scholarly journals Do nitrogen and zinc application alleviate the adverse effect of heat stress on wheat (Triticum aestivum L.)?

2021 ◽  
Vol 49 (2) ◽  
pp. 12252
Author(s):  
Seyed Nader MOSAVIAN ◽  
Hamid Reza EISVAND ◽  
Naser AKBARI ◽  
Ali MOSHATATI ◽  
Ahmad ISMAILI

Late-season heat stress (LSH) is a limiting factor for wheat production. Besides, low zinc and poor protein diet usually is a problem in low-income countries. The primary calorie source in such countries is prepared from bread. This study aims to mitigate heat stress by zinc and nitrogen application and improve zinc and protein content in wheat grain. We did the field experiments as a split-split-plot based on a randomized complete block design with four replications to assess zinc and nitrogen’s possible mitigation effect on LSH and protein and zinc enrichment of wheat grain during two years. Factors included LSH by delay in planting date (optimum, late, and very late) as the main plot, nitrogen (0, 75, 150, and 225 kg ha–1) in subplots, and zinc (0, 10, and 20 kg ha–1) as sub-subplots. We measured yield, yield components, physiological traits, zinc, and protein contents in the grain. Results showed that the highest relative water content and cell-membrane thermal stability were attained at the optimum planting date, 150 kg N ha–1 and 20 kg Zn ha–1. The maximum chlorophyll a and carotenoids contents in wheat cells were recorded in the optimum planting date, 225 kg N ha–1, and 20 kg Zn ha–1. Heat stress reduced the grain yield. In the second year of the experiment, the grain number per unit area was more than that of the first year; however, the highest grain yield was achieved in the first year owing to the higher mean grain weight. Nitrogen application decreased the adverse effects of heat stress on grain yield by increasing the grain number. Zinc application diminished the adverse effects of heat stress by increasing the mean grain weight. The adverse impact of the LSH on grain yield was more than that of biological yield. Heat stress reduced the hectolitre weight and zinc content of the grain. Meanwhile, it increased grain protein. In general, under LSH, the application of 225 kg N ha–1 and 20 kg Zn ha–1 can reduce the adverse effects of heat on the grain quality and quantity.

2020 ◽  
Vol 71 (19) ◽  
pp. 6015-6031
Author(s):  
Bing Liu ◽  
Leilei Liu ◽  
Senthold Asseng ◽  
Dongzheng Zhang ◽  
Wei Ma ◽  
...  

Abstract Grain yield of wheat and its components are very sensitive to heat stress at the critical growth stages of anthesis and grain filling. We observed negative impacts of heat stress on biomass partitioning and grain growth in environment-controlled phytotron experiments over 4 years, and we quantified relationships between the stress and grain number and potential grain weight at anthesis and during grain filling using process-based heat stress routines. These relationships included reduced grain set under stress at anthesis and decreased potential grain weight under stress during early grain filling. Biomass partitioning to stems and spikes was modified under heat stress based on a source–sink relationship. The integration of our process-based stress routines into the original WheatGrow model significantly enhanced the predictions of the biomass dynamics of the stems and spikes, the grain yield, and the yield components under heat stress. Compared to the original model, the improved version decreased the simulation errors for grain yield, grain number, and grain weight by 73%, 48%, and 49%, respectively, in an evaluation using independent data under heat stress in the phytotron conditions. When tested with data obtained under field conditions, the improved model showed a good ability to reproduce the decreasing dynamics of grain yield and its components with increasing post-anthesis temperatures. Sensitivity analysis showed that the improved model was able to reproduce the responses to various observed heat-stress treatments. These improvements to the crop model will be of significant importance for assessing the effects on crop production of projected increases in heat-stress events under future climate scenarios.


Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1532
Author(s):  
Uchechukwu Paschal Chukwudi ◽  
Funso Raphael Kutu ◽  
Sydney Mavengahama

A rise in global temperature will reduce maize yield, particularly in Africa, where maize is a staple food. Therefore, improving maize yield under heat stress will promote food security in the region. The objective of this study was to assess the influence of heat stress on the grain yield of drought-tolerant maize varieties under varied growth conditions. The experimental design used was a 2 × 3 × 3 × 2 factorial fitted into a completely randomized design with four replications. The factors were heat stress, maize variety, soil amendment, and soil type. The results showed a better yield from sandy clay loam over loamy sand soil. Varieties WE5323 and ZM1523 amended with poultry manure gave the best yield under the non-heat and heat-stressed environments, respectively. Heat stress reduced the cob weight, grain weight, grain number, and stover dry weight by 64, 73, 69, and 23%, respectively. Grain number, grain weight, and cob weight were the most informative yield attributes in this study and should be considered in a maize selection program. The ranking for the maize varieties was WE5323 > ZM1523 > WE3128. Drought-tolerant maize varieties can be useful in heat stress mitigation. This information is useful for the simulation of maize yields for heat stress-prone areas in Sub-Saharan Africa.


