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1.
Field trials were conducted with autumn- and spring-sown faba beans in Northern Germany during four seasons to examine the expected preceding development of autumn-sown plants, its possible transformation into a higher yield potential and its dependence on sowing dates and varieties. Height, appearance of leaves, inflorescences, mature flowers, potential and actual pot set was rated weekly, and flower initiation and tillering occasionally. Comparison was made for one winter type sown in autumn and spring, and between 6 winter types and 3 spring types, in two seasons each.
Development of autumn-sown plants significantly preceded that of spring-sown in each year, regardless of the plant material used. The mean advance, diminished considerably with time due to prolonged developmental phases in autumn-sown plants which, however, did not improve vegetative, generative or reproductive potentials of main tillers. Potentials formed by the six winter types, interacted strongly with the seasons, at least in part due to changing plant densities. Thus, only a very few traits appeared typical: a short stature with few leaves for Avrissot and the opposite for Bourdon , a high number of ripening pods for Avrissot and a low number for Banner . Early compared to late sowing in autumn increased the number of leaves, and in one year even the number of mature flowers and ripening pods per tiller, but values of early sowing never exceeded those of spring sowing. Enhancement of tiller formation by early compared to late sowing diminished after spring; nevertheless about two reproductive tillers per plant in autumn-sown stands always led to a higher density of tillers than in spring-sown.  相似文献   

2.
Slow leaf formation in spring is regarded as the main factor limiting sugar beet yield. It is therefore expected that yield can be enhanced when plants develop leaves earlier resulting in an extended growing period. The aim of this study was to analyse leaf and storage root growth of sugar beet plants sown in autumn or very early in spring with regard to possible yield increases. In 2005/06 and 2006/07, field trials were conducted at 4 sites with 6 sowing dates: August, beginning and mid of September, and in February, March and April. Sequential harvests were conducted to follow yield formation.Field emergence of autumn sown sugar beets was fast and reached 90% whereas in early spring it was severely restricted due to low temperature. Leaf and root yield formation of autumn and spring sown sugar beets could well be described with thermal time confirming that sugar beet growth is temperature driven and day length insensitive. Despite longer growing periods autumn sown beets did not form more cambium rings in the storage root than spring sown beets. That might be partly due to the bolting process after winter. However, early spring sown beets as well did not achieve more cambium rings than plants sown in April pointing to a presumably limited ability to adapt cambium ring formation. Because of the shift to reproductive growth, autumn sown beets formed high amounts of shoot dry matter, but not much root dry matter. Furthermore, the root dry matter consisted of a lower sugar and a higher marc content and would therefore not be suitable for sugar recovery. Earlier sowing in spring did not result in a significant yield increase because the benefit from early sowing diminished throughout the season as also obvious from the distance between the cambium rings.For bolting resistant sugar beet varieties, which are expected to be available in near future, the presented data form a basis to predict yield with models. However, it has to be investigated to what extent sugar beet growth and yield formation benefits from early sowing and extended growing periods.  相似文献   

3.
Outcrossing Rates in Autumn and Spring-Sown Barley   总被引：1，自引：0，他引：1  
H. Doll 《Plant Breeding》1987,98(4):339-341
Natural outcrossing is a potential cause of the admixtures which are often observed, especially in winter barley. Outcrossing was studied in yield trials with hap laid -derived homozygous offspring, lines from tour crosses between winter and spring barley varieties. Outcrosses were recognised by heterozygosity in storage protein loci Hor1 and Hor2 as revealed by electrophoresis. Outcrossing, was, on average, about 5% in lines sown in the autumn and less than 0.5% after spring sowing. Autumn-sown lines from one of the four crosses studied had about 10% outcrosses.  相似文献   

