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1.
Growth Responses of Twelve Wheat Cultivars and their Phosphorus Utilization from Rock Phosphate 总被引：1，自引：0，他引：1
Growth responses of 12 wheat cultivars and their phosphorus utilization were studied in a greenhouse. They were grown for 18 days in a solution containing rock phosphate as the phosphorus (p) source. Biomass of 26 day old plants of all the cultivars varied significantly whereas their shoot to root ratio stayed constant. The dry matter yield of all the 12 cultivars was significantly correlated with the p uptake (r = 0.74). Whereas the higher p uptake by all the cultivars was significantly (P < 0.01) related to the drop in the root medium pH, which was presumably owing to the H+ efflux from their roots. The wheat cultivar Blue Silver proved to be the most efficient p user and therefore seems to have the highest potential of making best growth in soils with poor p availability among the 12 wheat cultivars under investigation. 相似文献
2.
The aim of this investigation was to obtain information about differences between spelt and wheat in relation to their performance under low-input conditions. Two spelt varieties ( Oberkulmer, Hercule ) and two wheat varieties ( Anna, Iend ) were grown at two different seeding rates (S1 = 200; S2 = 400 kernels/m2 ) and two nitrogen levels (Nl = 80 kg N/ha; N2 = 110 kg N/ha) at two contrasting locations (Muri; altitude 459 m asl; Oberwallestalden: altitude 1011 m asl). No growth regulators and fungicides were applied.
The overall mean for the "husked" yield (grains and glumes) of spelt was not significantly different from the grain yield of wheat. At the higher site Oberwallestalden however, the "husked" yield of spelt was 10.5 % higher than the grain yield of wheat. Although the number of ears per m2 was higher at S2 than at S1, spelt and wheat produced a similar yield at both seeding rates (spelt: S1 = 96 % of S2; wheat: S1 = 95 % of S2) due to the higher single ear weight at S1.
The reaction of spelt and wheat to nitrogen was similar. The yield was 10 % higher at N2 than at Nl for both species. The performance of spelt under low-input conditions was better than for wheat in marginal areas for cereal production only. 相似文献
The overall mean for the "husked" yield (grains and glumes) of spelt was not significantly different from the grain yield of wheat. At the higher site Oberwallestalden however, the "husked" yield of spelt was 10.5 % higher than the grain yield of wheat. Although the number of ears per m
The reaction of spelt and wheat to nitrogen was similar. The yield was 10 % higher at N2 than at Nl for both species. The performance of spelt under low-input conditions was better than for wheat in marginal areas for cereal production only. 相似文献
3.
Increasing sink size (i.e. number of grains m−2 ) has been the way of the genetic improvement for obtaining higher grain yield of wheat. We have studied under field conditions the number of fertile florets and grains per spike and individual grain weight of three bread wheat cultivars ( Klein Favorito, Eureka FCS and Buck Pucara ) which were previously selected to represent cultivars released at different eras (1920, 1940 and 1980, respectively) in Argentina (S lafer and A ndrade 1989).
The three cultivars Buck Pucara, Eureke FCS , and Klein Favorito averaged 56.9, 48, and 34.5 grains spike−1 . Differences were observed in both main shoot and tiller spikes. The number of fertile florets at anthesis was greater in the modern cultivar than in the other two cultivars; however, the intermediate and old cultivars did not significantly differ in this trait. Differences in number of florets and number of grains spike were independent of the number of spikelets spike−1 ; spikelet numbers did not vary among the three cultivars. Therefore, both the number of fertile florets produced per spikelet and the ability of the cultivar to set grains in those florets were responsible for the different number of grains spike−1 among cultivars. The modern, high yielding cultivar had a lower individual grain weight than the old, low yielding cultivar when the average of all grains were considered; but basal grains of its central spikelets were as heavy as those of the other cultivars.
