Northern Growing Conditions Research Articles

DNA evidence for multiple introductions of barley into Europe following dispersed domestications in Western Asia

It has long been recognised that the Neolithic spread across Europe via two separate routes, one along the Mediterranean coasts, the other following the axis of the major rivers. But did these two streams have a common point of origin in south-west Asia, at least with regard to the principal plant and animals species that were involved? This study of barley DNA shows that the domesticated barley grown in Neolithic Europe falls into three separate types (groups A, B and C), each of which may have had a separate centre of origin in south-west Asia. Barley was relatively rarely cultivated by the early Linearbandkeramik farmers of Central and Northern Europe, but became more common during the fifth and fourth millennia BC. The analysis reported here indicates that a genetic variety of barley more suitable for northern growing conditions was introduced from south-west Asia at this period. It also suggests that the barley grown in south-eastern Europe at the very beginning of the Neolithic may have arrived there by different routes from two separate centres of domestication in south-west Asia. The multiple domestications that this pattern reveals imply that domestication may have been more a co-evolutionary process between plants and people than an intentional human action.

Uniculm and conventional tillering barley accessions under northern growing conditions

SUMMARYAt high northern latitudes, growing seasons are short with long days. In these conditions, tillering is an unwanted trait in barley (Hordeum vulgare L.), because the grains on tillers develop later than those on the main stem and are often harvested before they are fully mature, leading to reductions in overall quality. Hence, the uniculm growth habit has been considered an interesting option for boreal barley production. The aim of the present study was to determine the differences in the yield formation of conventional tillering and uniculm barley, using two pairs of near-isogenic lines and two controls. Uniculm and conventional tillering barley were grown in three experiments conducted at Suitia Experimental Farm, University Helsinki, Finland during 1999–2001. Samples were collected frequently to monitor the biomass and leaf area accumulation. Water-soluble carbohydrate content was analysed at anthesis and at maturity in different plant parts. At maturity, the numbers of spikes/plant and grains/spike were calculated and grain yield weighed. The grain yield of the uniculm barleys was stable over these growing seasons, but it was only half that of the conventional barley cultivars due to the absence of spike-bearing tillers, lower spike grain number and spike weight. In addition, the ability to transport photosynthesized carbohydrates to grains may have been reduced. Thus, it seems that uniculm barleys do not provide further improvement in barley yield.

Polymer coated turnip rape seed did not facilitate early broadcast sowing under Finnish growing conditions

An alternative sowing time for summer turnip rape (Brassica rapa L. var. oleifera subvar. annua) and canola rape (Brassica napus L. var. oleifera subvar. annua) was investigated under northern European growing conditions, where the growing season is very short and seedling establishment in spring is difficult. Using a method termed carrier technology, seeds of spring canola were coated with polymer and sown in winter or early spring. Two types of polymer were tested: water-impervious PoligenÆÊWE3 (polyethylene wax at five rates depending on experiment) and water-soluble, freeze sensitive ExtenderÆÊ (GrowTech at 3% of seed weight). Four separate field experiments at two locations (Jokioinen, 60¢X81¡¦N and Mietoinen, 60¢X38¡¦N) and two laboratory experiments were carried out in 2002¡V2004. Early sowing times were used in combination with autumn control of weeds using non-selective herbicides and broadcast sowing onto cereal stubble to promote cost-efficiency. Such sowing method failed to produce even plant stands, as only few seedlings emerged. The polymer coatings were successful and the water-soluble, freeze sensitive polymer designed to allow an alternative sowing time performed well in laboratory tests. Large numbers of early sown coated and control seeds remained viable until the end of spring. Under field conditions germination or seedling establishment failed probably due to poor seed-to-soil contact. Moreover, unfavourable winter and spring conditions likely resulted in lack of synchrony between adequate temperature and water availability needed for seed imbibition and germination.;

Characterising strengths, weaknesses, opportunities and threats in producing naked oat as a novel crop for northern growing conditions

