播期对麦茬大豆生长发育特点及产量形成规律的影响

探讨了播期对麦茬复种大豆生长发育特点和产量构成各因素的影响。结果表明,在栽培条件相同的情况下,除受品种本身丰产潜力等因素影响外,播种期的早晚是影响麦茬大豆产量的主要因素。要想提高春麦区麦茬复种大豆产量和品质,必须抢时早播,为创造高产提供较充余的生育时间。     

Integrating the effects of climate and plant available soil water holding capacity on wheat yield

In the Mediterranean farming systems of the Western Australian wheatbelt, crop yields are influenced primarily by the amount and distribution of rainfall and the soil's capacity to hold moisture. The wheatbelt's growing season rainfall varies in the range of 200–400 mm (average) and the plant available water holding capacity (PAWC) of soils is generally in the 40–140 mm range. The grain yield of wheat is sensitive to this combination of small rainfall and small storage capacity.In this study, we explore the relationship between yield and PAWC using a combination of simulation modelling and analysis of field data. Crop yields and soil properties were monitored in detail at 17 locations (PAWCs 43–131 mm) across six seasons (1997–2005). Crop yields were also simulated using the APSIM crop simulator (RMSE = 311 kg/ha) to evaluate the long-term relationship between crop yield and plant available water capacity using 106 years of historical climate data.The relationship between crop yield and PAWC varied with season, and two important factors emerged: (1) for PAWC < 65 mm, there was a linear relationship with crop yields that ranged from 17 kg/ha/mm to 58 kg/ha/mm of PAWC across seasons; (2) for PAWC 65–131 mm the crop yield response to PAWC ranged from 11.5 kg/ha/mm in 45% of seasons to no response.The impact of PAWC on crop yield was reduced in seasons with late rainfall, and magnified in seasons with reduced rainfall late in the growing season. Six distinct season types with different yield–PAWC relationships are identified and season-specific management strategies that exploit within-field variation in PAWC are developed to manage the spatial variation of PAWC in a field.     

Tolerance of winter wheat (Triticum aestivum L.) to pre-emergence and post-emergence application of saflufenacil

Saflufenacil is a new herbicide being developed for pre-plant burndown for non-selective removal of broadleaf weeds and pre-emergence (PRE) broadleaf weed control in field crops, including maize, soybean, sorghum and wheat. As part of studying the potential use pattern of this herbicide, four field studies were conducted in 2006 and 2007 at Concord, northeast Nebraska, to determine winter wheat tolerance to PRE and post-emergence (POST) applications of saflufenacil. The fall POST applications were conducted at the 2–3 leaf stage (5 cm height) whereas the spring POST and tank-mixes studies were sprayed at the 4th node stage (40 cm height) of crop. Dose-response curves based on log-logistic model were used to determine the ED (effective dose) values of saflufenacil for visual ratings of crop injury and relative yield. There was no crop injury or yield reduction with PRE applied saflufenacil dose of up to 400 g a.i. ha⁻¹. However, there was significant crop injury in the POST applications in the fall (up to 95%) and in the spring (up to 67%). There was also yield reduction of as much as 66% in the fall and 58% in the spring POST applications. Addition of adjuvants also increased crop injury levels. For example, at 14 days after treatment in the fall applications, about 5% visual crop injury (ED₅) was evident with 82, 67 and 10 g a.i. ha⁻¹ of saflufenacil compared with 51, 30 and 11 g a.i. ha⁻¹ in the spring, with no adjuvant, or non-ionic surfactant (NIS), or crop oil concentrate (COC), respectively. Saflufenacil at half the proposed used dose of 25 g a.i. ha⁻¹ was safe to mix with the currently used POST herbicides of wheat with no visible crop injury and yield reduction. PRE applications of saflufenacil would be safe for use in winter wheat; however, the POST application of saflufenacil alone or with the adjuvant NIS or COC produces unacceptable injury and yield loss. These results are similar to the proposed PRE use pattern of saflufenacil. In addition, the proposed label does not suggest the POST use of saflufenacil in winter wheat, or any other cereal crops, which is similar to what we have concluded from this study.     

