上海地区蔬菜害虫研究——Ⅲ.迁入甜椒田黄色水盘中有翅蚜的研究

本文报道作者1983年在市郊嘉定县采集迁入甜椒田黄色水盘中的有翘蚜,已鉴定的有4科20属33种,标本存于植保系。在甜椒生育期间,迁入黄色水盘中的有翅蚜出现一次高峰。当候平均气温在15℃以上时有翅蚜的迁入量随温度上升而增加,在候平均气温20～23℃时为迁入盛期,超过25℃迁入量明显减少。调查了迁入黄色水盘中6种主要蚜虫的消长情况。     

模拟犁底层条件下春玉米叶片形态发育及衰老表征

通过模拟犁底层和模拟打破犁底层处理进行试验,研究犁底层对春玉米叶片形态发育及衰老表征,明确犁地层对东北春玉米生产易引发早衰的机理。结果表明,模拟犁底层处理的第8片到第11片叶玉米叶片长度以及第13片叶到第20片叶叶片宽度均小于模拟打破犁底层处理,达到极显著水平;从5片叶全展开到小喇叭口期,模拟犁底层处理比模拟打破犁底层处理晚发育9 d;模拟犁底层处理缩短了中部叶片的持绿时间6 d;模拟犁底层处理相对模拟打破犁底层处理降低了开花期绿叶面积及开花后相对绿叶面积,生产上采用农业机械深松打破犁底层可延缓后期叶片衰老进程。     

植酸酶耐热性评价方法的研究

植酸是畜禽常规植物性饲料中磷的主要存在形式,也是一种广谱性的抗营养因子。在饲粮中添加植酸酶来消除这种抗营养因子的不利效应、提高家禽的生产性能、降低饲料成本已成为饲料业中常用的方法。在实际应用中,饲料加工过程对添加在饲料中的植酸酶产生的不利影响是限制植酸酶进一步推广应用的重要因素。目前,市场上已有多种耐高温植酸酶产品推出,但产品对饲料制粒过程的耐受性能仍然是最受关注的焦点。因此,如何对不同的耐高温植酸酶产品进行耐热性能的评价具有重要的现实意义。文中比较了几种实验室条件下评价植酸酶耐热性的方法,并结合饲料制粒试验,结果表明,在蒸汽消毒器中利用湿热蒸汽处理的方法是一种简单、快速,并接近饲料加工过程中酶活损失情况的植酸酶耐热性评价方法。     

Leaf Extract of Aerva javanica Suppresses Excessive Growth of Granulation Tissue in Horses

Wound healing in horses is complicated by the excessive growth of granulation tissue, commonly known as proud flesh and is similar to keloids in human beings. At present, there is no satisfactory treatment for proud flesh in horses. In this study, we, for the first time, demonstrated that leaf extract of Aerva javanica suppresses excessive growth of granulation tissue in horses. Many plant flavonoids are claimed to have antiproliferative properties. Kaempferol is a natural flavonoid containing 3-hydroxy flavone backbone found in many plants in its aglycone form and attached with various sugars. Ecdysteroids are steroidal analogs of invertebrate steroidal hormones found in plants. Both flavonoids and ecdysteroids accumulate more in plants during abiotic stress. We hypothesized that Aerva javanica may have high levels of ecdysteroids and kaempferols for surviving in stressful conditions of desert. Those kaempferols may suppress the growth of granulation tissue by their antiangiogenesis property. Ecdysteroids may control the larvae of habronema if associated with proud flesh. Extract was prepared using solvent-based fractionation and silica gel column flash chromatography. Application of the leaf extract in horses suppressed growth of granulation tissue along with restoration of normal skin function. Various purification steps and mass spectrometry were used to identify the active components in the study.     

Growth, yield and water productivity of zero till wheat as affected by rice straw mulch and irrigation schedule

Intensive cultivation of rice and wheat in north-west India has resulted in air pollution from rice straw burning, soil degradation and declining groundwater resources. The retention of rice residues as a surface mulch could be beneficial for moisture conservation and yield, and for hence water productivity, in addition to reducing air pollution and loss of soil organic matter. Two field experiments were conducted in Punjab, India, to study the effects of rice straw mulch and irrigation scheduling on wheat growth, yield, water use and water productivity during 2006-2008. Mulching increased soil water content and this led to significant improvement in crop growth and yield determining attributes where water was limiting, but this only resulted in significant grain yield increase in two instances. There was no effect of irrigation treatment in the first year because of well-distributed rains. In the second year, yield decreased with decrease and delay in the number of irrigations between crown root initiation and grain filling. With soil matric potential (SMP)-based irrigation scheduling, the irrigation amount was reduced by 75 mm each year with mulch in comparison with no mulch, while maintaining grain yield. Total crop water use (ET) was not significantly affected by mulch in either year, but was significantly affected by irrigation treatment in the second year. Mulch had a positive or neutral effect on grain water productivity with respect to ET (WP_ET) and irrigation (WP_I). Maximum WP_I occurred in the treatment which received the least irrigation, but this was also the lowest yielding treatment. The current irrigation scheduling guidelines based on cumulative pan evaporation (CPE) resulted in sub-optimal irrigation (loss of yield) in one of the two years, and higher irrigation input and lower WP_I of the mulched treatment in comparison with SMP-based irrigation scheduling. The results from this and other studies suggest that farmers in Punjab greatly over-irrigate wheat. Further field and modelling studies are needed to extrapolate the findings to a wider range of seasonal and site conditions, and to develop simple tools and guidelines to assist farmers to better schedule irrigation to wheat.     