We suggest (i) that the modern cultivars of Argentina have increased their ability both to produce fertile florets and to set grains, and (ii) that the lower individual grain weight of the modern cultivars does not imply an increased competition for resources as a consequence of their higher number of grains. 相似文献
The three cultivars Buck Pucara, Eureke FCS , and Klein Favorito averaged 56.9, 48, and 34.5 grains spike
We suggest (i) that the modern cultivars of Argentina have increased their ability both to produce fertile florets and to set grains, and (ii) that the lower individual grain weight of the modern cultivars does not imply an increased competition for resources as a consequence of their higher number of grains. 相似文献
4.
A. Rashid R. H. Qureshi P. A. Hollington R. G. Wyn Jones 《Journal of Agronomy and Crop Science》1999,182(3):199-208
Seedling growth and ion content of Pakistani bread wheat cultivars was assessed in solution culture in the absence and presence of NaCl (100 and 200 mol m−3 ) to determine whether seedling traits could be used in breeding programs for salt-tolerance. Growth was recorded as seedling fresh weight, and the shoot and leaves analysed for major inorganic ions. Plants subjected to salt stress excluded Na+ and Cl− ions from the shoot to varying extents. Exclusion preferentially maintained lower Na+ and Cl− levels in the apical tissue, as the leaf to leaf gradient in Na+ and Cl− became steeper as the external salinity increased, although there were significant differences between cultivars. Correlation analysis on individual plants indicated that excluding Na+ at low salinity, and Na+ and Cl− at high salinity, were correlated significantly with growth performance, although it was clear that other factors were also involved. The relationship of tolerance to ion exclusion was stronger when the data were examined on an individual plant basis than when related to pooled cultivar data or to the cultivar rank order derived from field trials, probably due to large variations in Na+ , and to a lesser extent, Cl− transport in supposedly homozygous cultivars. 相似文献
5.
G. Geisler 《Journal of Agronomy and Crop Science》1986,157(1):67-71
Plants of maize ( Zea mays L.), spring barley ( Hordeum vulgare L.) and broad bean ( Vicia faba L.) were raised in tubes filled with a soil-sand mixture and supplied with nutrient solution. The nutrient supply was varied with regard to concentration and typ of compound of "N". Due to the relatively high concentrations of "N", dry matter of shoots and roots was reduced in comparison to the control; root morphology was affected in terms of root length and root thickness. The N-compounds, used in the experiment, exerted quantitatively different influences on dry matter production and root morphology, NH4 NO3 being the N-form which had the weakest detrimental effects. There was no specific response to NH+ 4 or NO− 3 but a strong influence could be shown for NH4 Cl and Na NO3 . Probably not only the concentration of "N" and the form of "N" have a specific influence, but also the cations and anions associated with the N-containing ion are effective. 相似文献
6.
7.
Five cultivars of sorghum viz: PU-7, Sarokartuho, Bagdar, Redjanpur and Potobar 4–8 were studied for their growth, N uptake and utilization efficiency at 5 mM N in solution culture. These cultivars differed significantly in their dry matter accumulation and relative growth rate of shoot. Differences in shoot/root of the cultivars were also notable. Markedly different mean N intake rate among the sorghum cultivars was 108 μmol g−1 root dry wt. hr−1 in Bagdar and 53 μmol g−1 root dry wt. hr−1 in PU-7 and Redjanpur. Both relative accumulation rate of N and efficiency of biomass accumulation per unit N absorbed also differed appreciably among the cultivars. 相似文献
8.
The identification of genotypes having potential salt tolerance is an effective approach to solve the problems of saline soils.
Seed germination and seedling establishment are limiting factors in crop production. Seven wheat ( Triticum aestivum L.) and one Triticale (X Triticosecale Wittmak) genotypes were evaluated for salt tolerance at emergence and early seedling growth in solution culture with NaCl salinities up to 300 mM L−1 (electrical conductivity equals 27.6 dS m−1 ).
