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Ottman, Michael J., Michael D. Sheedy, and Richard W. Ward. "Clipping small grains to increase subsequent grain yield." College of Agriculture, University of Arizona (Tucson, AZ), 2016. http://hdl.handle.net/10150/625423.
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6 pp.Wheat is commonly grown as a dual purpose crop especially in the Southern Great Plains where the forage is grazed then allowed to mature into a grain crop. In Arizona, clipping a crop planted in October may increase tillering and grain yield. A trial was conducted at the Maricopa Ag Center where various small grain varieties were planted on October 12, 2015, cut for forage on January 10, 2016, and allowed to go to grain and compared with the same varieties planted on December 3, 2016 and not cut for forage. No differences in grain yield due to planting date and clipping were detected. However, the October 12 planting with clipping had larger kernels, greater grain protein, and higher stem density. The income from the sale of the forage was $99/acre based a yield of 2639 lb/acre and a forage value of $75/ton. The added cost per acre to produce this forage included $29 for water (6.27 inches of water at $55/acre-ft) plus $34 for fertilizer (50 lb N/acre of urea at $433/ton). Therefore, even though grain yield was not increased by planting early and clipping, a net increase in revenue of $36/acre was realized from the sale of the forage.
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Norng, Sorn. "Statistical decisions in optimising grain yield." Thesis, Queensland University of Technology, 2004. https://eprints.qut.edu.au/15806/1/Sorn_Norng_Thesis.pdf.
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This thesis concerns Precision Agriculture (PA) technology which involves methods developed to optimise grain yield by examining data quality and modelling protein/yield relationship of wheat and sorghum fields in central and southern Queensland.
An important part of developing strategies to optimisise grain yield is the understanding of PA technology. This covers major aspects of PA which includes all the components of Site-
Specific Crop Management System (SSCM). These components are 1. Spatial referencing, 2. Crop, soil and climate monitoring, 3. Attribute mapping, 4. Decision suppport systems and 5. Differential action. Understanding how all five components fit into PA significantly aids the development of data analysis methods.
The development of PA is dependent on the collection, analysis and interpretation of information. A preliminary data analysis step is described which covers both non-spatial and spatial data analysis methods. The non-spatial analysis involves plotting methods (maps, histograms), standard distribution and statistical summary (mean, standard deviation). The spatial analysis covers both undirected and directional variogram analyses.
In addition to the data analysis, a theoretical investigation into GPS error is given. GPS plays a major role in the development of PA. A number of sources of errors affect the GPS and therefore effect the positioning measurements. Therefore, an understanding of the distribution of the errors and how they are related to each other over time is needed to complement the understanding of the nature of the data. Understanding the error distribution and the data give useful insights for model assumptions in regard to position measurement errors.
A review of filtering methods is given and new methods are developed, namely, strip analysis and a double harvesting algoritm. These methods are designed specifically for controlled traffic and normal traffic respectively but can be applied to all kinds of yield monitoring data.
The data resulting from the strip analysis and double harvesting algorithm are used in investigating the relationship between on-the-go yield and protein. The strategy is to use protein and yield in determining decisions with respect to nitrogen managements. The agronomic assumption is that protein and yield have a significant relationship based on plot trials. We investigate whether there is any significant relationship between protein and yield at the local level to warrent this kind of assumption.
Understanding PA technology and being aware of the sources of errors that exist in data collection and data analysis are all very important in the steps of developing management decision strategies.
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Norng, Sorn. "Statistical decisions in optimising grain yield." Queensland University of Technology, 2004. http://eprints.qut.edu.au/15806/.
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This thesis concerns Precision Agriculture (PA) technology which involves methods developed to optimise grain yield by examining data quality and modelling protein/yield relationship of wheat and sorghum fields in central and southern Queensland. An important part of developing strategies to optimisise grain yield is the understanding of PA technology. This covers major aspects of PA which includes all the components of Site- Specific Crop Management System (SSCM). These components are 1. Spatial referencing, 2. Crop, soil and climate monitoring, 3. Attribute mapping, 4. Decision suppport systems and 5. Differential action. Understanding how all five components fit into PA significantly aids the development of data analysis methods. The development of PA is dependent on the collection, analysis and interpretation of information. A preliminary data analysis step is described which covers both non-spatial and spatial data analysis methods. The non-spatial analysis involves plotting methods (maps, histograms), standard distribution and statistical summary (mean, standard deviation). The spatial analysis covers both undirected and directional variogram analyses. In addition to the data analysis, a theoretical investigation into GPS error is given. GPS plays a major role in the development of PA. A number of sources of errors affect the GPS and therefore effect the positioning measurements. Therefore, an understanding of the distribution of the errors and how they are related to each other over time is needed to complement the understanding of the nature of the data. Understanding the error distribution and the data give useful insights for model assumptions in regard to position measurement errors. A review of filtering methods is given and new methods are developed, namely, strip analysis and a double harvesting algoritm. These methods are designed specifically for controlled traffic and normal traffic respectively but can be applied to all kinds of yield monitoring data. The data resulting from the strip analysis and double harvesting algorithm are used in investigating the relationship between on-the-go yield and protein. The strategy is to use protein and yield in determining decisions with respect to nitrogen managements. The agronomic assumption is that protein and yield have a significant relationship based on plot trials. We investigate whether there is any significant relationship between protein and yield at the local level to warrent this kind of assumption. Understanding PA technology and being aware of the sources of errors that exist in data collection and data analysis are all very important in the steps of developing management decision strategies.
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Clover, Matthew William. "Soil and fertilizer potassium impacts on corn and soybean grain yield, potassium uptake, and within-field grain yield variation." [Ames, Iowa : Iowa State University], 2008.
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Sukumaran, Sivakumar. "Genomic mapping for grain yield, stay green, and grain quality traits in sorghum." Diss., Kansas State University, 2012. http://hdl.handle.net/2097/15084.
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Doctor of PhilosophyDepartment of Agronomy
Jianming Yu
Knowledge of the genetic bases of grain quality traits will complement plant breeding efforts to improve the end use value of sorghum (Sorghum bicolor (L.) Moench). The objective of the first experiment was to assess marker-trait associations for 10 grain quality traits through candidate gene association mapping on a diverse panel of 300 sorghum accessions. The 10 grain quality traits were measured using the single kernel characterization system (SKCS) and near-infrared reflectance spectroscopy (NIRS). The analysis of the accessions through 1,290 genome-wide single nucleotide polymorphisms (SNPs) separated the panel into five subpopulations that corresponded to three major sorghum races (durra, kafir, and caudatum), one intermediate race (guinea-caudatum), and one working group (zerazera/caudatum). Association analysis between 333 SNPs in candidate genes/loci and grain quality traits resulted in eight significant marker-trait associations. A SNP in starch synthase IIa (SSIIa) gene was associated with kernel hardness (KH) with a likelihood ratio–based R[superscript]2 (R[subscript]L[subscript]R[superscript]2) value of 0.08. SNPs in starch synthase (SSIIb) gene (R[subscript]L[subscript]R[superscript]2 = 0.10) and loci pSB1120 (R[subscript]L[subscript]R[superscript]2 = 0.09) was associated with starch content. Sorghum is a crop well adapted to the semi arid regions of the world and my harbor genes for drought tolerance. The objective of second experiment was to identify quantitative trait loci (QTLs) for yield potential and drought tolerance. From a cross between Tx436 (food grain type) and 00MN7645 (drought tolerant) 248 recombinant inbred lines (RILs) was developed. Multi-location trials were conducted in 8 environments to evaluate agronomic performance of the RILs under favorable and drought stress conditions. The 248 RILs and their parents were genotyped by genotyping-by-sequencing (GBS). A subset of 800 SNPs was used for linkage map construction and QTL detection. Composite interval mapping identified a major QTLs for grain yield in chromosome 8 and QTL for flowering time in chromosome 9 under favorable conditions. Three major QTLs were detected for grain yield in chromosomes 1, 6, and 8 and two flowering time QTLs on chromosome 1 under drought conditions. Six QTLs were identified for stay green: two on chromosome 4; one each on chromosome 5, 6, 7, and 10 under drought conditions.
