Spring-sown Oats Research Articles

Impact of varying N fertiliser rate and timing on yield formation and grain filling in winter and spring-sown oats

The influence of N timing and N rate on yield formation and grain-filling procedures in winter and spring-sown oats is unclear. Factorial trials investigating the effect of six rates of applied N fertiliser (0,30. 60. 90. 120 and 150 kg N ha−1) applied at three timings (Zadoks GS 21, 30 and 50) were conducted at four spring sown sites and three winter sown sites (Cv Husky) over the period 2016–2019 in the east of Ireland.Significant interactions were frequently observed on grain yield following spring and winter sowing, associated with increases in grain number where N was applied at early growth stages (GS 21, GS30) relative to GS50 application. This was linked with increases in panicles/m2 in response to available N during early developmental periods. Grain weight was maintained as the level of N applied at GS50 increased with reductions observed at earlier applications, but had no effect on yield.Responses to applied N rate were in the range of 0.5–1.9 t ha−1 in spring sown crops and 1.2–3 t ha−1 in winter sown crops, with grain yield reducing by 0.5–2.1 t/ha −1 (spring) and 1.2–1.5 t ha−1 (winter) as N application was delayed. N application timing impacted spikelet and grain number per panicle in winter crops, with spring crops unaffected.The relative importance of panicle number when spring sown, and grains/panicle when winter sown, is also discussed. This paper highlights the role of N application during early developmental in increasing the yield components contributing to grain number.

Effects of cultivar, seed rate, N rate and plant growth regulator on key processing quality parameters of winter and spring-sown oats

AbstractThe effects of three seeding rates (250, 350 and 450 seeds/m2), six applied N rates (40, 70, 100, 130, 160 and 190 kg N/ha) and the application of plant growth regulator on the grain quality of two spring oat cultivars (Husky and Keely) were evaluated at four spring-sown sites over a 3-year period (2016–2018). The same cultivars, seeding rates and five applied N rates (80, 110, 140, 170 and 200 kg N/ha) were evaluated at three winter-sown sites, in 2017–2019. Keely had a significantly higher kernel content (KC) in spring (0.7%) and winter-sown (0.6%) oats. Specific weight (SW) decreased as N rate increased in spring-sown crops (1 kg/hl) with no effect observed in winter-sown oats. Hullability (HB) increased (0.92%) in spring-sown crops as N rate increased with a reduction (0.9%) observed when winter-sown. Increases in grain protein percentage (GPP) were observed in spring (1.8%) and winter (1.2%) sowings in response to N rate. The application of plant growth regulator reduced SW (0.4 kg/hl), GPP (0.3%), KC (0.6%) with no effect on HB. Kernel size was highly responsive too applied N rate, with reductions in grains >2.5 mm and increases in grains of smaller size observed as N rate increased. HB had a marked relationship to kernel size with GP inconsistently linked to SW. The results of this study suggest that cultivar, N rate and PGR application are of importance to milling quality and that changes in grain size in response to agronomic practices contribute to changes in specific weight and hullability.

A Dual-Purpose Model for Spring-Sown Oats in Cold Regions of Northern China

Alpine regions in northern China are the traditional animal husbandry base. The lack of high-quality forage supply resulting from degradation of natural grasslands and low forage production due to short growing seasons greatly restricts development of animal husbandry in these areas. Spring oats have been widely planted in cold regions worldwide harvesting as either grains or forages because of their great adaptative ability to low temperatures and early maturation and high nutritional values. To maximize forage and grain production, we developed a dual-purpose model for spring-sown oats in the cold regions of northeastern China using two oat species, Avena nuda L. (cv. Bayou6) and Avena. sativa L. (cv. Qinghai444). Growth, forage production and quality, grain yield, and re-growth ability of the two oats were investigated in field trials and field demonstration. Maximal dry weight was found to occur at 70 days of emergence for both oats with higher forage production and crude protein (CP) in Bayou6 than Qinghai444 oat species. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) of the two oats increased with time during the early vegetative growing stage, while the relative feed value showed a decrease during vegetative growing stage. The re-growth ability following cutting for the two oats reduced with increasing growth times during vegetative stage. Plant height, tiller density, CP and NDF contents of re-growing seedlings harvested at 30–40 days of emergence did not significantly differ from those of un-cutting control. The overall cumulative dry weight of biomass following cutting at 30 days of emergence was significantly higher than that of control without cutting in both oat species. Seed yield from plots cut at 30 days of emergence for both oat species was insignificantly different from that of control plots. Harvesting of spring-sown oats at 30 days of emergence enhanced forage production, but it did not influence seed yield. Results from 2-year field demonstration confirmed these conclusions. These findings highlight that this dual-purpose oat management model can have great applications in the cold regions of China.