Seedling emergence was delayed by increasing NaCl in nutrient media. At 200 mM L−1 NaCl, the emergence percentages of wheat genotypes ranged between 68.7 % and 91.3 % after 7 days and 79.3 % and 98.7 % after 15 days. While at 300 mM L−1 , the emergence percentages of the wheat genotypes were 0.0 % after 7 days. After 15 days the emergence percent ranged between 24 % and 72 %. The emergence percent of the Triticale line was 88.7 after 7 days and 89.3 after 15 days at 200 mM L−1 , while it was 25.3 % and 84 % after 7 and 15 days, at 300 mM L−1 , respectively. Root and shoot dry weight were greatly reduced by increasing NaCl, however, the Triticale line showed less reduction in growth compared to the wheat genotypes. K+ , Ca2+ and Mg2+ were decreased with increasing salinity levels while Na+ content was decreased in the shoot tissues of wheat and Triticale genotypes. 相似文献
Seed germination and seedling establishment are limiting factors in crop production. Seven wheat ( Triticum aestivum L.) and one Triticale (X Triticosecale Wittmak) genotypes were evaluated for salt tolerance at emergence and early seedling growth in solution culture with NaCl salinities up to 300 mM L
Seedling emergence was delayed by increasing NaCl in nutrient media. At 200 mM L
9.
Phosphorus Accumulation and Translocation in Wheat as Affected by Cultivar and Nitrogen Fertilization 总被引：1，自引：0，他引：1
To improve nutrient management strategies in wheat more information is needed about the interaction effects among nutrients in their uptake and redistribution in the plants, in relation to different genotypes. Therefore, two bread ( T. aestivum L.) and two durum ( T. durum Desf.) winter wheat cultivars were grown in the field for 2 years (1986, 1987) in a silty-clay soil under different nitrogen (N) levels, in Northern Greece. Nitrogen at a rate of 150 kg ha−1 was applied before planting or 100 kg ha−1 before planting and then 50 kg ha−1 at early boot stage. Cultivar differences in phosphorus (p) concentration were observed only in vegetative parts but not in the grain. Maximum p accumulation was observed either at anthesis or at maturity. During grain filling dry matter and p accumulation in the grain followed almost the same pattern. Phosphorus translocation efficiency of the cultivars at the 2 years ranged from 70.7 to 84.3 % and the amount of p in the grain derived from translocation 52 to 100 %. Phosphorus translocation efficiency was weakly correlated with p content in grain only in 1986, while phosphorus harvest index (PHI) was positively correlated with harvest indst (HI) both years (r = 0.82** in 1986 and 0.75** in 1987). Nitrogen application mainly affected p accumulation of the cultivars via its effect on biomass production. The split N application promoted slightly the p uptake in 1987 and this resulted in the reduction of both the contribution of the translocated p to the grain and the efficiency of p utilization for total biomass. Results indicated that p accumulation and translocation and the efficiency of p utilization in wheat were mainly determined by the genotype in relation to environmental condition of growth. 相似文献
10.
Small, medium and large headsetts of a traditional ( Nine ) and an improved ( Alafua Sunrise ) cultivar of taro were grown for 33 days in pots in a screenhouse.
Differences between the cultivars were greatest in root growth where density of root primordia, number of primary roots and root surface area at the final harvest were 53, 82, and 60 % greater respectively in the improved over the traditional variety. Relative rate of leaf elongation and leaf appearance rate were about 30 % faster in the improved variety. Correlation between leaf area and root surface area was cultivar dependent.
Large headsetts produced more primary roots and a larger root surface area than small headsetts. They also produced 46 % more leaf area than small headsetts because of larger individual leaves, but not the rate of leaf appearance.
Dry matter and nitrogen content declined in petioles, remained relatively constant in corm and accumulated in new shoot and root during establishment. Losses of N were similar but accumulation was greater in new growth of Alafua Sunrise than Niue.
We conclude that differences in productivity between the improved and traditional cultivars used in this experiment are at least partly attributable to differences in rate of development of new shoot and root during establishment. Previously reported correlations between corm yield and size of planting material are probably due to large headsetts producing a greater area of leaf and root than small headsetts during early growth. 相似文献
Differences between the cultivars were greatest in root growth where density of root primordia, number of primary roots and root surface area at the final harvest were 53, 82, and 60 % greater respectively in the improved over the traditional variety. Relative rate of leaf elongation and leaf appearance rate were about 30 % faster in the improved variety. Correlation between leaf area and root surface area was cultivar dependent.
