Grain Yield Of Oats Research Articles

Effect of nitrogen and cutting management on grain production of multicut oat (Avena sativa)

A field experiment was conducted during 1988-89 and 1989-90 to study the effect of 5 nitrogen levels (0. 40. 80. 120 and 160 kg Nnla) and 3 cutting-management practices (no cutting for fodder, 1 cutting for fodder 55 days after sowing and 1 at 75 days after sowing) on grain yield of oat ( A v e ~ a saIi11a LJ. Grain yield increased only up to 80 kg Nha but the fodder production increased up to 160 kg Ntha. There was no significant difference among the cutting-management practices for grain yield, but the . fodder yield was 3 times higher when cutting was done 75 days after sowing than when it was done 55 days after sowing. In ternls of econon~ics, taking grain after 1 cutting for fodder 75 days afler sowins and fertilized with 120 kg Nha was more profitable.

Response of oat (Averza sativa) to cutting management, method of sowing and nitrogen

A field experiment was conducted during winter (rabl) seasons of 1997 98 and 1998 99 at Agricultural Research Station, Sriganganagar, to study the effect of cutting management, method of sowing and nitrogen doses on forage and grain yield of oat (Avena sativa L.). No cut treatment gave higher grain (26.05 and 28.40 qlha) and straw (82.83 and 86.55 qlha) yields than cutting at 65 or 85 days after sowing. However, higher fodder yield (1 58.08 and 168.80 qlha) was recorded when cutting was taken at 85 days. Net returns (Rs 15,619) and benefit : cost ratio (2.50) were higher with 1 cutting at 65 days and then the crop was left for grain production. Line sown crop recorded higher forage (142.23 and 153.05 L qlha) and grain (19.40 and 20.56 qlha) yield as well as net returns (Rs 17,329) and benefit : cost ratio (2.85) during both years than that of broadcast crop. Increasing level of nitrogen recorded higher yield, yield attributes as well as net returns and benefitcost ratio. The highest yield of forage (1 58.97, 169.90 qlha in 2 years), grain (23.55 and 23.73 qlha in 2 years), net return (Rs 20,129), and benefit : cost ratio (3.24) were recorded with 80 kg Nlha.

Grain yield of oat (Avena sativa) as influenced by cutting and nitrogen management

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Allelic Shifts and Quantitative Trait Loci in a Recurrent Selection Population of Oat

Recurrent selection to enhance grain yield of oat (Avena sativa L.) has been ongoing at the University of Minnesota since 1968. Grain yield was increased by 21.7% after seven cycles of recurrent selection. The objectives of this study were to monitor the long‐term genetic changes in this recurrent selection population using restriction fragment length polymorphisms (RFLPs). Ninety‐seven RFLP loci detected by 73 cDNA clones were used to evaluate changes in allelic frequencies during the recurrent selection process. Significant allelic shifts were detected in eight genomic regions. Four linkage groups were studied in greater detail to localize putative quantitative trait loci (QTL). In total, seven primary or major QTL regions were identified using allelic shift, correlation, and single‐factor analysis of variance (ANOVA) data. Six of these regions were associated with grain yield and one was associated with plant height. Thirty‐three other minor QTL were detected using correlation and/or ANOVA data. Multiple regression models for grain yield, heading date, and plant height indicated that associated markers accounted for 30, 38, and 27% of the phenotypic variance, respectively. Our results indicate that we have identified genomic regions containing favorable alleles selected during the recurrent selection process. Thirteen of the 40 QTL identified for the individual traits in the recurrent selection population were previously identified in the Kanota × Ogle recombinant inbred mapping population. Therefore, these QTL may be generally important in oat.

