Micromorphology and petrography of Late Weichselian glaciolacustrine varves in southeastern Sweden

The purpose of this investigation is to describe and interpret the sedimentology and petrography of Late Weichselian varves in southeastern Sweden in order to determine their nature and origin. It is focused on the microscopic evidence for glaciolacustrine varve sedimentation in the Baltic Ice Lake and the possibilities of making a detailed facies classification of the sediments in an area with an established varve chronology. The material examined was cores taken from five representative localities in an area below the highest shoreline of the Baltic Ice Lake in the provinces of Skåne and Blekinge, i.e., below an altitude of 55–65 m. The investigations included chemical analyses, XRD, microscopy (polarized) and SEM-EDX investigations of the summer and winter layers of the varves. The results of the chemical, clay mineralogy (XRD) and microscopic examinations of the bedrock and mineral fragments indicate that the material in the different facies of the varved clay is mainly produced by moderate alteration and erosion from the local bedrock of predominantly granitoid rocks and of residual kaoline deposits. It is possible to distinguish microscopic evidence of four varve types differing in texture depending on the water depth and how close to the ice the different facies were deposited, i.e., if they were deposited proximally, distally or extramarginally in relation to the ice margin. It is also possible to relate these differences to changes in the palaeoclimate during the deglaciation of the area in the Bölling and Older Dryas chronozones.     

Bibliography: Farmer knowledge and management of crop disease

Nearly all contemporary people subsist on cultivated plants, most of which are vulnerable to diseases. Yet, there have been few studies of what traditional people know – and do not know – about crop disease. Agricultural scientists in general are becoming aware of the potential contribution of social scientists and farmers in developing integrated management of crop diseases. The International Potato Center (CIP) has focused on stimulating farmer-scientist collaboration in developing management of late blight, a major fungal disease of potatoes and other plants. Understanding farmers' knowledge of this and other plant diseases is an important element in furthering such collaboration. Although not all agricultural scientists recognize the value of social science, this literature search shows that some agricultural scientists now actively collaborate with farmers, in ways that cross the boundary into social science research. During this search, much of the work we found was written by plant pathologists and entomologists. We found over fifty publications on farmer knowledge of crop disease, and we have annotated the material that we thought most relevant to farmer- scientist collaboration for research of crop diseases, especially late blight.     

利用VIGS技术研究马铃薯抗晚疫病基因R3a和RB的信号传导

 利用VIGS技术,在烟草中沉默已知的抗病信号传导关键基因SIPK、NDR1、SGT1、HSP90、NPR1、Rar1、EDS1、WRKY1,再瞬时表达马铃薯抗病基因和其相应的无毒基因RB-Avrblb1和R3a-Avr3a,根据过敏反应（Hypersensitive Response,HR）反应是否被阻断来研究RB和R3a介导的抗病信号传导。结果发现SGT1和HSP90基因沉默阻断了HR反应的发生,表明SGT1和HSP90是参与RB和R3a抗病信号传导途径过程中的关键基因。该技术体系的建立,为以后发现新的晚疫病抗病相关基因的功能验证提供了一个高效的技术平台。     

避晚霜核桃新品种——元林的选育

元林是以中国核桃元丰为母本与美国核桃强特勒为父本杂交育成的早实核桃新品种。该品种坚果长圆形,纵径4.25 cm,横径3.6 cm,侧径3.42 cm,平均单果质量16.84 g。壳面刻沟较浅,较光滑美观,浅黄色。壳厚1.26 mm左右;内褶壁退化,易取整仁;核仁充实饱满,出仁率55.42%左右,脂肪质量分数为63.6%,蛋白质质量分数为18.25%,味香微涩。果实成熟期8月下旬;具有果个大、萌芽晚、避晚霜、早实、丰产特点。     

不同秧龄对晚稻产量的影响

[目的]探讨杂交籼稻品种新优188和粳稻品种华粳295不同移栽秧龄对其产量的影响规律。[方法]采用裂区试验和SPSS软件统计分析。[结果]新优188和华粳295两种水稻的实际产量均随着秧龄的增加而下降;在相同秧龄的情况下,晚籼品种新优188的实际产量均高于华粳295。[结论]以产量为指标,新优188比较适宜在京山地种植,其最佳秧龄为15 d,在此条件下,水稻新优188的实际产量可以达到8 289.0 kg/hm2。     

