Der Einfluss der Reifedifferenz von Korn zu Restpflanze auf den optimalen Erntezeitpunkt und die standortgerechte Sortenwahl von Energie- und Silomais

Maize production trials carried out in eastern middle of Germany from 1999–2008 were used for statistical analysis of the optimum date for silage maize ripeness. The Knowledge about difference in ripeness between grain and residual plants at the harvest were used for exactly choice of cultivar under drought conditions for silage and energy maize. The Silage maize Ripeness Index (the ratio of dry matter content of maize grains to dry matter content of residual plants) is more suitable for the leading of plant development, the determination of harvest date and the choice of cultivar as the dry matter content of the plant. The analysis is cheaper as well as not so material and time-consuming with a better financially results in food-, milk- and methane production in comparison to the dry matter content of the silage maize of different hybrid maize populations and environments. Ensilage optimum and yield maximum correspond with the physiological ripeness of silage maize and are close to the grain dry matter content of 64%, to the dry matter content of starch of 33% and a ripeness index from 2.55 to 2.9 for parameter of quality and quantity. Only under these conditions it is possible to reach the optimal ripeness of 33 to 35% in the whole plant silage maize. But under suboptimal conditions the harvest is carried out, if SRI had a maximal value. In dependence on the Silage maize Ripeness Index (SRZ) and (SRI) parameters of silage and energy maize were predicted differential development of ripeness and yield. The aims of silage and energy maize are similar. The Silage maize Ripeness Index (SRI) is, for whole plant maize, better than the Whole Plant Maize Ripeness Index (SRZ) for the choice of a hybrid in Germany. The dry matter content of grain in interaction with the dry matter of residual plants are better than dry matter content of the whole plant maize as ripeness indicator in the production of silage and energy maize at the harvesting time. SRI is also universal suitable for use as a standard in scientific trials and for better characteristic of cultivar types and environmental influence.     

Energie zum richtigen ERNTE-Zeit-Punkt bei Optimierung von Qualität, Ertrag, Produktsicherheit und Umweltverträglichkeit im Siliermaisanbau durch Dynamische ReifeAnalyse (DRA)

Maize production trials carried out in eastern middle of Germany from 1999 to 2009 were used for statistical analysis of the optimum date for silage maize ripeness. The knowledge about difference in ripeness between grain and residual plants at the harvest were used for exactly choice of cultivar under drought conditions for silage and energy maize: The Silage maize Ripeness Index (the ratio of dry matter content of maize grains to dry matter content of residual plants) is more suitable for the leading of plant development, the determination of harvest date and the choice of cultivar as the dry matter content of the whole plant. The analysis is cheaper as well as not so material and time-consuming with the better financially results in feed-, milk- and methane production in comparison to the dry matter content of the silage maize of different hybrid maize populations and environments. Basically, the harvest of silage maize to be carried out at the maximum possible ripeness index in all years, on every site, regardless of the variety to perform their silage maize ripeness number (SRZ), the heat sum and the calendar. The requirements for the varieties in the silo and energy maize are identical. The phenological ensilage optimum and yield maximum correspond with the physiological ripeness of silage maize and are close to the grain dry matter content of 63% and a ripeness index from 2.6 to 2.9 depending on quality and yield parameters. The maximum ripeness on the basis of SRI from greater than 2.9 at physiological ripeness grain to be exceeded. Only under these conditions it is possible to reach the optimal ripeness of 30–35% in the whole plant silage maize (22–24% dry matter in the stover). The wide ripeness ratio between grain and stover is multifunctional guarantor for the better plant health, for example with regard to the zearalenone and carotene content, the resource efficiency of fertilizer-N in accordance with the yield-related N denials and soil stocks in N as well as basic product safety and sustainability of the procedure of silage maize. The Silage maize Ripeness Index (SRI) is, for whole plant maize, better than the Silage maize Ripeness Number (SRZ) for the choice of a hybrid in Germany. The dry matter content of grain in relation with the dry matter of residual plants are better than dry matter content of the whole plant maize as ripeness indicator in the production of silage and energy maize at the harvesting time. SRI is also universal suitable for use as a standard in scientific trials and for better characteristic of cultivar types and environmental influence universally appropriate and multifunctional.     

