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Difficulties in efficient utilization of seasonal precipitation cause limitations in yields and even total crop failure on rainfed farms in semi-arid East Africa. The objective of the present study was to find out if covering the soil with plant residue mulch at a semi-arid site could retain water in the soil between precipitation events and build dry spell resilience by reducing soil water evaporation and increasing infiltration to deeper soil. Covering soil with plant residue mulch was studied at a smallholder farm in semi-arid Kenya by continuously measuring volumetric soil moisture content with soil sensors at multiple depths in bare soil and in maize (Zea mays L.) plant residue mulched soil. A physically based one-dimensional soil moisture model was calibrated and used to estimate the effect of plant residue mulch on soil moisture over a two-year period (multiple growing seasons). The modelled multiyear time series provides an estimate of the effect residue mulches of different thicknesses have on soil moisture over time. The simple soil moisture model was able to estimate soil moisture in the effective root zone of maize. By comparing measured data from mulched and uncovered soil and by model prediction, it was demonstrated that maize residue mulch conserved soil moisture over time in the effective root zone of maize compared to bare soil. During the two-year period mulching increased the total amount of days when measured relative soil moisture (s) exceeded water stress limit of maize (s*) by 24%-46%. Moisture accumulated in the mulched profile, especially in the deeper layers of the effective root zone. Calculations indicated that further increasing mulch thickness (delta(m)) from 1 to 3 cm would have increased the total days when s > s* 59%. Furthermore, increasing delta(m) from 3 to 5 cm would have resulted in 25% increase in total days when s > s*. According to our calculations mulching (delta(m) > 1 cm) could have maintained s > s* throughout a 19 days dry spell that occurred during the measurement period. The demonstrated moisture conserving effect of mulch increases with delta(m), but availability of plant residue may set limits on mulch application rates. The results suggest that maize residue mulching is as an accessible and feasible method for conserving soil moisture in the effective root zone in dryland smallholder systems in East Africa.

Mixed cropping, including intercropping, is the oldest form of systemized agricultural production and involves the growing of two or more species or cultivars of the same species simultaneously in the same field. However, mixed cropping has been little by little replaced by sole crop systems, especially in developed countries. Some of the advantages of mixed cropping are, for example, resource use efficiency and yield stability, but there are also several challenges, such as weed management and competition. The boreal-nemoral region lies within the region 55° to 70° N. In this area, for example in Finland, the length of the thermal growing season varies from less than 105 to over 185 days. Typically, variation between locations and years is marked. However, during the year, there can be a wide range of temperature extremes between −70 and +30 °C. The majority of cropping systems in this region are usually monocultures, except for forage grass mixtures. The possibility of having several crops in a mixture is very challenging in the region due to the short growing season and extreme cold temperatures, meaning that crop earliness and overwintering capacity are a considerable restriction for year-round mixed cropping. A further restriction is the quality requirements set by the industry. Our review will explore a range of mixed cropping possibilities for the boreal-nemoral region, including different possible combinations of spring, winter, perennial, biennial, catch, and cover crops. The reviewed mixed cropping systems could considerably improve the sustainability and efficiency of crop production, particularly with an emphasis on nutrient cycling.

Phosphorus (P) is an essential element for plant growth and development. Finding new P sources and ways to improve crop P utilization are necessary due to the depletion of phosphate reserves. Five crop species, buckwheat (Fagopyrum esculentum L.), maize (Zea mays L.), oilseed rape (Brassica napus L. ssp. oleifera (Moench) Metzg.), spelt wheat (Triticum spelta L.), and white lupine (Lupinus albus L.), were grown in pots containing sandy soil with chemical nutrients, digestate, and meat bone meal (MBM) without added nutrients. Thirty days after the seeding plants were harvested, the growth stage, soil-plant analysis development (SPAD) value, biomass, P content of the plants, colonization of the roots with endomycorrhiza, and soil pH were analyzed, and the number of fungal spores in the soil was counted. All species showed interaction with the P sources for measured traits, except for the rhizosphere pH. A high biomass was recorded in all species fertilized with various P sources compared to the unfertilized treatment. Buckwheat and spelt wheat showed a higher P uptake with MBM, and the mycorrhizal symbiosis improved with digestate or MBM compared to synthetic P. The results indicate that different species have adaptative mechanisms to various P sources which could improve the resilience and sustainability of cropping systems.

Jerusalem artichoke (Helianthus tuberosus L.) produces substantial shoots not used as food. To test its potential as a sustainable bioenergy crop, we studied the effects of synthetic fertilizer and intercropped legumes as nitrogen (N) sources on the growth, aboveground biomass dry matter yield and energy qualities of this crop. Plant height, leaf area index (LAI), SPAD-value, biomass yield, ash content and mineral element composition were determined. Mean aboveground biomass yields were not significantly affected by N source (legume intercrops and synthetic fertilizer) and ranged from 13 to 17 t ha(-1). Remarkably, plants given no fertilizer yielded equally to plants given 90 N kg ha(-1). These results confirm that Jerusalem artichoke, compared to other energy crops, have less need for N and can potentially be sustained by N fixing legumes in an intercropped system. This could reduce or eliminate production and environmental cost in cultivation of biomass feedstock for energy use.

Allelochemicals of Brassica can inhibit a wide range of soil-borne pathogenic fungi. In the present study, the effects of different turnip rape ( Brassica rapa ) cultivation treatments on the soil fungal community were investigated in two experiments in 2009 2010 and 2010 2011. The treatments used turnip rape as a green manure, as a mixed-crop with barley, or as a rotational crop after barley, with continuous barley as the reference. The composition of the soil fungal community was monitored with capillary-based length heterogeneity PCR using primers ITS1F/ITS4. The operational taxonomic units (OTUs) identified as the pathogens Botrytis cinerea , Rhizoctonia solani and Sclerotinia sclerotiorum did not respond to different treatments. Fungal diversity was the lowest and the relative abundance of Fusarium spp. the highest in barley monoculture. Incorporation of turnip rape plants into the soil as green manure was associated with a low relative abundance of Fusarium spp. Turnip rape as a mixed crop or rotational crop did not substantially decrease the relative abundance of Fusarium spp. Aqueous and non-polar extracts of allelochemicals from turnip rape had very little effect on the growth of Fusarium culmorum in vitro . We conclude that high fungal diversity, resulting from either application of fertilizer or incorporation of organic matter of turnip rape, was more important than allelochemicals in affecting the growth of Fusarium spp. in field soils.