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Harper, John, and David K. Parsons. "Small Grain Variety Yield Comparisons, Maricopa Agricultural Center." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200517.
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Cluff, Ronald E., David K. Parsons, and Lee J. Clark. "Small Grain Variety Yield Comparison, Maricopa Agricultural Center." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200518.
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Ekanayake, Lukshman Jayampathi. "Selenium on Increasing Lentil (Lens Culinaris Medikus.) Grain Yield." Thesis, North Dakota State University, 2014. https://hdl.handle.net/10365/27405.
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Selenium is an essential element for mammals but it has not been considered as essential for higher plants. The effect of Se application on lentil grain yield, antioxidant activity, nitrogen fixation, and seed Se concentration studied. Experiments were conducted at Carrington Research and Extension Center in 2012 and 2013. Selenium fertilization increased the lentil grain yield by 5 % in 2012 and by 9 % in 2013. Selenium application increased the antioxidant activity (70 % inhibition) of lentils compared to the untreated control (61% inhibition). Percentage nitrogen derived from air was increased with Se fertilization by 17 % and 12 % in 2012 and 2013, respectively, with Se fertilization. Seed Se concentration was significantly higher in selenate treated lentils (1.4 mg/kg) compared to selenite (0.9 mg/kg) and the control (0.6 mg/kg). Overall, application of Se increased lentil grain yield, nitrogen fixation, antioxidant protection, and seed Se concentration.
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Sheedy, M., M. Ottman, and T. Ramage. "Oat Variety Grain and Forage Yield Trials at the Maricopa Agricultural Center 1989." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201031.
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Sheedy, M., M. Ottman, and T. Ramage. "Oat Variety Grain and Forage Yield Trials at the Maricopa Agricultural Center, 1990." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201345.
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Twelve oat varieties (9 hulled and 3 hull-less) were yield tested for both forage and grain production at the Maricopa Agricultural Center during the '89-90 growing season. Highest forage producing varieties were generally later maturing - Cayuse and Stampede; while lower yields were produced by early maturing varieties - Montezuma and Palestine. Highest grain yields were produced by Swan and FMC400.
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Gao, Si. "Yield Point Phenomena in Ultrafine Grained Materials." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215534.
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Moghadam, Manoochehr Salahi. "Yield and quality of cereals in response to inputs and spatial variability." Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270926.
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Broeckelman, Jonathan. "Grain sorghum response to water supply and environment." Thesis, Kansas State University, 2016. http://hdl.handle.net/2097/32666.
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Master of ScienceDepartment of Agronomy
Ignacio Ciampitti
Sorghum [Sorghum bicolor (L.) Moench] has greater drought resilience than many other crops, producing food in the most stressful environments. Sorghum is a reasonable crop choice for farmers working with limited-water supply. The objective of this study was to compare sorghum hybrids differing in yield strategies under varying water supply environments. Yield, biomass, grain harvest index (HI), and yield components (seed number and seed weight) were compared in both rainfed and irrigated situations. Field experiments were established in 2014 and 2015 at Topeka, Scandia, Hutchinson, Garden City, and Tribune, KS. Three sorghum hybrids (Pioneer 85Y40, Pioneer 84G62, and Dekalb 53-67) with different yield potentials at varying water supply were studied. Hybrids 85Y40 and 84G62 tended to have greater yields than hybrid 53-67 when the environment's average yield level was greater than 8.5 Mg haˉ¹. The opposite scenario where hybrid 53-67 had greater yields than the other two hybrids tended to occur for environments yielding less than 8.5 Mg haˉ¹. Both biomass and HI were significantly correlated with grain yield (r values of 0.62 and 0.32 respectively), with biomass having an overall stronger correlation than HI in all environments. In yield group 3 (<8.5 Mg haˉ¹), biomass was much more strongly correlated (r=0.85) to yield than in the yield groups 1 and 2 (>9.5 Mg haˉ¹ and 8.5-9.5 Mg haˉ¹ with r values of 0.35 and 0.52 respectively) suggesting that biomass production is of utmost importance for yield production in drought prone environments. Harvest index on the other hand had a much stronger correlation with yield in group 1 (r=0.62) when compared to group 2 and 3 (r 0.13 and 0.36 respectively) showing the importance of not only biomass, but also of HI to maximize yield in high yielding environments. Hybrids 85Y40 and 84G62 had larger HI values relating to the yield trends in the highest yielding environments. Seed number had a stronger correlation with yield (r=0.77) than seed weight (r=0.37) supporting the importance of increasing seed number to improve yield in sorghum.
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Al-Ghzawi, Abdul Latief Ali. "The physiological processes determining grain yield potential in winter wheat." Thesis, University of Nottingham, 2007. http://eprints.nottingham.ac.uk/12885/.