Population structure and genome-wide association analysis for frost tolerance in oat using continuous SNP array signal intensity ratios.

Key messageInfinium SNP data analysed as continuous intensity ratios enabled associating genotypic and phenotypic data from heterogeneous oat samples, showing that association mapping for frost tolerance is a feasible option.Oat is sensitive to freezing temperatures, which restricts the cultivation of fall-sown or winter oats to regions with milder winters. Fall-sown oats have a longer growth cycle, mature earlier, and have a higher productivity than spring-sown oats, therefore improving frost tolerance is an important goal in oat breeding. Our aim was to test the effectiveness of a Genome-Wide Association Study (GWAS) for mapping QTLs related to frost tolerance, using an approach that tolerates continuously distributed signals from SNPs in bulked samples from heterogeneous accessions. A collection of 138 European oat accessions, including landraces, old and modern varieties from 27 countries was genotyped using the Infinium 6K SNP array. The SNP data were analyzed as continuous intensity ratios, rather than converting them into discrete values by genotype calling. PCA and Ward’s clustering of genetic similarities revealed the presence of two main groups of accessions, which roughly corresponded to Continental Europe and Mediterranean/Atlantic Europe, although a total of eight subgroups can be distinguished. The accessions were phenotyped for frost tolerance under controlled conditions by measuring fluorescence quantum yield of photosystem II after a freezing stress. GWAS were performed by a linear mixed model approach, comparing different corrections for population structure. All models detected three robust QTLs, two of which co-mapped with QTLs identified earlier in bi-parental mapping populations. The approach used in the present work shows that SNP array data of heterogeneous hexaploid oat samples can be successfully used to determine genetic similarities and to map associations to quantitative phenotypic traits.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-016-2734-y) contains supplementary material, which is available to authorized users.

DEVELOPMENT AND EVALUATION OF A LOGISTIC RISK MODEL: PREDICTING FRIT FLY INFESTATION IN OATS

Forecasting insect pest damage allows for an adjustment of pesticide use to the actual need, and it is important to establish the potential benefits of pest forecasts in terms of profitability and reduction of pesticide use. Here I calibrate and evaluate a risk algorithm for frit fly infestation in spring-sown oats, aiming to improve damage forecasts and assess the profitability of different control strategies with regard to regional infestation prevalence. Oat fields in two regions in Sweden with high and low frequencies of infestation were surveyed for 11 and 13 yr, respectively. The surveyed fields were classified either as infested or noninfested, depending on whether or not the infestation level exceeded the economic threshold. The relation between various risk factors and frit fly damage was examined by logistic regression, and risk points were assigned to significant factors. Regional action thresholds (risk point sums) resulting in the lowest average costs were calculated. In regions where pest ou...

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.