4.
A relay cropping system of cereals, whereby winter wheat (Triticum aestivum L.) was undersown in two‐row spring barley (Hordeum distichum L.), was established in a field trial in central Sweden in 1999 and continued until 2000. The purpose of the study was to examine crop and weed responses to different plant densities of the undersown winter crop. Winter wheat was sown at four seed rates (187, 94, 47 and 0 kg ha?1) immediately after the sowing of barley. Barley was harvested in the first autumn after sowing and winter wheat in the second autumn. The grain yield of barley was not affected by the seed rate of wheat, and averaged 4580 kg ha?1. Winter wheat did not vernalize during the first growing season but remained at the vegetative stage. The grain yield of wheat was 1990 kg ha?1 for the lowest and 5610 kg ha?1 for the highest seed rate of wheat. Whilst the undersowing process itself stimulated weed emergence in this experiment, increasing the undersowing seed rate reduced the population of perennial weeds by 40–70 %. In the second growing season, the total biomass of weeds was 66 % higher at the highest seed rate compared with the lowest seed rate.  相似文献   

5.
Two seed lots of white clover ( Trifolium repens L.) cultivar 'Makibashiro' classified as high and poor quality seed lots, based on the speed of germination (T50), were used to examine the influence of seed quality on field establishment and forage yield. Field emergence rate was estimated approximately three weeks after sowing and found that plots sown with high quality seeds (Lot 1) had 452 seedlings m-2 compared with 392 seedlings in the plots sown with low quality seed lot (Lot 2), but the difference was not significant. However, plant density in autumn (November, 1993), 3 months after sowing, was significantly (P < 0.05) higher in the plots of the Lot 1 seed than that from the Lot 2 seed. The percentage of clover plants surviving over the winter from Lot 1 plots was 55% compared with 39% from the Lot 2 plots, but the difference was not significant. Total forage yield in Lot 1 plots harvested in July and monthly intervals to October, was significantly increased by 44% (P < 0.05) over that of Lot 2 plots, but this greater forage yield in high seed quality seed lot plots was produced early in the season. The results strongly imply that the primary advantage to be gained from high quality seed is an improved field establishment, which led to increased yield of clover. In Lot 1 plots, the percentage of weed dry matter in all the four harvests remained below 1% of die seasonal dry matter production, whereas in Lot 2 plots die percentage of weed dry matter ranged from 3.3–16.9%.  相似文献   

6.
Changing climatic conditions in north-western Europe are accompanied by occasional extreme weather conditions. This requires breeding of winter oilseed rape cultivars which are resilient to diverse abiotic stress factors, e.g. frost, drought and heat. The degree of vernalization requirement of winter oilseed rape has been found to be related to frost tolerance and winter hardiness. Shoot elongation before winter in particular has been identified as one decisive factor for frost tolerance in winter oilseed rape. However, the relationship between vernalization requirement and shoot elongation before winter is not known. In the present study the genetic variation for shoot elongation before winter and vernalization requirement of 19 genetic diverse breeding lines and cultivars were analyzed. Autumn and spring sown field experiments in multiple environments were performed to determine shoot elongation before winter and vernalization requirement, respectively. In spring sown field experiments, genotypes with a low vernalization requirement were characterized by the occurrence of long bolting plants with flower buds. Large and significant genotypic variation was found for shoot length in the autumn sown and spring sown environment. Broad sense heritability was quite high for shoot length in the spring sown environment (h2?=?97%), whereas it was only of medium size for shoot length before winter (h2?=?62%). Although the correlation between shoot length before winter and shoot length in the spring sown environment was positive (Spearman’s rank rS?=?0.48*), a number of genotypes with reduced shoot elongation before winter and low vernalization requirement were identified. Results indicate that genotypes with a reduced shoot elongation before winter independent of their vernalization requirement can be selected in breeding programs.  相似文献   

7.
Undersowing a main crop enables establishment of a catch crop in areas characterized by a short post-harvest period before the onset of winter. Techniques with lower costs than conventional undersowing by separate drilling are often regarded as unreliable. Undersowing by drilling after sowing spring barley ( Hordeum vulgare L.) was compared with broadcast sowing simultaneously with drilling barley. Various implements were coupled behind the combined drill in cases where seed was broadcast: a press-wheel attachment, a long-tined harrow and a cage roller. A fourth treatment did not include an implement coupled behind the drill. The undersown crop was sown as a seed mixture of 3 kg ha–1 red clover ( Trifolium pratense L.) and 6 kg ha–1 meadow fescue ( Festuca pratensis Hudson). The numbers of plants and weeds and the plant height were measured five times during the growing season. Above-ground biomass of the undersown species was determined at barley harvest and in late autumn. Grain yield of spring barley was recorded. Drilling resulted in the highest yield of undersown crop when an early summer drought occurred, but broadcasting in combination with use of seed covering equipment led to the least variation in biomass production over the 4 years the experiment was conducted. The relative proportion of meadow fescue in the crop was low in three years, and lower when broadcast than when drilled. Barley grain yield was highest when the seed was broadcast and seed covering equipment was used. Use of a cage roller increased weed biomass, but press-wheels and a long-tined harrow did not. Separate rolling after undersowing increased undersown crop yield in one year, but decreased grain yield in some cases.  相似文献   