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Winter wheat (Triticum aestivum L. ) is the most important crop grown extensively in the UK. There is a gap between yield production and world demand for wheat. So, there is a need to fill this gap. The overall objective of the present study is to investigate the physiological determinants of grain yield potential in winter wheat grown in UK conditions using doubled-haploid lines derived from a cross between winter wheat varieties Rialto and Spark. These varieties are known from previous work to contrast for source and sink type traits and for the presence/absence of the 1 BL/ IRS translocation and the Rht-Dl b semi-dwarf allele. Three field experiments (at Sutton Bonington, University of Nottingham 2003/4, 2004/5 and 2005/6) were conducted examining 25 DH lines of the Rialto x Spark population and the two parents. Two post-anthesis shading treatments (with and without shading) were applied to six genotypes (four DII lines and two parents) in 2003/4 and 2004/5. Two post anthesis de-graining treatments (with and without degraining) were applied to twelve genotypes (ten DH lines and two parents) in 2003/4 and 2004/5. Detailed measurements of grain growth were carried out on the two parents for five pre-determined grain positions within the ear. A range of physiological traits were measured, including developmental stages, light extinction coefficient, radiation interception, radiation-use efficiency (RUE), green area and biomass, stem water-soluble carbohydrate reserves, floret fertility, potential grain weight, grain filling rate and duration, final grain weight and combine grain yield. A source-sink balance model which quantified the source: sink balance during grain growth indicated that the four DH lines and the two parents were sink-limited during grain growth. The sink manipulation treatment (de-graining) generally confirmed the sink limitation in this population although small positive responses of grain growth to de-graining for a few lines indicated they may have been close to source limitation. Radiation-use efficiency measured as the regression slope of dry matter on accumulated PAR intercepted between onset of stem elongation and anthesis differed amongst genotypes in 2004,2005 and 2006. Pre-anthesis RUE was positively correlated with each of grains m2 and specific leaf weight (SLW). The 1BL/IRS translocation increased RUE significantly. The characterisation of the 25 DH lines in this study showed that the differences in grain yield were positively correlated with grains m'2 but not individual grain weight. There was positive correlation between stem WSC reserves and yield in one of the experimental seasons, 2006. The ten DH lines and the two parents differed in the length of the period between GS31 and GS61 by nine days. There was a positive correlation between the duration from GS31 to GS61 and radiation interception during this period which positively affecting grains m '2 Rate and duration of grain growth and final grain weight were assessed for five grain positions (G1 to G5) for Rialto and Spark under 50% shading and a control treatment. Rialto had heavier grains associated with a longer grain filling duration than Spark. The five grain positions had similar durations of grain filling but differed in final grain weight and rate of grain growth. Grains in the central spikelet (G1, G2 and G3) were sink-limited as they did not respond to de-graining. However, grains in the basal (G4) and apical (G5) spikelets were marginally source-limited since their final weight was increased by de-graining. These results suggest that breeders should consider selecting for extra grains in proximal grain positions in basal spikelets (e. g. G4) rather than in distal grain positions in central spikelets, because these grains in this position were heavier, had faster filling rate and had the ability to respond to extra assimilates later in the season. Harvest biomass was positively correlated with grain yield amongst the DH lines. So traits to improve biomass whilst maintaining harvest index may be important for future breeding progress. It is suggested that breeders might select for an extended duration between GS31 and GS61 and higher RUE (via high SLW) to improve grains M-2 and yield potential in future years. They also should select for higher stem carbohydrate reserves to increase source size alongside grain sink size.
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Shepherd, Michelle J. "Planting Date and Relative Maturity Effects on Soybean Grain Yield." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1524010217273909.
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Frank, Brian James. "Corn grain yield and plant characteristics in two water environments." Thesis, Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/3280.
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Roel, Dellazoppa Alvaro. "Factors underlying grain yield spatiotemporal variability in California rice fields /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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Kirigwi, Francis M. "Identification of markers associated with grain yield and components of yield under water stress in wheat /." Search for this dissertation online, 2005. http://wwwlib.umi.com/cr/ksu/main.
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Kennedy, Shane. "Identifying constraints to increasing yield potential of spring barley." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/16177.
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The literature suggests that grain number largely determines and as such limits yield in barley. Many of the reported studies were conducted in relatively low yielding environments and it is unclear if grain number is also a limiting factor in high yield potential climates. Nor is it known with certainty what physiological or morphological traits must be targeted in order to increase grain number. There may be a degree of trade-off between yield components whereby grain number is adjusted according to resource availability to the plant, either pre- or post-anthesis, in a way that ensures consistently well-filled grains at harvest. If mechanisms exist for adjusting grain numbers or grain storage capacity after anthesis to match assimilate availability, this may place limits on how far yield can be increased without increasing post-anthesis assimilate production. In order to determine the scope for increasing the yield potential of barley a more thorough understanding of the potential trade-offs between grain number, grain storage capacity and post-anthesis assimilate supply is required. The aim of research reported in this thesis was to establish what determines the yield of spring barley in Ireland and to investigate the timing and possible mechanisms involved in regulating grain number and grain storage capacity in relation to the supply of photoassimilates. Field experiments were carried out on spring barley (Hordeum vulgare L., cv. Quench) at several locations in Ireland from 2011 to 2013. A sub-set of experiments involving destructive sampling and in-field assessments on plots managed as per current best farm practice gathered crop growth, development, and yield component data across sites and seasons in order to establish what determines yield under typical crop production conditions. Separate experiments artificially manipulated the source:sink ratio of plots via shading and seed rate treatments to investigate in more detail the mechanisms determining grain number and grain weight and any potential trade-off between the two components. Grain number accounted for most of the variation in yield across 9 site/seasons of crops managed as per current best practice in Ireland (P < 0.001; R2 = 0.84) while grain weight remained relatively conserved. Ear number accounted for most of the variation in grain number (P = 0.002; R2 = 0.75) and ear number itself was largely determined by shoot survival from an early season peak through to harvest (P <0.001; R = 0.96). Shoot size and weight at the beginning of stem extension had the largest influence on shoot survival. Shading treatments were used to test whether there was a mechanism for adjusting grain numbers after anthesis to match the availability of assimilate for grain filling. Substantial post-anthesis reductions in assimilate supply during grain filling in 2011 and 2012 did not significantly reduce grain number (P > 0.05). A small reduction in grain number (8%) was found in response to shading for a two week period early post-anthesis in 2013, however this was likely a reduction in grain set in shoots or spikelets that reached anthesis after the treatment was imposed rather than a post-anthesis abortion or down-regulation of grain number. Percentage light interception by well managed (unshaded) canopies shortly after anthesis was generally greater than 93% across several sites and seasons, therefore increasing grain numbers to increase sink capacity would likely be associated with an unavoidable decrease in the amount of light intercepted per grain during the early grain development period. However, experiments showed that grain weight at harvest was neither reduced nor increased in response to variations in light interception during this period of endosperm development (P > 0.05), because soluble sugar concentrations in the grain were maintained at the expense of storage reserve deposition in the stems. Results suggest that grain number and grain storage capacity may both be determined pre-anthesis resulting in a trade-off during stem extension whereby grain numbers are adjusted in a way that helps conserve grain weight. A strong negative relationship between ear number and grain number per ear (P < 0.001; R2 = 0.81) across two sites of seed rate experiments in 2013 resulted in a plateau in overall grain number of approximately 18,000 grains m-2 suggesting that there may be a limit to how many grains can be established in a given environment; this was achieved with an ear number of approximately 1000 ears m-2. Yield potential for Irish conditions was estimated at 12.29 t ha-1 at 85% dry matter based on estimates of potential assimilate supply during grain filling; with a grain number of 26,481 m-2 required to utilise this. These estimates are both 44% higher than the mean yield and grain number achieved in crops managed as per current best farm practice. Once high potential ear numbers are secured (> 1000 m-2), breaking the negative relationship between ear number and grain number per ear may hold the key to further increasing grain number and hence yield potential. Increasing assimilate production and partitioning to ears during stem extension, either through increases in the duration of stem extension or solar radiation use efficiency, may enable larger grain numbers to be produced whilst maintaining or increasing individual grain storage capacity and deposition of stem storage reserves. Water and nutrient availability, as well as susceptibility to lodging may present further limitations to yield in the future.