INFLUENCE OF CROPS ON NUMBERS OF MICROSCLEROTIA OF VERTICILLIUM DAHLIAE IN SOILS AND THE DEVELOPMENT OF WILT IN SOUTHWESTERN ONTARIO

Verticillium dahliae was studied in Harrow Sandy loam and Colwood loam using a root bioassay to determine microsclerotial numbers in soil. Plots established in the autumn of 1971 were sampled over a period of 12 mo to follow changes in populations under a susceptible crop, eggplant (Solanum melongena L.), indigenous weeds, spring-sown oats (Avena sativa L.), peas (Pisum sativum L.), snap bean (Phaseolus vulgaris L.) and bare fallow. At first, populations declined under all treatments, then increased in both soils under eggplant and in the weed plot on Harrow Sandy loam, which was heavily infested with velvet leaf (Abutilon theophrasti Medic). There was no increase in numbers of microsclerotia in the weed plot on Colwood loam, which was free from susceptible weeds. When populations in Harrow Sandy loam were reduced by fall fumigation with Vorlex (20% methyl isothiocyanate, 80% chlorinated C3 hydrocarbons) and Mylone (tetrahydro-3, 5-dimethyl-2H-1, 5-thiodiazine-2-thione), the rate of wilt development and fruit yields in eggplant were correlated with microsclerotial numbers in soil. The study showed that populations of 6–12 microsclerotia per gram of soil caused severe wilt in two field soils, and that the root bioassay was sufficiently sensitive to detect differences in numbers of microsclerotia ranging from 1–13 per gram of soil.

Fatty acid composition of grain from winter and spring sown oats, barley and wheat.

AbstractThe fatty acid composition of grain has been studied in six varieties of oats, two of wheat and two of barley, sown in pots in an unheated glasshouse in winter and in spring. Differences were found between the species in composition and in their response to sowing date. Oats showed the greatest varietal variation in both total fatty acid (TFA) content and in the proportion of its component fatty acids. The content and degree of unsaturation of the oat TFA was higher in the winter sown than in the spring sown crop. Increases in the TFA content of oats, whether arising from differences in variety or sowing date, were generally followed by an increase in the proportion of oleic acid and a decrease in the proportions of palmitic and linoleic acid in the TFA. Winter sowing, as compared with spring, led to a small, but significant, decrease in the TFA content of barley and an increase in its degree of unsaturation. There were no significant changes in the content or composition of wheat TFA as a result of differences in sowing date. Factors influencing the differences in TFA content and composition between species, varieties and sowing dates are discussed.

YIELD AND DISEASE-ESCAPE POTENTIAL OF FALL-SOWN OATS POSSESSING SEED DORMANCY

Several "dormoat" lines that resemble Avena sativa L. ’Clintland’ in seed and plant morphology but having the seed dormancy of A. fatua L. were synthesized to test the hypothesis that fall-sown dormant oats that do not germinate until the following spring will yield more grain in Canada than spring-sown oats. In 1966, seed yield increases of 13 and 24% were obtained at Ottawa from 1965 fall sowings of dormant seed compared with spring sowings of non-dormant seed of the same "dormoat" lines. Greater seed size and escape from diseases because of early maturity were mainly responsible for the higher yields of the fall-sown as compared with the spring-sown plots. In spite of these encouraging results, "dormoats" will not be commercially useful until the spring emergence of fall-sown seed is greatly increased.

Copper deficiency in crops in north-east Scotland

SummeryField and pot experiments were carried out to determine how copper deficiency can be corrected on some soils in north-east Scotland. Spring-sown oats and barley are more susceptible to this deficiency than mixed herbage, while potatoes and swedes have not responded to Cu. The deficiency can be corrected by applying 10–20 lb CuSO4.5H2O per acre to the soil. Both field and pot experiments show that such treatments have large residual effects and under field conditions are effective for at least 8 years. A foliar spray supplying 1 lb CuSO4. 5H2O per acre is usually less effective than a soil dressing.Using soil undiluted with sand, the increase in grain yield produced by Cu treatment in pots was appreciably greater than in the field. The Cu content of mature oats and barley was practically unaffected by soil dressings but foliar spraying produced a considerable increase.Significant correlation coefficients have been obtained between soil Cu, extracted by 0·05 M EDTA, and the increase in grain yield produced by Cu applications in both field and pot experiments. In field experiments in north-east Scotland, cereal yields were not restricted by a deficiency if the EDTA-extractable Cu was above 1·1 ppm. With soil contents below 0–75 ppm Cu, the grain yields from spring-sown oats and barley were usually increased considerably; small responses were possible with contents between 0·75 and 1·1 ppm.