Naked oat (Avena sativa ssp. nuda L.) is the highest quality small-grain cereal that can be grown at the northernmost margin of cereal production. It remains an under-utilised crop and it contributes less than 0.1% to the total oat area in Finland. In general, limited interest in growing naked oat more extensively is attributed to its weaknesses, which ironically result from nakedness that improves the quality of the crop. This paper reviews the available literature and assesses the balance of the arguments for and against naked oats. Results from the study were transformed into quantitative variables and analysed for strengths, weaknesses, opportunities and threats (SWOT) using an analytical hierarchical process. As the importance of different SWOT-factors depends largely on targeted end-use of yield, separate analyses were done for use of naked oats as on-farm feed and as an input for the feed and food industry. If we aim at increasing area under naked oat in Finland, the most feasible starting point would be on-farm feed. In this case, strengths (high nutritional quality and energy content) outweighed weaknesses (sensitivity to grain damage) and threats (problems in germination). Increasing naked oat production in this respect is likely to encourage solving the remaining problems that deter industry. Threats (availability) regarding the feed industry and weaknesses (incomplete expression of nakedness) in the food industry out-weighed strengths (high nutritional quality and storability) and opportunities (potential niches).;

Photoperiod sensitivity in narrow-leafed lupin (Lupinus angustifolius L.)

The influence of photoperiod and vernalization on flower initiation in six genotypes of narrow-leafed lupin (Lupinus angustifolius L.) was investigated under growth chamber conditions to better understand the effect of these parameters in the crop's adaptation to northern European growing conditions. Time to flowering was decreased by long days in all six varieties when these were not subject to vernalization. The combined treatment of both vernalization and long days always resulted in the shortest time to flowering. The effect of daylength was most pronounced in the thermosensitive varieties. In the nonvernalized thermoneutral varieties time to flowering was reduced by 10 to 21 days. There was no flowering in the thermosensitive varieties without vernalization during the 132 days of the experiment. A reduced number of main-stem leaves in nonvernalized treatments in 24-h compared with 10-h days indicates that part of the hastening of flowering in long days was caused by a photoperiod-sensitive flower initiation, and not only caused by increased growth rate. A juvenile, photoperiod-insensitive pre-inductive phase was further established in another experiment where plants were transferred from short (11 h) to long day (18 h) and vice versa at set times. The results showed a well defined juvenile phase of about 35 days where the photoperiod had no effect. After this phase a clear daylength effect was evident both when expressed as time to flowering and as number of main stem leaves developed before flower initiation. Time to flowering was reduced from about 144 days to 65 days and the number of main-stem leaves from 78 to 45. Only a few diurnal cycles in the inductive phase were necessary to reach full photoperiod response.

Variation in harvest index of modern spring barley, oat and wheat cultivars adapted to northern growing conditions

SUMMARYIncreased harvest index (HI) has been one of the principal factors contributing to genetic yield improvements in spring barley (Hordeum vulgareL.), oat (Avena sativaL.) and wheat (Triticum aestivumL.) cultivars. Although high HI demonstrates high-yielding ability when cultivars are compared, it can also indicate challenges to yield formation when comparisons are made across differing growing conditions. The present study was designed to investigate variation in HI among modern cereal cultivars relative to that brought about by a northern environment, to assess whether HI still explains the majority of the differences in grain yield when only modern cereal cultivars are compared, and to monitor key traits contributing to HI. Stability of HI was also investigated with reference to the role of tillers. Twelve experiments (3 years, two locations, two nitrogen fertilizer regimes) were carried out in southern Finland to evaluate 12 two-row spring barley, 10 six-row barley, 10 oat and 11 wheat cultivars. In addition to HI, days to heading and maturity, length of grain filling period, grain yield, test weight and 13 traits characterizing plant stand structure were measured and analysed with principal component analysis (PCA) to detect traits associated with HI and those contributing to stability of HI. Although only modern cereals were studied, differences among cultivars were significant both in mean HI and stability of HI, and HI was associated with short plant stature in all modern cereal species. Also, single grain weight was associated with HI in all species. Differences between, but not within, species in HI were partly attributable to differences in tiller performance. Grain yield was associated closely with HI except in two-row barley. It may be possible to further increase HI of wheat, as it still was relatively low. High HI did, however, not indicate the degree of success in yield determination when environments are compared.

Duration of vegetative and generative development phases in oat cultivars released since 1921