Produktsicherheit bei Silomais durch optimiertes Reifemanagement

Maize production trials carried out in Germany from 1999–2004 were used for statistical analysis of the optimum date for silage maize ripeness. The Silage maize Ripeness Index (the ratio of dry matter content of maize grains to dry matter content of stover) is more suitable for the determination of harvest date, yield maximum and silage maize quality as the dry matter content of the plant. The analysis is cheaper as well as less material and time-consuming in comparison to the dry matter content of the silage maize of different hybrid maize populations and environments. Ensilage optimum and yield maximum almost correspond to the physiological ripeness of silage maize and are close to the grain dry matter content of 60–65%, to the dry matter content of stover under 24% and a ripeness index from 2.5 and higher. Recently, the silage maize harvest depends on dry matter content of maize plants. This can result in grain ripening rates less than 55 % and low starch as well as energy contents. The dry matter content of the silage maize is at a certain ripeness of grain and/or of starch only expression of aging of the stover. The stover has, together with the grain, a strong influence on the dry matter content of the whole plant maize. On these locations the crop should be harvested before reaching the optimum of ripeness and yield maximum. Therefore only hybrids with a long harvesting time, high starch storage and displaying a high digestibility of plant cell wall with slow drying of the stover, should be grown in the future. The Silage maize Ripeness Index (SRI) is, for whole plant maize, better than the Whole Plant Maize Ripeness Index (SRZ) for the choice of a hybrid in Germany. The dry matter content of grain in interaction with the dry matter of stover are better than dry matter content of the whole plant maize as ripeness indicator in the production of maize. SRI is also suitable for use in scientific trials as a standard for the harvesting time and for better “stay green” characteristic. It is a strong correlation between the Silage maize Ripeness Index (SRI) and Silage maize Nutrient Index (SNI) or Silage maize Quality Index (SQI), respectively, as indicator for the physiological reaction of starch and metabolised energy in the rumen as well as for the choice of a hybrid.     

Beitrag zum Qualitäts- und Ertragspotenzial stress- und trockenheitstoleranter Sorten für Silo- und Energiemais bei optimaler Reife

Maize production trials carried out in eastern middle of Germany from 1999–2007 were used for statistical analysis of the optimum date for silage maize ripeness, quality and yield potential as well as choice of cultivar under drought conditions for silage and energy maize. The Silage maize Ripeness Index (the ratio of dry matter content of maize grains to dry matter content of stover) is more suitable for the determination of harvest date, yield maximum and silage maize quality as the dry matter content of the plant. The analysis is cheaper as well as not so material and time-consuming in comparison to the dry matter content of the silage maize of different hybrid maize populations and environments. Ensilage optimum and yield maximum correspond almost with the physiological ripeness of silage maize and are close to the grain dry matter content of 60 to 65%, to the dry matter content of stover under 24% and a ripeness index from 2,5 and higher. Only under these conditions it is possible to reach the optimal ripeness of 30 to 35% in the whole plant silage maize. In dependence on the Silage maize Ripeness Index (SRZ) parameters of silage and energy maize were created differential ripeness optimum, quality and yield potential. The aims of silage and energy maize are similar. The vitality of stover has a greater importance for energy maize. The Silage maize Ripeness Index (SRI) is, for whole plant maize, better than the Whole Plant Maize Ripeness Index (SRZ) for the choice of a hybrid in Germany. The dry matter content of grain in interaction with the dry matter of stover are better than dry matter content of the whole plant maize as ripeness indicator in the production of silage and energy maize for the harvesting time. SRI is also suitable for use as a standard in scientific trials and for better characteristic of cultivar types and environmental influence.     

