台风"南玛都"路径突变原因分析

对0428号冬季台风“南玛都”的移动路径分析表明,台风“南玛都”在南海移动路径发生明显突变转向是一小概率事件,“南玛都”路径突变前的移动路径与500hpa副热带高压南侧的环流相平行,突变点与副热带高压西脊点相一致;高空槽东移与副热带高压东退是“南玛都”路径突变的重要原因,突变后的路径基本上与θse的高值区相一致。在高空低槽(500hpa)前部大范围深厚的西南气流和低层(地面层和850hpa)干冷空气的共同作用下,台风的强度有明显的减弱,且移动速度明显加快。     

天津地区冬小麦需水分析

利用联合国粮农组织(FAO)最新推荐的彭曼-蒙蒂斯模式(FAO-PM)计算了天津市蓟县、武清、宝坻、静海等主产麦区的冬小麦各发育期的需水量、缺水量,据此分析了该地区冬小麦需水规律及分布特征,并提出生产管理对策建议。     

优质油菜新品种(H组合)比较试验与综合评价

研究了6个优质杂交油菜新品种(H组合)在安徽地区的适应性。结果表明:优质油菜新品种(H组合)H4-1-1、H4-2-2、H4-5-1表现经济性状协调、丰产性好、适应性广、抗性较强,具有较好的推广价值。     

氮、磷、钾肥对冬小麦根系营养效应的研究

1986～1988年,在校内网室采用盆栽进行试验。初步探讨了氮磷钾对冬小麦根系营养效应;明确了冬小麦一生中,根内养分浓度因小麦不同生长时期以及施氮磷钾肥种类不同而异,根内氮和钾养分浓度变化为:播种～返青和抽穗～成熟这两段含量低;拔节～抽穗含量高。磷是前期明显地高于中期和后期。根对氮磷钾营养的吸收累积表现为播种～返青为平缓上升阶段;返青～抽穗为急剧上升阶段:抽穗～成熟为迅速下降阶段.根重的变化也表现为返青前根重较轻,返青～抽穗根重迅速增加至根重绝对量的最高点,后期根重又下降,全生育期根重变化呈抛物线型.显著性检验表明:氮磷处理对根重、养分浓度、养分吸收积累量及其强度影响最为明显.     

优质油菜新品种(系)适应性初步研究

研究了9个优质油菜新品种(系)在安徽的适应性.结果表明,优质油菜新品种(系)崇阳2号、华99-24、华99-28表现抗性强,经济性状协调,丰产性好,具有一定推广价值.     

Impacts of the nitrogen application on productivity and nutrients concentrations of the corn-Congo grass intercropping system in the dry season

ABSTRACT

The corn-grass intercropping system began to be used in the dry season, as it provides increased straw production for the no-tillage system. However, corn and grass are plants demanding in nitrogen. The corn cultivated in the dry season is called out-of-season corn in Brazil. The objective of this study was to evaluate the productivity and nutrients concentrations of out-of-season corn and Congo-grass intercropped in the no-tillage system, as a function of the nitrogen rates applied in sidedressing. The treatments were four nitrogen rates, 0, 30, 60 and 90?kg?ha^?1. The experimental design was randomised complete blocks with four replicates. The experimental period corresponded to the harvests of 2015 and 2016. There were evaluated: corn grain yield, dry mass production and nutrient concentration in the shoots of the plants intercropped. The evaluations were carried out at the physiological maturity stage of the corn and at the time of desiccation of the grass. Nitrogen increased grain yield and dry mass production of the plants intercropped. Nitrogen maximised the magnesium concentration in out-of-season corn and the nitrogen, calcium, magnesium and sulphur concentrations in Congo grass. Excess nitrogen promoted reduction of the phosphorus in the Corn-Congo grass intercropping system in the dry season.     

