Genetic variability and interrelationships of grain yield and its components of selected bread wheat genotypes

High temperature is one of major constraints of bread wheat production in the Sudan. Evaluation of different genotypes under heat stress conditions is one of the main tasks of breeders for exploiting genetic variations to improve cultivars under heat stress. Also, association of yield and yield contributing traits is important for selection. The objective of this study was to evaluate bread wheat genotypes under the irrigated hot environment of the Gezira, Sudan. Experiments were conducted at Gezira Research Farm, Wad Medani, Sudan for two consecutive seasons 2006/07 and 2007/08. The experiments were arranged in an augmented design with six checks, 4 and 12 blocks in the first and second seasons, respectively. Results showed wide ranges of variations in grain yield among these genotypes in both seasons. Grain yield ranged from 965 to 4019 kg/ha and from 133 to 6258 kg/ha in the first and second seasons, respectively. Similar wide ranges of variations were found in biomass, harvest index, number of spikes m-2, days to heading, days to maturity and plant height. Grain yield showed positive and significant correlation coefficients with biomass and harvest index, in both seasons. Path coefficient analysis indicated that biomass and harvest index were the most directly related parameters to grain yield, in both seasons

Awareness of Final-Year Medical Students of Omdurman Islamic University on Their Career Choices

Background: Medical students undergo a complex process as a student to make a career decision and pursue further specialization. This study explores the factors that influence the career choices of the two genders studying in the final year of medicine at Omdurman Islamic University.Methods: This institution-based cross-sectional study was conducted on 194 male and female fifth-year medical students studying at Omdurman Islamic University. The questionnaire contains 15 multiple-choice questions to determine the factors affecting students’ career choices – lifestyle, income, family impact,…etc. – and the association between gender and the specialties they choose to pursue.Results: The specialties were preferred in the following order: surgery by 22.9%, internal medicine by 18.3%, obstetric gynecology by 13.8%, and pediatric by 10% (limited to the four major specialties). The least chosen specialties were histopathology, emergency medicine, psychiatry, and anesthesia (all were 0.9%). Family medicine and forensics were not chosen by any participant. Females significantly preferred dermatology, obstetrics and gynecology, otolaryngology, and pediatrics compared to their male counterparts. Whereas, males compared to females significantly preferred orthopedics and surgery. The factors influencing change in students’ specialties based on their gender were family views and family obligations. Nearly 80% of students choose a career based on personal interest; lifestyle and financial reward were also seen to play an important role in choosing a specialty. About 91% of participants agreed that there is a need for guidance. A great proportion of final-year students (62%) preferred to specialize abroad and related it to a good lifestyle and financial stability.Conclusion: This study showed that the students’ awareness about specialty choices was limited to certain specialties as seen in the literature. The most preferred specialties were surgery (22.9%), internal medicine (18.3%), obstetrics and gynecology (13.8%), and pediatric (10%). There are many factors influencing the selection of specialties, however, the most common one is personal interest followed by lifestyle issues and financial reward. Additionally, there is a significant gender difference in career-choice decisions

Effect of Digestate and Biochar Amendments on Photosynthesis Rate, Growth Parameters, Water Use Efficiency and Yield of Chinese Melon (Cucumis melo L.) under Saline Irrigation

Despite the recent interest in biochar and digestate as soil amendments for improving soil quality and increasing crop production, there is inadequate knowledge of the effect of the combination of biochar and digestate, particularly under saline irrigation conditions. A pot experiment with Chinese melon was conducted in a greenhouse, biochar (5%) and digestate (500 mL/pot) were used with and without the recommended mineral NPK (Nitrogen, Phosphorus and Potassium) fertilizer dose (120-150-150 Kg ha−1). The plants were irrigated with tap water (SL0) and 2 dS/m (SL1) NaCl solution. The growth, photosynthesis rate, water use efficiency (WUE) and yield of Chinese melon were affected positively when biochar was combined with digestate amendment, particularly under saline irrigation water with and without mineral NPK fertilizer. The maximum yield under normal water was obtained by digestate (SL0: 218.87 t ha−1) and biochar amendment combined with digestate (SL1: 118.8 t ha−1) under saline water. The maximum WUE values were noticed with the biochar and digestate combination under all water treatments (SL0: 32.2 t ha−1 mm−1 and SL1: 19.6 t ha−1 mm−1). It was concluded that digestate alone was more effective than the use of biochar, particularly with normal water. The combination of biochar with digestate had a significant effect on the Chinese melon growth, photosynthesis rate, water use efficiency and yield under saline irrigation, and it can be used as an alternative fertilizer for mineral NPK fertilizer

Efficiency of Two Models for Prediction of Exchangeable Sodium Percentage from Sodium Adsorption Ratio on Saline and Non Saline Soil

Abstract The relationships between soil physical and chemical properties play a key role in facilitating the measurement of soil properties, particularly Exchangeable Sodium percentage (ESP) measurement, which is often using laborious and time-consuming laboratory tests. The aim of this study is to investigate the efficiency of the United States Salinity Laboratory (USSL) model and the ESP-SAR model for prediction of exchangeable Sodium percentage (ESP) from Sodium Adsorption Ratio (SAR) on saline and non-saline soil samples. For this purpose, 23 soil samples were collected from the field of experiment, Jabal Awliya, south of Khartoum state, Sudan. Exchangeable Sodium Percentage (ESP) was estimated as a function of soil SAR in order to compare the predicted results with measured ESP using laboratory tests. The results show that on saline soil samples, the Standard Error of Mean (SEM) of predicted ESP obtained by USSL model and ESP-SAR model was (1.084) and (1.463) respectively. On non-saline soil samples, the Standard Error of Mean (SEM) of predicted ESP acquired by USSL model was (0.7034) and (0.6070) for ESP-SAR model. The statistical results indicated that USSL model has a good prediction on saline soil samples compared with ESP-SAR model. On non-saline soil samples, USSL model showed less prediction performance than ESP-SAR model. It can be concluded that the United States Salinity Laboratory model can be recommended on saline soil samples and ESP-SAR model is more reliable on non-saline soil samples