Die Silomaisernte bei optimaler Silierreife

Maize production trials carried out in the middle of eastern Germany from 1999–2005 and were used for statistical analysis of the optimum date for silage maize ripeness. The Silage maize Ripeness Index (SRI, the ratio of dry matter content of maize grains to dry matter content of stover) is more suitable for the determination of harvest date, yield maximum and silage maize quality as the dry matter content of the plant. The analysis is cheaper and less material and time-consuming in comparison to the dry matter content of the silage maize of different hybrid maize populations and environments. Ensilage optimum and yield maximum correspond almost with the physiological ripeness of silage maize and are close to the grain dry matter content of 60–65%, to the dry matter content of stover under 24% and a ripeness index from 2.5 and higher. Recently, the silage maize harvest depends on dry matter content of maize plants (30–35%). This can result in grain ripening rates less than 55% and low starch as well as energy contents. The dry matter content of the silage maize is at a certain ripeness of grain and/or of starch only expression of aging of the stover. When the stover has a stronger influence as the grain on the dry matter content of the whole plant maize, than the crop should be harvested before reaching the optimum of ripeness and yield maximum. Therefore only hybrids with a long harvesting time, high starch storage and displaying a high digestibility of plant cell wall with slow drying of the stover should be grown in the future. The Silage maize Ripeness Index is, for whole plant maize, better than the Whole Plant Maize Ripeness Index (SRZ) for the choice of a hybrid in Germany. The dry matter content of grain in interaction with the dry matter of stover are better than dry matter content of the whole plant maize as ripeness indicator in the production of maize for the harvesting time. SRI is also suitable for use as a standard in scientific trials and for better type-characteristic of varieties.     

Dynamisches Reife- und Analyse (DRA)-System im Maisanbau

The Dynamic Ripeness and Analysis (DRA)-System in maize cultivation describe with the phenological ripeness, stress and selection indicator, the Silage maize Ripeness Index (SRI), the differentiated ripening development in the whole maize plant in addressing the most dominant ripening, growing and environmental conditions at the time of harvest period. The SRI is the quotient of ripeness of grain and residual plant. In addition to fix the correct optimum or agro-eco-efficiently harvest time. The SRI is also capable of the location suitability of the variety to characterize the ripeness specific type of variety as well as the environmental and cultivation conditions to quantify. The consistent use of the DRA-System by the maize growers leads to the desired momentum of ripeness, harvest and choice of varieties parameter. Only few environmentally stable maize varieties with the greatest variety and resistance performance for all utilization from the supposed varieties oversupply reach a consensus economic and ecological if the genotype for sowing corresponds to the phenotype for harvest. When the reference point of ripeness (SRI 2.8), there are only minor, ripeness-specific differences between the types of use (gas, fattening, grain and milk). Associated with the ripeness difference decrease the ripeness degree, better plant health, higher palatability and structure activity in the dairy cow feeding receiving maximum amounts of absolute ground fodder (healthy residual plant), which ultimately leads to a maximum milk production at a lower metabolic load of animals.     

Agro-?koeffizienz im Maisanbau durch Selektion des Sortenmaterials und Ermittlung der Reifestadien von Siliermais (Silo- und Energiemais) – aus der Sicht von ?konomie und ?kologie

Data from silage maize variety trials of the years 1999?C2010 in the Central German dry region were subjected to a secondary analysis using methods of mathematical statistics: With the phenological ripeness indicators (grain dry matter content/TM of the residual plant) the differences in the ripeness dynamics of grain to residual plant and their effects on the economy and ecology compared to the current ripeness system with use-specific ripeness numbers are documented. This dependence on all directions of use in the maize of the environments and varietal types taking into account of the different plasticity of maize varieties is been quantified. The achievement of physiological ripening of the grain is the interface of all usage directions and at the same time basis for the comparable, agro-eco-efficient level of maturity (63% TM) in conjunction with the silage ripeness index (SRI of 2.8) by eco-silage maize crops. The specific characteristics of the usage directions are low and with regard to efficiency, environmental and consumer protection discussed. With the phenological stage indicator (SRI) can both replaced the DM content of the whole plant as a parameter to the harvest date of silage and energy maize as the usage-specific ripeness numbers to the variety choice for silage and grain maize. A classification of the varieties according to ripeness groups would fully correspond to the environmental maize production. In the preparation of production (breeding, approval, testing and type of election), the SRI serves as selection and during inventory management through differential ripening control in compliance with the environmental and field production conditions as ripeness index. The wide ripeness ratio between grain and residual plant is the phenotypic expression of maize varieties as indicator for the agro-eco-efficiency and multifunctional guarantee better plant health, the resource efficiency, as well as basic product safety and sustainability of the process of maize silage. A precise fixing of harvest time point (HTP) is possible only with the SRI. The correct HTP is in principle maximum possible SRI. This HTP differently from the silage optimum can be according to the environments and the type of election. Ideally a maximum high SRI of 2.9 and over to a high basic intake of ground feed when reaching for exclusive maize silage feeding ruminant more friendly, better structural efficiency and grain hardness for the bypass of starch in the small intestine. The variety and the harvest strategy are to focus their reasons of economy and ecology on a high proportion of stocks ripeness in the field of silage optimum (SRI >?2.6) reach. Standard for maximum efficiency of production process maize and its environmental and consumer protection in the field of view of social line is the reaching of the agro eco-efficient ripeness point (SRI of 2.8 at physiological ripeness of grain by 63%).     