Assessing yield losses caused by the harvester ant Messor barbarus (L.) in winter cereals

Harvester ants from the species Messor barbarus (L.) are important seed predators in semi-arid cereal fields of NE Spain, and can contribute substantially to weed control. However, occasionally they harvest newly sown crop seeds at sowing in autumn, or ripe cereal grains close to harvest in summer, causing yield losses.A preliminary study was conducted in 34 commercial winter cereal fields to measure yield loss, and to identify factors that influence it. The area affected by ants was measured ten days prior to the anticipated harvest date. Ant colony size, nest density, crop height, weed densities and temperatures at sowing were assessed.At sowing, harvester ants did not cause yield losses (0.2% of potential yield on average). At harvest, yield losses were generally low as well (0.6%) although occasionally higher losses were recorded (max. 9.2%). Yield losses significantly increased with increasing nest density, nest size and with number of years of no-till. The results of this study show that in 2009 yield losses caused by M. barbarus were insignificant and more than offset by the benefits provided by the destruction of weed seeds.     

Tolerance of spring barley (Hordeum vulgare L.), oats (Avena sativa L.) and wheat (Triticum aestivum L.) to saflufenacil

Saflufenacil is a new herbicide being developed by BASF for pre-emergence application for broadleaved weed control in maize and other crops. Three field studies were conducted in Ontario, Canada over a 2-year period (2006 and 2007) to evaluate the tolerance of spring cereals (barley, oats, and wheat) to pre-emergence and post-emergence applications of saflufenacil at 50 and 100 g ai ha⁻¹. Saflufenacil pre-emergence caused minimal visible injury (1% or less) at 3, 7, 14 and 28 days after emergence and had no adverse effect on plant height or yield of barley, oats, and wheat. Saflufenacil plus the surfactant Merge (1% v/v) applied post-emergence caused as much as 76, 60, 52 and 35% visible injury in spring cereals at 3, 7, 14 and 28 DAT, respectively. Injury with saflufenacil plus Merge applied post-emergence decreased over time and was generally greater as dose increased. Saflufenacil plus Merge applied post-emergence reduced plant height by as much as 16% and reduced yield of spring barley and wheat by 24 and 13%, respectively, but had no effect on the yield of spring oats. Based on these results, saflufenacil applied pre-emergence at the proposed dose can be safely used in spring planted barley, oats and wheat; however, the post-emergence application of saflufenacil results in unacceptable injury and yield loss. These results are consistent with the proposed pre-emergence use pattern for saflufenacil.     

Response of spring planted barley (Hordeum vulgare L.), oats (Avena sativa L.) and wheat (Triticum aestivum L.) to mesotrione

There is little information on the response of spring planted barley (Hordeum vulgare L.), oats (Avena sativa L.) and wheat (Triticum aestivum L.) to mesotrione under Ontario environmental conditions. Four field studies were conducted in Ontario, Canada over a two-year period (2008 and 2009) to evaluate the sensitivity of spring planted cereals (barley, oats, and wheat) to pre-emergence (PRE) and post-emergence (POST) applications of mesotrione at 50, 100, and 150 g ai ha⁻¹. Mesotrione applied PRE caused minimal visible injury at 3, 7, 14 and 28 days after emergence (DAE) and had no adverse effect on plant height or yield of barley, oats and wheat. Mesotrione applied POST caused as much 11% injury and reduced plant height as much as 6% in spring planted cereals. Injury was higher in wheat compared to barley or oats. Mesotrione applied POST had no adverse effect on the yield of barley or oats but decreased the yield of wheat as much as 14%. Based on this study, mesotrione applied PRE at 50, 100 or 150 g ai ha⁻¹ can be safely used in spring planted barley, oats, and wheat. Mesotrione applied POST at the proposed dose of 50, 100 or 150 g ai ha⁻¹ can also be safely used in spring planted barley and oats. However, mesotrione applied POST results in unacceptable injury in spring planted wheat.     

Relation between susceptibility to wheat bug attack and digestibility of glutenin

Two trials of winter wheat, embracing 17 varieties and 4 breeding lines, harvested in 2003 from locations in the semi-arid eastern part of Austria, were severely infested by naturally occurring bugs (Eurygaster sp.). In these trials bug damage was determined by selecting and weighing the infested kernels. Glutenin degradation was determined by the addition of meal from bug-infested kernels to meal from sound kernels from the same trials to reach sample mixtures representing a degree of bug attack of 6%. These mixtures and blanks made from sound meal were incubated in buffer solution (pH=8.5) at 37 °C for 45 min. The reduction in glutenin content due to the activity of bug proteinases was measured by RP-HPLC analysis of the glutenin fraction and comparison of the results of damaged and sound samples. The results showed good correlations between the degree of bug attack and the digestibility of glutenin (location 1: R²=0.69, P<0.01; location 2: R²=0.36, P<0.01). Both parameters seem to be variety specific. The determination of digestibility of glutenins was repeated in material from a trial harvested in 2005 in another location in eastern Austria, with eight varieties being the same as used in the 2003 trials. A correlation with the degree of bug attack in location 1 from the 2003 harvest was found again (R²=0.61, P<0.01).     