宁夏2014年苹果晚霜冻害调查分析

苹果是易受霜冻影响的经济林果之一,2014年春季宁夏冷空气频发,出现多次霜冻天气过程,为了了解2014年晚霜冻对宁夏苹果的综合影响,文章运用调查和统计方法,分析了宁夏苹果遭受晚霜冻危害情况。结果表明,2014年宁夏苹果花期和幼果期均遭受霜冻危害,平均综合危害程度在30%~35%;综合晚霜冻危害受日最低气温出现次数和阶段内极端日最低气温影响较大;各地差异明显,从有限调查点来看,中宁轿子山林场受冻较为严重;不同品种之间,富士受冻最严重。文章的调查分析结果有助于进一步把握宁夏苹果产业受霜冻危害的潜在危险性。     

Resistance Evaluation of Some Hybrid Rice, Conventional Early Indica and Late Japonica Rice to Magnaporthe grisea

Thirty isolates of Magnaporthe grisea collected from 18 provinces/cities representing 21 pathotypes and 9 different lineages were inoculated to rice varieties with known resistance genes and some hybrid rices,conventional early indica and late japonica varieties cultivated recently in China.Virulence spectrum of the 30 isolates was very different,showing that they recognize numerous different resistance genes.Varieties also revealed very different resistance patterns showing that they carry different resistance genes or combinations of resistance genes.On the basis of comparisons with international differential varieties with known resistance genes,resistance genes in certain Chinese varieties could be speculated.The results indicated that some of them were resistant to most of the isolates tested and that they could be of interest as resistance sources for hybrid parents or to be planted in the field directly.     

The effect of a mixture of two plant growth-promoting bacteria from Argentina on the yield of potato,and occurrence of primary potato diseases and pest – short communication

In 2017, we conducted a field experiment to test the influence of a mixture of two plant growth-promoting bacteria (Pseudomonas fluorescens and Azospirillum brasilense) on the yield of three potato varieties. In addition, the influence of the mixture on potato susceptibility to infection by the pseudofungus Phytophthora infestans and fungus Alternaria solani and to attacks by the Colorado potato beetle (Leptinotarsa decemlineata) was investigated. It was the first experiment of its kind in Europe. In the unusually hot and dry year, a positive influence on the yield (17%–31%) was found in all three varieties when the tubers were soaked in the bacterial mixture prior to sowing. We observed no significant differences in potato resilience/susceptibility to harmful organisms among the different treatments (soaked tubers, sprayed tubers, untreated tubers); however, there were significant differences in the productivity between the tuber varieties. The results of our research indicate the bacterial mixture used in this study has a high potential to support satisfactory potato yields under dry conditions and under low levels of infection by foliar fungal diseases and attacks by foliar insects.     

杂交晚粳甬优8号高产配套栽培技术

2006~2008年,甬优8号在当涂县的试种表现,田间长相、产量和稻米品质均表现突出,是一个很有开发潜力的超高产优质杂交粳稻新组合。笔者总结了杂交晚粳甬优8号的主要特征及栽培技术要点,为该组合生产利用和大面积推广提供依据。     

Simulated N management effects on corn yield and tile-drainage nitrate loss

Thoroughly tested simulation models are needed to help quantify the long-term effects of agriculture. We evaluated the Root Zone Water Quality Model (RZWQM) response to different N management strategies and then used the tested model with observed weather data from 1961-2003 to quantify long-term effects on corn (Zea mays L.) yield and flow weighted nitrate-N concentration in subsurface “tile” drainage water (Nconc). Fourteen years (1990-2003) of field data from 30, 0.4 ha plots in northeast Iowa were available for model testing. Annual crop yield, nitrate-N loss to subsurface “tile” drainage water (Nloss), Nconc, and subsurface “tile” drainage amount (drain) for various management scenarios were averaged over plots and years to create five chemical fertilizer and five swine manure treatments. Predicted corn yield and Nconc for the 10 treatments were significantly correlated with observed data (R² > 0.83). The Root Mean Square Errors (RMSE) were 15% and 18% of its observed average Nconc for chemical fertilizer and manure treatments, respectively. Corresponding RMSEs for corn yields were 8% and 10% of its observed average corn yields for chemical fertilizer and manure treatments. The long-term simulations indicate that average corn yield plateaus and Nloss accelerates as quadratic functions of increasing spring UAN-N rates from 100 to 200 kg N/ha. Winter wheat (Triticum aestivum L.) sowed after corn and soybean [Glycine max (L.) Merr.] harvest was predicted to reduce long-term Nloss by 5 to 6 kg N/ha, which appears consistent with published field studies and may be a treatment to ameliorate agricultural management with potential for elevated Nloss such as swine manure application to soybean. The results suggest that after calibration and thorough testing, RZWQM can be used to quantify the relative effects of corn production and Nconc under several alternative management practices.