Large headsetts produced more primary roots and a larger root surface area than small headsetts. They also produced 46 % more leaf area than small headsetts because of larger individual leaves, but not the rate of leaf appearance.
Dry matter and nitrogen content declined in petioles, remained relatively constant in corm and accumulated in new shoot and root during establishment. Losses of N were similar but accumulation was greater in new growth of Alafua Sunrise than Niue.
We conclude that differences in productivity between the improved and traditional cultivars used in this experiment are at least partly attributable to differences in rate of development of new shoot and root during establishment. Previously reported correlations between corm yield and size of planting material are probably due to large headsetts producing a greater area of leaf and root than small headsetts during early growth. 相似文献
11.
D. G. Stout S. N. Acharya J. W. Hall K. Broersma 《Journal of Agronomy and Crop Science》1998,180(1):27-31
In British Columbia, Lucerne stand persistence is reduced by inadequate disease resistance, winter hardiness, or both. We evaluated the possibility that persistence could be improved by sowing mixtures of winter hardy and verticillium wilt (VW) resistant cultivars. Our hypothesis was that dry matter yield of mixtures of two Lucerne cultivars could be calculated simply from the proportion of each cultivar in the mixture and their yield in pure stand. A winter hardy cultivar, Beaver, was grown in mixtures with each of three VW (caused by Verticillium albo-atrum Reinke & Berthier) resistant cultivars (WL316, Sparta, or Barrier) in proportions of 0, 0.25, 0.5, 0.75, and 1.0. The yield of a mixture of two cultivars could be calculated from the proportion of each cultivar in the seed mixture and their yields in monoculture. In the absence of a winter where severe injury to Lucerne stands occurred, the VW-resistant cultivar Barrier yielded about 2 t ha−1 year−1 more than the more winter hardy Beaver. 相似文献
12.
V. Nenova M. Merakchiyska G. Ganeva E. Zozikova & S. Landjeva 《Journal of Agronomy and Crop Science》2009,195(3):197-203
Two wheat lines (TL3 and TL5) derived from selection for Cu tolerance among wheat – Aegilops sharonensis hybrids were compared when grown as hydroponics at zero (control), 10−6 and 10−5 m CuSO4 . The morphometric measurements showed that the line TL5 with a more inhibited root system under 10−6 m CuSO4 had a less inhibited shoot growth under 10−5 m CuSO4 as compared to TL3. The decreased maximum efficiency of photosystem II and the more pronounced trend towards increased catalase activity suggested that despite the better shoot growth, the leaves of TL5 were more functionally injured. The increased content of carotenoids at excess Cu and the higher peroxidase and catalase activities of TL3 in control plants might contribute to its better stress tolerance. While no significant changes in enzyme activities were found at 10−6 m Cu, at 10−5 m the activities tended to increase. Although the close values of free phenolics concentrations in control plants, at Cu excess their content was higher in TL5 compared to TL3. The free phenolics content in roots at 10−6 m Cu decreased, and although higher at 10−5 m Cu, it remained below the control in TL3, and above the control in TL5. From the obtained results TL3 emerged to be more tolerant to excess Cu than TL5. 相似文献
13.
探讨秧盘铺垫麻育秧膜对水稻秧苗生长发育的影响及其机理。以常规稻‘湘晚籼13’和杂交稻‘Y两优’1号为材料,研究了麻育秧膜的应用对水稻秧苗地上部生长发育和根系呼吸酶活性带来的变化。研究表明,与无膜对照处理相比,秧盘铺垫麻育秧膜处理的秧苗生物量,叶绿素含量,可溶性糖含量,硝态氮含量,伤流强度均得到了不同程度的提高;铺膜处理秧苗根系的整体呼吸代谢水平显著上升,乙醇脱氢酶(ADH)和苹果酸脱氢酶(MDH)活性和对照相比显著提高,乳酸脱氢酶(LDH)活性和对照相比无明显差异。‘湘晚籼13号’秧苗各项生理指标和‘Y两优1号’的品种间差异未达到显著水平。说明秧盘铺垫麻育秧膜对水稻秧苗的生长发育具有明显的改善作用。 相似文献
14.