氮磷钾配施对大豆产量的影响

在两点进行"3414"肥料试验,通过肥料效应函数拟合,研究了氮磷钾肥不同比例配施对大豆产量的影响。结果表明:氮磷钾肥配施能够显著提高大豆产量,单株粒数受磷施用量影响较大,百粒重受氮磷施用量影响较大。推荐的高产施肥量为:N75～85kg/hm2、P2O565～70kg/hm2、K2O45～55kg/hm2,比例为:N:P2O5:K2O=1.60:1.35:1;经济施肥量为:N65～75kg/hm2、P2O545～50kg/hm2、K2O30～40kg/hm2,比例为:N:P2O5:K2O=2:1.36:1。     

追肥结束期对烤烟生长发育及产质量的影响

以K326为材料，在南昌进行了3个追肥结束期对烤烟生长发育和产质量影响的研究。试验结果表明，追肥结束期早(栽后25d)有利于提高烟株的株高、总叶数、有效叶数、单株叶面积及上部10叶的叶面积和产量；追肥结束期中(栽后35d)有利于提高上等烟比例、均价和产值；追肥结束期晚(栽后45d)有利于提高平均单叶重及上中等烟比例。认为烤烟追肥结束期以栽后25～35d为宜。     

甘蓝型油菜产量性状的遗传及相关与通径分析

以7个不育系和4个恢复系为材料,采用增广NCⅡ交配设计进行油菜4个产量性状的遗传及6个产量构成因子间的相关与通径分析,结果显示：(1)油菜千粒重的遗传符合加性—显性模型,单株有效角果数、角粒数和单株粒重的遗传符合加性—显性—上位性模型。(2)育种上应在保持较多角粒数的前提下,提高千粒重,适当控制单株有效角果数,减少分枝尤其是二次分枝进而提高单产。     

Effect of temperature, time and wheat gluten moisture content on wheat gluten network formation during thermomolding

A plastic-like material can be obtained by thermomolding wheat gluten protein which consists of glutenin and gliadin. We studied the effect of molding temperature (130-170 °C), molding time (5-25 min) and initial wheat gluten moisture content (5.6-18.0%) on the gluten network. Almost no glutenins were extractable after thermomolding irrespective of the molding conditions. At the lowest molding temperature, the extractable gliadin content decreased with increasing molding times and moisture contents. This effect was more pronounced for the α- and γ-gliadins than for the ω-gliadins. Protein extractabilities under reducing conditions revealed that, at this molding temperature, the cross-linking was predominantly based on disulfide bonds. At higher molding temperatures, also non-disulfide bonds contributed to the gluten network. Decreasing cystine contents and increasing free sulfhydryl and dehydroalanine (DHA) contents with increasing molding temperatures and times revealed the occurrence of β-elimination reactions during thermomolding. Under the experimental conditions, the DHA derived cross-link lanthionine (LAN) was detected in all gluten samples thermomolded at 150 and 170 °C. LAN was also formed at 130 °C for gluten samples containing 18.0% moisture. Degradation was observed at 150 °C for samples thermomolded from gluten with 18.0% moisture content or thermomolded at 170 °C for all moisture contents.     