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Fall, Sidi 1951. "Induced water stress effects on grain yield and yield components of twelve maize (Zea mays L.) genotypes." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/277913.
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Three maize populations developed for their ability to withstand drought and salinity, and their reciprocal F1 crosses were tested under induced water stress and normal moisture conditions. Two commercial hybrids and one open-pollinated variety were also included in the study. The objective was to investigate yield and its components under induced drought. Significant differences in yield were observed in both irrigation treatments. DeKalb 689, one of the commercial hybrids, outyielded all the other entries under wet conditions, whereas under dry conditions the open-pollinated variety, Page Ranch, had the highest yield. Significant differences between populations and their hybrids were also observed. Significant correlations were noted in grain yield as observed in wet and dry conditions and the reduction in the number of ears per plant was positively correlated with the reduction in grain yield resulting from drought.
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Latiri-Souki, Kawthar. "Analysis of the effects of water and nitrogen supply on the yield and growth of durum wheat under semi-arid conditions in Tunisia." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240207.
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Bibb, Jenny Lee. "Impact of corn earworm on field corn yield and grain quality." Thesis, Mississippi State University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1604199.
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Field corn, Zea mays L., has been introduced to the market with pyramided Bacillus thuringiensis (Bt) corn technologies. These technologies reduce kernel damage from ear feeding caterpillar pests, including corn earworm, Helicoverpa zea (Boddie). The first generation Bt traits in field corn demonstrated limited activity on corn earworm feeding on grain in ears. The pyramided corn technologies have greater cumulative protein concentrations and improved expression throughout the plant, so these corn traits should provide an effective management tool against these pests. In addition, reduced kernel injury may also have a direct effect on physical grain quality. The results for this trial showed no relationship between number of damaged kernels and yield was observed for corn hybrid expressing the Herculex®, YieldGard®, or Genuity VT Triple Pro® technologies. A significant relationship between both damaged kernels and test weight and damaged kernels and aflatoxin concentrations was observed in two technologies.
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Gonzalez, Navarro Oscar. "Understanding the developmental basis of grain yield potential in bread wheat." Thesis, University of East Anglia, 2017. https://ueaeprints.uea.ac.uk/63110/.
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Grain yield potential in wheat is a complex trait controlled by sub-traits like grain number, grain size, and assimilate partitioning. To achieve further understanding of grain yield potential, this thesis combines physiological and genetic dissection of wheat development. In particular, how the length of developmental phases can be optimized in favour of increased partitioning of assimilates to the spike, in order to reduce abortion rates of florets. The physiological section of the thesis (Chapter 2 and 3) comprises the in depth study of the CIMCOG panel (CIMMYT Core Germplasm). In this section the variation in patterns of floret and phenological development was determined, ascertaining how these differences affect the number of fertile florets. The differences in floret development were clear in the intermediate florets (floret primordia 3, 4, and 5 from the rachis). Floret survival was found to be positively related to the length of the period of floret development. Also fruiting efficiency, using the frontier concept, show a positive relationship with the stem elongation period. The genetic section (Chapter 4 and 5) involves the use of quantitative trait locus (QTL) analysis with a segregating population to determine the chromosomal locations affecting key developmental traits. A Buster x Charger doubled haploid population provided a crucial contrast between similar genetic background and differences in length of phenological phases. The results show that a QTL on chromosome 7A has an effect on the time to terminal spikelet phase, i.e. the onset of stem elongation, and QTL affecting time to heading was found on chromosomes 2D and 4A. Furthermore, this population also varies in lodging resistance. A major QTL was found on chromosome 2D affecting height and providing lodging resistance. These studies provide the basis to optimise wheat developmental patterns and, therefore, maximize spike fertility.
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Legwaila, Gabatshele Mbona. "Effects of panicle removal and nitrogen on yield of grain sorghum." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06162009-063221/.
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Saieed, Md Atik Us. "Identification and characterization of novel genes contributing to wheat grain yield." Thesis, Saieed, Md Atik Us (2022) Identification and characterization of novel genes contributing to wheat grain yield. PhD thesis, Murdoch University, 2022. https://researchrepository.murdoch.edu.au/id/eprint/66631/.
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Grain yield is one of the most important aspects of wheat breeding. Being a polygenic trait, wheat grain yield is regulated by multiple genes and influenced by environmental factors. It is a complex trait which is linked to several traits such as seed number, thousand kernels’ weight etc. The interaction of these yield components with environmental stimulus are poorly understood. In the current study, to improve our understanding, phenotypic plasticity of contributing traits to the grain yield was explored. The phenotypic plasticity is the variations in the expressed phenotype by an individual genotype under environmental influences. The experiment consisted of 225 Westonia-Kauz double haploid (DH) lines and evaluated in five environmental conditions. The result demonstrated that, across the DH lines, the spikelets/spike was the most plastic trait. The least plastic character was the grain protein content. Yield plasticity was found higher at favourable conditions. An increase in yield plasticity by 0.1 units was associated with an increase in maximum yield by 4.45 kg ha−1 (p≤0.001). The generated knowledge regarding trait plasticity will be useful in dissecting the genetics for yield improvement particularly at the situation of rapid climate change. Identifying quantitative trait loci (QTL) and incorporating them in the breeding program has been a widely used approach for genetic improvement of yield and its components. QTL mapping suggests a considerable size of chromosomal location harbouring genes contributing to the trait which also contains many non-target genes. Thus, a more precise identification of contributing gene would be much helpful for an efficient breeding approach. However, functional confirmation of each individual gene of a QTL region is quite laborious and expensive work. In-silico approach provides the opportunity to reduce the down-stream workload by reducing the number of candidate genes in a systematic approach. Apart from the trait plasticity research, the current study also used a pipeline combining bioinformatics and laboratory approaches to identify the contributing genes of a grain yield QTL from a double haploid (DH) population of Westonia × Kauz. Assembling the QTL region on the International Wheat Genome Sequence Consortium (IWGSC) whole-genome sequence using the flanking 90K SNP markers identified the genomic region of 20 Mbp. Gene annotation revealed 16 high confidence genes and 41 low confidence genes in that genomic region. Further functional gene annotation, ontology investigation, pathway exploration, and gene network study using publicly available expressional data enabled short-listing of four genes for down-stream functional confirmation. Complete sequencing of those four genes demonstrated that only two genes namely ferredoxin-like protein and tetratricopetide-repeat (TPR) protein gene are polymorphic between the parental cultivars. Two single nucleotide polymorphism (SNP) variations were observed in the exon for both genes, and one SNP resulted in changes in amino acid sequence. The qPCR-based gene expression showed that both genes were highly expressed in the high-yielding double haploid lines. In contrast, gene expression was significantly lower in low-yielding lines. Results indicate that these two genes are potentially the underlying genes for the grain yield QTL. To investigate the association of the selected genes with grain yield and yield components at a wider level, further genetic and phenotyping experiments were conducted on a set of 143 historical wheat cultivars of Australia. For both genes, the identified alleles in the parental cultivars have been named as Westonia and Kauz allele. Characterising the allelic composition of the genes demonstrated that, for ferredoxin gene, 34.9% cultivars possessed Westonia allele and 16.9% cultivars possessed Kauz allele. In case of TPR gene, 20.9% cultivars possessed Westonia allele and 23.8% cultivars possessed Kauz allele. For both genes, cultivars having Westonia allele showed significantly higher seed width, thousand kernels’ weight and grain yield at different environmental conditions which clearly indicated that these genes are playing important roles in determining grain yield. For further level of functional confirmation, CRISPR-Cas9 based genome editing experiment was carried out on the TPR gene in Arabidopsis using orthologous gene. Agrobacterium mediated floral dip transformation was performed using immature inflorescence containing Cas9 gene. Knock-out mutants were selected by sequencing the target gene. Phenotypic data were collected from T2 generation on leaf length, stem length, number of branches on the main stem, days to flowering, days to maturity, pods/plant, and pod length. A significant reduction was observed in pods/plant, leaf length, and days to flowering and maturity. Gene expression analyses was performed on the selected genes responsible for increased seed size, seed number, and vegetative growth, in transgenic lines of Arabidopsis. Significant reduction in gene expression was observed for ARGOS, GRF1 and GW2 genes suggesting the role of TPR gene in downregulating essential growth regulator genes and its involvement in grain yield indirectly. Overall, this study demonstrated successful use of multiple research approaches in identification of a novel candidate genes of a yield related QTL. This approach can be utilised in exploring the candidate genes of other QTLs. The identified novel genes demonstrated the potential of improving the wheat grain yield which might be included in the breeding program for further yield improvement.