Winter turnip rape [Brassica rapa L. ssp. oleifera (DC.) Metzg.] is an oilseed crucifer mainly grown in Nordic and Baltic countries. It can be undersown in a spring cereal as an alternative to sowing of pure stand in late July. Establishment by undersowing helps to utilize the short growing season at high latitudes. However, as undersown crops tend to affect the growth and yield of their companion crops, the effect of undersown winter turnip rape on cereal yield and quality needs to be assessed. Additionally, an evaluation of the suitability of different cereals as companion crops to winter turnip rape is required before practical recommendations can be made. The suitability of four spring cereals as companion crops to winter turnip rape was studied in three field experiments. Two-row barley, six-row barley, wheat and oat were sown at two different densities, with and without undersown winter turnip rape, sowing density depending on the density of the cereal. Undersowing winter turnip rape in a cereal did not markedly affect cereal yield. In some years six-row barley and oat with undersown winter turnip rape produced more yield than corresponding pure stands, indicating a possible facilitative effect of the undersown crucifer on the two cereal species. The results suggest that the most compatible cereals as companion crops with undersown winter turnip rape are six-row barley and oat. Mixed stand cultivation could be improved trough the identification of the optimal cereal–winter turnip rape combinations.

The biomass potential of eight high yielding maize cultivars was studied in the sub-boreal climate of southern Finland. The effects of harvest date on lignin and sugar production, biomass yield, mineral element composition, bioenergy potential and soil nutrient management were determined in two years. The eight maize cultivars produced 17.6–33.3 t ha-1 of biomass. The ear fraction contained 50–60% of the biomass, and ash and mineral element composition of the plant fractions were significantly different (p < 0.001), with more ash, Ca and S in the above-ear fractions of the plants than in the mid-stalk portions, whereas the C:N ratio was highest in the lower stalk. Cultivars with less lignin content produced more fermetable sugars. Despite the relatively cool growing conditions and short season of the sub-boreal region, maize has potential for use as biomass, for biofuel or other uses. The crop can be fractioned into ear and stalk, with the lower 20 cm of stalk left in the field to maintain soil organic matter content.

Bioenergy cropping, like all agricultural practices, may lead to the release of greenhouse gases. This study was aimed at determining biomass and energy yields of reed canary grass (RCG) (Phalaris arundinacea), galega (Galega orientalis) and a mixture of these, and to relate these to fluxes of nitrous oxide (N2O), a potent greenhouse gas, emitted from the soils. Plots including a bare fallow as control were established in 2008. Gases emitted from the soil surface were collected in closed chambers from May 2011 to May 2013, except during periods of snow cover, and analysed by gas chromatography. Seasonal and annual cumulative emissions of N2O and CO2 equivalents per unit energy yield were calculated. Soil moisture content, nitrate (NO3 −)-N and ammonium (NH4 +)-N were also determined. Both species composition and crop yields affected energy yields and N2O emission from the soil. The annual cumulative emissions from mixture were marginally lower than those from fertilized RCG soils. Fertilized RCG produced twice as much biomass and correspondingly higher nitrogen and energy yields, so its low emission of N2O per Mg of dry matter was not significantly different from that of the mixtures. Cropping an RCG–galega mixture for biofuel may replace N fertilizer input since it resulted in lowering N2O fluxes, but requires management to maintain grass as the major component in order to minimize N2O emissions. In a time of climate change, low-input bioenergy crops may be a suitable strategy for land left uncropped after ploughing for one season or longer.

Poor water retention capacity (WRC) and nutrient deficiency commonly limit crop yields in sandy soils. The use of biochar as a soil amendment has been previously reported to improve these limiting factors in subtropical and temperate soils. We studied the effects of biochar on soil properties and yield formation of spring wheat (Triticum aestivum L.) when applied together with inorganic fertiliser or meat bone meal (MBM) to an Endogleyic Umbrisol with a loamy sand texture in boreal conditions. In a two-year field experiment, biochar was applied at 0, 5, 10, 20 and 30 t ha−1 combined with three fertiliser treatments (unfertilised control, MBM and inorganic fertiliser) providing equal amounts of nitrogen (N), phosphorus (P) and potassium (K). Soil WRC and fertility as well as wheat yield, yield components and quality were analysed. Soil moisture content, leaf area index and leaf chlorophyll values (SPAD) were monitored during the experiment. Biochar increased the plant-available water content of the topsoil in the first year and reduced the bulk density in the second year after application. It also increased the contents of easily soluble K and soil organic C (SOC) in the 20 cm of topsoil, but had no effects on other soil nutrients, pH or moisture content. Biochar amendment decreased the soil NO3−-N content below control values in the first year but increased it significantly in the second year. The addition of biochar did not significantly affect the nitrogen uptake, grain yield or quality of wheat, possibly because of its low nutrient availability and the high organic matter content of the soil.

International audience; Leaching of nitrogen fertilizers such as nitrates from agricultural systems causes watershed eutrophication and is an economic loss for the farmer. This issue may be solved by including a catch crop in a crop rotation. For instance, winter turnip rape is a potential N catch crop for cold climates. Here, we studied winter turnip rape as a catch crop from 2009 to 2011 in Finland. Winter turnip rape was either undersown with barley in May or sown after harvesting barley in late July. In two reference treatments, the barley stubble was either left over the winter or ploughed into the soil in autumn. We collected samples from topsoil, 0-20 cm, and subsoil, 30-50 cm, in early autumn, before snowfall and in the following spring. We measured soil ammonium-N and nitrate-N, and the N content of winter turnip rape plants. Results show that undersown winter turnip rape did not change the yield and quality of barley. Winter turnip rape decreased nitrate-N in the subsoil by 83 % in 2009 and by 61 % in 2010, compared to ploughed barley. By the end of October 2009, winter turnip rape undersown in May took up 74 kg N/ha, whereas the crop sown after barley in July took up 57 kg N/ha. We conclude that winter turnip rape, either undersown with barley or sown after barley, is effective in depleting subsoil nitrates. Even though numerous reports describe the efficiency of different crucifers as catch crops under temperate climate, this is the first article concerning winter turnip rape as a catch crop under cold and humid climate.

