Posts Tagged ‘grain yield’

Yield gain due to fungicide application in varieties of winter wheat (Triticum aestivum) resistant and susceptible to leaf rust

Posted by gabrielamartinez on , in Journal Articles

56912Authors: Morgounov, A.I.; Akin, B.; Demir, L.; Keser, M.; Kokhmetova, A.; Martynov, S.; Orhan, S.; Ozdemir, F.; Ozseven, I.; Sapakhova, Z.; Yessimbekova, M.

Published in: Crop and Pasture Science 2015, vol. 66, no.7, p. 649-659


 

In three independent experiments in Turkey and Kazakhstan, winter wheat germplasm with variable degrees of resistance to leaf rust was subjected to fungicide protection. The yield loss of genotypes susceptible to leaf rust varied from 30% to 60% depending on the environment and severity of infection. Genotypes completely or moderately resistant to leaf rust also responded positively to fungicide protection, with average yield increases in the range 10–30%. This increase was observed even in one season without leaf rust infection. The main character affected by fungicide was 1000-kernel weight. There was stable expression of the magnitude of yield gain in resistant genotypes in different seasons, confirming genetic variation for this trait. Possible mechanisms of yield gain from fungicide protection in resistant genotypes are related to a positive physiological effect of the chemical used as well as a possible ‘cost of resistance’ to wheat plants. The magnitude of yield gain by resistant germplasm justifies its capture in breeding programs to develop varieties resistant to diseases and with greater benefits from the fungicide protection.

Grain yield of newly developed wheat cultivar (NARC 201) as enhanced by foliar application of humic acid under rainfed conditions

Posted by Carelia Juarez on , in Journal Articles

Published in Sarhad Journal Agriculture 30 (2173-178, 2014.

Abbas, S.H.; Sohail, M.; Hussain, I.; Saleem, M.; Qamar, M.; Aslam, M.; Imram, M.

A newly developed wheat cultivar NARC 2011 was evaluated for physio- agronomic traits by varying Humic acid concentrations and Effective microbes at different phenological stages during rabi season of 2010-11 in the field area allocated to national coordinated wheat program of national agricultural research centre, Islamabad. The experiment was laid out using randomized complete block design (RCBD) for an assortment of growth and yield characters at various Humic acid concentrations and Effective microbe under rainfed conditions. There were six treatments and were replicated three times. Results revealed that E.M enhanced sub stomatal CO2 concentration in the flag leaf of mother shoot significantly, whereas for transpiration rate, spike length, number of spikelets spike-1 , flag leaf area and thousand seed weight, its effect but statistically at par. The highest grain yield of 3566 kg ha-1 was achieved at N P (115:85 kg ha- 1) in combination with 3000 mL ha-1 concentration of humic acid at tillering +flag leaf initiation +grain filling stages hence resulting in 30 percent greater yield than control (2747 kg ha-1). Similarly the highest biological yield of 12667 kg ha-1 was achieved at same level of NP in combination with 3000 mL ha-1 concentration of humic acid at tillering +flag leaf initiation +grain filling stages hence resulting in 31 percent greater biological yield than control (9667 kg ha-1). Hence in order to achieve higher biological and grain yield in rainfed regime, humic acid along with optimum recommended area specific NP levels depending up on soil nutritional status may be applied at appropriate phenological stages of wheat crop.

Genetic control of grain yield and grain physical characteristics in a bread wheat population grown under a range of environmental conditions

Posted by Carelia Juarez on , in Journal Articles

Published in Theoretical and Applied Genetics, 2014

Maphosa, L.Langridge, P.Taylor, H.Parent, B.Emebiri, L.C.Kuchel, H.Reynolds, M.P.;Chalmers, K.J.Okada, A.Edwards, J.Mather, D.E. 