Phenotypic plasticity of yield and phenology in wheat, sunflower and grapevine

This paper focuses on the interaction between genotype and environment, a critical aspect of plant breeding, from a physiological perspective. We present a theoretical framework largely based on Bradshaw's principles of phenotypic plasticity (Adv. Gen. 13: 115) updated to account for recent developments in physiology and genetics. Against this framework we discuss associations between plasticity of yield and plasticity of phenological development. Plasticity was quantified using linear models of phenotype vs environment for 169 wheat lines grown in 6 environments in Mexico, 32 sunflower hybrids grown in at least 15 environments in Argentina and 7 grapevine varieties grown in at least 14 environments in Australia.In wheat, yield ranged from 0.6 to 7.8 t ha⁻¹ and the range of plasticity was 0.74–1.27 for yield and 0.85–1.17 for time to anthesis. The duration of the post-anthesis period as a fraction of the season was the trait with the largest range of plasticity, i.e. 0.47–1.80. High yield plasticity was an undesirable trait as it was associated with low yield in low-yielding environments. Low yield plasticity and high yield in low-yielding environments were associated with three phenological traits: early anthesis, long duration and low plasticity of post-anthesis development.In sunflower, yield ranged from 0.5 to 4.9 t ha⁻¹ and the range of plasticity was 0.72–1.29 for yield and 0.72–1.22 for time to anthesis. High yield plasticity was a desirable trait as it was primarily associated with high yield in high-yielding environments. High yield plasticity and high yield in high-yielding environments were associated with two phenological traits: late anthesis and high plasticity of time to anthesis.In grapevine, yield ranged from 1.2 to 18.7 t ha⁻¹ and the range of plasticity was 0.79–1.29 for yield, 0.86–1.30 for time of budburst, 0.84–1.18 for flowering, and 0.78–1.16 for veraison. High plasticity of yield was a desirable trait as it was primarily associated with high yield in high-yielding environments. High yield plasticity was associated with two phenological traits: plasticity of budburst and plasticity of anthesis.We report for the first time positive associations between plasticities of yield and phenology in crop species. It is concluded that in addition to phenology per se (i.e. mean time to a phenostage), plasticity of phenological development merits consideration as a distinct trait influencing crop adaptation and yield.     

宁夏小麦新品种特性及其与宁春4号的比较分析

本文对5份宁夏小麦新品种的产量稳定性、气象条件适应性、品质性状,结合当地的气象资料与宁春4号进行对比分析.结果表明,宁春39号、宁春38号为高产稳定品种;宁春40号、宁春37号为高产小稳定品种;宁春35号为低产不稳定品种.认定宁春39号、宁春38号为优势品种、宁春40号,宁春37号品种一般,适宜推广,宁春35号为劣势品种,不适宜推广.     

A simple model for chickpea development, growth and yield

Chickpea (Cicer arietinum L.) yield is unstable and low in major producer countries. A robust crop model can assist in evaluation of possible genetic improvements and cultural management practices to improve yield. The objectives of this study were to develop and test a chickpea simulation model that could be used across a wide range of environments. This model simulates phenological development, leaf development and senescence, mass partitioning, plant nitrogen balance, yield formation and soil water balance. Responses of crop processes to environmental factors of solar radiation, photoperiod, temperature, nitrogen and water availability, and genotype differences were included in the model. The model uses a daily time step and readily available weather and soil information. The model was tested using independent data from a wide range of growth and environmental conditions. In most cases, simulated grain yield were similar to observed yield (ranging from 20 to 379 g m⁻²) with a root mean square root of 26 g m⁻² (15% of average measured yield). It was concluded that the model generality, i.e., constant parameters for genotypes across locations, and applicability to a wide range of environmental conditions factors made this model especially useful.     

Physio-morphological Studies of F1 Hybrids in Rice (Oryza sativa L.): Photosynthetic ability and yield

Summary

Photosynthetic ability in terms of CO₂ exchange rate and leaf area, dry matter accumulation (dry weight) and other important growth components along with yield and yield contributing characters in two F₁ hybrids of Akebono × Chiyonishiki (A × C) and Zenith × Akebono (Z × A) were studied. The photosynthetic rate at the flowering stage was lower than that at the panicle initiation stage in all the inbred parent cultivars and F₁ hybrids. Heterosis in photosynthetic rate was higher at the panicle initiation stage than that at the flowering stage. Pre-anthesis leaf area in the F₁ hybrid was significantly larger than that in the parent cultivars. However, the post- anthesis decline in leaf area was more rapid in the F₁ hybrids than in the parent cultivars and its magnitude was the highest in the F₁ hybrid of Z × A which was tall having long and curved panicles. Pre-anthesis dry matter accumulation in both hybrids was significantly higher in the F₁ plants than the parental cultivars, but post-anthesis dry matter accumulation in the F₁ hybrid was lower than the mid-parental value in Z × A. The degree of heterosis in grain yield varied with the hybrid combination, an average heterosis being 1.03. Heterosis in grain yield was closely associated with heterosis in harvest index.     