APHID POPULATIONS AND THEIR DAMAGE TO OATS IN BRITISH COLUMBIA

Populations of aphids on Victory oats were studied during the 4 years 1957–60 at Vancouver, British Columbia. The aphids found, in order of abundance, were: the English grain aphid, Macrosiphum avenae (F.) (= granarium (Kirby)), the rose grass aphid, Metopolophium dirhodum (Walker), and the bird-cherry oat aphid, Rhopalosiphum padi (L.). M. avenae and R. padi overwintered as viviparae on small grains and grasses; M. dirhodum overwintered as eggs on Rosa spp. Winged migrants moved to spring-sown oats late in May or in June. Maximum aphid density was low in 1958, moderate in 1957 and 1959, and high in 1960. Predators and parasites were important factors in governing the aphid populations.Yield data from 25 pairs of insecticide-treated and untreated plots showed no significant advantage in yield of oats and only small gains in yield of straw from controlling aphids. The economic injury level for aphids on oats under conditions similar to those in the experimental fields is, therefore, higher than 47 aphids per tiller. General application of non-selective insecticides to control aphids on oats in British Columbia is not recommended.

Light and Soil Moisture beneath Several Companion Crops as Related to the Establishment of Alfalfa and Red Clover

1. Measurements were made of the penetration of light into six companion crops and of the available soil moisture under those crops as they advanced in maturity. Companion crops used were fall-sown winter rye and winter wheat and spring-sown oats, wheat, barley, and flax. The influence of the various companion crops on the establishment of alfalfa and medium red clover also was studied. 2. Winter rye and winter wheat were stronger competitors for light and soil moisture than the spring-sown companion crops and exerted these competitive effects over a much longer period. Consequently, the winter cereals caused reduced legume stands and hay yields. Winter rye was generally more competitive and less satisfactory as a companion crop than winter wheat. 3. Flax was least competitive of the spring-sown companion crops, and establishment of legumes was superior under flax. 4. The three spring-sown cereals furnished about equal competition for light and soil moisture, although barley was usually more competitive for light and oats for soil moisture. Spring wheat was generally less competitive for light than barley or oats. Legumes were slightly more vigorous under spring wheat than they were under barley and oats. Legume stands were essentially similar under the three spring-sown cereals with slightly thicker stands under wheat. Hay yields were slightly higher from legume stands established under barley than from stands established under wheat and oats and were slightly lower under oats. 5. The trends of both light and soil moisture beneath a given companion crop were quite similar. For example, a companion crop that caused early and extended shading also caused early and extended soil moisture stress. 6. Growth of weeds was always least in association with the companion crops that caused the most shading and the greatest soil moisture stress.

Studies in selective weed control II. The control of annual weeds in spring cereals