Beitrag zum Sortentyp und Merkmalskennung der Reifedynamik durch den phänologischen Indikator, dem Silomais-Reifeindex

Data from the Central German variety trials was evaluated, to with the Silage maize Ripeness-Index (SRI) the off-ripe-specific type in its significance and impact on selected parameters of the quality, the yield of silage and energy maize, as well as the appropriate feeding of ruminants with rations of higher maize proportions. The characterization of the ripe type on the basis of SRI is closely associated with statements to maize ripening, reproducibility of variety performance, site suitability and environmental conditions of production in the context of the Dynamic Ripening and Analysis system (DRA). The environmental stability of maize varieties characterizes the type of variety that exerts a dominant role over the ripeness level on the production of silage maize. The difference between type and productivity as well as feed value was demonstrated. For a location and physiological ruminant feeding of maize in relation to the type are been conclusions in the field of plant health, ground feeding uptake, structure impact and physiological grain hardness. As a result of this evaluation a comprehensive advantage of the environment stable variety type with slow ripening maize (residual) plant is to determine which cannot be evidenced and used with the present system of ripeness of use-specific classification.     

Maisernte nach Maß

The consistent appropriate selection of environment-stable varieties, the range of plant without ear up to maximal ripeness ratio of grain to residual plant are the cardinal question in maize cultivation respecting the ripeness, growing and environmental conditions. By permanent control of the ripening process in the pre-harvest period up to ripeness maximum possible ratio of grain to rest plant (real time of harvest) and its detection by the Silage maize Ripeness Index (SRI) as phenological performance, selection and stress indicator the environmental performance potential of all varieties can be exploited, in all years, as well as each location and in all directions of use. The plant without ear as a concrete expression of the reduction of biomass production caused by drought stress and the careless cultivation of unstable varieties provide the base inevitably for drastic, estimated losses with regard to quality, yield, as well as extensive risks in environmental, consumer and animal welfare. Ripe different maize with green, vital and active photosynthesis residual plant with 22?% dry matter is in the field of physiological ripeness of grain by 63?% up to the agro-eco-efficient ripeness point and the interface of all use directions. Silage and energy maize with the SRI of 2.8 and still green residual plant should be continued in the interest of the effectiveness of the high-performance feeding up to the maximum possible ripeness ratio. The establishment of the plant architecture in the form of high maize high of about 225 cm is better for improve the yield potential compared to compact. Such differences were indifferent and not pronounced at the quality indicators. By phenotyping of the production levels in maize, also the risks of all kinds are estimated preventable in addition to the appraisal of quality and yield. In addition an assessment of ripeness, growing and environmental conditions of the crop year can be on the other hand same range based on the SRI retroactively. Interfaces, as the agro-eco-efficient ripeness point, for the coupling of other crop models, a selection index for breeding objectives of all use directions (performance, resistance and food value) as an environmental variable and standard for trial basis have been created with this Dynamic Ripeness and Analysissystem (DRA). The efficiency of the entire production branch is also ecologically to justify itself according to maximize success in each direction of use maize.     

Relationship of sphinganine analog mycotoxin contamination in maize silage to seasonal weather conditions and to agronomic and ensiling practices