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Harper, John. "Oat Hay Variety Yield Comparisons, Coolidge." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200525.
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Harper, John, and David K. Parsons. "Alfalfa Variety Yield Comparison, Coolidge." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200500.
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Harper, John. "Alfalfa Yield and Cutting Interactions." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200496.
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Tickes, Barry, and Mike Ottman. "The Effect of Phosphorus on Alfalfa Yield." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/201366.
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Matei, Gilvani. "Genome-wide selection in soybeans and optimization of phenotyping for grain yield." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/3162.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Em um programa de melhoramento genético varios fatores influenciam na seleção de cultivares, basicamente pelo elevado número de genótipos em avaliação e pela reduzida capacidade experimental em fases iniciais do programa. Nesse contexto, o presente trabalho foi dividido em quatro partes. O primeiro estudo objetivou identificar locais chaves para avaliação e seleção de genótipos de soja nas nas macrorregiões 1 (M1) e 2 (M2), em gerações com pouca disponibilidade de semente. O conjunto de dados consistiu em 22 genótipos de soja cultivados em 23 locais por 3 anos. As análises GGL + GGE e G vs. GE foram usadas. As localidades Chapada-RS e Maracaju-MS foram os locais mais representativos e discriminantes macrorregiões 1 e 2, respectivamente. A identificação das localidades chave é fundamental para a avaliação, onde o número de locais de ensaio pode se resumir a um único local por macrorregião sojícola. O segundo estudo teve como objetivo avaliar a precisão experimental de diferentes métodos de análise estatística para ensaios com elevado número de genótipos de soja. Foram usados dados de produtividade de grãos de 324 genótipos de soja, avaliados em 6 repetições. Os dados foram analisados considerando os delineamentos de blocos ao acaso, látice triplo e uso do método de Papadakis. Os indicadores de precisão experimental do método de Papadakis são mais favoráveis, quando comparados com os delineamentos de blocos ao acaso e látice triplo. Pode-se usar duas repetições e analisar os dados, usando o delineamento de blocos completamente casualizados ou método Papadakis, sem redução da precisão experimental. No terceiro estudo foi avaliado o desempenho produtivo, a adaptabilidade e a estabilidade de cultivares modernas de soja, em ensaios multiambientes. Foram avaliados 46 cultivares em oito ambientes, nas microrregiões de adaptação 102, 201 e 202, na safra 2014/2015. Ocorreu interação genótipo x ambiente complexa, com alterações do ranqueamento de cultivares entre os locais. Dentre os genótipos avaliados a cultivar NA 5909 RG, parental das RILs no ensaio GWS, esteve presente entre genótipos de maiores médias produtivas, apresentando também elevada adaptabilidade e estabilidade. O quarto estudo teve três objetivos: avaliar a precisão da SG na soja; identificar o efeito da estrutura intrapopulação na precisão da seleção genômica; e, comparar a eficiência da seleção fenotípica e genômica na soja. Foi utilizado o modelo BayesB com validação cruzada para dados fenótipicos e genótipicos de 324 genótipos de soja. Avaliou-se a precisão do GS para caracteres fenotípicos com dados genotípicos de 5403 marcadores SNPs. Os resultados indicaram que a precisão genotípica foi semelhante, considerando, ou não, a estrutura da população. Se observou que a estrutura da população não afetou significativamente a precisão dos modelos para os caracteres avaliados. Constatou-se que com esta metodologia torna-se possível reduzir pela metade o tempo de seleção e aumentar a eficiência de seleção em 123% para produtividade de grãos.
In a breeding program, several factors influence the selection of cultivars, mainly due to the high number of genotypes under evaluation and the reduced experimental capacity in the initial phases of the program. In this context, the present study was divided into four parts. The first one aimed to identify the core locations for evaluation and selection of soybean genotypes in the macro-regions 1 (M1) and 2 (M2), in generations with low seed availability. The data set consisted of 22 soybean genotypes grown in 23 sites for three years. The GGL + GGE and G analyses versus the GE analysis were used. The locations Chapada-RS and Maracaju-MS were the most representative sites and discriminant macro-regions 1 and 2, respectively. Identification of the core location is fundamental to evaluation, since it is where the number of test sites can be summarized to a single site by soybean growing macro-region. The second study aimed to evaluate the experimental accuracy of different statistical methods used to analyze the assays with large numbers of soybean genotypes. The grain yield data from 324 soybean genotypes, evaluated in six replicates, were used. The data were analyzed by using the randomized block design, triple lattice design, and Papadakis method. The experimental accuracy indicators of the Papadakis method were more favorable when compared to those of the randomized block and triple lattice designs. Two replicates could be used when analyzing the data without reducing experimental accuracy: a randomized complete block design or the Papadakis method. In the third study, the productive performance, adaptability, and stability of modern soybean cultivars were evaluated in multi-environment assays. A total of 46 cultivars were evaluated in eight environments, in the adaptation micro-regions 102, 201, and 202, during the 2014/2015 harvest. Genotype × complex environment interactions occurred with changes in the ranking of cultivars between the sites. Among the genotypes evaluated, the cultivar NA 5909 RG, parental to the RILs in the genome-wide selection (GWS) assay, was considered to be among the genotypes with higher mean productivities, and it also showed high adaptability and stability. The fourth study had three objectives: to evaluate the accuracy of genomic selection in soybean, to identify the effect of intra-population structure on the accuracy of genomic selection, and to compare the efficiencies of the phenotypic and genomic selections in soybean. The BayesB model with cross validation was used for analyzing the phenotype data from the 324 soybean genotypes. The accuracy of GS for phenotypic characters with genotypic data of 5403 SNP molecular markers was also evaluated. The results indicated that the genotypic accuracy was similar, irrespective of consideration of the population structure. It was observed that the population structure did not significantly affect the accuracy of the models for the traits evaluated. It was verified that with this methodology it is possible to halve the selection time and increase the selection efficiency by 123% for grain yield.
