest productivity of sugar beet was achieved with the application of 40 t/ha of manure + N90P60K90: yield of roots – 79.6 t/ha, sugar content – 18.2 %, sugar yield – 14.5 t/ha with an increase in yield compared to the control without fertilizers – by 37.0 t/ha, sugar yield – by 6.7 t/ha. The application of straw + green manure + N90P60K90 was determined to be promising under sugar beet: roots yield – 70.3 t/ha, sugar content – 18.2 %, sugar yield – 12.8 t/ha. The specified fertilization system was inferior to the application of 40 t/ha of manure + N90P60K90 in yield by 9.3 t/ha, sugar collection – by 1.7 t/ha. The use of fertilizers insignificantly increased the loss of sugar in molasses compared to the control without fertilizers: with the application of mineral fertilizers - by 0.01–0.05 %, 40 t/ha of manure + N90P60K90 – by 0.07 %, straw + green manure + N90P60K90 – by 0.04 %.

MANY agronomic practices must be need modified to maximize quantity and quality of sugarbeet crop. Two field experiments were sconducted at Belkas town, Dakahlia Governorate, Egypt, near Dakahlia Sugar Company, during two successive winter seasons 2014/2015 and 2015/2016. A comparative study was conducted to assess the performance and stability of four multigerm sugar beet varieties (Beeta vulgaris L.), i.e. Dema-Poly, Pleno, Glloria and Ras-Poly in relation to three sowing dates, i.e. 1st September, 1st October and 1st November as well as their interaction to select the superior varieties in respect to highest yield and quality with suitable both early and late swing dates. A split-plot design with four replications was used. Results of study revealed that different sowing dates have significant effect on all beet characters. Sowing sugar beet plants at 1st October was significantly associated with the highest yields of root and sugar as well as quality traits in terms of sucrose (S%), purity % and recoverable sugar (R S%). On the other hand, leaf area index (LAI) and top yield ton/fed (fed= 4200m2) significantly decreased with delayed sowing dates. Sowing sugar beet plants at 1st September associated with maximum total soluble solids (T.S.S%) and impurities content, i.e. Na %, K %, α-amino N % as well as sucrose loss to molasses (SLM %) compared with late sowing date. Also, results clearly showed that the variances due to sugar beet varieties were significantly in all studied traits. Ras-Poly variety recorded the highest values of root dimension (cm), root fresh weight (gm/plant), root yield (RY) ton/fed, white sugar yield (WSY) ton/fed, sucrose %, purity % and recoverable sugar (RS%) followed by Dema-poly and Glloria in a descending order in both seasons. While, Glloria variety produced the maximum LAI and top yield (TY) ton/fed. The highest values of impurities content, i.e. Na %, K %, and α-amino-N %, as well as sucrose loss to molasses (SLM%) were recorded with planting Pleno variety on 1st September. Generally, sowing Ras-poly variety at the optimum date on 1st October produced the highest root, white sugar yields and lowest impurities content followed by Dema-poly and Glloria. While, the highest values of LAI and top yield ton/fed were obtained when Glloria variety planted on early date followed by Pleno variety under studied environmental conditions.

Field trials for two seasons (2018/2019 and 2019/2020) were conducted to investigate the influence of the addition of three levels of potassium (K) (K1 = 60, K2 = 120, and K3 = 180 kg K2O ha−1) and/or sulfur (S) (S1 = 175, S2 = 350, and S3 = 525 kg CaSO4 ha−1) to the soil, as well as the sowing date (the 1st of September, D1; or the 1st of October, D2) on the potential improvement of physiology, growth, and yield, as well as the quality characteristics of sugar beet yield under soil salinity conditions. With three replicates specified for each treatment, each trial was planned according to a split-split plot in a randomized complete block design. The results revealed that early sowing (D1) led to significant improvements in all traits of plant physiology and growth, in addition to root, top, and biological yields and their quality, gross and pure sugar, and K- and S-use efficiencies based on root yield (R-KUE and R-SUE). The K3 level (180 kg K2O ha−1) positively affected the traits of plant physiology, growth, yield and quality, and R-SUE, and reduced the attributes of impurities, impurity index, and R-KUE. Additionally, the S3 level (525 kg CaSO4 ha−1) affirmatively affected plant physiology, growth, yield and quality traits, and R-KUE, and decreased impurity traits, impurity index, and R-SUE. The interaction of D1 × K3 × S3 maximized the yield of roots (104–105 ton ha−1) and pure sugar (21–22 ton ha−1). Path coefficient analysis showed that root yield and pure sugar content had positive direct effects with 0.62 and 0.65, and 0.38 and 0.38 in both studied seasons, respectively, on pure sugar yield. Significant (p ≤ 0.01) positive correlations were found between pure sugar yield and root yield (r = 0.966 ** and 0.958 **). The study results recommend the use of the integrative D1 × K3 × S3 treatment for sugar beet to obtain maximum yields and qualities under salt stress (e.g., 8.96 dS m−1) in dry environments.

Salinity is one of the most important constraints in sugar beet production in Asia. An understanding the genetic basis of sugar beet (Beta vulgaris) performance under salinity stress is crucial to gaining insight into salinity tolerance trajectories as well as to designing appropriate breeding strategies in saline stress conditions. In this study, a mating design (North Carolina Design II) was used to generate 116 hybrid combinations (29 × 4) from four male sterile and ten pollinator parents in sugar beet. Genetic variance components, combining ability, and heritability of 24 physiological and root yield and quality related traits were estimated by growing the hybrids and their 14 parents under normal and salinity stress conditions in the field. The results showed high genetic variation among the tested populations for most of traits. Estimates of genetic components for root, sugar and white sugar yield showed higher contribution of the dominance variance ( $$ \upsigma_{\text{D}}^{2} $$ ) than the additive variance ( $$ \upsigma_{\text{A}}^{2} $$ ) in both growing conditions, but with much greater magnitude of the $$ \upsigma_{\text{D}}^{2} $$ values observed for saline conditions. Narrow-sense heritability (Hn) was generally higher in stress environment for physiological traits compared to those of normal ones and the reverse held true for the yield traits. The results of general combining ability (GCA)for the yield traits showed a non-consistent trend across normal and stress environments. Both GCA and specific combining ability (SCA) were found to be important for the performance of individual hybrid combinations, and no clear relationship between GCA and SCA was found for these sugar beet genotypes. Given the higher impact of dominance variance and the lower narrow sense heritability of sugar yield in saline conditions compared to normal conditions, it can be concluded that hybrid breeding strategy should be more favored in saline environments than normal environments.