Awareness of Final-Year Medical Students of Omdurman Islamic University on Their Career Choices

Abstract Background: Medical students undergo a complex process as a student to make a career decision and pursue further specialization. Thisstudy explores the factors that influence the career choices of the two genders studying in the final year of medicine at Omdurman Islamic University. Methods: This institution-based cross-sectional study was conducted on 194 male and female fifth-year medical students studying at Omdurman Islamic University. The questionnaire contains 15 multiple-choice questions to determine the factors affecting students' career choices – lifestyle, income, family impact,...etc. – and the association between gender and the specialties they choose to pursue. Results: The specialties were preferred in the following order: surgery by 22.9%, internal medicine by 18.3%, obstetric gynecology by 13.8%, and pediatric by 10% (limited to the four major specialties). The least chosen specialties were histopathology, emergency medicine, psychiatry, and anesthesia (all were 0.9%). Family medicine and forensics were not chosen by any participant. Females significantly preferred dermatology, obstetrics and gynecology, otolaryngology, and pediatrics compared to their male counterparts. Whereas, males compared to females significantly preferred orthopedics and surgery. The factors influencing change in students' specialties based on their gender were family views and family obligations. Nearly 80% of students choose a career based on personal interest; lifestyle and financial reward were also seen to play an important role in choosing a specialty. About 91% of participants agreed that there is a need for guidance. A great proportion of final-year students (62%) preferred to specialize abroad and related it to a good lifestyle and financial stability. Conclusion: This study showedthat the students' awareness about specialty choices was limited to certain specialties as seen in the literature. The most preferred specialties were surgery (22.9%), internal medicine (18.3%), obstetrics and gynecology (13.8%), and pediatric (10%). There are many factors influencing the selection of specialties, however, the most common one is personal interest followed by lifestyle issues and financial reward. Additionally, there is a significant gender difference in career-choice decisions

Effect of Irrigation Regimes and Soil Texture on the Potassium Utilization Efficiency of Rice

Understanding the effects of irrigation regime and soil texture on potassium-use efficiency (KUE) of rice (Oryza sativa. L) is essential for improving rice productivity. In this regard, experiments were conducted from July to October in 2016 and 2017 by using a randomized complete block design in a factorial arrangement with four replications. The rice plants were grown in three soils, with clay contents of 40%, 50%, and 60%, which were marked as S (40%), S (50%), and S (60%), respectively. For each soil type, irrigation regimes, namely, R (F, S100%), R (F, S90%), and R (F, S70%), were established by setting the lower limit of irrigation to 100%, 90%, and 70% of saturated soil water content, respectively, and the upper limit of irrigation with 30 mm of flooding water above the soil surface for all irrigation regimes. Results showed that the responses of the roots and shoots and the potassium accumulation (KA) and KUE of rice were significantly affected by the water regime and soil texture. In the same irrigation regime, increasing the soil clay content improved the K utilization of rice. Under the same soil type, R (F, S100%) was the optimal water management practice for growing rice. The R (F, S100%) S (60%) treatment presented the highest KUE, which was 56.4% in 2016 and 68.1% in 2017. The R (F, S70%) S (40%) treatment showed the lowest KUE, which was 13.8% in 2016 and 14.9% in 2017. These results enrich knowledge regarding the relationship among soil, water, and rice, and provide valuable insights on the effect of irrigation regime and soil texture on the KA and KUE of rice

Durum Wheat Field Performance and Stability in the Irrigated, Dry and Heat-Prone Environments of Sudan

Developing climate-resilient crop varieties with better performance under variable environments is essential to ensure food security in a changing climate. This process is significantly influenced, among other factors, by genotype × environment (G × E) interactions. With the objective of identifying high-yielding and stable genotypes, 20 elite durum wheat lines were evaluated in 24 environments (location–season combination) during 5 crop seasons (2010/11–2014/15). The REML (residual maximum likelihood)-predicted means of grain yield of 16 genotypes that were common across all environments ranged from 3522 kg/ha in G201 to 4132 kg/ha in G217. Results of additive main effect and multiplicative interaction (AMMI) analysis showed that genotypes (G), environments (E), and genotype × environment interaction (GEI) significantly affected grain yield. From the total sum of squares due to treatments (G + E + GEI), E attributed the highest proportion of the variation (90.0%), followed by GEI (8.7%) and G (1.3%). Based on the first four AMMI selections for grain yield in the 24 environments, genotypes G217, G219, G211, and G213 were selected in 23, 12, 11, and 9 environments, respectively. The genotype and genotype × environment biplot (GGE) biplot polygon view showed that the environments were separated into three mega-environments. The winning genotypes in these mega-environments were G217, G214, and G204. Genotypes G212, G220, G217, G215, and G213 showed low AMMI stability values (ASV), whereas genotypes G217, G220, G212, G211, and G219 showed low genotype selection index (GSI), indicating their better stability and adaptability to the test environments. The results indicated that genotypes G217, G219, G211, G213, and G220 combined both high grain yield and stability/adaptability under dry but irrigated and heat-prone environments. An in-depth analysis of the superior genotypes could help better understand the stress-adaptive traits that could be targeted to further increase durum wheat yield and stability under the changing climate