Environmental conditions such as moisture deficit and high temperatures during the growing period affect the grain yield and grain characteristics of bread wheat (Triticum aestivum L.). The aim of this study was to map quantitative trait loci (QTL) for grain yield and grain quality traits using a Drysdale/Gladius bread wheat mapping population grown under a range of environmental conditions in Australia and Mexico. In general, yield and grain quality were reduced in environments exposed to drought and/or heat stress. Despite large effects of known photoperiod-sensitivity loci (PpdB1 andPpdD1) on crop development, grain yield and grain quality traits, it was possible to detect QTL elsewhere in the genome. Some of these QTL were detected consistently across environments. A locus on chromosome 6A (TaGW2) that is known to be associated with grain development was associated with grain width, thickness and roundness. The grain hardness (Ha) locus on chromosome 5D was associated with particle size index and flour extraction and a region on chromosome 3B was associated with grain width, thickness, thousand grain weight and yield. The genetic control of grain length appeared to be largely independent of the genetic control of the other grain dimensions. As expected, effects on grain yield were detected at loci that also affected yield components. Some QTL displayed QTL-by-environment interactions, with some having effects only in environments subject to water limitation and/or heat stress.

A study on some characteristics of new registered triticale (x Triticosecale Wittm.) varieties (Aysehanim and Mehmetbey) in Turkey

Posted by Carelia Juarez on , in Journal Articles

Published in Journal of Food, Agriculture and Environment 12(2370-374, 2014

Yildirim, M.Gezginc, H.Paksoy, A.H.Aktas, B.Cakmak, M.Belen, S.Bolat, N.Yorgancilar, O.;Keser, M.Braun, H.J.Pfeiffer, W.H.

The spring triticale cultivars Aysehanim and Mehmetbey (X Triticosecale Wittm.) were developed by Agricultural Research Station of The Eastern Mediterranean Transition Zone and they had been registered by Variety Registration and Seed Certification Center in Turkey. In this experiment, some characteristics of two new varieties were studied. The experiments were conducted at four locations of the Eastern Mediterranean Transition Zone in Turkey with three check triticale cultivars (Egeyildizi, Taceddinbey and Focus) under rain-fed conditions during the 2009 – 2010 and 2010 – 2011 growing seasons. The locations were Kahramanmaras, Adana and Hatay provinces and Ceyhan town. The genotypes were tested for agronomic, quality and botanical characteristics. Also, resistance of some cereal disease and lodging of the genotypes were determined. Aysehanim and Mehmetbey cv. had good adaptation and agronomic performance in the Eastern Mediterranean Transition Zone. The grain yields of Aysehanim and Mehmetbey cv. were 6459 and 6387 kg ha-1, respectively, and these values were significantly higher than the grain yields of Egeyildizi and Focus check cultivars, 5916 and 4919 kg ha-1, respectively. The cultivars had acceptable quality traits compared to the check cultivars. While their hectolitre weights and 1000 kernel weights were higher than the averages of check cultivars, protein content was not higher than those of the checks. Aysehanim and Mehmetbey cv. had good resistance for rust disease and lodging.

 

Relationship of line per se and testcross performance for grain yield of tropical maize in drought and well-watered trials

Posted by Carelia Juarez on , in Journal Articles

Published in Crop Science 53 (4) : 1228-1236, 2013

Kebede, A.Z.; Melchinger, A.E.; Cairns, J.E.; Araus, J.L.; Makumbi, D.; Atlin, G.N.

To optimize the efficiency of maize (Zea mays L.) drought breeding, the ability to predict testcross performance (TP) under drought stress using line per se performance (LP) of the parental inbreds would be useful. We evaluated LP and TP of tropical inbreds in well-watered and drought environments in Kenya and Mexico. Our main objective was to determine if LP under drought stress was predictive of TP for grain yield under drought stress and if selection for LP under drought stress would result in reduced yield potential for TP under well-watered conditions. Average yield reduction under drought stress was 77% for lines and 68% for testcrosses. Average genotypic correlations between lines and testcrosses under drought stress were positive and low (genotypic correlation = 0.48), but correlations increased with increasing levels of drought stress in both LP and TP trials. Averaged over all sets, indirect selection for LP was predicted to be only 57% as effective as direct selection for TP under drought stress but was on average substantially higher in testcross sets where yield reduction due to drought was 70% or more. Therefore, LP under drought stress could be used to develop hybrids for severely drought-prone environments. Moreover, LP under drought stress was uncorrelated with TP for grain yield under well-watered conditions, showing that selection of lines per se for drought tolerance would likely not reduce yield potential of testcrosses.

Effect of climate change and variety on long-term variation of grain yield and quality in winter wheat in Kazakhstan

Posted by Carelia Juarez on , in Journal Articles

Published in Cereal Research Communications, 2013

Morgounov, A.; Abugalieva, A.; Martynov, A.S.