Genetic yield improvements in oat ( Avena sativa L.) cultivars grown at high latitudes have resulted from marked changes in harvest index and yield components. This study was designed to investigate whether such changes have entailed alterations in duration of different developmental phases: vegetative, generative and grain filling phases and pre-anthesis generative sub-phases such as pre-fertile, pre-abortion, fertile pre-abortion, fertile and abortion sub-phases. We tested 14 oat cultivars released between 1921 and 1988 and 6 breeding lines. Ten randomly sampled plants of each oat entry were collected every 3–4 d (18 times) from seedling emergence until pollination, and apical developmental stages were determined on the most advanced spikelet. Cumulated degree-days (Cdd) for each critical developmental stage and component phases were determined (5 °C as a base temperature). At each measurement the number of leaves, green leaves and tillers on main shoot, apex length (mm) and height to the uppermost node, and stipule (cm) were recorded. Phyllochron (°C d leaf −1) and relative elongation rates (RER) for height characterising traits were calculated. Grain filling was the only period altered by breeding, while no consistent effects on duration of vegetative and generative pre-anthesis phases and sub-phases were detected. Different developmental phases were interrelated: in some cases cultivars with similar duration of pre-anthesis phase, however, differed in duration of some pre-anthesis sub-phases. Their duration was not, however, consistently associated with measured growth and yield parameters. Likely long days that make the northern growing conditions exceptional and unique, substantially narrowed the differences among oat entries in duration of different developmental phases, thereby making their role also less critical in yield determination contrary to the situation in the main global temperate cereal production regions.

Radiation-use efficiency of modern and old spring cereal cultivars and its response to nitrogen in northern growing conditions

The typical features of high latitude growing seasons, particularly the short and intensive growth period and intense solar radiation during early growth, limit crop development and yield formation. A field study was conducted over two years to assess the differences between old and modern spring cereal cultivars in radiation-use efficiency (RUE), to characterise the traits contributing to the differences and to gauge the effect of nitrogen on the traits. Field experiments were conducted with wheat ( Triticum aestivum L.), barley ( Hordeum vulgare L.) and oat ( Avena sativa L.) under two nitrogen regimes (90 kg N ha −1 and control with 0 kg N ha −1). RUE was reduced at 0 kg N ha −1. Pre-heading RUE was not influenced by year, but post-heading RUE was, with values being either higher or nearly the same in comparison with pre-heading values. RUE values for barley, wheat and oat were similar to those reported elsewhere. Old two- and six-row barley cultivars had higher pre-heading RUE than modern cultivars. After heading, under decreasing light levels biomass accumulation was high due to the high RUE values. Old oat and six-row barley cultivars had higher post-heading RUE than modern cultivars. In intensive northern growing conditions, RUE varied seasonally and increased at increasing N application rate.

Quality of triticale cultivars suitable for growing and bread-making in northern conditions

Rye and wheat are the major cereals consumed by people of northern and eastern Europe. However, it has become important to widen the use of cereal products. Attempts have been done to adapt western triticale cultivars to northern growing conditions. Serious investigations of triticale bread commenced as late as in 1997 in Estonia. The first attempts to grow the triticale cultivars Modus, Dato, Presto, SV 92280 in Estonian conditions have been successful. They are productive, resistant to leaf and stem rust, powdery mildew, and with good grain quality. The aim of this work was to investigate the bread-making quality of western winter triticale cultivars grown in Estonia. The following grain quality parameters were estimated: grain protein content, SDS-sedimentation, falling number, water absorption, bread loaf volume. HMW glutenin subunit composition, which was used to predict the baking quality, was determined by sodium dodecyl sulphate– polyacrylamide gel electrophoresis (SDS–PAGE). Seven different alleles were revealed in the set of 12 triticale cultivars. The best cultivars had HMW glutenin subunits 2 ∗ encoded by the Glu-A1 locus, 7+26 and 7+19 encoded by the Glu-B1 locus.

Characterization of development and stem elongation of reed canary grass under northern conditions

Reed canary grass ( Phalaris arundinacea L.) is a potential crop for energy and paper production and might also be a useful forage crop under northern growing conditions. Knowledge of phenological traits is needed to adjust the production system according to various end-use requirements. This study aimed at describing variation in plant development, plant height and stem elongation among local and elite populations of reed canary grass. Field experiments were carried out between 1994 and 1997 in Finland. Six developmental stages were determined and plant height was measured at weekly intervals. Differences among groups of reed canary grass were statistically significant. Cultivars developed earlier than local groups, although they needed 3 days more for seed ripening. They were also taller than local populations at time of seed ripening. However, local groups were slightly taller than cultivars during early stages of development. At time of seed ripening some local populations were taller than elite material. Their places of origin could represent potential collection areas for populations showing increased plant height. Seed ripened approximately 95 days from the beginning of the growing season, when the temperature sum was 737 °C days of degree. At time of seed ripening 98% of maximum plant height was reached. A long latent period from reaching maximum plant height to harvest in the following spring is justified for non-food production because biomass continues to increase markedly after seed ripening. Stem elongation was fastest around flag leaf emergence and appearance of inflorescences. Knowledge of the fixed stage of plant development and plant height at each stage provides possibilities to adjust the production system and harvest time according to different end-uses: forage, non-food, and seed production. Information from this study will serve as a basis for further investigations and could be used in breeding reed canary grass.