Field evaluation of phenology and success of hardy,micro-propagated old shrub roses in northern Finland

Abstract

Five old shrub rose taxa were studied in field experiments in northern Finland during the years 1993–1999. The plant material was micro-propagated from woody plants selected for their ornamental value and hardiness for northern areas of Finland. The observations in the experiments were based on phenological monitoring and survey of plant success. The results revealed significant differences in the success of the different rose genotypes, and the most valuable genotypes were identified. Micropropagation was successfully used as a propagation method and these in vitro propagated roses grew naturally under harsh field conditions. The Rosa ‘Tornedal’ origins, R. ‘Poppius’ and R. ‘Sipi’ were ranked the most suitable cultivars for northern landscaping. Overall, all of the studied roses succeeded fairly well.     

Effect of Foliar Application of Phosphorus on Winter Wheat Grain Yield,Phosphorus Uptake,and Use Efficiency

ABSTRACT

One would expect foliar applied phosphorus (P) to have higher use efficiencies than when applied to the soil, but limited information is available concerning this. Experiments were conducted in 2002, 2003, and 2004 to determine the effect of foliar applications of P on winter wheat grain yields, P uptake, and use efficiency. Twelve treatments containing varying foliar P rates (0, 1, 2, and 4 kg ha^{? 1} in 2002 and 2003 and additional 8, 12, 16, and 20 kg ha^{? 1} in 2004) with and without pre-plant rates of 30 kg ha^{? 1} were evaluated. Foliar applications of P at Feekes 7 generally increased grain yields and P uptake versus no foliar P. Use efficiency was higher when P was applied at Feekes 10.54. Results from this study suggested that low rates of foliar applied P might correct mid-season P deficiency in winter wheat, and that might result in higher P use efficiencies.     

Biofumigant Biomass,Nutrient Content,and Glucosinolate Response to Phosphorus

Information on biofumigant-green manure vegetative biomass, nutrient, and glucosinolate content sensitivity to phosphorus (P) is lacking for species used in potato and sugarbeet production. Therefore, available P effects on field-grown condiment yellow mustard (Sinapis alba, cv. IdaGold) and oilseed radish (Raphanus sativa, cv. Colonel) were evaluated (2001–03). Low soil P was generally more limiting to radish foliage P concentrations or uptake than to the mustard, suggesting inherent differences in their ability to access and accumulate P. While radish P and S concentrations increased with higher P, concentrations in mustard were either unaffected or reduced. Foliage P concentrations were more closely related to biomass of radish (r² = 0.46) than mustard (r² = 0.11). Mustard exceeded radish in biomass and S accumulation. Phosphorus effects on glucosinolates producing ionic or isothiocyanates were relatively insignificant. These biofumigants differ appreciably in their ability to access and accumulate P, but P effects on nutrient content or glucosinolates were minor.     

SOURCES OF SULFUR FOR DRY MATTER,SEED YIELD,AND OIL CONCENTRATION OF CANOLA GROWN IN SULFUR DEFICIENT SOILS OF SOUTH-WESTERN AUSTRALIA

Leaching of sulfur (S) on sandy soils may limit the effectiveness of S fertilizers especially when applied at sowing. The effectiveness of S sources for canola (oil seed rape, Brassica napus L.) grown in sandy low S soils of south-western Australia is not known. This study was completed to determine the relative effectiveness of gypsum and a gypsum-based by-product from synthetic rutile processing called Canola Blue for canola grown in low S soils of the region. Canola Blue is a mixture of gypsum and elemental S, and is granulated so its effectiveness may vary from gypsum. We measured the effectiveness of the two S sources in the glasshouse for young seedling growth and for minimizing S leaching. In the four field experiments, the two S sources were evaluated for relative effects on canola seed yield and the concentration of oil in seed. Canola Blue applied at sowing was as effective as gypsum for canola growth in the glasshouse and when applied at 35 days after sowing (DAS) was as effective as gypsum for seed yield in the field. For the glasshouse study, Canola Blue when applied to the soil surface (topdressed) at 35 DAS was as effective as gypsum in achieving a rapid recovery of leaves from S deficiency symptoms and of shoot growth. Where S deficiency appears during the growing season, topdressing with Canola Blue appears to be as effective under the conditions of this experiment as was gypsum. However, the S in Canola Blue was less prone to leaching than that applied as gypsum.