M. Filek K. Pazurkiewicz-Kocot F. Dubert I. Marci&#;ska J. Biesaga-Koscielniak 《Journal of Agronomy and Crop Science》1993,171(4):243-250
Water stress was imposed by cessation of watering (CW) on bread wheats and, in some experiments two spelt wheats, during 9–17 days, starting at the 4–5 leaves stage. Main shoot foliar stages (MSS) were delayed by CW and the effect remained thereafter.
The presence of side tillers (intact or partly destroyed by heat or potassium iodide (KI) was not beneficial to main shoot foliar development after the end of CW. Emergence of tillers after the onset of CW was also delayed, but the effect was small if timing was expressed in MSS. Secondary tillers were the most sensitive to water shortage, their number, size and foliar stage were drastically reduced.
The two cultivars of spelt wheats were not less sensitive to CW than the bread wheat tested. 相似文献
The presence of side tillers (intact or partly destroyed by heat or potassium iodide (KI) was not beneficial to main shoot foliar development after the end of CW. Emergence of tillers after the onset of CW was also delayed, but the effect was small if timing was expressed in MSS. Secondary tillers were the most sensitive to water shortage, their number, size and foliar stage were drastically reduced.
The two cultivars of spelt wheats were not less sensitive to CW than the bread wheat tested. 相似文献
15.
采用室内盆栽接种法,测定了全蚀病菌?禾顶囊壳小麦变种对小麦初生根与次生根的侵染性。结果表明,小麦初生根易感全蚀病菌,是禾顶囊壳小麦变种的主要侵染部位,而次生根相对抗病,其发病轻重与次生根的生理年龄和小麦品种的抗病性有关。小麦8793-8较76120抗禾顶囊壳小麦变种的侵染。 相似文献
16.
Genetic relationships and diversity among Tibetan wheat, common wheat and European spelt wheat revealed by RAPD markers 总被引：13，自引：0，他引：13
An endemic hexaploid wheat found in Tibet, China was taxonomically classified as a subspecies in common wheat, i.e. Triticum
aestivum ssp. tibetanum. Seven accessions of the Tibetan wheat, 22 cultivars of common wheat and 17 lines of spelt wheat were
used for RAPD analysis to study the genetic relationships of the Tibetan wheat with common wheat and spelt wheat, and to assess
the genetic diversity (GD) among and within the taxa. RAPD polymorphism was found to be much higher within spelt wheat and
the Tibetan wheat than within common wheat. The GD value between the Tibetan wheat and common wheat is lower than that between
the Tibetan wheat and spelt wheat. The result of cluster analysis showed that the 46 genotypes were distinctly classified
into two groups. Group 1 included all European spelt wheat lines, while group 2 includes all Chinese common wheat and the
Tibetan wheat accessions. However, the Tibetan wheat was substantially differentiated from Chinese common wheat at a lower
hierarchy. Our results support an earlier classification of the Tibetan wheat as a subspecies in common wheat. European spelt
wheat and the Tibetan wheat showed much higher genetic diversity than Chinese common wheat, which could be used to diversify
the genetic basis for common wheat breeding.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
Dry Matter Production of Spelt ( Triticum spelta L.) and Wheat ( Triticum aestivum L.) under Different Environmental Conditions in the Field
The primary aim of our work was to obtain information regarding the germination characteristics of spelt under different environmental conditions in field experiments, and to trace possible differences between spelt and wheat, with regard to crop production. For the present study two spelt varieties ( Ostro/Rouquin) and two wheat varieties ( Arina/Probus) were used. In addition the spelt cultivars Altgold, Oberkulmer and Hercule were included in some of the experiments. To obtain information on the influence of the glumes, spelt was planted in the hulled (SP +) and dehulled (SP-) form.
Field emergence of spelt SP- was up to 40 % lower than that of SP+, Under water logged soil, the percentage of germination was higher for spelt SP+ than for wheat.
