Estimates of relative yield potential and genetic improvement of wheat cultivars in the Mediterranean region

2009 ◽  
Vol 147 (3) ◽  
pp. 323-332 ◽  
Author(s):  
O. SENER ◽  
M. ARSLAN ◽  
Y. SOYSAL ◽  
M. ERAYMAN

SUMMARYInformation about changes associated with advances in crop productivity is essential for understanding yield-limiting factors and developing new strategies for future breeding programmes. National bread wheat (Triticum aestivum L.) yields in Turkey have risen by an average of 20·8 kg/ha/year from 1925 to 2006. Annual gain in yield attributable to agronomic and genetic improvement averaged c. 11·6 kg/ha/year prior to 1975, but is now averaging c. 15·1 kg/ha/year. In the Mediterranean region, however, the wheat yield trend line (10·9 kg/ha/year) is c. 0·38 lower than that of Turkey. In order to understand whether such a trend was due to the cultivars released over the years, 16 bread wheat cultivars, commonly grown in the region and representing 23 years of breeding, introduction and selection (from 1976 to 1999), were grown in a randomized complete block design with three replicates across 2 years. Data were collected on maturation time, plant height, spike length, spikelet number/spike, grain number/spike, grain weight/spike, 1000 seed weight, harvest index and grain yield. None of the measured plant traits showed any historical cultivar patterns; therefore, the increase in grain yield could not be attributed to a single yield component. Several physiological traits changed during two decades of cultivar releases in the Mediterranean region that led to a genetic gain in grain yield of about 0·5% per year. Years of data and the present field study in the Mediterranean region suggested that the genetic improvement in wheat seemed inadequate and should be reinforced with modern agricultural management practices as well as technological innovations.

2017 ◽  
Vol 39 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Julia Abati ◽  
Cristian Rafael Brzezinski ◽  
José Salvador Simoneti Foloni ◽  
Claudemir Zucareli ◽  
Manoel Carlos Bassoi ◽  
...  

Abstract: The use of high quality seeds, the appropriate management practices and the selection of promising genotypes are strategies to exploit the wheat yield potential. Thus, the goal of this study was to evaluate the effect of the vigor level of wheat seeds submitted to different sowing densities on seedling emergence, tillering and yield performance culture. The experiments were conducted in Londrina and Ponta Grossa, Paraná state, Brazil, with a completely randomized block design, in a 2x2x2 factorial scheme, with four replications. Two levels of seed vigor (high and low), two sowing densities (200 and 400 viable seeds per m2) and two wheat cultivars (BRS Sabiá and CD 150) were evaluated. The conducted tests were: seedling emergence, number of tillers, yield components, grain yield and apparent harvest index. The use of high vigor seeds helps the establishment of the plant stand and yield performance in both locations. The 400 seeds per m2 seedling density results in a lower number of tillers per plant in both locations. BRS Sabiá, in Ponta Grossa, has the highest grain yield.


2019 ◽  
Vol 50 (Special) ◽  
Author(s):  
Baqir & Al-Naqeeb

 The objective of this study was to investigate the effect of some amino acids on tillering and grain yield of bread wheat cultivars. A field experiment was carried out at the agricultural experiment station, College of Agriculture Engineering Sciences, University of Baghdad during the two winter seasons, 2016-2017 and 2017-2018. Randomized Complete Block Design within split plots arrangement was used in three replicates. The experiment included two factors, the first (main plots) was the wheat cultivars (IPA 99, Buhooth 22, and Abu-Graib3) and the second (sub-plots) was foliar application three amino acids (L-Tryptophan, L-Glycine, and L-Lysine) with concentrations 50 and 100 mg L-1 and the amino acid L-Cystine at 100 and 150 mg L-1 and control treatment. The treatments of foliar application were applied during two growth stages, the first was when the main stem had three leaves (ZGS: 13) and the second was when the plant entered the flowering stage (ZGS: 60). Results showed the significant superiority of Buhooth 22 in most growth traits, which produced the highest number of tillers.m-2 (556.30 and 568.15 tillers m-2), number of spikes (476.74 and 494.19 spikes m-2), weight of 1000 grains (31.09 and 32.43 g), and grain yield (5.39 and 5.15 Mg ha-1) for the two seasons respectively. The treatment of foliar application L-Tryptophan at 50 mg L-1 was significantly superior in most traits of yield components which produced the highest values of the number of tillers (616.89 and 627.78 tillers m-2), number of spikes (477.00 and 944.67 spikes m-2), weight of 1000 grains (32.01 and 33.55g), and grain yield (5.77 and 5.33Mg ha-1) in the two seasons, respectively. The response of wheat cultivar growth and yield to amino acids differed significantly.      