SELEÇÃO INDIRETA EM AVEIA PARA O INCREMENTO NO RENDIMENTO DE GRÃOS

Os diferentes caracteres de importância econômica para a cultura da aveia estão correlacionados entre si em magnitude e sentido variado. Tal fato implica que a seleção realizada sobre um caráter pode proporcionar alterações em outros, cujo resultado pode ou não ser de interesse. Assim, a quantificação dos efeitos diretos e indiretos da seleção de um ou vários caracteres sobre outros é de fundamental importância para orientar programas de melhoramento em que se tenham constituições genéticas que reúnam atributos favoráveis, constituindo-se no objetivo do trabalho. Foram avaliadas 58 linhagens de aveia, em Pelotas, em delineamento de blocos ao acaso com três repetições, sobre as quais foram realizadas avaliações fenotípicas, que foram utilizadas para a determinação dos coeficientes de correlação simples entre as variáveis. A partir desses coeficientes, aplicou-se o procedimento de análise de trilha sobre a variável rendimento de grãos. De acordo com os resultados obtidos, nenhuma variável analisada apresentou efeito direto sobre o rendimento de grãos semelhante ao coeficiente de correlação fenotípico total, demonstrando a existência de outras características influenciando, tanto na magnitude, como no sentido da correlação, impedindo a seleção isolada sobre um caractere visando ao rendimento de grãos. O caráter peso de panícula apresentou a maior correlação positiva com o rendimento de grãos, ao passo que os caracteres estatura de planta e ciclo apresentaram os menores coeficientes de correlação, o que dificulta a seleção indireta para rendimento de grãos por essas variáveis. Os caracteres número de grãos e peso de grãos, embora positivos e contribuindo para a determinação do peso de panícula, apresentaram correlação intermediária com o rendimento de grãos. Assim, considerar os efeitos do peso de panícula, número de grãos e peso de grãos parece ser a melhor estratégia para seleção indireta visando ao rendimento de grãos em aveia.

Impact of weather on yield components of spring cereals over 30 years

This investigation examines the relationships between atmospheric influences and the grain yield of spring cereals (spring barley, oats). Also, three yield components — crop density (ears/panicles m −2), number of kernels per ear/panicle and kernel weight — are considered. The study uses data of a long-term field experiment at Berlin–Dahlem for the period between 1962 and 1996. The results show that grain yields as well as the formation and differentiation of yield parameters are clearly influenced by weather fluctuations. Altogether it is possible to explain nearly 60% of the grain yield variability by meteorological variables for both species. The yield components are strongly influenced by weather in different months: the number of kernels per ear/panicle in May during spikelet formation and development, the crop density in June during tiller reduction (declining number of tillers due to intraspecific competition effects), and, finally, the kernel weight in June and July during grain filling. Grain yields of spring barley are mainly influenced by crop density and number of kernels per ear; for the grain yield of oats, the most important component is the number of kernels per panicle, which depends highly on the weather conditions in May.

Type and time of autumn tillage with and without herbicides at reduced rates in southern Sweden: 1. Yields and weed quantity

Environmental as well as economic incentives support the use of integrated weed management (IWM) systems for crop production. In order to reduce the input of agrochemicals for weed control, it may be possible to combine reduced doses of herbicides with appropriate tillage strategies and still maintain acceptable weed population levels. The purpose of this study was to compare the efficiency of different tillage strategies, with and without herbicides at 50% of normal rates, on weed populations and crop yields. The influences of type and time of stubble cultivation, harrowing and mouldboard ploughing were followed in eight long-term field trials in southern Sweden from 1988 until the spring of 1994. The crop rotations were dominated by spring-sown oats ( Avena sativa L.) and barley ( Hordeum distichon L.). Although significant site-by-year-by-treatment interactions were found, certain trends in influences of tillage on weeds and yields were identified. Weed density and weight often decreased in the order: stubble cultivation without ploughing > solely ploughing > stubble cultivation succeeded by ploughing. Grain yields of oats and barley varied 6–50% among tillage systems and the highest yields were often obtained in plots where ploughing succeeded stubble cultivation. Effects of tillage on weeds or yields were usually not influenced by herbicide application. Although only subnormal herbicide rates were used, weed density and weight were mostly reduced by 70–90%, while yields increased by 10–20%. In the spring of 1994, 1 year after the last herbicide application, densities of annual broad-leaved weeds were 40–65% lower in plots previously treated by herbicides than in non-treated plots, and differences among tillage systems were still significant. This study shows the advantage of combining herbicides at reduced rates with stubble cultivation and ploughing.

Changes in genetic diversity during seven cycles of recurrent selection for grainyield in oat, Avena sativa L.

AbstractVariability for desirable alleles within elite breeding populations is a requirement for long‐term genetic improvement. Changes in genetic diversity were evaluated in a recurrent selection programme for enhanced grain yield in oat, Avena sativa L., using coefficient of parentage (rp) and restriction fragment length polymorphism (RFLP) based genetic similarity (S) estimates. Both rp and s increased during seven cycles of recurrent selection, indicating a reduction in the level of genetic diversity within the population. The relationship between genetic diversity and agronomic performance was also examined. Genetic similarity measures were poor predictors of the near‐homozygous progeny performance and general and specific combining ability effects for three agronomic traits in the recurrent selection programme. In addition, there was no apparent trend for preferential selection of progeny from either more similar or more diverse parents within a given cycle of selection. The overall reduction in genetic diversity in this population has not affected selection response for grain yield. Variability remaining at important loci or de novo variation are possible explanations for the continued selection progress.