Spelt produced more tillers per plant than wheat. However, tiller reduction was also higher for spelt so finally both species had similar numbers of ears per plant. Plants with a high tiller production might be more flexible in response to unfavourable growing conditions.
Grain yield of spelt and wheat was developed in different ways. Spelt produced fewer but larger kernels per ear, whereas wheat produced more but smaller kernels. In 1986 grain yield was up to 20 % higher in wheat than in spelt. In 1987, an unfavourable year for cereal crop production in marginal areas, grain yield was higher for spelt than for wheat. For the farmer, the "husked" form of spelt is economically important. This was equal or higher than the grain yield of wheat in both years.
The high germination rate under unfavourable conditions, in combination with a high tillering capacity and the production of large kernels appear to be the major reason for the stable yielding ability of spelt. 相似文献
The primary aim of our work was to obtain information regarding the germination characteristics of spelt under different environmental conditions in field experiments, and to trace possible differences between spelt and wheat, with regard to crop production. For the present study two spelt varieties ( Ostro/Rouquin) and two wheat varieties ( Arina/Probus) were used. In addition the spelt cultivars Altgold, Oberkulmer and Hercule were included in some of the experiments. To obtain information on the influence of the glumes, spelt was planted in the hulled (SP +) and dehulled (SP-) form.
Field emergence of spelt SP- was up to 40 % lower than that of SP+, Under water logged soil, the percentage of germination was higher for spelt SP+ than for wheat.
Spelt produced more tillers per plant than wheat. However, tiller reduction was also higher for spelt so finally both species had similar numbers of ears per plant. Plants with a high tiller production might be more flexible in response to unfavourable growing conditions.
Grain yield of spelt and wheat was developed in different ways. Spelt produced fewer but larger kernels per ear, whereas wheat produced more but smaller kernels. In 1986 grain yield was up to 20 % higher in wheat than in spelt. In 1987, an unfavourable year for cereal crop production in marginal areas, grain yield was higher for spelt than for wheat. For the farmer, the "husked" form of spelt is economically important. This was equal or higher than the grain yield of wheat in both years.
The high germination rate under unfavourable conditions, in combination with a high tillering capacity and the production of large kernels appear to be the major reason for the stable yielding ability of spelt. 相似文献
18.
L. Song D.‐W. Zhang F.‐M. Li X.‐W. Fan Q. Ma N. C. Turner 《Journal of Agronomy and Crop Science》2010,196(5):323-335
Competition for water generates a classic aspect of the tragedy of the commons, the ‘race for fish’, where crops must allocate more resource to acquisition of the limiting resource than is optimal for crop yield allocation. A pot experiment using a simple additive (target–neighbour) design was conducted to examine the above‐ground and below‐ground growth of three spring wheat (Triticum aestivum L.) cultivars when grown alone and in mixtures at three levels of water availability. The effects of competition and water availability were compared by observing patterns of growth, biomass allocation and below‐ground outcomes. Competitive interactions were investigated among cultivars ‘HST’, ‘GY602’ and ‘LC8275’, target plant of each cultivar grown without neighbouring plants are referred to herein as control plant and one target plant of each cultivar sown surrounded either by same or another cultivar as intra‐ or inter‐cultivar competition. Competitive ability was assessed as the response ratio (lnRR) between the target plant surrounded by six other plants and the target plant in isolation. Our results showed that the cultivar ‘HST’, released over a century ago, produced a higher biomass and grain yield than the more recently released cultivars ‘LC8275’ and ‘GY602’ when grown as isolated plants with sufficient water supply. However, competition for resources from neighbours led to target plant biomass and grain yield being significantly reduced relative to controls in all three cultivars, particularly in ‘HST’. When subjected to intra‐cultivar competition, the two recently released cultivars ‘LC8275’ and ‘GY602’ had higher grain yields and water use efficiency for grain than ‘HST’ in all three water regimes. The landrace ‘HST’ had better and significantly linear relationships between biomass and biomass allocation, root length and specific root length, whereas the recent and modern cultivars had much more water‐related species‐specific changes in root morphology and allocation patterns. These results suggest that crop traits that influence competitive ability, such as biomass allocation to roots and root plasticity in response to drought have changed in modern wheat cultivars because of breeding and selection. 相似文献
19.