2019 ◽  
Vol 9 (4) ◽  
pp. 661-664
Author(s):  
S. Shibeshi

Bread wheat (Triticum aestivum L.) is the most important cereal occupying a protruding position among major food crops in the world in terms of acreage and production and is an important cereal crop which is receives the most attention of specialists in plant breeding and production in the world wide in general and in Ethiopia in particular. And also a number of improved bread wheat varieties have been released by different research centres for different agro-ecology in Ethiopia. Evaluate the performance of different bread wheat varieties at diverse agro-ecology is an important for effective selection of the variety. This experiment was conducted on ten bread wheat varieties against local check (Digalu) at Meskan and Dalocha wereda with the objective of identify and recommend high performance in terms of yield, insect pest tolerant, and stable varieties. The varieties were assigned in randomized complete block design with four replication. Data were collected on six major agronomic traits. Based on the mean separation, the highest average grain yield was recorded from Hidasse and Ogolcho varieties with 5210 and 5080 kg/ha respectively. However the lowest average yield (3220kg/ha) was recorded from Digalu variety. In both locations Digalu variety provided the lowest yield due to high susceptibility for stem rust. Statistically, the variety Hidasse gave the highest number of tillers per plant and the tallest spikes length at both locations those are positive contributions to grain yield. There were significantly positive and negative correlations between traits. In this study, it is found that there is 38.19% increment of yield for using Hidasse variety (high yielder) as compared to Digalu variety (low yielder) at the study area. Therefore, farmers located at the study areas are recommended to use Hidasse variety to increase bread wheat yield.


2011 ◽  
Vol 41 (8) ◽  
pp. 1375-1382 ◽  
Author(s):  
Marcelo Carvalho Minhoto Teixeira Filho ◽  
Salatiér Buzetti ◽  
Marcelo Andreotti ◽  
Orivaldo Arf ◽  
Marco Eustáquio de Sá

Proper management of nitrogen fertilization and using cultivars with high productive potential are essential to obtain high wheat yield. Thus, the objective of the present study was to assess the effects of different N doses and sources, one with a nitrification inhibitor, applied at sowing or as side dressing, on the production components and yield of two wheat cultivars irrigated, under no till, cultivated in a region of low altitude Cerrado (Selvíria - MS). A randomized block design was used in a 5x3x2x2 factorial arrangement, that is, five nitrogen doses (0, 50, 100, 150 and 200kg ha-1), three nitrogen sources (ammonium sulfonitrate with nitrification inhibitor (Entec®), ammonium sulfate and urea) and two nitrogen application times (at sowing or side dressing) on two wheat cultivars ('E 22' and 'E 42') with three replications. There was no difference for grain yield between the wheat cultivars and among the nitrogen sources. The application of nitrogen totally at sowing is feasible as well as the traditional application at sowing and side dressing. The nitrogen doses increased the leaf N content of the 'E 22' cultivar, resulting in a reduction in the hectolitric mass of the 'E 42' cultivar and increased grain yield of the 'E 22' and 'E 42' wheat yield cultivars, respectively, up to doses of 126 and 122kg ha-1 N, regardless of the application time and the nitrogen source.


Plant Disease ◽  
2011 ◽  
Vol 95 (11) ◽  
pp. 1401-1406 ◽  
Author(s):  
Karen V. Lackermann ◽  
Shawn P. Conley ◽  
John M. Gaska ◽  
Mark J. Martinka ◽  
Paul D. Esker

Knowledge is limited about the impact of foliar diseases on wheat yield in Wisconsin. The objective of this study was to compare yield and diseases of wheat cultivars in several locations in Wisconsin in 2009 and 2010. Thirty-six wheat cultivars were planted in a randomized complete block design at field sites near Arlington, Chilton, and Lancaster, WI. At a fourth location, Janesville, WI, the design was a split plot with foliar fungicide application at Zadoks growth stage (GS) 45 at the whole-plot level and cultivar at the subplot level. Disease assessments were made four times during the growing season for powdery mildew (PM), Septoria/Stagonospora leaf blotch (SLB), and leaf rust. Incidence and severity of Fusarium head blight were assessed on 100 heads per plot at GS 85. Linear mixed-model analyses were used to study the effects of location, cultivar, and disease on grain yield (α = 0.05). Overall, SLB and PM were the most prevalent diseases. SLB severity was uniform among locations and PM was most prevalent at Arlington and Chilton. In both years, yield was affected by location, cultivar, location–cultivar interaction, and location–SLB and location–PM interactions. Yield was also negatively affected by PM in 2010. No effect of fungicide on disease severity or yield was observed at Janesville in either year. These results suggest that cultivar selection and location strongly influence grain yield in Wisconsin and that powdery mildew is capable of reducing grain yield.


2009 ◽  
Vol 45 (2) ◽  
pp. 149-163 ◽  
Author(s):  
HAMID REZA MIRI

SUMMARYIn order to understanding the changes in morpho-physiological traits of wheat cultivars released from 1940 to 2000 in Iran and to determine the association of these traits with grain yield, an experiment was conducted with 15 wheat cultivars released over the past 60 years using an randomized complete block design with four replications. The experiment was conducted on an experimental farm of Arsanjan Islamic Azad University in 2005/6 and 2006/7. Results indicated that cultivar grain yield was significantly correlated with year of release over the 60 years (r = 0.878, p < 0.01). Harvest index and biological yield increased significantly with increasing grain yield. The change in the photosynthesis rate was not significant during this period but transpiration rate and stomatal conductance and chlorophyll index increased significantly. Among yield components, grain number per ear increased significantly but increase in ear number was not significant. Plant height decreased significantly in new cultivars. In conclusion the results showed that wheat yield improvement in Iran is associated with increasing harvest index, grain number per ear, transpiration rate, stomatal conductance and decreasing plant height.