ABSTRACT Sphinganine analog mycotoxins (SAMs) are reported in maize and maize based feeds. Our objectives were to detect and quantify fumonisins B(1) and B(2) and Alternaria toxins (AAL toxins) AAL-TA and AAL-TB and determine how agronomic practices, weather conditions, and ensiling affected the occurrence and levels in maize silage. Silage was collected at harvest and after ensiling in 2001 and 2002 from 30 to 40 dairies, representing four regions in Pennsylvania. SAMs were quantified using high pressure liquid chromatography (HPLC) with fluorescence detection and high pressure liquid chromatography-mass spectrometry HPLC-MS. The average concentrations and ranges were as follows: fumonisin B(1) 2.02 mug/g (0.20 to 10.10), fumonisin B(2) 0.98 mug/g (0.20 to 20.30), AAL-TA 0.17 mug/g (0.20 to 2.01), and AAL-TB 0.05 mug/g (0.03 to 0.90). Fumonisin B(1) was the most frequently detected toxin (92%) in all samples, followed by fumonisin B(2) (55%), AAL-TA (23%), and -TB (13%). Temperature during maize development was positively correlated with fumonisin occurrence and levels and negatively with AAL-TA, while moisture events were negatively correlated with fumonisins and positively with AAL-TA. Fumonisin levels were higher in silage harvested at later developmental stages (dough through physiological maturity). Ensiling did not affect toxin concentration nor did agronomic practices (tillage system, inoculant use, or silo type) or silage characteristics (dry matter, pH, or organic acid concentration). This is the first report of AAL-TB in silage and on factors that affect SAM frequency and levels in maize silage.     

Contamination of fresh and ensiled maize by multiple penicillium mycotoxins

Toxins produced by Penicillium species are reported in maize silage and have been associated with health problems in cattle. Our objectives were to evaluate the prevalence and dynamics of patulin (PAT), mycophenolic acid (MPA), cyclopiazonic acid (CPA), and roquefortine C (ROC) in fresh and ensiled maize. To achieve these objectives we developed a high-performance liquid chromatography method coupled with mass spectrometry to detect all four toxins simultaneously in silage. In addition we collected weather data, information on agronomic practices, and silage fermentation characteristics for each study site. Silage was collected at harvest and after ensiling in 2001 and 2002 from 30 Pennsylvania dairies. The average concentration of toxins (range in parentheses) was: PAT 0.08 microg/g (0.01 to 1.21), MPA 0.16 microg/g (0.02 to 1.30), CPA 0.12 microg/g (0.02 to 1.43), and ROC 0.38 microg/g (0.01 to 5.71). ROC was the most frequently detected toxin (60%), followed by MPA (42%), CPA (37%), and PAT (23%). Of 120 samples tested, 15% contained no detectible levels of toxin, 25% were contaminated with one toxin, 32% with two, 18% with three, and 10% with all four toxins. All four mycotoxins were found in freshly harvested material, contradicting the belief that Penicillium toxin formation occurs exclusively during storage. We observed that weather conditions during specific growth stages of the crop affected the final concentration of toxins in freshly harvested maize. In ensiled material, PAT levels were affected by concentrations of propionic and isobutyric acids. Based on our data, Penicillium mycotoxins can form while the crop is in the field and after ensiling, suggesting that preventative measures should begin prior to ensiling.     

黄土区不同熟制玉米延收增产技术研究

研究了延迟收获对不同熟制玉米株粒重、千粒重及植株器官千物质运移的影响.结果表明,玉米适时延收具有明显的增产效果.延收15 d,春、夏玉米植株器官干物质向籽粒中运移量分别达28.89 g·株-1和23.81g·株-1,叶和茎秆的干物质对籽粒的贡献率高达80％左右;春玉米单株粒重增加29.2 g,单株粒重日增1.95 g,千粒重增加53.8 g,平均日增3.58 g,增产1 336.5 kg·hm-2,增产16.6％;夏玉米单株粒重增加31 g,平均日增重2.1g,千粒重增加81.7 g,平均千粒重日增5.5g,产量增加1488.0 kg·hm-2,增产18.9％,增产效益显著.     

土壤盐分含量对滴灌复播青储玉米光合特性及土壤水盐动态的影响

通过盆栽试验,研究了不同土壤含盐量(0.14%(CK)、0.60%、0.80%、0.90%、1.00%)条件下,青储玉米光合特性及土壤水盐运动规律变化。结果表明:随着土层深度的增加,土壤含水率和含盐量均表现出增加的趋势,土壤盐分含量越高其平均含水率越高,由含盐量为0.14%处理的12.30%增加到含盐量为1.00%处理的15.82%;从7月初到10月初,各处理0~40 cm土层盐分变化量依次为-0.03%、-0.08%、-0.12%、-0.14%、-0.17%,盐分变化率依次为-11.52%、-13.34%、-13.88%、-14.81%、-17.41%,所有处理0~40 cm土层处于脱盐状态;土壤盐分抑制青储玉米叶片气孔导度,因气孔限制因素,玉米叶片净光合速率、蒸腾速率、胞间CO_2浓度等均下降,影响光系统的正常运行,导致玉米叶片水分利用效率和光能利用率降低。     