The effect of incorporation time of different crops on the residual effect on spring cereals

The effect of the time of incorporation of different green manures and barley residues on the grain yield of spring cereals in two successive seasons was studied in seven field trials. Annual hairy vetch (Vicia villosa Roth), red clover (Trifolium pratense L.), westerwold ryegrass (Lolium multiflorum Lam. var. westerwoldicum) and straw of spring barley (Hordeum vulgare L.) were incorporated into the soil by ploughing in early September, late October and the following May, and by reduced tillage in May. Spring barley was established in the following spring, and spring oats (Avena sativa L.) one year later. In general the grain yield of spring barley after legumes was similar to that after barley, in spite of the fact that N fertilization was reduced by 40 kg ha-1. The two autumn ploughing treatments resulted in a good yield of spring barley more reliably than did the spring incorporations. Because delayed autumn ploughing did not decrease the grain yield, a delaying procedure can be recommended for its potential of decreasing nitrogen leaching. Spring ploughing could be used on all but clay soils. Incorporating ryegrass or red clover in spring by using reduced tillage often decreased the grain yield of barley. Timing of incorporation did not have a consistent effect on the grain yield of oats in the third experimental year.;

Continued response through seven cycles of recurrent selection for grain yield in oat (Avena sativa L.)

Long-term selection experiments provide germplasm to study the effects of selection in a closed population. Recurrent selection to enhance grain yield in oat has been ongoing at the University of Minnesota since 1968. The objectives of this study were: (i) estimate the GCA and SCA effects for three agronomic traits in the seventh cycle of selection, (ii) assess the effect of the current methods of selection on parental contribution and unselected traits, and (iii) determine the direct and indirect responses to seven cycles of recurrent selection for grain yield. Progeny of the Cycle 6 parents and parents for Cycles 0 through 7 were grown in two separate tests. Grain yield, heading date and plant height were evaluated in each test. Grain yield was increased by 21.7% after seven cycles of selection. Evaluation of Cycle 6 progeny showed that GCA effects were significant for all three traits studied, and SCA effects were significant only for grain yield. Four Cycle 6 parents did not have any progeny selected as Cycle 7 parents. Results from this study indicate that long term recurrent selection has continued to increase grain yield. Alternative selection strategies may be necessary to maintain the genetic variability in this population, particularly when improvement of secondary traits is required.

Recurrent Selection in Oat: Stability of Yield and Changes in Unselected Traits

Recurrent selection, primarily for grain yield in oat (Avena sativa L.), has been practiced at a single location for four cycles. Previous evaluations of this program had indicated that grain yield had been increased and that correlated changes, some undesirable, had also occurred. In some studies in other species, yield increases have come at the expense of stable productivity. The objectives of this study were to evaluate the stability of grain yield and to assess changes in nine unselected traits to determine the potential of lines from this program for cultivar development. Grain yield was measured in 23 trials during a 5‐yr period to evaluate gain from selection and compare the average yield stability of the 12 initial parents with that of the 21 fourth cycle parents (lines selected from the third cycle). Seven agronomic and seed quality traits (days to heading, plant height, resistance to lodging, test weight, groat percentage, percentage groat protein, and percentage groat oil) were evaluated in 12 trials to examine correlated response to yield selection. Barley yellow dwarf (BYD) and loose smut reactions were evaluated in inoculated disease nurseries. Gain from four cycles of yield selection ranged from ✕2.0 to 44.6% in the individual environments, and was usually significantly positive. Also, based on regression stability statistics, selection for grain yield increased the ability of the selected materials to respond to more favorable environments. Finally, there were significant correlated responses for all but two of the unselected traits, groat percent and BYD reaction; however, even though most of the changes were undesirable they were relatively small and should not detract from the potential of the fourth cycle parents in a cultivar development program.