湖南年蒸发量时空演变特征及气象影响因子分析

利用湖南省地面气象站点1971—2012 年的地面气象观测数据,采用线性趋势、经验正交函数分 解、相关分析法和相对权重法,分析了湖南省蒸发皿年蒸发量时空变化及主要气象影响因子。结果表明：在过去的42 年,湖南全省年平均蒸发量呈不显著下降趋势;大部分地区年蒸发量有比较明显的年代际波动,在湘中及湘东大部分地区表现为显著的下降趋势,湘东南的东部地区表现为显著上升趋势,其余区域变化趋势不明显;蒸发量与日照时数、降水量、平均气温、气温日较差和饱和水汽压差等多个气象因子都存在显著的相关关系,与日照时数的正相关程度最大,与降水量的负相关程度最大;在年蒸发量下降的区域的主导因素是日照时数的减少,在年蒸发量上升的区域的主导因素是降水量的减少。     

不同氮肥类型及施氮水平对大棚黄瓜产量和水分利用效率的影响

在水资源严重短缺情况下,水分高效利用研究对设施蔬菜生产进行科学水分管理具有重要意义。笔者根据20cm直径水面蒸发量(EP)和土壤水分实时监测数据确定大棚黄瓜(中农16)补灌水量。在水分充足供给条件下,确定尿素、尿素添加硝化抑制剂(尿素与硝化抑制剂5∶1配比施用)、包膜尿素(缓施肥)三种氮肥类型及其0、350、550、750kg/hm2不同氮肥水平下春茬大棚黄瓜水分耗散、产量及其水分利用效率。结果表明,550kg/hm2施氮水平下尿素+硝化抑制剂的处理大棚黄瓜产量最高为10.9×105 kg/hm2,比空白对照的产量高41.5%;其累积水分消耗量为462.0mm,比对照增加15.2%;大棚黄瓜水分利用效率为14.11kg(干物质)/(mm.ha),比对照增加44.7%。该研究证明550kg/hm2中等施氮水平的尿素添加硝化抑制剂施肥方式利于大棚黄瓜获取较高的产量和具有较高的水分利用效率。     

机械深松营造"土壤水库"工程技术在兰州地区的推广研究

旱作区耕地的“犁底层”已成为农业耕作的一大障碍。介绍了机械深松营造“土壤水库”工程技术及推广研究中采用的方法和主要技术措施;综述了在兰州地区推广应用情况及对比试验结果;并分析探讨机械深松营造“土壤水库”工程技术的增产机理。经过分析认为,该技术是旱作区农业增效农民增收的有效途径,推广前景十分广阔。     

几种聚合材料包膜尿素的研制及评价方法研究

为研究尿素养分释放特性,以有机物质(淀粉A/聚乙烯醇V)为基底材料,无机非金属矿物(硅藻土G/膨润土P/沸石粉F)为改性材料制备复合材料并包膜尿素,测定了包膜尿素的成粒率及抗压强度,采用水中溶出率法与土壤培养法探讨了包膜肥料养分的释放规律,并对两种方法的测定结果进行比较。研究结果表明:包膜尿素各粒径颗粒成粒率差异显著,3种包膜尿素中粒径3~4 mm颗粒成粒效果最好,均在60%左右,成粒效果及抗压强度均表现为AVGUAVPUAVFU,说明粘结性能表现为AVGAVPAVF。包膜肥料在水、土两介质中的养分释放率与释放期均有所不同,AVFU在水中的初期溶出率高达30%,7 d累积释放率高达75.02%,释放期仅约为11 d;AVGU与AVPU氮素释放缓释性能显著,其初期溶出率仅为12%~15%,7 d累积释放率为42.24%~58.36%,释放期约为36~44 d;而在相同培养时间内土壤中养分溶出率仅为水中的26%~57%,但释放期增长到了42~112 d。在聚乙烯醇-淀粉聚合物的基础上添加改性剂能够对膜材料的耐水性能以及缓释效果有不同程度的优化,膜材料的吸水特性很好地保证肥料养分的缓慢释放,更好地为植物的生长提供养分。     

废水生物处理中的污泥颗粒化

文章综述了废水生物处理中的污泥颗粒化及其优点 ,总结了颗粒污泥反应器的发展与应用 ,并对反应器中污泥颗粒化的影响因素进行了讨论和分析