Quantitative relationships between Ostrinia nubilalis activity and deoxynivalenol contamination in French maize

We investigated the indirect effect of an insecticide spray against the European Corn Borer (Ostrinia nubilalis Hübner; Lepidoptera: Crambidae) on mycotoxin contaminations of grain maize at the harvest stage. Between 2004 and 2009, 45 paired plots comparing insecticide treatment with untreated control were studied in Alsace administrative region, in the northeast of France. An average reduction of 78% in O. nubilalis larval densities was observed in insecticide-treated plots compared with control plots. Mean levels of deoxynivalenol mycotoxin in harvested grain were significantly reduced from 849 ppb in the control samples to 152 ppb in the insecticide-treated samples. A statistical modelling approach involving Generalized Linear Models (GLMs) was employed to identify and rank the associated variables for damage and pest density on different plant parts, on deoxynivalenol levels in harvested grain at harvest. The modelling revealed that the occurrence and the density of O. nubilalis larvae in maize stalks and in ears are the best indicators for deoxynivalenol contamination. The identification of these deoxynivalenol contamination risk factors, along with other factors such as genetic background, harvest date and crop rotation allows improvement of the risk assessment and risk forecasting in maize crops in order to manage crop safety and maintain maize deoxynivalenol mycotoxin levels below the European Regulation (EC) No. 1126/2007 threshold.     

Effects of density and sowing pattern on weed suppression and grain yield in three varieties of maize under high weed pressure

We tested the hypothesis that improved weed suppression by maize can be achieved through increased crop density and spatial uniformity. Field experiments on three varieties of maize sown at three densities (5, 7 and 10.5 seeds m^?2) and in two spatial patterns (grid pattern and rows) under very high weed pressure from Brachiaria brizantha were performed in 2012 and 2013. We measured weed biomass 1 month after sowing and at harvest, and grain yield at harvest. Density, variety and sowing pattern all had strong and significant effects on both weed biomass and yield. On average, weed biomass was reduced (by 72% in the first year and 58% in the second year), and grain yield was increased (by 48% and 44%) at the highest density in the grid pattern compared with standard sowing practices (medium density, row pattern). There was a significant density × variety interaction, which is evidence for genetic differences in the response of the varieties to density in characteristics that influence weed suppression. The variety that suppressed weeds best at high density had the lowest variation in the angle of insertion of the oldest living leaf at harvest (leaf 6), supporting the hypothesis that reduced phenotypic plasticity may be advantageous for weed suppression under high density and spatial uniformity. Increased density and uniformity can contribute to weed management in maize in many cases, potentially reducing the need for herbicides or mechanical weed control.     

DON content in oat grains in Norway related to weather conditions at different growth stages

High concentrations of the mycotoxin deoxynivalenol (DON), produced by Fusarium graminearum have occurred frequently in Norwegian oats recently. Early prediction of DON levels is important for farmers, authorities and the Cereal Industry. In this study, the main weather factors influencing mycotoxin accumulation were identified and two models to predict the risk of DON in oat grains in Norway were developed: (1) as a warning system for farmers to decide if and when to treat with fungicide, and (2) for authorities and industry to use at harvest to identify potential food safety problems. Oat grain samples from farmers’ fields were collected together with weather data (2004–2013). A mathematical model was developed and used to estimate phenology windows of growth stages in oats (tillering, flowering etc.). Weather summarisations were then calculated within these windows, and the Spearman rank correlation factor calculated between DON-contamination in oats at harvest and the weather summarisations for each phenological window. DON contamination was most clearly associated with the weather conditions around flowering and close to harvest. Warm, rainy and humid weather during and around flowering increased the risk of DON accumulation in oats, as did dry periods during germination/seedling growth and tillering. Prior to harvest, warm and humid weather conditions followed by cool and dry conditions were associated with a decreased risk of DON accumulation. A prediction model, including only pre-flowering weather conditions, adequately forecasted risk of DON contamination in oat, and can aid in decisions about fungicide treatments.     