Recurrent Selection for Test Weight and Grain Yield of Oat

Continued advances in oat (Avena sativa L.) breeding rely in part on the improvement of test weight and grain yield while maintaining genetic variability. The objective of this study was to determine the efficacy of three cycles of recurrent selection for high test weight (HT population) or Smith‐Hazel index of test weight and grain yield (HTG population) in oat. The recurrent selection procedure consisted of intermating selected S0:1 lines, growing the S0 seeds to produce S0:1 lines, and field evaluating the S0:1 lines. Each cycle took 1 yr to complete and about 300 lines were evaluated in each population of each cycle. Twenty S0:1 lines were selected from each population to initiate the next cycle. Response to selection in a population was evaluated by testing 95 S0:1 lines randomly chosen from among Cycles 0, 1, and 2, the complete Cycle 3 population, parents from all cycles, and a set of check cultivars. There were significant (P < 0.05) increases in mean test weight of 17.8 ± 3.5 kg m−3 and 6.9 ± 1.5 kg m−3 per cycle in the HT and HTG populations, respectively. For grain yield, there was a significant decrease of 0.11 ± 0.03 Mg ha−1 per cycle in HT populations, and an increase of 0.12 ± 0.07 Mg ha−1 per cycle in HTG populations. Broad‐sense heritabilities and genotypic variances remained high in all cycles of each population. The results of this study show that recurrent selection in oat is an effective breeding procedure for improving test weight and grain yield without significant reductions in genetic variability.

Recurrent Selection for Increased Grain Yield in Oat

Grain yield is a primary consideration in choosing oat (Avena sativa L.) cultivars. This research examines gain from five cycles of recurrent selection for grain yield in oat, and compares the yield responses when evaluated in hill and row plots. A secondary goal was to examine the yield components that contributed to the yield gains in the two plot types. Parents of all five cycles of recurrent selection and the checks ‘Don’, ‘Hazel’, ‘Moore’, ‘Noble’, ‘Ogle’, ‘Starter’, and ‘Steele’ were grown in hill and row plots in 1988 and 1989 at St. Paul and Rosemount, MN. Experimental design for both experiments was a randomized complete block and data were recorded on grain yield (g m−2), seed weight (g 100 seed−1) and seed number (seed m−2). Grain yield gain per cycle, as measured by weighted linear regression, was 15.1 g m−2 in hill plots and 12.8 g m−2 in row plots. Examination of the yield components seed weight and seed number indicated that the grain yield gain resulted from an increase in both traits. The relationship between seed weight and seed number was numerically different in the two plot types, with seed weight showing a larger increase per cycle in row plots and seed number a larger increase per cycle in hill plots. Phenotypic correlations of parent performance in the two plot types were 0.85 for grain yield, 0.81 for seed weight and 0.69 for seed number (P < 0.01). The large gain in grain yield per cycle and the excellent agreement in performance of the parents of all five cycles in hill and row plots indicate the effectiveness of recurrent selection in oat.

Association of pre- and post-heading growth traits with grain-yield in oats

Identifying traits that contribute significantly to growth and productivity is an important aspect of yield improvement in crop plants. Growth rate and harvest index are two traits that have been positively associated with grain-yield improvement in oats ( Avena spp.). In this study, growth rate and dry-matter accumulation were divided into pre- and post-heading phases. The objective was to evaluate the association of pre- and post-heading growth rate and dry-matter accumulation with grain-yield and other traits in 12 A. sativa L. cultivars. The study was conducted at Arlington and Madison, Wisconsin, in 1985 and 1986. The experimental design was a randomized complete block with four replications in each environment. There were significant differences among cultivars for all traits measured at heading and maturity. Phenotypic correlation coefficients for pre-heading growth rate with grain-yield and harvest index were −0.35 and −0.85 ∗∗, respectively, while phenotypic correlation coefficients for post-heading growth rate with grain-yield and harvest index were 0.86 ∗∗ and 0.83 ∗∗, respectively. The cultivar Ogle was significantly higher than any other in grain-yield and in post-heading growth rate and dry-matter accumulation. The results of this study indicate that differences in rate and amount of dry-matter accumulation after heading are highly associated with grain-yield differences among oat cultivars currently grown in the north central region of the United States.