(Received 6 June 2013; revised 22 November 2013; accepted 31 January 2014)SUMMARYCultivationofwinterturniprape(BrassicarapaL.ssp.oleifera(DC.)Metzg.)inFinlandhasbeenlimitedbecauseofits reputation as an unreliable crop and its mid-season sowing time of July, when fields are already sown to othercrops. An alternative management practice for winter turnip rape is proposed whereby it would be sown as amixed crop simultaneously with spring cereals. The growth and yield formation of winter turnip rape grown inmixed stands with four different spring cereals was studied in two field experiments conducted in 2009–11. Pureand mixed stands of winter turnip rape and spring cereals were established in May at two different cereal andwinter turnip rape stand densities. Subsequent to cereal harvest, one-third of each winter turnip rape plot washarvested for biomass in autumn, before cessation of growth. Three plant stand types, May- and July-sownmonocrops and a mixed crop with oat (Avena sativa L.) were sampled for forage analysis. Plant stand densitieswere monitored from establishment until maturity. Winter turnip rape yield and its quality, including oil content,protein content and thousand seed weight, were determined. Following favourable overwintering conditions,winter turnip rape established with cereals yielded comparably to that of pure stands in terms of both quantityand quality. However, a pure stand of winter turnip rape out-yielded mixed crop stands after unfavourableoverwintering conditions. Leaf removal decreased plant survival and seed yield. Establishing winter turnip rapewithacerealinMayisanalternativetosowingitasamonocropinJuly.Ahigherseedingrateisneededforunder-sown winter turnip rape. Furthermore, autumn-harvested winter turnip rape monocrop forage potentiallyrepresents a high-protein supplement for ruminants.INTRODUCTIONWinter turnip rape (Brassica rapa L. ssp. oleifera (DC.)Metzg.) is a cruciferous oilseed crop better adapted tothe Nordic climate than oilseed rape (Brassica napusL. ssp. oleifera (Moench) Metzg.). Because of its rapidgrowth, it out-competes weeds and consequentlysuitsorganic farming production systems (Makela et al.2011). Moreover, winter turnip rape can be harvestedbefore other crops because it reaches maturity earlierthanothercrops,i.e.inJuly,andsinceitisalsosowninJuly, it is in the ground for 12 months of the year. InFinland, winter turnip rape is sown by the end of Julybecause late sowing results in yield reduction (Valle1951). This is a limiting factor for winter turnip rapecultivationsincefarmsusuallyhavenofreelandatthattime because most field crops do not mature beforeAugust. A potential solution to this problem would beto sow winter turnip rape in May with a cereal andthereby reduce the costs of establishing the cropwhileincreasing land-use efficiency. The cereal would beharvested, as usual, in autumn and the winter turniprape would remain in the field to overwinter andproduce seed in the following growing season (Valle1951). Mixed crop stands often capture more mineralnutrients than pure stands (Midmore 1993; Morris &Garrity 1993a) and are also more water-use efficient(Morris & Garrity 1993b). This could also be the case

Utilization of sludge is an attractive option for fertilizing bioenergy crops, since in addition to its valuable macro- and micro-nutrients, it may also contains some pollutants. Therefore, a three-year field experiment was conducted to investigate the suitability of sewage and digested sludge in comparison to synthetic fertilizer on biomass production and its quality in three crop species, with specific attention to the relationship between N availability and biomass accumulation. Fertilizer treatments for each crop species were standardized on the basis of total Nitrogen as follows: maize 120 kg ha−1, fibre hemp 60 kg ha−1 and oilseed rape 90 kg ha−1 Nitrogen. The highest biomass yield of maize (30 Mg ha−1 Dry Mass) and hemp (15 Mg ha−1 Dry Mass) was obtained from the sewage sludge treatment. The sludge treatment also gave the highest leaf Nitrogen mass in biomass of both maize (14 g kg−1) and hemp (18 g kg−1) at 60 DAS (flowering stage). Sewage sludge increased slightly gross energy yield of maize (438 GJ ha−1) and hemp (272 GJ ha−1) in comparison to other treatments. The mass fraction of ash and the combustion-relevant elements such as Chlorine, Potassium, Sodium and Calcium were lower in crops fertilized with sewage sludge than in those fertilized with synthetic fertilizer. In conclusion, sewage sludge produced as high biomass yield as synthetic fertilizers. In addition, it improved growth and quality of biomass.

We studied the effect of different biochar (BC) application rates on soil properties, crop growth dynamics and yield on a fertile sandy clay loam in boreal conditions. In a three-year field experiment conducted in Finland, the field was divided into three sub-experiments with a split-plot experimental design, one for each crop: wheat (Triticum aestivum), turnip rape (Brassica rapa), and faba bean (Vicia faba). The main plot factor was BC rate (0, 5 and 10 t DM ha−1) and the sub-plot factor was the N-P-K fertiliser rate. Soil physico-chemical properties as well as plant development, yield components and quality were investigated. BC addition did not significantly affect the soil chemical composition other than the increased C and initially increased K contents. Increased soil moisture content was associated with BC application, especially at the end of the growing seasons. BC decreased the N content of turnip rape and wheat biomass in 2010, thus possibly indicating an initial N immobilisation. In dry years, the seed number per plant was significantly higher in faba bean and turnip rape when grown with BC, possibly due to compensation for decreased plant density and relieved water deficit. However, the grain yields and N uptake with BC addition were not significantly different from the control in any year. Even though BC application to a fertile sandy clay loam in a boreal climate might have relieved transient water deficit and thereby supported yield formation of crops, it did not improve the yield or N uptake.

Recycling nutrients saves energy and improves agricultural sustainability. Sewage sludge contains 2.6% P and 3.1% N, so the availability of these nutrients was investigated using four crops grown in either soil or sand. Further attention was paid to the role of mycorrhiza in improvement of nutrient availability. The content of heavy metals and metalloids in the feedstock was analyzed. Sewage sludge application resulted in greater biomass accumulation in ryegrass than comparable single applications of either synthetic fertilizer or digested sludge. Sewage sludge application resulted in more numerous mycorrhizal spores in soil and increased root colonization in comparison to synthetic fertilizer. All plants studied had mycorrhizal colonized roots, with the highest colonization rate in maize, followed by hemp. Sewage sludge application resulted in the highest P uptake in all soil-grown plants. In conclusion, sewage sludge application increased feedstock yield, provided beneficial use for organic wastes, and contributed to the sustainability of bioenergy feedstock production systems. It also improves the soil conditions and plant nutrition through colonization by mycorrhizal fungi as well as reducing leaching and need of synthetic fertilizers.

Sewage sludge is rich in essential plant nutrients, but its use is restricted for crop production due to the pollutants it contains, such as metalloids and heavy metals. Sludge is also very sticky and compact. Therefore, the objectives of this work were to evaluate (1) the impact of various amounts of sludge on bioenergy crop productivity and quality and (2) the use of peat as an adjuvant to reduce the stickiness, density and nutrient richness of the sludge. Three different applications of sludge were examined, high, low (50% of high) and low mixed with an equal volume of peat. The sludge–peat mix increased significantly leaf area and biomass accumulation of maize and hemp. High sludge and sludge–peat mix applications increased significantly the leaf area and biomass accumulation as well as the net photosynthesis of oilseed rape. High sludge application resulted in the highest heavy metal and metalloid accumulation in maize and hemp. Sludge–peat mix resulted in the highest heavy metal and metalloid accumulation in oilseed rape. However, the sludge–peat mix application provided the best feedstock quality in all three crops, since chloride, silicon and sulfur concentrations and ash content in plant material were the lowest of the three sludge treatments.

Potassium (K) plays a significant role in preventing outbreaks of pathogenic infections and thereby maintains the photosynthetic leaf area, which supplies assimilates for grain filling. The aim of this research was to investigate the role of K in barley straw anatomy, plant stand architecture, and yield formation. Growth and yield of barley improved with increasing K application rates. This appeared to be due to increased number of spike-bearing tillers, number of grains per spike, and single-grain weight. Straw and walls of cuticle, epidermis, and sclerenchymatous cells thickened in relation to applied K. Thick and firm internodes as well as efficient use of resources resulting from K applications are among key features for good-quality crop production in the field.