As part of a general programme for the development of new techniques of selective weed control, numerous experiments have been carried out during 1943–7 on the eradication of annual weeds from spring-sown oats and barley. These multifactorial experiments consisted essentially of simultaneous comparisons of the relative merits of sulphuric acid, copper salts, dinitro-o-cresol and the two growth-regulating substances 2:4-dichloro-phenoxyacetic acid and 2-methyl-4-chloro-phenoxyacetic acid. All the compounds were applied as aqueous solutions or suspensions at a spray rate of 100 gal./acre.Within groups of compounds, cupric chloride is more toxic than cupric nitrate, and this in turn is more toxic than cupric sulphate to such weeds as Raphanus raphanistrwn. Similarly, dinitro-o-cresol or its ammonium salt is more effective than the sodium salt for the control of R. raphanistrum and Galeopsis tetrahit. There is some evidence that sodium methyl-chloro-phenoxyacetate is slightly superior to sodium dichloro-phenoxyacetate for the control of Galeopsis tetrahit and Sinapis arvensis.Between groups of compounds, as long as the weeds are in the young seedling stage there is little to choose between sulphuric acid, cupric chloride, ammonium dinitro-o-cresylate and the growth-regulating substances for the control of Sinapis arvensis, Raphanus raphanistrum, Thlaspi arvense and Polygonum convolvulus when the concentration ranges for the four groups are respectively 9–18, 1–4, 0·4–0·8 and 0·1–0·4%. Within these limits of concentration P. persicaria is best controlled with sulphuric acid and Atriplex patula by dinitro-o-cresol.In general, there is a decrease in the toxic effects with increasing age. There are however complex interrelationships between weed species, compound and stage of development. Whereas for cupric chloride its effectiveness against Sinapis arvensis is little changed between the cotyledon and flowering stage there is with flowering a marked falling off in the efficiency of sodium methyl-chloro-phenoxyacetate. In the intermediate phase of development the growth-regulating substances are most toxic to Raphanus raphanistrum.The results for crop yield demonstrate that sulphuric acid and cupric chloride are less selective than dinitro-o-cresol or the substituted phenoxyacetic acids, since for equivalent degrees of weed control smaller increases in grain production have often been recorded. These injurious effects are maximal at the higher concentrations and when spraying is delayed until after tillering is completed. There is a similar age trend for dinitro-o-cresol and the two growth-regulating substances, and in the case of the latter some indication of a concentration effect, i.e. the compounds are most selective at concentrations of 0·2% or less.For the twenty experiments in which the yields were recorded the most appropriate herbicidal treatments have resulted in gains in yield over the controls ranging from 0·4 to 82·2% with a mean of 23·8.

Field experiments in electro-culture

Four years' additional experimental work on the application of a high tension discharge to the growth of field crops is described. Ten experiments with spring-sown oats and barley, two with winter-sown wheat, one with spring-sown wheat, and four with clover-hay have now been described.The discharge was usually given at the rate of 0·5 to 1·0 milliamp. per acre from thin insulated wires stretched above the crop at a height of about 7 ft. and charged to a voltage of 40,000 to 80,000 (crest value). The discharge was usually given for 6 hours a day in two periods, 3 hours in the morning and 3 hours in the afternoon.If the two experiments with spring-sown oats described in previous papers are included and the experiment of 1919 with spring-sown wheat (which yielded only 8 bushels to the acre) is excluded a series of 18 results is available spread over a period of 6 years. Of these 18 field experiments with various crops, 14 gave positive results in favour of the electrified plots, while 4 showed negative results, i.e. decreased yields compared with the controls. Of the 14 positive results only 3 show increases of less than 10 per cent, while 9 show increases of 30 per cent, and over, some reaching 50 per cent, and over. Of the 4 negative none shows a decrease of as much as 10 per cent.Of the 12 experiments with spring-sown cereals 10 were positive and 2 negative. Of the positive results only 2 show increases of less than 10 per cent, while 6 show increases of 30 per cent, to 57 per cent.; on the other hand both the negative results are quite small, being 6 per cent. and 9 per cent. respectively.The effect of electrification in increasing the yield of spring-grown oats and barley has thus been demonstrated. The mean increase in yield for such crops was 22 per cent.A beneficial effect of the discharge on clover-hay is probable while the effect on winter-sown wheat is still uncertain.Our knowledge of the proper conditions under which the discharge should be given is still so meagre that there is no reason to believe that the increased yields here described are the maximum obtainable as a result of electrification.The mode of action of the current in producing increased growth and yield is still obscure. In several cases the electrified field crops showed a deeper green tint than that of the controls, and work already published has shown that in the case of the coleoptile (plumule sheath) of barley minute electric currents are able to bring about an increase in the rate of growth.The effect of the discharge is of the nature of a stimulus. The additional energy available from the current is too small to have any direct effect since it is only about 1/1000th, or less, of the energy which the plant obtains from sunlight.There is no evidence that gaseous products of the discharge play any part in the stimulation of growth. The additional supply of nitrogen brought to the soil from oxides of nitrogen produced as a result of electrification must be exceedingly small.