Interrelationships between Panicle Weight, Grain Yield, and Grain Yield Components in Oat

The value of panicle weight as a selection criterion for improving grain yield in oat (Avena sativa L.) is largely unknown. Panicle weight in oat combines two of the three primary yield components, spikelets per panicle and seed weight, into a single trait that is easy to measure. Three oat populations were evaluated in 1987 through 1989 for the effect of selection for panicle weight on grain yield. Genotypes in each population were identified as having either high, intermediate, or low panicle weight in F5 progeny rows, and progenies were evaluated for panicle weight and grain yield in the F6 and F7 generations. A random group of genotypes in each population served as a control. The high panicle weight group did not differ from the random group for mean panicle weight and mean grain yield in all three populations. However, the low panicle weight group had the lowest mean panicle weight and mean grain yield in two (X4020‐15‐l/‘Ogle’ and ‘Centennial’/‘Coker 81‐32’) of the three populations. The correlation between F5 panicle weight and F6 and F7 grain yield was 0.34, 0.06, and 0.56 for X4020‐15‐l/Ogle, ‘Don’/X3530‐47, and Centennial/Coker 81‐32, respectively. Panicle weight had a high positive phenotypic correlation with spikelets per panicle (0.57 to 0.90), but a high negative correlation with number of panicles per unit area (−0.54 to −0.81). Although high panicle weight was not consistently associated with high grain yield, the fact that low panicle weight identified low grain yielding genotypes in two of three populations suggests that low panicle weight would be useful in a truncation selection approach for grain yield improvement. Visual selection, however, would probably be as effective and require less resources.

High Phytomass Producing Oats for Cultivation in Northern Growing Conditions

AbstractIt has been argued that the breeding of cultivars with higher weight per panicle but constant phytomass (i.e., improved harvest index) is unlikely to improve grain yield of cereals in the future. To examine this question in oats, this study observed relationships between above‐ground phytomass production and grain yield as well as 18 morphological and physiological traits representing maturity class and architecture of oat stand. The study was conducted in two dissimilar growing seasons. Material consisted of 29 Finnish and Scandinavian oat cultivars and breeding lines. Correlations between phytomass and other traits were evaluated by linear regression analysis. The study revealed that there has already been a trend toward improving the above‐ground phytomass production in cereal breeding in Finland. The phytomass elevation can be attributed to both higher panicle weight as well as increased above‐ground vegetative phytomass. Thus, improved grain yield of oats is not merely a consequence of increased harvest index, as is often mentioned, but is also a result of higher phytomass as such. The weight of the above‐ground phytomass did not correlate with undesirable traits such as plant height or susceptibility to lodging, but it did have a positive relationship with days to yellow ripening. The applicability of phytomass weight in indirect yield breeding of oats in the northern growing conditions is discussed.

Inheritance of Test Weight and Its Relationship with Grain Yield of Oat

Test weight is a measure of grain quality and market value of oat (Avena saliva L.). This study was conducted to evaluate the degree of genetic variability for test weight among elite oat germplasm, and to assess the feasibility of breeding oat cultivars with increased test weight. Variance components and heritability of test weight were estimated by evaluating 50 random F2:3 lines from each of 13 singlecrosses. Evaluations were conducted in a trial with four replications at each of three locations in Iowa. Significant genetic variance (P≤ 0.01) occurred for test weight in all populations. Heritabilities for test weight, calculated on a line‐mean basis, ranged from 63 to 91%. Transgressive segregation occurred in 10 populations, but lowtest‐weight segregates were more frequent than high transgressive lines. High heritabilities, the general concurrence between mating means and midparent values, and normality of the distributions of segregating lines suggest that gene action for test weight is primarily additive. Correlations between test weight and grain yield were positive for eight populations, negative for one, and not significant for four. We found significant genetic variance and high heritability for test weight and grain yield. Because test weight and grain yield were typically positively correlated, breeding high‐yielding oats with improved test weight should be possible.

Effect of epigeal predators on infestation by the aphid Rhopalosiphum padi and on grain yield of oats in monocrops and mixed intercrops