Sludge is a good source of plant nutrients, but its use as fertilizer for food or fodder crops is questionable due to its potential content of heavy metals and metalloids. In two pot experiments, germination and growth of maize (Zea mays L., cv. Ronaldino), fiber hemp (Cannabis sativa L., cv. Uso 31) and oilseed rape (Brassica napus L. ssp. oleifera (DC.) Metzg., cv.Wildcat) were studied when treated with sewage sludge and biogas sludge in comparison with chemical fertilizer during 2011. The experiment included five treatments: soil+sewage sludge, soil+fertilizer, sand mixed with peat+sewage sludge, sand mixed with peat+fertilizer, and soil+biogas sludge. Sludge content was calculated to deliver the same content of nitrogen that was added for each species. Germination percentage was recorded at 7, 10 and 14 days after sowing. Length and dry weight of roots and shoots were measured at 14 days after sowing for all species.Sewage sludge treatments resulted in higher germination percentage compared to biogas sludge and fertilizer application in soil and sand mixed with peat. The longest roots were in the sewage sludge treatment. In addition, shoot lengths in maize were highest when fertilized with sludge or fertilizer in soil. Furthermore, sewage sludge or fertilizer added to soil increased root and shoot dry weight of maize. In conclusion, there is an existing excellent potential for using sewage sludge not only as organic matter but also as a valuable plant nutrient source for improving growth of bioenergy crops.

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.

Water is the primary regulator of yield formation in cereals. The effect of water limitation and its timing on development of yield components were studied in detail at spike and spikelet level in spring barley (Hordeum vulgare L.). An experiment with three watering treatments (control watering, CONT; drought prior to pollination, DR1 and terminal drought, DR2) was set up in a large greenhouse (20 x 30 m). In addition to watering treatments, two NPK fertilizer application rates (0 and 120 kg N ha ―1 ) were used to investigate the fertilizer effect. The drought effect exceeded the effect of fertilizer application for grain number and single grain weight (SGW). DR1 reduced the number of grains, whereas DR2 reduced both SGW and the number of grains. Resuming the watering at pollination (DR1) restored photosynthesis and enhanced grain filling, resulting in almost similar SGW in DR1 and CONT plants. Spikelets in the upper mid-section of the spike dominated yield formation in all treatments. This was particularly emphasised in DR1 plants as 58 % of the grain yield was produced in spikelets 3―5, whereas in DR2 and CONT plants it was 39 % and 36 %, respectively. Hence, drought prior pollination strongly reduced yielding capacity (=grain number) in apical and basal spikelets. DR1 and DR2 reduced substantially grain yield and grain N yield resulting in low nitrogen use efficiency.

Legumes are an important component of sustainable crop rotations around the world, but are under-represented in European agriculture. Finnish use of grain legumes is exceptionally low. These experiments were initiated to test the possibility of extending the range of grain legumes that can be grown in Finland. A small range of germplasm of blue lupin, white lupin, lentil and some other annual species were tested in a trial that also included familiar cultivars of faba bean. Faba bean yields were 6.0 – 7.3 Mg ha-1, blue lupin yields 3.3 – 4.8 Mg ha-1. Two of the cultivars of blue lupin reached maturity in a timely fashion, showed little disease and did not lodge, so they have potential for use in the national agricultural system. Lentils also ripened, but presented management problems that require further investigation. White lupin showed potential as a producer of biomass, with one cultivar exceeding 18 Mg ha-1 dry matter.

Water and nitrogen (N) availability are the main factors influencing crop growth globally. Poorly distributed or insufficient water for crop growth requirements decreases yields in drought-prone areas such as those with a Mediterranean type environment. Cereal grain yield is a complex trait of interrelated components: plants per unit land area, spikes per plant, spikelets per spike, grains per spikelet, and single grain weight (SGW). The effect of water limitation and timing on development of yield components was studied in detail at the spike level in spring wheat (Triticum aestivum L.) cultivar Amaretto. An experiment with three watering treatments (control watering, CONT; drought prior to pollination, DR1 and terminal drought, DR2) was arranged in a large greenhouse (20 m × 30 m), with the use of standard field-trial machinery. Automated blackout curtains were used to control day length, which was set to correspond to that at 40°N. With watering treatments, two N application rates (60 and 120 kg N ha−1) were used to investigate the N effect and potential watering × N interaction on yield formation and realisation. The water deficit effect exceeded the effect of N on fertile floret and grain number and SGW. DR1 strongly reduced the number of fertile florets and grains, whereas terminal drought reduced the number of grains per spike. Resuming the watering at pollination markedly enhanced photosynthesis, and hence grain filling capacity, resulting in the highest SGW in DR1. Enhancement in availability of key resources was associated with reduced rate of fertile floret and grain abortion, which resulted in higher grain to fertile floret ratio in DR1. Spikelets in the mid-section of the spike dominated yield formation in all treatments. In DR1 this was especially emphasised as 53% of the grain yield was produced in spikelets 4–6, whereas in DR2 and CONT this was 45 and 41%, respectively. Grains in proximal position in the spikelets produced about 80% of the spike grain yield, the proportion being slightly higher in stressed plants and plants receiving 60 kg N. No marked N × water deficit treatment interaction occurred for any of the measured parameters.

Maize ovary development is linked to kernel formation. Soil water deficit results in ovary abortion because of low water potential (Ψ w ) resulting in inhibition of photosynthesis from anthesis to silking stage. Thus, drought is a key factor causing yield losses in maize, especially near the time of pollination. Earlier studies have indicated that selenium (Se) maintains antioxidative defence systems and enhances sugar and starch accumulation. The effects of Se on maize ovary development were studied in drought stress conditions. Maize ovary development was studied through observations on starch, membrane integrity, fresh weight and dry weight in drought-treated or unstressed glasshouse-grown plants, and crop yield, yield structure, leaf, stem and ear biomass accumulation were also analyzed. Results indicated that Se increased the stress tolerance of the crop, even though ovary abortion was not eliminated by Se treatments under low Ψ w . Under well-watered control conditions, Se had also negative effects. When the first ear was not succesfully pollinated or the ovaries aborted, the plants developed more ears. Even though these later formed ears did not produce kernels, they significantly increased the dry weight of the plants under water deficit. It could be concluded that The optimal concentration for maize of Se applied through roots is about 0.01 mg kg −1 (supplied as Na 2 SeO 4 ) soil or less.