Winter wheat yield in three administrative regions of Kazakhstan (Almaty, South Kazakhstan, and Zhambyl) was analyzed during 1972–2009. Yield gains were greatest during 2000–2009, but absolute yields remain low (1.5–1.7 t/ha) and much below the production potential. Changes in important weather parameters over the same time period were also analyzed. Results indicated significant (15–20%) warming in winter and spring, as well as some increase in precipitation (spring and annual), especially in the last ten years. Increased temperatures in winter and precipitation in spring/annually were positively correlated with winter wheat yield, while increased temperatures in May had a small but negative effect on grain yield. Data from the four stations of the official variety testing system from 1972–2009 were also analyzed to evaluate the effect of variety on yield and quality. Genetic gain of the varieties released in the 1990s and 2000s, compared to Bezostaya 1 (1960s), was around 30%. However, the bread-making quality of new varieties, as well as the overall grain quality in variety trials, were reduced in protein content, with deteriorated dough physical properties, and therefore did not meet superior class requirements. Genetic diversity (coefficient of parentage and Shannon’s diversity index) of the winter wheat varieties tested in the 2000s was broader compared to the 1970s and 1980s, reflecting enhanced international cooperation and germplasm exchange. A negative association between genetic diversity parameters and some quality traits can be attributed to the utilization of more diverse high yielding parents with limited grain quality potential. Further yield increases and reductions in the yield gap should be based on improved agronomy, and the use of broadly-adapted varieties, with resistance to the biotic and abiotic stresses likely due to climate change.

Determination of physiological traits related to terminal drought and heat stress tolerance in spring wheat genotypes

Posted by Carelia Juarez on , in Journal Articles

Published in International Journal of Agriculture and Crop Sciences 5 (21) : 2511-2520, 2013

B. Zarei, A. Naderi, M. R. Jalal Kamali, Sh. Lack and A. Modhej

Terminal drought and heat stress are two most important environmental factors affecting wheat in south-west of Iran.To determine physiological traits related to both terminal drought and heat stress tolerance, this research was conducted in three separate experiments with 15 spring wheat genotypes in two cropping seasons (2010-11 and 2011-12), under warm and semiarid climate field conditions in south west of Iran. In control (irrigated) and drought-stressed experiments, genotypes were sown at optimum planting date, while for heat-stressed experiment planting date was delayed. In drought stress experiment irrigations were done until flowering stage. All experiments were conducted in randomized complete block design with three replications. Flag leaf area (FLA), days to flowering (DTF), biomass at flowering stage (BMF), leaf relative water content (RWC), flag leaf chlorophyll content (Chlo), canopy temperature (CT), stomatal conductance of flag leaf (SC), light extinction coefficient (k), grain filling period (GFP), grain filling rate (GFR), thousand grain weight (TGW), grain yield, and stress susceptibility index (SSI) were measured and recorded. Results of correlation and principal component analysis showed that Chlo, GFR and TGW were associated with both terminal drought and heat stress tolerance. It can be concluded that under both terminal drought and heat stress conditions, these traits could be more focused in wheat breeding programs. Furthermore, results of slicing of genotype× environmental conditions interaction showed grain yield reduction of durum cultivars were not significant under terminal drought stress as compared to bread wheat genotypes (6.1% and 28.6%, respectively). All wheat genotypes showed significant grain yield reduction under terminal heat stress condition, except for cv. Dena. High yielding genotypes under non-stressed condition showed significant grain yield reduction, when subjected to a stressed condition (36.2% and 45.8% under terminal drought and heat stress conditions, respectively); consequently based on SSI these genotypes were not classified into tolerant group (1.45 and 1.48 under terminal drought and heat stress conditions, respectively).

Insights into genotype × tillage interaction effects on the grain yield of wheat and maize