2011 ◽  
Vol 91 (1) ◽  
pp. 37-48 ◽  
Author(s):  
M. Cogliatti ◽  
F. Bongiorno ◽  
H. Dalla Valle ◽  
W J Rogers

Fifty-seven accessions of canaryseed (47 populations and 10 cultivars) from 19 countries were evaluated for agronomic traits in four field trials sown over 3 yr in the province of Buenos Aires, Argentina. Genetic variation was found for all traits scored: grain yield and its components (grain weight, grain number per square meter, grain number per head and head number per square meter), harvest index, percent lodging, and phenological characters (emergence to heading, emergence to harvest maturity and heading to harvest maturity). Although genotype × environment interaction was observed for all traits, the additive differences between accessions were sufficient to enable promising breeding materials to be identified. Accessions superior in performance to the local Argentinean population, which in general gave values close to the overall mean of the accessions evaluated, were identified. For example, a population of Moroccan origin gave good yield associated with elevated values of the highly heritable character grain weight, rather than with the more commonly observed grain number per square meter. This population was also of relatively short stature and resistant to lodging, and, although it performed best when sown within the normal sowing date, tolerated late sowing fairly well. Other accessions were also observed with high grain weight, a useful characteristic in itself, since large grains are desirable from a quality point of view. Regarding phenology, the accessions showed a range of 160 degree days (8 calendar days in our conditions) in maturity, which, while not large in magnitude, may be of some utility in crop rotation management. Some accessions were well adapted to late sowing. Grain yield in general was strongly correlated with grain number per square meter. Principal components analysis (PCA) carried out for all characteristics provided indications of accessions combining useful characteristics and identified three components that explained approximately 70% of the phenotypic variation. Furthermore, a second PCA plus regression showed that approximately 60% of the variation in grain yield could be explained by a component associated with harvest index and grain number per square meter. Pointers were provided to possible future breeding targets.Key words: Phalaris canariensis, canaryseed, accessions, yield, phenology, genetics, breeding


2010 ◽  
Vol 56 (No. 5) ◽  
pp. 218-227 ◽  
Author(s):  
A. Madani ◽  
A. Shirani-Rad ◽  
A. Pazoki ◽  
G. Nourmohammadi ◽  
R. Zarghami ◽  
...  

The experiments were laid out to understand the mechanisms causing yield limitations imposed by post-anthesis water and nitrogen deficiencies in plants with modified source-sink ratios. Two soil-water regimes were allotted to the main plots. At anthesis, three levels of N were applied: none, 25% and 50% of total the N supply. Spike-halving caused reduction in grain yield at both water regimes and all N supply levels, showing that the reduction in grain number can not be compensated by a higher individual grain weight. Sink reduction by trimming 50% of the spikelets reduced grain number per ear by 38.5% and increased individual grain weight by 12.0%, which shows the plasticity in grain weight and grain set of wheat if sufficient assimilates are available. Additional nitrogen supply at anthesis had no significant effect on the total aboveground biomass, but increased grain yield through more allocation of dry matter to grains. Our findings suggest that for rainfed wheat with optimum N supply and supplemental irrigation, wheat growers should choose cultivars with a high grain number per ear and manage the crop to increase grain number per unit of land (sink capacity).


1998 ◽  
Vol 78 (1) ◽  
pp. 71-77 ◽  
Author(s):  
F. M. Epplin ◽  
T. F. Peeper

The five-year moving average (5YRMA) wheat (Triticum aestivum L.) grain yield per harvested hectare has declined by more than 18% over the past decade in Oklahoma. By contrast, world wheat yields have increased steadily over the same period. The Oklahoma wheat yield trend during the past decade is inconsistent with expectations. The objective of the research was to determine why the 5YRMA wheat grain yield per harvested hectare did not increase in Oklahoma during the past decade. Five types of potential explanatory variables were investigated: structural change (including government programs), fertilizer use, proportion grazed, planting date and environment. Regression analysis was used to determine that the consequences of improvements in technology, research and education programs, as measured by a linear trend variable, were positive. However, during the past decade, these advancements were overwhelmed by changes in planting date and environmental factors. Key words: Wheat, yield, trend, planting date, environment


1970 ◽  
pp. 24-27
Author(s):  
Maysoun M. Saleh ◽  
Dyab S. Moussa ◽  
Nader I. Alkaraki ◽  
Abbas Lateef Abdurahman

Seven wheat genotypes (Triticum dicoccum) and the local check sham5 were planted all at Al-Ghab and Izra Research centers in The General Commission for Scientific Agricultural Research in Syria during growing season 2010/2011. Yield components (number of total and fertile tillers per plant, number and weight of grains per spike, weight of thousand grain and individual plant grain yield) were studied in two sites in order to predict their effect and to determine their effects on grain yield in order to define selection criteria for grain yield. Results revealed all studied traits except total tillers number were positively correlated with grain yield, and only (fertile tillers number and grain number per spike and grain weight per spike) had a significant regression with grain yield and these traits can explain about (27.6, 67.7, 62.2)% respectively of the variation final grain yield. Results of path analysis indicated that the direct effect of fertile tillers per plant and grain weight per spike on grain yield was positive and high (0.6178, 0.7563) respectively, so that we can depend on them in breeding program as selection criteria to increase grain yield in plant.