Reducing grain damage in naked oat through gentle harvesting

The caryopsis of naked oat is sensitive to mechanical damage at harvest, especially at high grain moisture content. For producing high quality naked oat seed, it is recommended that harvesting be carried out at as low grain moisture content as possible. This reduces mechanical damage to the grain and promotes germination. Under northern growing conditions, grains are often harvested at 20% moisture content or higher. In this study, reduced grain resulted from using gentler settings on the combine harvester. Two naked oat cultivars and one conventional oat were harvested at different grain moisture content using three combine harvester settings: the first setting that recommended for conventional oat, the second a reduced cylinder speed and the third a narrow concave clearance. The greater the grain moisture content of naked oat at harvest, the more damage was caused by threshing. Lower cylinder speeds tended to result in better germination than higher speeds, even under moist conditions. Narrowing the concave clearance did not affect germination.

Chlormequat chloride and ethephon affect growth and yield formation of conventional, naked and dwarf oat

Department of Plant Production, PO Box 27, FIN-00014 University of Helsinki, Finland. Current address: MTT Agrifood Research Finland, Plant Production Research, FIN-31600 Jokioinen, Finland. e-mail: pirjo.peltonen-sainio@mtt.fi Plant growth regulators (PGRs) are not usually applied to oat (Avena sativa L.) crops. This study was designed to test whether the antigibberellin chlormequat chloride (CCC) and ethylene-releasing ethephon sprayed on to oat foliage represent potential agents for manipulation of yield formation under northern growing conditions. Effects of these PGRs on yield components and tiller growth and productivity were examined in detail. This study included a long-strawed landrace, a modern standard height cultivar, two naked (A. sativa ssp. nuda L.) and two dwarf oats. Field experiments were conducted at Viikki Experimental Farm, University of Helsinki, in 1995 and 1996. Chlormequat chloride was sprayed at the two-node stage and ethephon when the flag leaf ligule was just visible on the main shoot. Various traits characterizing growth and yield formation were assessed. Chlormequat chloride increased grain yield by 0% to 13% depending on cultivar and year, while ethephon most often decreased it by up to 17%. No lodging occurred and the recorded increase in grain yield of CCC treated plants was not therefore due to prevention of lodging. However, CCC treatment resulted in more panicles per square meter and in 1995 tillers contributed more to grain yield. Ethephon treated plants had less grains per main shoot panicle, lower panicle filling rate (PFR) and parallel decreased harvest index (HI). Stem elongation of dwarf oat was enhanced by CCC, in contrast to that of conventional and naked cultivars.;

Agronomic comparison of Minnesota-adapted dwarf oat with semi-dwarf, intermediate, and tall oat lines adapted to northern growing conditions

Development of a dwarf oat (Avena sativa L.) for northern growing conditions may further improve many important agronomic features of the oat crop including lodging resistance, yield stability, yield potential, grain-straw ratio, and fertile tillering. Our objective in this study was to assess the performance of a Minnesota-adapted dwarf line at high latitudes, through measurement of several traits that characterize duration of pre- and post-anthesis growth and plant stand structure, with special reference to tiller growth and tiller productivity. Response of the dwarf line to seeding rate (250, 500, and 750 viable seeds m−2) and nitrogen fertilizer application rates (80, 120, and 160 kg N ha−1) was compared with that of a semi-dwarf line, a conventional height cultivar, and a landrace cultivar, all of which are adapted to long-day conditions. The experiments were conducted in Finland (60°13′N) in 1993 and 1994. The dwarf line produced less grain (≤ 30%) than the other lines but out-yielded the lodging-sensitive landrace in 1994 at a high seeding rate and high rate of nitrogen fertilizer application. As for the semi-dwarf line and conventional height line, the dwarf line produced the highest grain yield at 500 seeds m−2 which is the standard planting density for oat in Finland. The particularly short duration of the generative phase and associated low number of grains per main shoot panicle are likely to be principal contributors to low mean panicle-filling rate, panicle weight, and grain yield of the dwarf line. However it was better able to tiller and produce head-bearing tillers than the other lines. This increased number of tillers was, however, unable to compensate for yield reduction resulting from low yield potential of the main shoot. Key words:Avena sativa L., oat (dwarf), grain yield, landrace, partitioning, straw length, yield components