Weed control and wheat (Triticum aestivum L.) yield under application of 2,4-D plus carfentrazone-ethyl and florasulam plus flumetsulam: Evaluation of the efficacy

Three field experiments were conducted at the research fields of Plant Protection Research Institute, Iran, at different locations in 2004–2005 to study the efficacy of different broadleaved herbicides to control weeds in wheat. Treatments were the full-season hand weeded and weed-infested controls, and post-emergence applications of florasulam plus flumetsulam at 8.75, 10.50, and 12.25 g a.i./ha, 2,4-D plus carfentrazone-ethyl at 210, 245, 280, and 490 g a.i./ha, bromoxynil plus MCPA at 75, 100, and 150 g a.i./ha, 2,4-D at 560, 720, and 1120 g a.i./ha, tribenuron methyl, and 2,4-D plus MCPA. Herbicides were applied at wheat tillering stage. Naturally occurring broadleaved weed populations were used in experiments. Results indicated that bromoxynil plus MCPA at 150 g a.i./ha, 2,4-D plus MCPA, and 2,4-D plus carfentrazone-ethyl at 490 g a.i./ha were the best options to control weeds. Bromoxynil plus MCPA at 150 g a.i./ha and 2,4-D plus MCPA also resulted in the highest wheat yield. Overall, it could be concluded that rotational application of bromoxynil plus MCPA at 150 g a.i./ha, 2,4-D plus MCPA, and 2,4-D plus carfentrazone-ethyl at 490 g a.i./ha would be the best option to achieve satisfactory weed control, high grain yield and prevention of evolution of herbicide-resistant weeds.     

ClayF缓释复肥对小麦生长发育的影响

ClayF缓释复肥是一种包含丰富中、微量元素的缓释粘土矿物包膜肥料,具有多种生物活性.盆栽试验结果表明:红壤旱土施用适量的ClayF缓释复肥可有效提高小麦的根重、株高、有效分蘖、穗长、实粒数、千粒重和地上部分干重,籽粒产量比对照增加12%.适量的ClayF缓释复肥同时能增强小麦对氮、磷、钾养分的吸收,促进氮、磷、钾养分向小麦籽粒转运.     

密度和施肥水平对双低油菜苏油1号产量及分枝习性的影响

密度和施肥水平两因子对苏油1号产量及分枝习性影响的研究结果表明：（1）移栽11．25万株/hm2，施纯氮270kg/hm2是适宜苏油1号的种植密度和施肥处理，产量达到3452.0kg/hm2.(2)产量结构因子以单位面积有效角果数对产量的影响较大，其次为千粒重和每角粒数。（3）随密度和施氮量增加，单位面积有效果数呈先增后减的趋势，千粒重与施氮量关系密切，但过量施氮则降低千粒重，（4）单位面积为枝数多，分枝角果数多和分枝籽粒多是苏油1号的高产表现。     

Mute swan grazing on winter crops: estimation of yield loss in oilseed rape and wheat

Yield loss due to grazing by mute swans was measured on two fields each of autumn-sown oilseed rape and winter wheat, located in three regions of the UK. Using a paired plot design, a 33.7% reduction in yield (total dry weight of seed) and a 12.1% reduction in the thousand-seed weight was measured in the rape field subjected to the highest grazing intensity. No significant yield loss was measured in the other three fields. Yield loss was related to: (i) the timing of the onset of grazing, and (ii) the duration of grazing (both estimated from counts of mute swan droppings). Management measures which delay the onset of grazing and/or reduce the duration of grazing are therefore likely to reduce yield loss.     

Grain yield,starch, protein,and nutritional element concentrations of winter wheat exposed to enhanced UV-B during different growth stages

In order to alleviate the damage of UV-B on plants, it is important to determine at which growth stages are plants more sensitive to enhanced UV-B. The objective of the study was to evaluate the effects of UV-B on wheat yield and quality during different growth stages. Enhanced UV-B during heading, flowering and the whole growth stages (UCK, from seedling to grain filling) decreased yield by 6.6, 4.4 and 9.6%, respectively. Protein content in grain was decreased by enhanced UV-B during flowering and UCK over the control. Amylose, amylopectin and total starch content were not affected by UV-B treatments. UCK treatment resulted in a decrease of nitrogen (N), phosphorus (P) and iron (Fe) concentrations, while zinc (Zn) and manganese (Mn) concentrations increased. Enhanced UV-B during tillering, heading and flowering stages reduced Fe concentration, but increased Mn, copper (Cu) and Zn (except for flowering) concentrations. The results indicated that the changes in wheat yield and quality induced by enhanced UV-B during the whole growth stage were probably from the effects of UV-B radiation during heading and flowering stages. Therefore, to better defend the damage of UV-B to wheat, some methods should be undertaken during heading and flowering stages.