Posted by Carelia Juarez on , in Journal Articles

Published in Crop Science 53 (5) : 1845-1859, 2013

J.M. Herrera, N. Verhulst, R.M. Trethowan, P. Stamp and B. Govaerts

No tillage or zero tillage (NT) is the extreme form of reduced tillage; NT with residue retention is a main component of conservation agriculture. Using a literature survey and meta-analysis, this study aimed to (i) summarize the results of studies comparing the grain yield of wheat [Triticum aestivum L. and Triticum turgidum L. subsp. durum (Desf.) Husn. (syn. Triticum durum Desf.)] and maize (Zea mays L.) genotypes under contrasting tillage, (ii) identify sources of variation in the grain yield response of wheat and maize genotypes to tillage practices, and (iii) identify potential traits for NT breeding programs. Grain yield was compared under NT and conventional tillage (CT) for 112 wheat genotypes (44 spring, 60 winter, and eight durum wheat genotypes) across 12 locations and 24 yr and for 93 maize hybrids across six locations and 5 yr. Most of these studies showed slightly higher grain yields under CT for maize (+5%) and winter (+5%) and spring (+2%) wheat. In the few studies where selection had been conducted under NT, the effect of tillage on the grain yield was modified significantly by genotypes. Traits associated with the emergence of vigorous seedlings and resistance to a changed spectrum of diseases increase genotype performance under NT. There is a need to evaluate genotypes developed under NT and extend the research on genotype performance under NT to locations with reduced input use and, in addition to tillage, investigate other factors that differentiate conservation agriculture from conventional practice.

Climate change at winter wheat breeding sites in central Asia, eastern Europe, and USA, and implications for breeding

Posted by Carelia Juarez on , in Journal Articles

Published in Euphytica, 2013

A. Morgounov, S. Haun, L. Lang, S. Martynov and  K. Sonder

Key weather parameters (monthly minimum and maximum temperature, precipitation) were extracted for 35 winter wheat breeding sites in central Asia, eastern Europe and Great Plains of USA from 1961 to 2009. Autumn and winter warming happened gradually, over a long period of time, but mostly before 1991. Climate changes after 1991 were mainly expressed through higher temperatures in spring, May, and June. Clear regional differences were observed for air temperature variation. Breeding sites in the USA seemed to be least subjected to climate change. There were no significant linear trends in yearly, seasonal, or monthly precipitation. Changing climates expressed through rising temperatures during critical stages of winter wheat development have already negatively affected yield gains in several countries, especially in eastern Europe. There are some positive changes associated with warmer winters, which may not require additional investment in traits associated with winter survival. Rising temperatures in spring are of particular concern since their effect on yield is negative in some regions. They certainly accelerate wheat development and shift heading to earlier dates. The interaction of higher temperatures in spring with the rate of crop development and yield is a fundamental issue which requires research. Rising temperatures in June are detrimental for grain development and filling and heat tolerance warrants high priority in breeding  programs.

 

Simple sequence repeats markers for grain filling traits and yield components in tropical maize

Posted by Carelia Juarez on , in Journal Articles

Published in Journal of Agricultural Sciences 1 (2) : 25-29, 2013

E. Gasura, P.S. Setimela, R. Edema, P.T. Gibson and P. Okori

Probiotics has gained momentum only recently with considerable and significant advances in functional and health food market across the world. The Joint FAO/WHO Expert Consultation on Evaluation of Health and Nutritional Properties of Probiotics in Food held in Córdoba, Argentina from 1-4 October, 2001 recognized the need for guidelines to set out a systematic approach for the evaluation of probiotics in food leading to the substantiation of health claims. The Global Standards for Evaluation of Probiotics are : identification of the genus and species of the probiotic strain, in vitro testing to delineate the mechanism of the probiotic effect and substantiation of the clinical health benefit of probiotic agents with human trials. In the EU there is no legal definition of the term probiotic, no specific legislation governing them, but there are regulations which lay down some general principles and requirements of EU food law. In the U.S the use of probiotics in products can result in several regulatory categories. In Japan reference for legislation on the subject of functional foods is made to the Japanese system of Foods for Specified Health Use (FOSHU).The main purposes of the Codex Alimentarius Commission are protecting health of the consumers, ensuring fair trade practices in the food trade, and promoting coordination of all food standards work undertaken by international governmental and nongovernmental organizations. The Indian Council of Medical Research, along with the Department of Biotechnology of the Ministry of Science and Technology have proposed ‘Guidelines for Evaluation of Probiotics in Food in India’, which articulates the base for the law to govern probiotics. Multinational companies have found the Indian market very challenging in the past owing to supply shortages, poor cold chain, storage facilities, poor infrastructure, and underdeveloped and complicated distribution channels. There are many aspects pertaining to the regulation of functional foods, such as probiotic. The regulatory framework to be established should include issues related to probiotics, such as efficacy, safety, labeling, fraud and claims.