Response to Daylength in Oats: Pre‐Anthesis Development and Set of Spikelets and Florets

AbstractDaylength ranges between 15 h and 22 h when oats are sown in Finland. This study evaluated the effect of 15‐h, 18‐h and 24‐h daylengths on apical development, pre‐anthesis growth, and spikelet and floret set in two oat cultivars (Avena sativa L.) adapted to northern growing conditions. Experiments were done in a growth chamber at 18°C.Increases in daylength shortened the period of apical development. The oat cultivars were especially responsive to increase in daylength from 15 h to 18 h. The increase in daylength resulted in a 45 % reduction in number of fertile florets and a slight increase in the proportion of incompletely development and stunted florets. Fertility of florets was most reduced on the lower primary and secondary branches of the panicle. Total number of leaves and phyllochron decreased as daylength increased. Moreover, the longer the day, the lower the number of green leaves per main stem until developmental stage 11. However, at pollination, oats exposed to 15‐h days had the lowest number of green leaves. Results of study indicated that delayed sowing, when associated with longer days at pre‐anthesis, hastened apical development and decreased yield potential in oats.

Improving grain yield and quality traits of oats in northern growing conditions

This study on 29 oat cultivars and breeding lines (Avena sativa L.), evaluates the correlations of grain yield and 13 morpho-physiological traits — characteristics such as maturity class and architecture of the oat stand, with grain quality properties such as grain protein concentration, protein quality, crude fat concentration, fiber concentration, and husk content. Field experiments were conducted in two contrasting growing seasons, 1988 and 1989.Under northern growing conditions high yielding ability was not associated with lower quality traits, but grain yield correlated positively with fat concentration, and negatively with both fiber concentration and husk content. In addition, there was no association between grain yield and protein concentration. Closer examination indicated that earliness, one of the most important traits of oats in northern growing conditions, correlated negatively with fat and grain protein concentration and positively with fiber concentration, thereby limiting both grain yield and quality performance. On the basis of this study, selection for productive oat ideotype does not necessarily lead to cultivars with weakened quality properties. Key words: Avena sativa, ideotype, productivity, grain quality, northern growing conditons

Effect of moderate and severe drought stress on the pre-anthesis development and yield formation of oats

Greenhouse experiments were conducted at the University of Helsinki, Department of Crop Husbandry in 1989 and 1990 to provide information on the effects of drought stress on the developmental rate of the panicle, formation and abortion of florets, and formation of yield components in two oat cultivars, both adapted to the northern marginal growing conditions. Moderate water deficit and severe drought stress did not affect the developmental rate of the panicle, but the pre-anthesis and post-anthesis architecture changed considerably; leaves unrolled later, the number of green leaves was lower, the internodes lengthened less, and the inflorescence was shorter as a consequence of water deficit. Drought stress decreased the number of fertile florets in the panicle significantly, in the lower clusters of branches in particular. In the cultivar “Puhti”, 57 % of the fertile florets aborted as a consequence of moderate drought stress and 89 % as a result of severe drought stress when compared to well-watered individuals, while in “Virma”, a cultivar of significantly higher yield potential, 80 °lo and 90 % of the fertile florets wilted, respectively. In addition, water deficit caused considerable losses in all the morphological characteristics measured. Further implications of these results for yield formation are discussed.

Productive oat ideotype for northern growing conditions

Yield formation of four Finnish and three Nordic oat varieties and 12 breeding lines developed at the Hankkija Plant Breeding Institute was studied during four different growing seasons (1986–1989). Seventeen characteristics were measured, including traits representing the date of maturity and architecture of the oat stand. The variation between genotypes in the examined traits was studied by means of two-way analysis of variance. The relationship between grain yield and morpho-physiological traits was studied by means of simple correlation analysis and stepwise regression analysis.

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.

Environmental and genetic variation in protein content of peas under northern growing conditions and breeding implications

Association of protein content in peas with climatic factors was studied on data based on official cultivar trials at six locations in southern Finland in 1978—1985. Correlation and step-wise multiple linear regression methods were used to define the main climatic variables affecting protein content. Correlation studies showed that protein content was significantly and positively associated with temperature sum and mean June temperature and significantly negatively correlated with July precipitation. Regression analysis indicated that climatic factors accounted for 25 %—70 % of the total variation in protein content. Temperature sum and precipitation in July were the most important independent variables explaining protein variation. The role of environmental factors for protein variation and its implications for the improvement of protein content by plant breeding is discussed.