Nurminataa käytetään pääasiallisesti rehunurmien siemenseoksissa. Se onkin toiseksi eniten viljelty rehunurmikasvi timotein jälkeen. Nurminata on nopeakasvuinen, kestää toistuvaa niittämistä lyhyeen sänkeen ja on kilpailukykyinen. Sen rehulaatu ei kuitenkaan ole timotein luokkaa, minkä lisäksi se ei menesty hiekkaisilla mailla ja on arka kuivuudelle. Nurmirehun tuotannossa kotimaista, mieluiten paikallista alkuperää, olevan kylvösiemenen käyttö on suositeltavaa. Paikallisesti tuotettu kylvösiemen edesauttaa mm. kasvuston talvehtimista ja sadontuottokykyä. Nurminadan siemensadot ovat havaintojen mukaan laskeneet viimeisten kymmenen vuoden kuluessa. Tässä tutkimuksessa selvitettiin vanhan ja uuden nurminatalajikkeen satokomponenttien muodostumisessa esiintyviä eroja ja niiden selityskykyä siemensadolle. Tutkimuksessa käytettiin vanhaa, Kalevi, ja uutta, Fure, nurminatalajiketta. Määritimme nurminadoista niiden biomassan muodostuksen toisena kasvukautena toistuvin mittauksin, sadon osatekijät (mm. korsien, lehtien ja röyhyjen massat, versojen röyhyjen ja siementen lukumäärät sekä kukkien, tähkylöiden ja siementen muodostuksen) ja siemensadon. Lisäksi kasvustoista analysoitiin rehulaatu kahdesti (mm. D-arvo, raakaproteiini, kuiva-aine ja tuhka). Tulosten perusteella Fure muodostaa lehtevämmän kasvuston kuin Kalevi. Vaikka Kalevin kokonaisversomäärä on suurempi kuin Furen, Fure muodostaa Kalevia enemmän vegetatiivisia versoja ja sen biomassasta suurempi osa on lehdissä kuin Kalevilla. Fure muodostaa myös Kalevia enemmän tähkylöitä, kukkia ja siemeniä röyhyä kohden. Lajikkeiden siemensadossa ei silti ollut merkittävää eroa, joten ne pystyvät tehokkaasti kompensoimaan satokomponenteissa tapahtuvia muutoksia kuten viljat. Röyhyjen määrän lisääntyminen laski Kalevin siemensatoa samoin kuin siementen määrän lisääntyminen röyhyssä Furella. Biomassan lisääntyminen korrenkasvuvaiheen alussa vähensi Furen siemensatoa ja lisäsi Kalevin siemensatoa. Lajikkeiden rehulaadussa ei havaittu muita eroja kuin se, että Kalevin D-arvo pysyi pitempään korkeampana kuin Furen.

The ideotype of a crop is a model of a plant community where all necessary and beneficial traits for crop performance in a particular environment are combined. It is important to consider the environment when developing an ideotype since climatic, edaphic and agronomic features of the target region have a major role in determining crop performance. New technologies, high yielding cultivars, irrigation and water management, plant protection materials and more skilful farm management practices have increased yields and yield potentials on cereals in Finland as in many other countries. In this paper we aim to summarize traits which would be useful from the farmers’ perspective. The most important trait is increased early vigour of spring cereals, including faster rate of early development and increased leaf area to improve both the resource capture of the canopy and water use efficiency. Introduction of dwarfing genes would improve lodging resistance and harvest index due to improved partitioning of dry matter into grains whereas longer coleoptiles would improve emergence and seedling establishment. Improved ability of crops to utilize stem reserves during grain filling would increase resistance against environmental stresses. All of these traits would also increase the competitive ability of the plant against weeds as well as competition within the crop canopy and are already available from non-adapted germplasm of the various spring cereal species., Ideotyypillä tarkoitetaan kasvustoa, jossa yhdistyvätkaikki tarvittavat ja hyödylliset ominaisuudet hyvälaatuisen ja korkean sadon tuottamiseksi tietyssä kasvuympäristössä. Kasvuympäristön huomioiminen on erityisen tärkeätä ideotyyppiä hahmoteltaessa, sillä ilmastolla sekä edafisilla ja agronomisilla tekijöillä on keskeisin rooli kasvuston menestymisessä. Uudet viljelymenetelmät, ravinteet, satoisat lajikkeet, kastelu, kasvinsuojeluaineet sekä huolellinen viljelytoimien suunnittelu ja toteutus ovat parantaneet kevätviljojen satoja niin Suomessa kuin muuallakin maailmassa. Lajikkeita on kuitenkin kehitettävä edelleen erityisesti kasvinsuojeluaineiden ja typen käytön aiheuttaman ympäristökuormituksen vuoksi. Tarkastelemme tässä artikkelissa ominaisuuksia, jotka vaikuttavat keskeisesti elinvoimaisen ja hyvän kasvuston kehittymiseen ja menestymiseen ja samalla mahdollistavat panosten käytön vähentämistä kasvintuotannossa. Tarkastelun kohteena ovat siten kasvuston nopea ja elinvoimainen alkukehitys, sivuversojen muodostuminen, kääpiö- ja puolikääpiölajikkeet, veden- ja typenkäytön tehokkuus, korsivälivarastot sekä kasvuston kilpailukyky. Elinvoimainen kasvusto peittää maan nopeasti, mikä lisää kasvuston kilpailukykyä rikkakasveja vastaan ja samalla parantaa vedenkäytön tehokkuutta ja säästää maan vesivaroja. Kääpiömuotoja hyödyntämällä voidaan paitsi vähentää lakoutumista myös tehostaa hiiliyhdisteiden jakautumista kehittyviin jyviin korsien ja juurien sijaan. Keskittämällä sivuversojen muodostuminen yhteen tai kahteen tähkälliseen tai röyhylliseen sivuversoon voidaan edelleen tehostaa yhteyttämistuotteiden jakautumista sekä vedenkäyttöä. Erityistä huomiota tulisi kiinnittää kasvien kykyyn hyödyntää korsivälivarastoja jyväntäyttymisjakson aikana, koska sääolot ovat Suomessa usein hyvin vaihtelevat. Korsivälivarastoja hyödyntämällä jyväntäyttymistä voidaan jatkaa keskeytyksettä lähes sääoloista riippumatta. Kun kiinnitetään huomiota lajikkeiden valintaan ja viljelymenetelmiin, satotasoja ja keskisatoja on mahdollista nostaa Suomessa tulevaisuudessakin.

Rotation with dicotyledonous crops to break cereal monoculture has proven to be beneficial to successive cereals. In two fields where the soil had been subjected to prolonged, continuous cereal production, two 3-year rotation trials were established. In the first year, faba bean, turnip rape and barley were grown, as first crops, in large blocks and their residues tilled into the soil after harvest. In the following year, barley, buckwheat, caraway, faba bean, hemp and white lupin were sown, as second crops, in each block and incorporated either at flowering stage (except barley) or after harvest. In the third year, barley was grown in all plots and its yield and grain protein concentration were determined. Mineral N in the plough layer was determined two months after incorporation of crops and again before sowing barley in the following year. The effect of faba bean and turnip rape on improving barley yields and grain protein concentration was still detectable two years after they were grown. The yield response of barley was not sensitive to the growth stage of second crops when they were incorporated, but was to different second crops, showing clear benefits averaging 6-7% after white lupin, faba bean and hemp but no benefit from caraway or buckwheat. The effect of increased N in the plough layer derived from rotation crops on barley yields was minor. Incorporation of plants at flowering stage slightly increased third-year barley grain protein concentration but posed a great potential for N loss compared with incorporation of crop residues after harvest, showing the value of either delayed incorporation or using catch crops.