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Ottman, Mike, Robert Voigt, and Carl Schmalzel. "Summary of Commercial Hybrid Grain Sorghum Yield Tests at Marana, 1983-85." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/203833.
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Fromm, Bradley S. "Incorporating Grain Size Effects in Taylor Crystal Plasticity." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1275.
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A method to incorporate grain size effects into crystal plasticity is presented. The classical Hall-Petch equation inaccurately predicts the macroscopic yield strength for materials with non-equiaxed grains or materials that contain unequal grain size distributions. These deficiencies can be overcome by incorporating both grain size and orientation characteristics into crystal plasticity theory. Homogenization relationships based on a viscoplastic Taylor-like approach are introduced along with a new function, the grain size and orientation distribution function (GSODF). Estimates of the GSODF for high purity α-titanium are recovered through orientation imaging microscopy coupled with the chord length distribution. A comparison between the new method and the traditional viscoplastic Taylor approach is made by evaluating yield surface plots.
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Ottman, M. J. "Effect of Planting Date on Wheat Yield in Yuma, 2013." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2013. http://hdl.handle.net/10150/312151.
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Planting dates are known to affect wheat yields. Previous research has shown that the optimum planting date in Yuma is December 15 to January 15. Wheat is sometimes sown later than this in the Yuma area, and earlier planting dates have not been tested. To test a wide range of planting dates, six varieties(Duraking, Havasu, Joaquin, Kronos, WB-Mead, and Yecora Rojo) were planted at two seeding rates (160 and 240 lbs/A) and six planting dates at the beginning of each month from November through April at the Yuma Valley Agricultural Center. Grain yield averaged 6517 (Nov 4), 6339 (Dec 6), 6096(Jan 4), 5712 (Feb 1), 4962(Mar 1), and 3590(Apr 5). The late-flowering varieties performed relatively better at the earlier planting dates. Seeding rates of 160 and 240 lbs/A had no measureable effect on yield overall.
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Tan, Wan-Zhong. "Relationships between foliar disease and loss of grain yield in barley with particular reference to powdery mildew." Thesis, Cardiff University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283592.
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Aydin, Selahattin. "The relationship between grain yield and waxy endosperm in Sorghum bicolor (Linn.) Moench." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/2256.
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In sorghum, a single recessive gene Wx conditions waxy endosperm type. While parental inbred lines and hybrids with waxy endosperm have been developed, there has been little to no adoption of these hybrids by producers, primarily because waxy hybrids consistently yield 5-10% less than non-waxy hybrids and end-use buyers will not pay for the utilization benefits. While current waxy germplasm does not yield competitively at this time, there is a question as to whether the yield reduction is due to a negative relationship between waxy per se or due to the lack of effort to develop high yielding waxy germplasm. The purpose of this study is to determine the relationship between the waxy endosperm phenotype and grain yield in sorghum. From each of two F2 breeding populations segregating for waxy endosperm, 50 inbred lines were derived, selected only for homozygosity of endosperm type. No selection for yield was practiced during the development of these lines. Approximately 25 waxy and 25 non-waxy lines were selected for further evaluation from each population. These lines and a set of testcross hybrids were evaluated in four environments. When combined across environments and populations, waxy inbred lines and hybrids yielded 17% less than non-waxy inbred lines and hybrids. However, analysis of the individual inbred lines and hybrids indicated that several waxy inbred lines were competitive in yield with the best non-waxy genotypes. The results indicate that it should be possible to develop waxy hybrids that are competitive in yield, but that this will require additional breeding efforts to identify the correct inbred lines and hybrids.
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Veal, Matthew Wayne. "ENHANCED GRAIN CROP YIELD MONITOR ACCURACY THROUGH SENSOR FUSION AND POST-PROCESSING ALGORITHMS." UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_diss/249.
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Yield monitors have become an indispensable part of precision agriculture systemsbecause of their ability to measure the yield variability. Accurate yield monitor data availabilityis essential for the assessment of farm practices. The current technology of measuring grainyields is prone to errors that can be attributed to mass flow variations caused by the mechanismswithin a grain combine. Because of throughput variations, there are doubts regarding thecorrelation between the mass flow measurement and the actual grain volume produced at aspecific location. Another inaccuracy observed in yield monitor data can be attributed to inexactcut-widths values entered by the machine operator.To effectively address these yield monitor errors, two crop mass flow sensing deviceswere developed and used to correct yield monitor data. The two quantities associated with cropmaterial mass flow that were sensed were tension on the feeder housing drive chain and thehydraulic pressure on the threshing cylinder's variable speed drive. Both sensing approacheswere capable of detecting zero mass flow conditions better than the traditional grain mass flowsensor. The alternative sensors also operate without being adversely affected by materialtransport delays. The feeder housing-based sensor was more sensitive to variations in cropmaterial throughput than the hydraulic pressure sensor. Crop mass flow is not a surrogate forgrain mass flow because of a weak relationship (R2 andlt; 0.60) between the two quantities. The cropmass flow signal does denote the location and magnitude of material throughput variations intothe combine. This delineation was used to redistribute grain mass flow by aligning grain andcrop mass flow transitions using sensor fusion techniques. Significant improvements (?? = 0.05)in yield distribution profile were found after the correction was applied.To address the cut-width entry error, a GIS-based post-processing algorithm wasdeveloped to calculate the true harvest area for each yield monitor data point. Based on theresults of this method, a combine operator can introduce yield calculation errors of 15%. Whenthese two correction methods applied to yield monitor data, the result is yield maps withdramatically improved yield estimates and enhanced spatial accuracy.
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Jaddoa, K. A. "Effects of chemical growth regulators on plant development and grain yield in barley." Thesis, University of Reading, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370622.
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Riffel, Jarrett Daniel. "Yield response and economic impact of variable-rate nitrogen applications in grain sorghum." Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/13710.