M. El.-D. Ibrahim S. Prochézka V. Borkovec 《Journal of Agronomy and Crop Science》1988,160(5):339-344
The transport and distribution of 14C- sucrose and 14C- BA were studied in internode segments with ear of two winter wheat cultivars with a different mass of kernels in the period of kernel formation. While M C-sucrose was transported and accumulated intensively in the developing ear, 14C- BA was transported much less and only a small part of it was found in the ear. With the ear development the accumulation of both 14 C-sucrose and 14 C-BA in the ear increased but the 14 C-BA distribution pattern (ratio of the internode/kernel and the rest of the ear) did not change significantly. In the period of one to two weeks after anthesis the accumulation of 14 C-sucrose and 14 C-BA was higher in the kernels of the Slavia cv., i.e. in the cultivar with a higher mass of kernels. 相似文献
20.
J. Ellen 《Journal of Agronomy and Crop Science》1990,164(3):174-183
A field study was conducted on the winter wheat cultivars Arminda and Okapi , using two seed rates (80 and 160 kg/ha) and three N applications (40, 80 and 120 kg/ha).
The cultivars did not differ in total dry matter production but did differ in grain yield. The difference in grain yield was mainly attributable to a higher harvest index (HI).
Increased plant density reduced HI; it resulted in more shoots per m2 , but in a lower grain yield. The reduction in grain yield was caused by fewer kernels per ear and a lower 1000-grain weight in both cultivars.
A higher rate of N increased total dry matter production and grain yield, except in Okapi at the high plant density. The number of kernels per ear increased, but 1000-grain weight fell.
The higher the N applications, the higher the N-content of the roots was.
Total N yield was greater in Arminda than in Okapi. The cultivars differed in the amount of nitrogen they took up after anthesis.
The content of water-soluble carbohydrates (WSC) differed between the cultivars, N treatments and growth stages. Carbohydrate formed before anthesis accounted for 23 % of Arminda's grain yield and for 10 % of Okapi's grain yield.
The content of cell-wall constituents (CWC) depended on cultivar, growth stage and the rate of the N dressing. Differences in CWC were more pronounced in Arminda than in Okapi. During leaf, stem and ear development there was a strong increase in content and amount of CWC. Concomitantly, WSC decreased. This implies that a large consumption of WSC is necessary for the formation of CWC. The competition for the WSC, necessary for CWC and shoot and ear development influences kernel initiation. Per unit of dry matter Okapi contained more CWC than Arminda. This was not in agreement with differences in straw sturdiness. 相似文献
The cultivars did not differ in total dry matter production but did differ in grain yield. The difference in grain yield was mainly attributable to a higher harvest index (HI).
Increased plant density reduced HI; it resulted in more shoots per m
A higher rate of N increased total dry matter production and grain yield, except in Okapi at the high plant density. The number of kernels per ear increased, but 1000-grain weight fell.
The higher the N applications, the higher the N-content of the roots was.
Total N yield was greater in Arminda than in Okapi. The cultivars differed in the amount of nitrogen they took up after anthesis.
The content of water-soluble carbohydrates (WSC) differed between the cultivars, N treatments and growth stages. Carbohydrate formed before anthesis accounted for 23 % of Arminda's grain yield and for 10 % of Okapi's grain yield.
The content of cell-wall constituents (CWC) depended on cultivar, growth stage and the rate of the N dressing. Differences in CWC were more pronounced in Arminda than in Okapi. During leaf, stem and ear development there was a strong increase in content and amount of CWC. Concomitantly, WSC decreased. This implies that a large consumption of WSC is necessary for the formation of CWC. The competition for the WSC, necessary for CWC and shoot and ear development influences kernel initiation. Per unit of dry matter Okapi contained more CWC than Arminda. This was not in agreement with differences in straw sturdiness. 相似文献