The Finnish growing season is particularly short, with an intensive growth period, unfavourable rainfall distribution and frequently occurring fluctuations in climate that affect crop growth and yield formation. A three-year study was conducted in the field to determine the contribution of alterations in canopy structure, tillering and stem elongation among dwarf (D), semidwarf (SD) and tall (T) oat (Avena sativa L.) lines to yield formation. Yield components, leaf characteristics and straw traits were measured from six oat lines (D lines Pal and Grane, SD lines Hja 76416 and Salo, and T lines Veli and Jalostettu maatiainen) separately on the main shoot and tillers. Results indicated that long leaf area duration and high leaf area index were associated with increased grain yield probably due to more persistent and active assimilation. Also, higher number of leaves increased the grain yield. Higher peduncle, straw and node weights associating with increased grain yield may result from more abundant assimilate reserves; however, the longer the straw and peduncle, the lower the grain yield, which may result from increased lodging of SD and T lines. The traits contributing most to the grain yield varied greatly from year to year. It is concluded that no single dominant trait determined grain yield, since yield is a product of several different traits. SD lines seemed to be most promising for further breeding programs on the basis of their growth pattern and yielding ability., Kasvien kasvua ja sadontuottoa rajoittaa Suomessalyhyt ja nopeatempoinen kasvukausi, jolle on tyypillistä vaihteleva säätila ja sateiden epäedullinen painottuminen syksyyn. Kolmevuotisessa peltokokeessa tutkittiin eroja kääpiö-, ja puolikääpiökaurojen sekä pitkäkortisten lajikkeiden kasvustorakenteessa, sivuversojen tuotossa ja korrenkasvussa sekä arvioitiin näiden merkitystä sadonmuodostukseen. Kuuden kauralinjan pääversoista ja sivuversoista mitattiin satokomponentit sekä lehdistörakennetta ja kortta kuvaavia ominaisuuksia. Saatujen tulosten perusteella kääpiöt versoivat enemmän, mutta niiden sadontuottokyky ei parantunut versontakyvyn myötä. Määritetyistä ominaisuuksista korkeaan satoon olivat yhteydessä pitkään yhteyttämiskykyisenä säilyvä kasvusto ja suuri lehtialaindeksi, mikä saattaa johtua pitempään jatkuvasta tehokkaasta yhteyttämisestä. Myös suuri lehtilukumäärä lisäsi satoa. Kääpiöillä oli yleensä hieman vähemmän lehtiä kuin pitkäkortisilla lajikkeilla ja erityisesti Pal-lajikkeella epätyydyttävä kasvustorakenne. Hyvä sadontuottokyky oli yhteydessä painavampaan ylimpään nivelväliin, korteen ja solmuihin, mikä saattaa johtua siitä, että niissä oli enemmän välivarastoituja yhdisteitä, joita voitiin hyödyntää jyväntäyttymiseen. Pitkä korsi ja ylin nivelväli näyttivät kuitenkin olevan yhteydessä alhaiseen satoon johtuen oletettavasti lakoutumisalttiuden lisääntymisestä. Askeltava regressioanalyysi osoitti kuitenkin, että vuosittaiset vaihtelut olivat huomattavia ominaisuuksissa, jotka selittivät sadossa ilmenneitä vaihteluita. Siksi yksittäisiä, kasvuoloista riippumattomia, sadontuottoa hallitsevia ominaisuuksia ei voitu luonnehtia.

Maize cultivation for silage could be a sustainable option in Boreal conditions, especially when combined with nutrient recycling. Effects of digestate (sludge from biogas of domestic origin) application in comparison with synthetic fertilizer and two maturity stages on chemical composition and in vitro digestibility of whole-crop maize were investigated. Starch, neutral detergent fiber, water soluble carbohydrate (WSC) and digestible organic matter (DOM) contents of maize did not differ in response to the two fertilizer treatments. However, starch, DOM and metabolizable energy of maize increased, while ash, crude protein and WSC contents decreased with increasing maize maturity. Heavy metals in maize fertilized with digestate remained low. The results indicate that whole-crop maize fertilized with digestate and harvested at 150 days after sowing is a promising feed and has good nutritive value, even in Boreal conditions.

The effect of foliar application of glycinebetaine (50 and 100 mM) on photosynthesis, stomatal conductance, photorespiration and transpiration in tomato cv. Bos 3155 (Lycopersicon esculentum Mill.) and summer turnip rape cv. Kulta (Brassica rape L, ssp. oleifera) plants subjected to drought and salinity are reported. Glycinebetaine application increased net photosynthesis of stressed plants. This was mostly due to increased stomatal conductance following glycinebetaine application as there were no marked changes in light and CO 2 saturated rates of O 2 evolution. Moreover, glycinebetaine application resulted in a significant decrease of photorespiration both in drought- and salt-stressed plants.

Glycinebetaine, a novel product from sugar beet (Beta vulgaris L. v. altissima), is purified from molasses during sugar processing through chromatographic separation, enrichment and crystallisation. Glycinebetaine is environmentally safe, non-toxic and water-soluble and is found in animal, microbe and plant cells. Most halophytes, when grown under stress, synthesise glycinebetaine in their chloroplasts and accumulate it as an osmoprotectant. Here we show that foliarly applied glycinebetaine offers a new possibility to stabilise crop production under field conditions: fruit yield of tomato plants (Lycopersicon esculentum Mill.) grown in saline soils or exposed to high temperatures in California increased up to 39% when glycinebetaine was applied during midflowering. Similarly, glycinebetaine treatment of tomato plants in a commercial vegetable producer's greenhouse in Southern Finland increased the yield and the number of tomato fruits. In a separate greenhouse experiment, we showed that glycinebetaine application increased the rate of net photosynthesis of adequately watered and salt stressed tomato plants.

Seventeen morphological and physiological characteristics of three Avena barbata L. populations from Israel were measured in order to define possible combinations explaining adaptation of these populations to different precipitation, temperature and altitude regimes. Five genotypes from each A. barbata populations were collected from Ashqelon (31°63′N, low annual precipitation), En Hamifraz (32°46′N, high temperature), and Mount Carmel (32°73′N, high altitude), Israel. The behavior of the populations was followed by measuring the morpho-physiological characteristics under well-watered and moderately drought stressed conditions. The experiment was conducted at the Department of Plant Production, University of Helsinki, Finland (60°13′N). The measured traits characterized macro-morphology, transpiration rate, photosynthesis and chloroplast features. The data were subjected to principal component and discriminant analyses and the characteristic combinations that most adequately accounted for the differences among A.barbata populations were established. Differences among the populations were related to adaptation to low water availability and high altitude characterized by special light conditions. The Mount Carmel population (high water availability, high light intensities and increased proportion of UV-light) was characterized by higher tillering, hairy leaf sheaths, high transpiration, high stomatal conductance, slow fluorescence quenching capacity, and less starch granules per chloroplast when compared with populations adapted to lower altitudes. The En Hamifraz population (high mean temperature) was characterized by a high CO2 exchange rate and both En Hamifraz and Ashqelon populations (both adapted to arid conditions) used water sparingly when moderately drought stressed.