8.
Italian ryegrass (Lolium multiflorum Lam.) and perennial ryegrass (L. perenne L.) can be grown for seed and forage in cold winter regions provided the stand persists well over winter. Seed yield and plant characteristics during primary growth, and forage yield during regrowth, were determined for two Italian and one perennial ryegrass cultivars in Atlantic Canada. Establishment methods and dates included sowing ryegrass in cultivated soil alone or with barley in mid‐May and, after harvesting the barley crop, by sowing ryegrass following conventional or reduced cultivation and by no‐till drilling into barley stubble in mid‐August and early September. Despite some winterkill, particularly in Italian ryegrass, seed and forage yields were adequate in post‐establishment growing seasons. Seed yield for Italian ryegrass was greatest (1270 kg ha?1) when it was sown into cultivated soil in mid‐August and least (890 kg ha?1) when sown alone in May. Italian ryegrass yielded 15–17 % more seed when plots were established in mid‐August rather than in mid‐May or early September. Italian ryegrass cv. Lemtal had a greater density of fertile tillers (1030 m?2) in the sward than cv. Ajax (860 m?2) and its tiller density was greater when seeded into cultivated soil in September than in mid‐August. There were fewer spikelets per seed head for sowing Italian ryegrass with barley in May than for the other methods of establishment. Forage yield in regrowth was greater for Italian ryegrass cv. Ajax (2770 kg ha?1) than for cv. Lemtal (2480 kg ha?1). Seed yield of perennial ryegrass was greater when seeded in mid‐May than in mid‐August or early September. The seed yield of perennial ryegrass was greater when it was sown with barley in May and harvested for grain, than when it was sown alone or with barley harvested at late milk stage. The establishment methods for mid‐August and early September sowing had little effect on seed yield. However, the no‐till and reduced tillage methods resulted in a greater tiller density than sowing into the cultivated seedbed. Fertile tillers tended to be denser under reduced cultivation for sowing in August. Forage yield of perennial ryegrass regrowth was not influenced by the sowing method and timing. In conclusion, Italian and perennial ryegrasses produce adequate seed and forage regrowth under different establishment methods and timing. However, the poor persistence of Italian ryegrass may limit commercial production after the establishment year in Atlantic Canada.  相似文献   

9.
The influence of sowing date, seed rate, and variety on agricultural characteristics of winter wheat in a low external input system
Growth conditions of winter wheat in agricultural low external input systems, e.g. ecological agriculture, are very different compared to conventional agriculture (mineral nutrition, impact of diseases, competition of weeds). In 1986, 1987, and 1988 the influence of sowing date and seed rate on crop development and grain production was studied with two varieties of winter wheat in field experiments in Northern Hessia.
Drilling after the first decade of October decreases grain yield of both varieties significantly. The decrease was due to poor emergence, low plant densities, and low grain weights. Tillering could not compensate low plant densities, presumably because of low mineralization of nutrients in cold soils during respective growth stages.
Variation of seed rate (350, 500, and 650 viable seeds/m2) had little influence on grain yield. Low plant densities and low numbers of ears per nr after sowing in the end of October could not be improved satisfactorily by increased seed rates.
The ability of varieties of winter wheat to compensate unfavourable growth conditions due to "late" sowing varies considerably. Cultivars which are able to develop a high plant density seem to be more suitable for delayed sowing dates, as compared to varieties which own a high grain weight.
Further investigations concerning wheat production are needed to optimize agricultural low external input systems. Especially sandy soils with quick response to increased ambient temperature, and sites with favourable growth conditions in late autumn and early spring should be considered.  相似文献   