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Master of ScienceDepartment of Agronomy
J. Anita Dille
Variable-rate (VR) nitrogen (N) applications have the potential to improve efficiency of grain sorghum production. Field experiments were conducted in 2010 and 2011 in Stockton and Manhattan, KS. Four VR-N prescriptions were generated using various combinations of grid soil sampling data, soil electrical conductivity (EC) data, and yield maps, and were compared in the field with a uniform application based on a composite soil sample and whole field average yield goal. Soil EC data were used to create management zones that were individually soil sampled. Prescriptions were applied before planting and grain sorghum was harvested and recorded with a yield monitor in the fall. Grain sorghum yields responded to N at both sites with a higher response in 2010 due to more precipitation during the growing season. At Stockton in both years, greatest yields and returns were realized with prescription 4, a combination of management zone soil data and spatially-variable yield goal, while the smallest yields were realized with prescription 2 based on management zone soil data and field average yield goal. Prescription 5, which used grid-soil sampling and a spatially-variable yield goal, and prescription 2 resulted in the lowest returns in both years. At Manhattan in both years, greatest yields and returns were realized with prescription 3, combining a composite soil sample with spatially-variable yield goal. Prescription 5 was among the lowest returning treatments in both years. At Stockton, there was no correlation between yield and soil EC during the 2010 growing season, however there was a significant correlation between yield and shallow EC during the drier 2011 season. At Manhattan, yield was correlated to deep EC in 2010 and to shallow EC in 2011. Overall, increasing spatial intensity of data to develop the prescriptions did not necessarily result in an increased yield response to the application. Prescriptions that included a variable yield goal component tended to perform better across both sites and years.
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Diawara, Bandiougou. "Effect of planting date on growth, development, and yield of grain sorghum hybrids." Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/13944.
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Master of ScienceDepartment of Agronomy
Scott A. Staggenborg
In Kansas, productivity of grain sorghum [Sorghum bicolor (L.) Moench] is affected by weather conditions at planting and during pollination. Planting date management and selection of hybrid maturity group can help to avoid severe environmental stresses during these sensitive stages. The hypothesis of the study was that late May planting improves grain sorghum yield, growth and development compared with late June planting. The objectives of this research were to investigate the influence of planting dates on growth, development, and yield of different grain sorghum hybrids, and to determine the optimal planting date and hybrid combination for maximum biomass and grains production. Three sorghum hybrids (early, medium , and late maturing) were planted in late May and late June without irrigation in Kansas at Manhattan/Ashland Bottom Research Station, and Hutchinson in 2010; and at Manhattan/North Farm and Hutchinson in 2011. Data on leaf area index, dry matter production, harvest index, yield and yield components were collected. Grain yield and yield components were influenced by planting date depending on environmental conditions. At Manhattan (2010), greater grain yield, number of heads per plant, harvest index, and leaf-area were obtained with late-June planting compared with late May planting, while at Hutchinson (2010) greater yield was obtained with late May planting for all hybrids. The yield component most affected at Hutchinson was the number of kernels panicle-1 and plant density. Late-May planting was favorable for late maturing hybrid (P84G62) in all locations. However, the yield of early maturing hybrid (DKS 28-05) and medium maturing hybrid (DKS 37-07) was less affected by delayed planting. The effects of planting dates on growth, development, and yield of grain sorghum hybrids were found to be variable among hybrid maturity groups and locations.
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Mutava, Raymond N. "Characterization of grain sorghum for physiological and yield traits associated with drought tolerance." Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1458.
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Norton, Eric J. "Evaluation of multiple-rate biosolid applications on Sudangrass yield." College of Agriculture, University of Arizona (Tucson, AZ), 2003. http://hdl.handle.net/10150/205429.
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A field experiment was conducted during the 2003 growing season to evaluate the effect of multiple application rates of biosolids material on Sudan grass yield. Growers in the Mohave Valley region of the state have been using biosolids for the past several years principally as a source of nitrogen (N) and secondarily as a soil amendment. Mineralization rates vary widely based on environmental factors, in particular temperature and soil moisture. Little research been conducted in this particular growing region to refine recommended application rates. The objective of this study was to compare the typical agronomic rate that is currently recommended to several other rates and determine the effects on Sudan grass yield. Results showed that the current recommended application rates produced the greatest yield. However, due to space limitations and logistics, the study was laid out in large treated blocks and was not replicated. As such, definitive conclusions from results are difficult to draw.
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Yi, Cuilin. "Management of Fusarium graminearum-inoculated crop residues effects on head blight, grain yield and grain quality of subsequent winter wheat crops /." [S.l. : s.n.], 2001. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB9686268.
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Husaker, Douglas, and Dale Bucks. "Crop Yield Variability in Irrigated Wheat." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/200484.
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Optimum design and management of irrigated wheat production is limited by the scarcity of information available on yield variability. The purpose of this study was to evaluate the spatial variability in soil-water parameters and the effects compared to grain yield response under level-basin irrigation. Three levels of seasonal irrigation water and two border lengths were used. Grain yields were found to increase significantly with the amount of water applied and soil water depletion (estimate of crop evapotranspiration), although yield variability was greater with reduced or deficit irrigations. Variations in soil water content were responsible for about 22% of the variability in grain yield, indicating that other soil and crop- related factors had a significant influence on production. Spatial dependence was exhibited over a greater distance at the wetter compared with the drier irrigation regimes.
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Opole, Rachel Adoyo. "Effect of environmental stress and management on grain and biomass yield of finger millet (Eleusine coracana (L.) Gaertn.)." Diss., Kansas State University, 2012. http://hdl.handle.net/2097/13964.
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Doctor of PhilosophyDepartment of Agronomy
P.V. Vara Prasad
Productivity of grain crops is highly sensitive to changing climates and crop management practices. Response of finger millet [Eleusine coracana (L.) Gaertn.] to high temperature stress, and intensive management practices such as increased seeding rates and fertilizer application are not clearly understood. The objectives of this research were to determine the effects of (a) season-long, and short episodes of high temperature stress on growth and yield traits of finger millet, (b) seeding rates and nitrogen fertilizer application rates on grain and biomass yield, and (c) to evaluate the finger millet minicore collection for high grain and biomass yield. Controlled environment studies were conducted to determine the effects of high temperature stress on physiological, growth and yield traits. Field studies were conducted in Manhattan and Hays (Kansas) and Alupe (Kenya) to determine the effects of seeding and nitrogen fertilizer rates on growth and yield traits. Finger millet minicore collection was evaluated under field conditions in India, for phenology, growth and yield traits. Season long high temperature stress of 36/26 or 38/28°C compared to 32/22°C decreased panicle emergence, number of seeds per panicle, grain yield and harvest index. Finger millet was most sensitive to short episodes (10 d) of high temperature (40/30°C) during booting, panicle emergence and flowering stages, resulting in lower number of seeds, and grain yield. Finger millet responded to the interaction between environmental (locations) and temporal (years) factors. In general, locations with higher rainfall had greater grain and biomass yield than those with low rainfall. There was no influence of seeding rates (3.2 or 6.0 kg ha[superscript]-1) at Hays and Alupe. However, in one of the two years in Manhattan, higher seeding rate of 6.0 kg ha[superscript]-1 increased grain yield compared to 3.2 kg ha[superscript]-1. There was no influence of nitrogen rates (0, 30, 60 or 90 kg ha[superscript]-1) on grain or biomass yield at all three locations. However, higher fertilizer rates had greater percentage lodging. The finger millet minicore collection displayed large ranges for most quantitative traits including days to flowering, plant height, number of fingers panicle[superscript]-1, grain yield, biomass yield, and lodging; and had >60% heritability. Some of the genotypes from the minicore collection have the potential to increase grain and biomass yield and abiotic stress tolerance of finger millet.