AbstractThree field experiments, with factorial designs and consisting of monocrops of oats, Avenu sativa, and mixtures of oats with faba bean, Vicia faba, were conducted in 1983–1985. The densities of generalist epigeal predators were manipulated by vertical barriers or ingress and egress trenches. Pitfall trapping was used to measure the effect of manipulation. Tillers were sampled to monitor populations of the major pest of oats, the bird cherry‐oats aphid, Rhopalosiphum padi, and to estimate their peak densities. Also grain yields were measured.The barriers and the egress trenches significantly reduced the pitfall catches of carabids, staphylinids and spiders. The effect on Coccinella septempunctata was variable. The peak aphid densities were 11–125% higher in the predator reduction treatments than in the controls. The grain yields of oats were reduced by 19–22% in all cases where aphid densities were increased by the manipulations. Relief of predation pressure by generalist epigeal predators is the proposed explanation for the increased R. padi densities and subsequently decreased oat yields.Mixed cropping increased the pitfall catches of carabids by 14–36%. Trechus spp. contributed most to the pattern. In 1985 the early egress manipulation increased the aphids’ peak density and decreased the yield of oats significantly more in the monocrop than in the mixture: this was thought to be because the R. padi population escaped predation as the result of a higher colonization rate in the mixture, rather than being due to responses of the predators to crop diversification.RésuméInfluence des prédateurs épigés sur les contaminations par le puceron Rhopalosiphum padi et sur la production de grains d'avoine en cultures pures et mixtesTrois expériences en plein champ ont été réalisées en Finlande en 1983–85 pour étudier l'influence des prédateurs épigés sur le niveau de contamination par R. padi et la production de grains d'avoine en cultures pures ou associées à Vicia faba. R. padi est le principal ravageur de l'avoine dans ce système. Les captures réalisées par les prédateurs épigés, principalement des carabidae, des staphylinidae et des araignées ont réduit les attaques dans les parcelles entourées de barrières verticales (1983) ou de fossés inondés. Les réactions de Coccinella septempunctata à ces manipulations ne sont pas constantes et ne peuvent pas expliquer son influence sur les populations de R. padi. Les densités maximales de pucerons ont été de 11 à 125% élevées dans les parcelles modifiées que dans les parcelles témoins ou entourées de fossés inondés. Les récoltes d'avoine ont été réduites de 19 à 22% dans tous les cas où la densité de pucerons a augmenté.Dans la discussion, la limitation de la pression de prédation par les généralistes épigés a été mise en avant pour expliquer l'augmentation des densités de R. padi et la diminution consécutive de la récolte d'avoine. La comparaison des caractéristiques du système R. padi avoine de printemps et du système R. padi/blé d'hiver laisse supposer qu'elles ont contribué à la relative importance des prédateurs généralistes consommant R. padi tôt dans la saison.Ces résultats ne suggèrent aucun effet négatif de la culture mixte avec V. faba sur la prédation épigée. Cependant, des éléments montrent qu'une forte densité de colonisation par des immigrants ailés de R. padi dans les cultures peut permettre à la population proie d'échapper aux prédateurs généralistes quand ceux‐ci deviennent saturés aux densités de proies élevées. On peut en conclure que la contribution potentielle des prédateurs épigés aux récoltes de céréales de printemps, ‐qui ne se réalise que lorsque R. padi n'est pas limité d'une autre façon‐, dépend du niveau atteint par la première colonisation par R. padi ailés. Leur contribution est la plus faible lors d'une très faible ou d'une très forte colonisation.

A Procedure for One Cycle of Recurrent Selection per Year with Spring‐Sown Small Grains

The objective was to combine a set of crossing and evaluation techniques into a regime that permits a breeder to conduct one cycle of recurrent selection for protein or grain yield of oats (Avena sativa L.) per year. Parental strains are crossed in the greenhouse during September to December, S0 plants are propagated in the greenhouse during December to March, S0.1 lines are evaluated in a replicated multilocation experiment in the field during April to July, and data summary and selection of parental lines for a new cycle occur during August. The schedule is repeated for each cycle. Over three cycles, the gain per cycle (and per year) was 4.7% for protein yield and 5.4% for grain yield. Techniques employed to permit completion of a cycle of recurrent selection in 1 year were: (i) approach method of crossing, (ii) evaluating S0.1 lines, (iii) hill plots for field evaluation, (iv) infrared analyzer for N determinations, and (v) computer data analyses and line selection.

Morphological Changes Associated with Three Cycles of Recurrent Selection for Grain Yield Improvement in Oat1

To assess the potential for improving grain yield via indirect morphological trait selection, the original and third cycle parents from a recurrent selection program for grain yield in oat (Avena sativa L.) were compared. Evaluation was based on hill plots grown in three field environments. This selection increased grain yield 13.5% and total dry matter 15.9%; thus, there was no increase in harvest index. All morphological structures measured increased in size. Grain yield was not closely or consistently related to any individual morphological trait, nor to the photosynthetic area of the flag leaf and panicle. Analysis of allometric relationships (the size of one plant structure relative to another) indicated that the size of morphological structures within a genotype tended to be proportional, but variability in allometric relationships was present. Therefore, selection for altered allometric relationships may be successful, but construction of an ideotype based on certain levels of expression of individual morphological traits, or photosynthetic areas, is not likely to be effective in increasing grain yield.