10.
The cultivation of autumn sown sugar beet (winter beet) is supposed to result in a marked yield increase compared with spring sown sugar beet. Although the importance of the growth stage reached before winter for the survival of autumn sown sugar beet has already been shown, it is not clear to which extent osmotic and potentially frost protecting compounds may contribute to winter hardiness. The study thus aimed to analyse the acclimatization process of sugar beet to low temperatures and to identify compounds which are important for survival of frost. Field trials with autumn sown sugar beet were conducted at eleven environments in Germany from 2009/10 to 2012/13, which were accompanied by greenhouse experiments with controlled temperature regimes. In the field trials, the survival rates after winter varied from 0 % to 99 %, but only in four environments differences between the five genotypes occurred. During acclimatization, betaine, glutamine, proline and raffinose were markedly accumulated and osmolality was enhanced. In particular betaine, amino acids and osmolality showed a positive correlation to the survival rate and were thus identified as potentially frost protecting substances for sugar beet. In contrast, raffinose and proline seem to act rather as stress indicators as they were negatively related to survival. Possible frost protecting substances were identified which can be used in breeding to improve the winter hardiness of sugar beet.  相似文献   

11.
Autumn‐sown winter‐type faba bean (Vicia faba L.) has been shown to have a yield advantage over spring sowing. Still, adoption of this overwintered pulse crop remains limited in temperate locations, due to inadequate winter hardiness. This research sought to understand how the prevailing temperature during emergence and seedling development, that is pre‐acclimation, influences freezing tolerance. Seedlings grown under a controlled “warm” 17/12°C (day/night) pre‐acclimation environment were initially less freezing tolerant than those grown under a “cold” 12/5°C temperature treatment. Stem and particularly root tissues were primarily responsible for slower cold acclimation, and there was a genotype specific response of above‐ground tissues to pre‐acclimation treatment. Both above and below‐ground tissues should be tested across a range of pre‐acclimation temperatures when screening faba bean germplasm for freezing tolerance.  相似文献   

12.
为提高青稞种质资源的利用效率并筛选优异杂交亲本,分别在西藏林芝和拉萨两地的春播和秋播环境下对1605份青稞种质资源进行冬春性鉴定和抽穗期多样性分析。设拉萨春播2个播期,即正常春播I和晚10 d春播II,以2个播期的抽穗期变化作为冬春性区别依据。结果表明,96.2%的西藏青稞地方品种为春性,在西藏3个生态区均有分布,冬性品种仅有3.8%,且主要分布在以林芝为主的藏东南生态区;抽穗期的Shannon-Wiener's多样性分析表明,春播条件下抽穗期多样性高于秋播,拉萨春播条件下抽穗期多样性最高,林芝春播次之,林芝秋播最低;在相同环境下,地方品种的多样性高于育成品种;在环境稳定性分析中, 368份春性地方品种和21份育成品种在不同环境中抽穗期较为稳定,其中康青3号在两地所有参试品种中抽穗期稳定性最高。本研究为全面理解西藏青稞资源的冬春性、抽穗期多样性和环境稳定性提供了参考,为广适应性青稞品种培育筛选出环境稳定性佳的亲本材料。  相似文献   

13.
Growth and yield of wheat are affected by environmental conditions and can be regulated by sowing time and seeding rate. In this study, three sowing times [winter sowing (first week of September), freezing sowing (last week of October) and spring sowing (last week of April)] at seven seeding rates (325, 375, 425, 475, 525, 575 and 625 seeds m?2) were investigated during the 2002–03 and 2003–04 seasons, in Erzurum (Turkey) dryland conditions, using Kirik facultative wheat. A split‐plot design was used, with sowing times as main plots and seeding rates randomized as subplots. There was a significant year × sowing time interaction for grain yield and kernels per spike. Winter‐sown wheat produced a significantly higher leaf area index, leaf area duration, spikes per square metre, kernel weight and grain yield than freezing‐ and spring‐sown wheat. The optimum time of sowing was winter for the facultative cv. Kirik. Grain yields at freezing and spring sowing were low, which was largely the result of hastened crop development and high temperatures during and after anthesis. Increasing seeding rate up to 525 seeds m?2 increased the spikes per square metre at harvest, resulting in increased grain yield. Seeding rate, however, was not as important as sowing time in maximizing grain yield. Changes in spikes per square metre were the major contributors to the grain‐yield differences observed among sowing times and seeding rates. Yield increases from higher seeding rates were greater at freezing and spring sowing. We recommended that a seeding rate of 525 seeds m?2 be chosen for winter sowing, and 575 seeds m?2 for freezing and spring sowing.  相似文献   