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Olson, Daniel O. "Relationship of Vegetation Indices from Drone-Based Passive Optical Sensors with Corn Grain Yield and Sugar Beet Root Yield and Quality." Thesis, North Dakota State University, 2019. https://hdl.handle.net/10365/29887.
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The main goal of this study was to calibrate small unmanned aircraft system (SUAS) based vegetation indices with fertilizer-N application rate and yield for corn and sugar beet. It was hypothesized that canopy reflectance would change with increasing fertilizer-N application rates. The objectives of this study were (i) to determine the crop yield and quality in response to fertilizer application rates at two field sites, (ii) map vegetation indices of the experimental plots using drone-based optical sensors, and (iii) calibration of vegetation indices with crop yield. During 2017 and 2018 growing seasons, field trials were conducted to determine corn and sugar beet response to fertilizer-N application rates. In general, the use of optical sensors for quantitative and qualitative relationships were greater after the V6 growth stage in both corn and sugar beet. Early season moisture deficiency, disease, and crop size could impact the quality of the optical sensing data collection.
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Shantz, Kim. "1985 Western Plant Breeders Advanced Wheat Yield Trials, Casa Grande." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200531.
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Thompson, Andrew. "The comparative performance of wheat cultivars and genotypes in different organic systems of production." Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294863.
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Hudson, Donna. "Analysis of the effects of treatments on non-linear models for nitrogen response curves, with implications for design." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360011.
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Jebril, Jebril. "The potential of eliminating the grain sink for enhancing biofuel traits in sweet sorghum hybrids." Diss., Kansas State University, 2017. http://hdl.handle.net/2097/38550.
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Doctor of PhilosophyDepartment of Agronomy
Tesfaye Tesso
Sweet Sorghum [Sorghum bicolor (L.) Moench] is a type of cultivated sorghum grown primarily for its sugar-rich stalks. Because of its high fermentable sugar content, the crop is widely recognized as an alternative feedstock source for bio-fuel production. The extent to which stalk sugar accumulation occurs may be determined by several factors including the sink size. Grain is the most important sink in sorghum and other grain crops. Three experiments were conducted in this study to determine the extent to which the grain sink can reduce sugar accumulation in the stalks, to test and validate a genetic system that allows development of sterile sweet sorghum hybrids, and to assess the potential of sugar-rich hybrids to overcome stalk rot diseases. The first experiment, based on 22 sweet sorghum genotypes, was undertaken to study the effect of eliminating the grain sink (removing the head prior to anthesis) on stalk juice yield, sugar accumulation, and biomass. The data showed that the grain sink had a significant effect on all traits measured. Elimination of the grain sink significantly increased oBrix % (17.8%), dry biomass (27.8%), juice yield (23.9%), and total sugar yield (43.5%). The second experiment was aimed at validating the role of A3 genetic male sterility system for producing sterile sweet sorghum hybrids. Ten sweet sorghum pollinator lines of variable sugar content were selected among the entries included in the previous experiment. The lines were crossed to four A1 and A3 cytoplasmic male sterile (CMS) lines using a Design II mating scheme. The A3 females did not have effective restorers so that the hybrids were expected to be sterile. The parental lines and corresponding hybrids were evaluated for biomass production, oBrix, juice and sugar yield using a randomized complete block design. All A3 hybrids were sterile and did not produce seed when heads were covered prior to pollination. The effect of grain sink represented by the A1 vs. A3 CMS were highly significant for Brix%, biomass, juice, and sugar yield. Comparison of parents vs. crosses component was highly significant, indicating marked heterosis effect for the traits. Both general (GCA) and specific (SCA) combining ability effects were also significant for all traits, indicating the role of both additive and dominance genetic effects in the inheritance of the characters. Earlier studies have shown positive relationships between stalk sugar concentration and stalk rot disease resistance in sorghum. Thus, the objective of the third experiment was to study the effects of the CMS mediated differential accumulation of stalk sugar on severity of charcoal rot disease caused by Macrophomina phaseolina. The experiment provided an opportunity to test the effect of variable stalk sugar in the same genetic backgrounds. The data indicated that hybrids produced from A3 cytoplasm were more resistant to charcoal rot (7.1cm lesion length) compared to those produced from the A1 hybrids (9.5 cm lesion length). The enhanced resistance of hybrids with higher sugar yield could have significant agronomic advantage in sugar based bio-fuel feedstock production.
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Subirà, Fillol Joan. "Dissecting genetic changes on wheat adaptation, yield formation and grain quality in Mediterranean environments." Doctoral thesis, Universitat de Lleida, 2017. http://hdl.handle.net/10803/405468.
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L’objectiu de la present Tesi Doctoral ha estat contribuir al coneixement existent sobre la formació del rendiment en blat i la qualitat del gra, així com l’efecte que les variables ambientals exerceixen sobre ambdós. Per això, es va analitzar una sèrie històrica formada per 24 genotips de blat dur, representatius dels cultivats a España i Itàlia al llarg del segle passat, i una col•lecció de 20 varietats de blat fariner escollides entre les més cultivades a España durant les últimes dècades i representatives dels 4 grups de qualitat industrial. Es va estudiar l’efecte de l’al•lel enanitzant Rht-B1b sobre la biomassa aèria i radicular i les seves conseqüències sobre la formació del rendiment, els canvis causats per la millora genètica en la qualitat del gra i els patrons d’adaptació (interacció Genotip x Ambient), així com l’efecte de les variables meteorològiques sobre el rendiment, els seus components i la qualitat.El objetivo de la presente Tesis Doctoral fue contribuir al conocimiento existente sobre la formación del rendimiento en trigo y la calidad del grano, así como del efecto que las variables ambientales ejercen sobre ambos. Para ello se utilizó una serie histórica formada por 24 genotipos de trigo duro, representativos de los cultivados en España e Italia a lo largo del pasado siglo, y una colección de 20 variedades trigo harinero escogidas entre las más cultivadas en España en las últimas décadas y representativas de los 4 grupos de calidad industrial. Se estudió el efecto del alelo enanizante Rht-B1b sobre la biomasa aérea y radicular y sus consecuencias sobre la formación del rendimiento, los cambios causados por la mejora genética en la calidad del grano y los patrones de adaptación (interacción Genotipo x Ambiente), así como el efecto de las variables meteorológicas sobre el rendimiento, sus componentes y la calidad.
The objective of this Doctoral Thesis was to contribute to the existing knowledge of yield and grain quality formation, as well as the effect that the meteorological variables exert on them. For this, an historical series of 24 durum wheat genotypes was used, being all of them representative of those used in Spain and Italy during the last century. Moreover, a set of 20 bread wheat varieties was selected among the most cultivated in Spain during the last decades, which were representative of the four industrial quality groups. The effect of the Rht-B1b dwarfing allele on aerial and root biomass and its consequences on yield formation was assessed. Plant breeding effects on grain quality and adaptation patterns (Genotype x Environment interaction) and the effect of meteorological variables on yield, yield components and quality was also studied.