It has been reported that foliar application of glycinebetaine reduces the effect of abiotic stresses on crops, including tobacco (Nicotiana tabacum L.), soybean [Glycine max (L.) Merr.], and maize (Zea mays L.), especially during the recovery period. The aims of this study were to determine the effect of foliar application of glycinebetaine on biomass accumulation and photosynthetic capacity of turnip rape (Brassica rapa L. ssp. oleifera) and pea (Pisum sativum L.). Experiments were carried out in a greenhouse and in the field, and records were taken on differentiation and emergence of floral organs. Biomass accumulation, relative growth rate (RGR), specific leaf area, leaf chlorophyll content, and nitrogen uptake were also measured for pea. In the experiment in the greenhouse, glycinebetaine application increased relative growth rate of both crops, especially when drought‐stressed and when recovering from drought. Application of 0.20 M glycinebetaine increased RGR of pea, recovering from drought, by 13%...

Sulfonylureas represent one of the largest herbicide groups that have been widely used since 1980s. Their continuous use has resulted in development of sulfonylurea resistance in weeds. The aim of this research was to investigate options to manage putative sulfonylurea-resistant chickweed in barley stands and to evaluate the effect of chickweed and its management on barley yield. A field experiment was arranged as a randomized complete block design and included 14 herbicide treatments applied at two different times. Tribenuron-methyl (sulfonylurea) affected minimal control of chickweed. A bromoxynil-ioxynil (photosystem II inhibitor) mix did not control chickweed efficiently. However, nearly total control was achieved with fluroxypyr, mecoprop, and their mixtures (synthetic auxins and photosystem II inhibitors). Chickweed had no effect on barley yield whether controlled or uncontrolled. Therefore, further evaluation of the chickweed management threshold would be needed. It seems that even in the boreal region, typified by a cold climate, limited solar radiation, a very short growing season, and relatively low-intensity cropping systems, unilateral use of sulfonylureas might lead to herbicide resistance. Although resistant weed populations can be controlled with herbicides of groups other than the sulfonylureas, this represents an increasing problem when planning weed management, especially when including sulfonylurea-resistant crops.

Meadow fescue (Festuca pratensis Huds.) is grown widely in the Nordic countries in forage grass mixtures. Locally adapted cultivars are preferred for establishment of mixed swards. Meadow fescue seed yield is determined by seed weight, the number of panicle bearing tillers, size of panicles and the number of fertile florets. We aimed to determine the differences in components of seed yield in two different meadow fescue cultivars differing in forage quality; Kalevi, released in 1979, and Fure, released in 1999. Biomass accumulation was monitored, numbers of fertile and sterile florets, and seeds were counted, and the forage quality was analysed. Seed quality was also analysed. Fure was leafier and accumulated more vegetative biomass than Kalevi. Kalevi had significantly more panicles than Fure, although Fure compensated for the lower number of panicles with increased panicle size. There were no differences in number of sterile and aborted florets between cultivars. Based on the results it seems that these two meadow fescue cultivars have a completely different strategy in seed production even though the final seed yield was not markedly different. It is apparent that meadow fescues have good ability to compensate among the components of seed yield. Long-term field experiments should be conducted to investigate the interactions between plant stand ecology, seed production and cultivation technology., Nurminataa (Festuca pratensis Huds.) viljellään laajaltipohjoismaissa rehunurmiseoksissa. Seosnurmien perustamiseen halutaan usein käyttää paikallista alkuperää olevaa siementä mahdollisuuksien mukaan. Nurminadan siemensato määräytyy kasvustossa olevien röyhyllisten versojen, röyhyjen koon ja röyhyssä olevien fertiilien kukkien määrän sekä siementen painon mukaan. Tämän työn tarkoituksena oli tutkia, onko kahden kasvutavaltaan poikkeavan nurminatalajikkeen siemensadon muodostuksessa eroja. Lajikkeina olivat vuonna 1979 kauppaan laskettu Kalevi ja vuonna 1999 kauppaan laskettu Fure. Kasvustoista seurattiin biomassan muodostusta, laskettiin fertiilien ja steriilien kukkien lukumäärä sekä siementen lukumäärä ja analysoitiin kasvustojen rehulaatu. Lisäksi määritettiin siemensadon laatu. Fure oli lehtevämpi ja muodosti enemmän vegetatiivista massaa kuin Kalevi. Kalevi muodosti ensimmäisenä satovuotena enemmän röyhyjä kuin Fure, mutta Fure kompensoi vähäisempää röyhyjen määrää suuremmalla röyhyjen koolla. Steriilien ja abortoituneiden kukkien lukumäärässä ei lajikkeiden välillä ollut eroa. Tämän kokeen perusteella nurminata lajikkeet erosivat toisistaan täysin siemensadon muodostuksessa vaikkakaan merkitsevää eroa lopullisessa siemensadossa ei ollut. Nurminadalla näyttääkin olevan erinomainen kyky kompensoida siemensadon satokomponentteja. Siemensatojen nostamiseksi kasvustoekologian ja viljelytekniikan yhdysvaikutus tulisi selvittää monivuotisissa kokeissa.

Kasvinjalostus ja tutkimus kaipaavat nopeita ja yksinkertaisia menetelmia kuivuudensiedon arvioimiseksi. Tutkimuksessa verrattiin vanhojen (laskettu kauppaan ennen vuotta 1970) ja uusien kauralajikkeiden kuivuudenkestavyytta monivuotisten peltokokeiden ja kolmen kasvihuonekokeen perusteella.Peltokokeissa kunkin lajikkeen jyvasato laskettiin suhdelukuna mittarilajikkeisiin. Kokeet jaettiin eri ryhmiin touko-kesakuun sademaaran perusteella ja kullekin ryhmalle laskettiin suhdeluvun keskiarvo. Touko-kesakuun sademaaran vaikutusta lajikkeiden suhteelliseen jyvasatoon kuvattiin kayrilla. Kasvihuonekokeissa kauralajikkeet altistettiin kuivuudelle pensomisvaiheessa tai royhylle tulon yhteydessa. Lajikkeiden herkkyytta reagoida kuivuuteen verrattiin fysiologisten ominaisuuksien perusteella lasketuista indekseista (kuivuusstressioloissa saatu tulos jaettuna kontrollikoejasenen tuloksella). Mita enemman indeksi poikkesi arvosta yksi, sita voimakkaammin kyseinen lajike reagoi kuivuuteen. Peltokokeet osoittivat, etta useat uudet lajikkeet reagoivat vanhoja herkemmin alkukesan kuivuuteen. Virma ja Sisu olivat poikkeuksia. Kasvihuonekokeiden perusteella vanhojen ja uusien lajikkeiden erottelu oli vaikeaa ja suuntaus naytti olevan jopa painvastainen kuin peltokokeissa. Kasvihuonekokeessa kaurat kasvatettiin 7,5 litran purkeissa, jolloin syvajuurisuus kuivuudensietomekanismina jai huomiotta. Myos peltokokeista saatu tieto lajikkeiden reagoinnista alkukesan sademaaraan saattaa olla harhainen, koska sademaaran lisaksi useat muut tekijat vaikuttavat sadontuottoon. Koeaineiston tuleekin olla laaja luotettavan kasityksen saamiseksi, mika usein rajoittaa jalostusaineiston kuivuuden siedon arvioimista. Naista syista tassa tutkimuksessa kaytettyja yksinkertaisia menetelmia ei voida suositella kaytettavaksi lajikkeiden kuivuusherkkyyden selvittamiseksi.