14.
Planting times of potato in subtropical China vary and are often not optimal; their effects were studied in association with those of plant density. The research programme included 10 trials at three elevations (500, 750, 1200 m asl) in the spring and autumn seasons of 2 years with several contrasting varieties and different seed origins. Earlier planting in spring increased yield at 500 m asl. This effect was associated with better light use efficiency, higher rates of photosynthesis and more tubers per plant. At 750 m asl the effects of planting time in spring were the opposite: later planting increased yield. At 1200 m asl effects on yield were absent. Effects of planting time in autumn on yield were generally absent at all elevations, although plant stands at early planting were consistently and often severely reduced. Denser planting produced yields that were higher per unit area because of larger accumulated canopy cover but were lower per plant. Higher density consistently reduced plant stand. Density did not interact with planting time, not even in those experiments in which planting time also affected plant stands.
Optimal planting time depended on the amount of rainfall prior to planting especially in the autumn season, but also on cultivar and dormancy of the seed tubers used. The earlier variety yielded more than the later variety at low elevation, whereas the later variety yielded more at higher elevation. It is necessary to use cultivars that tuberize early to make better use of the limited growing period at lower elevation. The large variation of dormancy that affects plant growth and yield is caused primarily by differences in accumulated temperature sum (as affected by planting time, elevation of growth and storage, and season), genetics (variety), and their interaction with cultivation techniques.  相似文献   

15.
Soya bean is often grown in regions subject to periodic flooding, with the rooting zone most affected by flooding due to its proximity to the source of stress. Our objectives were to examine the effects of flooding soya bean on its primary roots, adventitious roots and root nodules, and to determine relationships between root morphological changes and early‐season flood tolerance. The experiment was conducted in Belle Glade, FL with 11 soya bean genotypes subjected to (i) no flood, (ii) 2‐week flood 21–35 days after sowing (DAS) or (iii) 4‐week flood 21–49 DAS. All plants were harvested 49 DAS. Flooding reduced soya bean primary root weight, length and volume across genotypes. Adventitious root length and volume were greater in the 4‐week than the 2‐week flood. Soya bean nodule dry weight was threefold higher in the non‐flooded treatments. Genotypic differences in root development and tolerance to flooding were noted, with early‐season flood tolerance correlated with primary root dry weight, length and surface area, and adventitious root dry weight. However, there was no correlation between this study's early‐season root development and late‐season flood tolerance based on seed yield from previous studies. Our results indicate that full season trials may be necessary to identify flood‐tolerant soya bean germplasm.  相似文献   

16.
红麻对短光钝感材料的发掘及其研究   总被引：3，自引：0，他引：3  
为解决我国长江、淮河流域红麻主产区春播能留种，大面积夏播不早花且纤维相对高产问题，在我国拥有的红麻育种材料中发现了１５份现蕾开花期对光长变化钝感的材料。纯感材料在短光下第一朵花节位在１９￣３７节之间，播种至始花在８０￣１０５天之间，变异丰富。其中１份材料在正常生长季节表现早熟，其余晚熟。敏感材料在短光下的始花节位在８￣１１节之间，始花时间比钝感材料提前２８￣５８天。经遗传分析，钝感对敏感表现为隐性  相似文献   

17.
采用不同的模型, 定量地研究了不同播期不同基因型油菜干物质积累、分配与转移规律. 结果表明: 油菜总干物质积累动态可拟合成Logistic模型. 油菜根、茎枝、叶干物质分配呈现出多项式函数的变化规律, 角果干物质分配表现为Logistic曲线的变化特征. 晚播油菜干物质冬前优先分配给叶, 角果发育成熟期优先分配给角果并主要给籽粒  相似文献   