不同枣粮间作模式物质积累及产量成因分析

在枣粮间作模式下对间作作物的物质积累及产量成因进行对比分析,以玉米品种先育335、高粱品种沈杂5号为试材,分别对其在出苗后45、60、75、90 d和105 d的净光合速率、干物质积累、产量构成因素、株高和茎粗等指标进行了测定与分析。结果表明：在枣粮间作模式下,玉米和高粱分别在ZY4和ZG8模式下粮食产量最高;高粱在各生育时期内的光合速率均高于玉米,在不同生长时期内差异较小,相对玉米可适当密植;在ZY4和ZG8的模式下玉米和高粱干物质积累平均速率高,为高产量的形成奠定物质基础;穗数和粒重受密度影响较大,穗粒数影响较小,ZY4和ZG8模式下枣树、玉米、高粱三者配置模式较好。     

Reduction of growth and reproduction of Cyperus esculentus by specific crops

To assess the potential contribution of growing highly competitive crops to control Cyperus esculentus in the Netherlands, the influence of silage maize, hemp, winter barley and silage winter rye on emergence, growth and reproduction of this weed was studied in two field experiments. Growth and reproduction of C. esculentus (determined both as tuber production per plant and density of the weed in the subseuent crop maize) was reduced by each crop, compared to plots in which no crop was grown. In hemp, hardly any tuber production was observed. By growing a green manure crop after harvest of the winter barley the tuber production of the weed was reduced to about 40% of that in winter barley followed by fallow. Decreasing the light regime in a greenhouse experiment in the same order as was observed in the crops winter barley, maize and hemp, caused a similar reduction of tuber production to that found in the field. Therefore, it is suggested that competition for light is the main factor explaining the observed crop effects on the population dynamics of the weed. It is concluded that growing competitive crops as hemp in rotation may effectively complement chemical control of C. esculentus.     

干旱胁迫下玉米自交系抗旱性评价及筛选

以39份玉米自交系为材料,2017—2018年在甘肃省张掖市设置田间自然抗旱鉴定试验,筛选抗旱鉴定指标,综合评价玉米自交系的抗旱性。结果表明：在干旱胁迫下,39份玉米自交系的粉丝间隔时间延长了0~3 d,株高、穗位高、穗长、穗粗、穗干重、籽粒干重、出籽率及百粒重均降低,其中,穗干重、籽粒干重和出籽率3个指标分别为正常灌水处理的81.5%、79%和88.5%。穗干重、籽粒干重和出籽率与平均抗旱系数呈显著正相关,可作为玉米自交系抗旱鉴定的主要指标。利用加权抗旱系数法综合评价筛选出强抗旱玉米自交系10份,其中自交系E28、DH351、陇1222、浚92-8和黄早四,抗旱性达到极强。本研究所筛选到的抗旱自交系可在选育抗旱新品种中加强利用。     

Increasing Farm Productivity and Soil Fertility on Sustainable Basis Through “Summer Gap” Utilization with Biochar and Legumes

To reduce reliance on scientific fertilizer due to rapid increase of fertilizer prices and environmental constraint, it necessary to improve crop productivity and soil fertility on sustainable basses. Utilization of “summer gap” through biochar and legumes have pleasant effects on improving crop productivity and soil fertility on long term basses. Two years’ field experiments were conducted on wheat and maize crops with “summer gap” utilization with legumes and biochar at research farm of agronomy, the University of Agriculture Peshawar during 2011–2013. Wheat-maize-wheat cropping system was followed with the adjustment of legumes in “summer gap” (land available after wheat harvest till maize sowing). Legumes i.?e. mung bean, cowpea and Sesbania with a fallow were adjusted in the “summer gap” with and without biochar application. Biochar was included at the rate of 0 and 50?t?ha^-1 with four N levels of 0, 90, 120, 150 and 0, 60, 90, 120?kg?ha^-1 to subsequent maize and wheat crops, respectively. In legumes’ experiment, biochar increased fresh and dry fodder yield in cowpea and Sesbania, grain and biological yields in mung bean. In maize experiments, biochar improved grain yield. Nitrogen application increased grain and biological yields. In wheat experiments with increasing nitrogen level enhanced biological and grain yields. It is concluded that use of biochar and legumes in “summer gap” improve overall farm productivity and soil fertility on sustainable basses.