Crop losses caused by environmental stresses might be reduced by applying osmoprotectans to crop canopies. Glycinebetaine is endogenously accumulated by some halophytes under stress conditions and represents such a compound. Glycinebetaine was applied exogenously to barley (Hordeum vulgare L.), oat (Avena sativa L.), spring wheat (Triticum aestwum L.), and summer turnip rape (Brassica rapa ssp. oleifera DC.) canopies and its optimal concentration was monitored in the greenhouse. In field experiments the response of crop plants to betaine applications was assessed by measuring accumulation of above ground biomass, leaf area index (LAI), leaf chlorophyll, and yield. The optimum betaine concentration producing advantageous effects on growth and crop physiology in turnip rape was close to 0.1 M and for wheat 0.3 M. Such concentrations promoted accumulation of betaine similar to that of halophytes under stress conditions [ca. 200 μmol (g DM)−1]. In the 1993 field experiment peak LAIs were recorded in irrigated wheat and barley treated with 17.5 kg ha−1 betaine applied at 300 1 ha−1. Green leaf area was slightly more persistent in wheat treated twice with 1 kg ha−1 betaine applied at 200 1 ha−1 in 1994, although it was not associated with increased grain yield. Our results indicated that betaine has no actual potential in Finland for the principal grain crops but further studies are needed in stress prone environments to assess the potential of betaine treatments for preventing crop failures.

Several methods have been developed to assess differences in cultivar response to drought. This study consisted of 19 oat (Avena sativa L.) cultivars and breeding lines and three species of wild oats, and focused on comparison of several physiological screening methods -CO2 exchange rate (CER), stomatal conductance, stomatal resistance, disparity between air and leaf temperatures, accumulation of abscisic acid (ABA) and proline, and relative water content (RWC) - with yield losses. Early drought, occurring at four-five leaf stage or close to pollination date resulted in significantly reduced above-ground vegetative biomass and panicle weight. Reductions in panicle weight due to drought were greater than those in vegetative phytomass, which resulted in decreased harvest index (HI). Drought stress significantly increased stomatal resistance and accumulation of ABA and proline, whereas stomatal conductance, disparity between air and leaf temperatures and RWC, decreased owing to water deficit. Compar...

In this study Mixed structural covariance, Path and Cultivation Value analyses and the CERES-Wheat crop model were used to evaluate vegetation and yield component variation affecting yield potential between different high-latitude (> 60° N lat.) and mid-European (< 60° N lat.) spring wheat ( Triticum aestivum L.) genotypes currently cultivated in southern Finland. Path modeling results from this study suggest that especially grains/ear, harvest index (HI) and maximum 1000 kernel weight were significant factors defining the highest yield potential. Mixed and Cultivation value modeling results suggest that when compared with genotypes introduced for cultivation before 1990s, modern spring wheat genotypes have a significantly higher yielding capacity, current high yielding mid-European genotypes even exceeding the 5 t ha -1 non-potential baseline yield level (y b ). Because of a forthcoming climate change, the new high yielding wheat genotypes have to adapt for elevated temperatures and atmospheric CO 2 growing conditions in northern latitudes. The optimized ideotype profiles derived from the generic high-latitude and mid-European genotypes are presented in the results. High-latitude and mid-European ideotype profiles with factors estimating the effects of concurrent elevated CO 2 and temperature levels with photoperiodical daylength effects can be utilized when designing future high yielding ideotypes adapted to future growing conditions. The CERES-Wheat ideotype modeling results imply, that with new high yielding mid-European ideotypes, the non-potential baseline yield (y b ) would be on average 5150 kg ha -1 level (+ 108 %) vs. new high-latitude ideotypes (y b 4770 kg ha -1 , 100%) grown under the elevated CO 2(700ppm) ×temperature (+3oC) growing conditions projected by the year 2100 climate change scenario in southern Finland.

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

The average annual global temperature increased by 0.76°C during the past century (Intergovernmental Panel on Climate Change (IPCC), 2007) and climate modelling results show an increase in annual temperature in boreal regions of 0.1 – 0.4°C/decade over the 21st century, depending on the scenario and model. Warming will be unevenly distributed, being greater in summer in lower and middle latitudes but greater in winter at higher latitudes, and this differential will increase. Mean annual precipitation is projected to increase in the North and decrease in the South, and winter precipitation will increase in northern and central Europe, continuing the trends established in the 20th century of a 10 – 40% increase in northern Europe and a decrease of up to 20% in southern Europe (IPCC, 2007). The increase in winter precipitation is due to the increased water carrying capacity of the atmosphere resulting from the higher temperature. Global warming will increase the frequency of soil freeze-thaw cycles (FTCs) in cooltemperate and high-latitude regions previously subject to prolonged winter soil frost (Kreyling et al., 2007; Henry, 2008). Warmer winters will result in fewer soil freezing days and in boreal Europe, lowland permafrost is expected to eventually disappear (Harris et al., 2009). The length of the frost-free season has already increased in most midand highlatitude regions of both hemispheres over the values established in the middle of the 20th century. In the Northern Hemisphere, this is mostly manifested as an earlier start to spring, which will arrive progressively earlier in Europe by 2.5 d per decade (Menzel et al., 2006). Increased precipitation in winter, when there is little plant growth, increases the probability of leaching, runoff and erosion from unprotected boreal soils. Climatic warming can paradoxically lead to colder soil temperatures in winter when it reduces the thickness of the insulating snow cover (Henry, 2008 and references therein) leading to root injury (Kreyling, 2010). Increased soil freezing when snow was removed led to root injury, increased leaching of C, N and P, and decreased soil microarthropod abundance (Groffman et al., 2001; Weih & Karlsson, 2002; Henry, 2008), but it is unclear what impacts FTCs and lower soil temperature will have on soil biological and physical processes. Observed nitrate losses to the groundwater after deep soil frost events are attributable more to reduced root uptake due to root injury than to increased N net mineralization (Matzner & Borken, 2008) (Figure 1). The intensity and frequency of summer heat waves is likely to increase (IPCC, 2007). Between 1977 and 2000, these trends were more extreme in central and north-eastern Europe and in mountainous regions than in the Mediterranean region. Temperatures are increasing