18.
Two series of field trials were performed at three sites in Schleswig-Holstein between 1981 and 1988 to inquire into the yield structure of European winter types of Vicia faba L. and to compare their yield potential with that of spring types. Due to low winter survival, 6 winter types could be evaluated only in 4 environments in dependence of 1–3 sowing times (series α: seed rate 30/m2) and 1 winter type in 5 environments in dependence of 3 sowing times and 3 seed rates (series β: seed rate 15, 30, 45/m2). Seed yield of winter type averaged 410 g/m2 (D.M.) surpassing spring types by about 14 %. Environments caused a considerable variation in yield (275–620 g/m2) and in each yield component of winter types, while sowing dates and seed rates hardly affected the components seeds/pod and seed weight, which displayed stable genotypic rank orders. Compensative forces among the components plants/m2, tillers/plant and pods/tiller, were established. Plant densities of less than 10/m2 in spring, generally led to seed yield below 350 g/m2. Variation between 15–30 plants/m2 due to environments, sowing times or seed rates were frequently not fully compensated by tillering of plants, but often variation of the thus formed yield potential was reduced by pod set of tillers resulting in 210–270 pods/m2. The direction of correlations of pods/tillers with tillers/plant and plants/m2 differed due to experimental conditions whereas negative correlations between pods/tiller and tillers/ m2 were generally evident. Tillering was significantly influenced by the sowing time, though the increase because of early sowing was often covered by compensative effects of different plant densities. A genotypic capability to produce reproductive tillers was demonstrated using an approach which considered different plant densities and compensative forces. Neither a genotypic capability of tillers to set pods nor direct effects of environments or sowing time on pod set were established.  相似文献   

19.
内蒙古平原灌区“春麦冬播”种植效应及品种适应性   总被引：1，自引：0，他引：1  
针对内蒙古春播小麦生育期短、干热风、高温逼熟等因素制约产量提高,且收获后光温资源极大浪费的现状,以及试种冬小麦发现的冬季冻害、春季干旱或“倒春寒”影响返青率及前茬限制等问题,本研究以“春麦冬播”种植模式为切入点,采用不同春化类型小麦品种,通过连续2年的田间试验,系统研究了不同小麦品种越冬出苗、叶片生理、根系性状及产量形成的差异,以期筛选适宜冬播的小麦品种。结果表明:供试的全部春性小麦品种及部分冬性品种可以以种子形式完成春化作用,第2年正常抽穗成熟。冬播条件下春季田间出苗率较春播小麦有所降低,但根系发达,对低温及干旱的适应性强。通过系统聚类筛选出适宜内蒙古平原灌区冬播的3个小麦品种,包括春性品种永良4号、冬性品种宁冬11号和半冬性品种河农7106,其共同特征为越冬出苗率高、抗逆性强、根系发达、产量表现较高,其中永良4号产量可达到与春播相同的水平。  相似文献   

20.
The effect of agronomic practices and cultivars on grain yield, grain protein and small grain sievings was examined in field experiments over four years in the winter rainfall wheatbelt of Western Australia. Rotation with legume crops and pastures was the main factor responsible for increasing grain protein percent. Grain proteins were increased by 4-5% for crops grown in good legume pasture rotations compared to continuous wheat rotations, but only by 1-2% by factors such as delayed sowing time, applied nitrogen, cultivar or grass weed control. In legume based rotations, wheat crops sown at their highest yielding times produced proteins in the appropriate ranges for premium paying grades. Applying N fertilisers up to the optimum rates for yield did not result in proteins below the levels required for premium paying grades, except for hard wheats at >11.5% grain protein. Legume rotations and appropriate soil types were required for hard wheats to exceed 11.5% at economic N rates. The yield penalty often associated with high quality cultivars has been reduced or eliminated in the modern cultivars used in the experiments. Some longer season cultivars only produced grain proteins >10% if sown after their optimum time for yield, but sowing at optimum time reduced the probability of producing small grain sievings. Some cultivars were more susceptible than others to producing excessive sievings, especially those with inherently smaller than average seed size. Seed rates up to the optimum for grain yield did not result in excessive small grain sievings except where the site was highly fertile, where the crop was sown too late for optimum yield or where too much N fertiliser was used. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

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