Author(s):  
Ravi Singh Thapa ◽  
Pradeep Kumar Sharma ◽  
Anuj Kumar ◽  
Tejbir Singh ◽  
Dharmendra Pratap

One ninety diverse wheat genotypes were evaluated for genetic varaibilty, heritability and genetic advance under norrmal and heat stress environment at the Research Farm of Department of Genetics and Plant Breeding, Chaudhary Charan Singh University, Meerut U. P. (India). The genotypes were grown in simple augmented block design and data were collected on fifteen morpho-agronomic characters. Analysis of observed data showed that the mean squares due to treatments for all the traits in both the environment were highly significant. GCV and PCV were highest for canopy temperature depression, grain weight/spike, biological yield/plant, grain yield/plant, tiller number./plant and lowest for days to anthesis. Heritability (bs) estimates were high for canopy temperature depression (CTD), followed by biological yield/plant, grain weight/ spike, grain number. /spike, 1000- grain weight, grain yield/plant, tiller number./plant and lowest for days to heading and days to anthesis in case of both environments. The estimates of genetic advance (GA) were highest for canopy temperature depression followed by grain weight/spike, biological yield/plant, grain yield/spike, tiller number./plant, grain number./spike and lowest for days to heading and days to anthesis under both ( numberrmal and heat stress) environment. This study suggests that the presence of adequate genetic variability, heritability and genetic advance for these traits under norrmal and heat stress environment is suitable for breeding programs and crop improvement.


2017 ◽  
Vol 9 (3) ◽  
pp. 1338-1342
Author(s):  
Amarjeet Kumar ◽  
Swati Swati ◽  
N. K. Singh ◽  
Birendra Prasad ◽  
Anil Kumar

To estimate the level of heat tolerance for different genotypes of bread wheat with respect to morphological characters under studied grains/ spike, grain weight/spike, grain filling duration (duration between the anthesis stage and the physiological maturity), 1000-kernel weight and grain yield/plant for yield. Physiological traits like relative injury (RI %), chlorophyll content, canopy temperature depression (CTD), were used in present investigation to contribute toward capability of plants to tolerate heat stress of the yield contributing traits during heat stress.The findings of present investigation had clearly explained that influences of environments on morpho physiological characters i.e. grain yield per plant (14886.15) and its attributing traits i.e. spike length (459.7), tillers per plant (622.34), spikelets per spike (278.1), 1000 kernel weight (13262.39), grain weight per spike (177.89) and number of grains per spike (2898.44) in wheat were highly significant and positive. Among the parent and their crosses had handsome amount of variations across the environment. The results of interaction for environments with parents, lines, testers and their crosses with respect to morpho physiological characters in wheat was found significant for some characters while variation was absent for other characters studied. Physiological traits like relative injury per cent, chlorophyll content and CTD were vital parameters to quantify the degree of heat stress to develop tolerant genotypes which is urgent and present need under changing climate scenario.


2018 ◽  
Vol 16 (3) ◽  
pp. e0903 ◽  
Author(s):  
Milan Mirosavljević ◽  
Vojislava Momčilović ◽  
Srbislav Denčić ◽  
Sanja Mikić ◽  
Dragana Trkulja ◽  
...  

Climate significantly affects cropping systems across Europe. Knowledge of the variability in grain number per unit area and grain weight across different growing seasons and its association with grain yield is important for further improving small grain crop production. The main aim of this study was to compare grain yield and its numerical components among triticale, wheat, two-rowed and six-rowed barley cultivars across different growing seasons in a typical Pannonian location (south-eastern part of Central Europe). Trials with twelve winter cereal genotypes (three two-rowed barley, three six-rowed barley, three wheat and three triticale genotypes) were carried out in four successive seasons in Novi Sad, Serbia. Results of this study showed that growing season, species, cultivar, and species × growing season interaction significantly (p<0.01) affected grain yield and its determinants. Generally, triticale had higher average grain yield, while the lowest grain yield was recorded in six-rowed barleys. Grain yield was more associated with the number of grains/m2 than with grain weight. Heading date was recognized as one of the important adaptive traits in crop development and yield determination. Short duration of the pre-anthesis phase in early cultivars and delayed anthesis in late cultivars significantly decreased the number of grains/spike in different species/spike types, reducing the final grain yield. Medium early cultivars had the highest number of grains/spike due to optimal duration of the pre-anthesis period and heading date and are suggested as recommendable for large scale production in the Pannonian environments.


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