2021 ◽  
Vol 42 (6supl2) ◽  
pp. 3581-3602
Author(s):  
Diogo Nascimento de Souza ◽  

Wheat is one of the most important cereals grown in the world, and in Brazil, increasing national production is still a challenge. Nitrogen (N) supply can favor grain yield and the physiological quality of wheat seeds. However, the definition of adequate N rate and fertilization timing must consider genotype, cultivation environment, and initial seed vigor level. The aim of this work was to evaluate the effect of initial seed vigor and the combinations of rates and timings of N application on grain yield and seed physiological quality of wheat cultivars under different edaphoclimatic conditions. The experiment was carried out in Londrina and Ponta Grossa, state of Paraná, in a randomized block design in a 2 × 2 × 7 factorial scheme, with four replicates. Treatments consisted of two seed vigor levels (vigorous and non-vigorous seeds), two wheat cultivars (BRS Gralha-Azul and BRS Sabiá) and seven combinations of fertilization timings and N rates (kg ha-1) (control-0N; 20N at sowing and 60N at tillering; 40N at sowing; 80N at sowing; 40N at sowing and 40N at tillering; 40N at tillering; 80N at tillering). Number of emerged seedlings, vegetation index, shoot dry matter, number of fertile spikes m-2 and grain yield were evaluated. Additionally, the physiological potential of seeds produced in Londrina was evaluated by the testes of first count, germination, seedling emergence in sand and emergence speed index. The climatic conditions during the experiment, in both cultivation environments, were similar to average historical records, with some periods of water deficit. The highest grain yield was obtained with the BRS Gralha-Azul in Londrina, and with BRS Sabiá in Ponta Grossa. The use of vigorous seeds favored the stand establishment and the response of plants to N fertilization. The treatments 40N + 40N, and 40N + 0N favored the majority of evaluated variables. Both cultivars showed potential for the production of high physiological potential seeds in Londrina environment. Inadequate N supply impairs wheat grain yield and seed production.


Agronomy ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 393 ◽  
Author(s):  
Marie Therese Abi Saab ◽  
Mohamed Houssemeddine Sellami ◽  
Pasquale Giorio ◽  
Angelo Basile ◽  
Antonello Bonfante ◽  
...  

Variable rainfall, water stress, and spring frost are the main challenges for cereal growers in the Mediterranean region. The potential of wheat and barley to adapt to contrasting weather conditions was investigated through the adoption of no-till, supplemental irrigation and drought tolerant cultivars over a period of three years. Seasonal precipitation was 732, 336 and 685 mm in the first, second and third seasons, respectively. The second and third seasons were characterized by the occurrence of spring frost. No tillage did not affect productivity in either crop, while supplemental irrigation increased yield only in barley. For wheat, the grain yield was 60 and 43% respectively lower in the second and third seasons than in the first season. For barley, grain yield was 43% higher in the first season than the other two. The negative effect of frost on wheat yield was indirectly assessed by crop growth simulation. Principal component analysis shows that freezing temperatures associated with spring frost and rainfall both dictated crop growth and productivity.


Author(s):  
Negasi Gebreslasie ◽  
Teame Shimgabr ◽  
Haile Alene ◽  
Nebyu Tsegay ◽  
Welesenbet Haftu

Decisions concerning optimum rates of fertilization directly involve fitting some type of rates to yield when several rates of fertilizer are tested. This study was carried out to investigate the effects of nitrogen fertilizer rates yields and yield components of bread wheat and determine optimum rate of N. The field experiment was carried out in 2016 and 2017 main cropping season at Tsegedie and Welkait districts in Western Tigray Regional State, Ethiopia. The experiment consists of seven levels of nitrogen (0, 23, 46, 69, 99, 115 and 138 kg ha-1) arranged in randomized completed block design with three replications. Nitrogen was applied splits, half at planting and remaining at tiller stage. NPSB was applied as basal application for all experimental plots except the negative control. Soil samples were collected before planting for analysis of some selected physicochemical properties. The soil properties of the experimental sites of the two districts varied in most of the soil properties. Application of nitrogen significantly influenced grain yield and yield components of wheat in both study sites. The highest grain yield 3926 kg ha-1 and 2131 kg ha-1 were obtained from 138 kg N ha-1 and 115 kg N ha-1 at the study sites of Tsegedie and Welkait districts, respectively. Highest marginal rate of returns were however obtained at nitrogen rates of 46 kg ha-1 and 23 kg ha-1 at Tsegedie and Welkait districts, respectively. Hence, it could be concluded that the use of N at 46 kg ha-1and 23 kg ha-1 with 100 kg NPSB fertilizer could give optimum bread wheat yield at Tsegedie and Welkait districts, respectively.


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