旅游干扰对鸡公山国家级自然保护区土壤理化性质的影响

采用野外调查和室内分析的方法,研究了河南鸡公山国家级自然保护区内森林风景区土壤理化特征对不同旅游干扰强度和干扰距离的响应。结果表明,重度干扰的土壤容重(1.23 g·cm^-3)显著高于轻度(1.03 g·cm^-3)和中度(1.07 g·cm^-3)干扰的(P<0.05),而其土壤总孔隙度(57.5%)则显著低于轻度(61.3%)和中度(59.6%)干扰的(P<0.05);中度及重度干扰下的土壤全氮含量(1.9 g·kg^-1和1.8 g·kg^-1)和有机碳含量(19.3 g·kg^-1和21.2g·kg^-1)均显著低于轻度干扰的(2.2 g·kg^-1和26.8 g·kg^-1)。与背景区(距干扰中心区边缘外10 m以上)相比,干扰导致缓冲区(距干扰中心区边缘外3~10 m)的土壤容重和总孔隙度变化随着干扰强度的增加而下降,而核心区(位于干扰中心区0~1 m)的土壤容重和总孔隙度的变化随干扰强度的增加而增加。以上研究结果可为森林风景区的规划和科学管理提供参考。     

重庆开县猕猴桃溃疡病药效试验研究初报

猕猴桃溃疡病是毁灭性病害,目前化学防治是预防该病的主要措施。试验采用碧生20％（噻唑锌）悬浮剂、可杀得1 01、农用链霉素72％可溶性粉剂、1．8％辛茵胺和有机硅对猕猴桃溃疡病防治进行药效研究。结果表明,蓰用链霉素72％可溶性粉剂1 000倍液对猕猴桃溃疡病防治效果最好,碧生20％（噻唑锌）悬浮剂、可杀得1 01、1．8％辛菌胺防治效果其次,且这5种药剂之间药效差异不显著。     

神农香菊化学成分及药理作用研究进展

介绍了神农香菊主要化学成分的研究成果,比较了花、茎、全草和叶等不同组织中主要活性成分的异同,并综述了其抑菌能力、抗氧化能力以及药用价值的最新研究进展。     

棕榈油的改性研究进展

概述了棕榈油组成、性质,综述了棕榈油的改性以及改性后在食品工业、日化工业及动力燃料上的应用,并对棕榈油的应用前景进行了展望。研究表明,棕榈油有着极高的利用价值和可再生性,可以为多个领域的可持续发展做出贡献,如可做成食用调和油、奶油、洗洁用品、化妆品、生物柴油等一系列的产品。棕榈油的改性利用前景广阔。     

Impacts of atmospheric CO<Subscript>2</Subscript> concentrations and soil water on the population dynamics,fecundity and development of the bird cherry-oat aphid<Emphasis Type="Italic">Rhopalosiphum padi</Emphasis>

The impacts of elevated CO₂ and soil water on the population dynamics, adult fecundity and nymphal period of the bird cherry-oat aphidRhopalsiphum padi (Linnaeus) were evaluated in three experiments: (i)Combined effects of CO ₂ and soil water on aphid populations. Spring wheat was grown in pots at three CO₂ concentrations (350, 550 and 700 ppm) and three soil water levels (40%, 60% and 80% of field water capacity, FWC) in field open-top chambers (OTC) and infested with the bird cherry-oat aphid. Aphid population dynamics were recorded throughout the growing season; at the same time, adult fecundity and duration of the nymphal period were recorded. Chemical composition of spring wheat leaves was also analyzed. (ii)Indirect effects of CO ₂ concentrations and soil water on aphid adult fecundity and nymphal period. The experiment was conducted with the leaf discs method in the laboratory. Aphids were reared on leaf discs excised from the treated wheat in OTC with different CO₂ and soil water levels. (iii)Direct effects of CO ₂ concentrations on aphid adult fecundity and nymphal period. Aphids were reared on leaf discs excised from the wheat grown under natural conditions. The experiment was conducted with the leaf disc method in OTC with the three CO₂ concentrations. It was found that the direct effect of CO₂ concentration on aphid population parameters was minor. CO₂ and soil water affected aphid population indirectly through their effects on wheat characteristics. The aphid population under 550 ppm CO₂ was far larger than the one under 350 ppm CO₂, whereas the population under 700 ppm CO₂ was slightly higher than that under 550 ppm CO₂. The largest aphid population was obtained with the 60% soil water treatment, regardless of CO₂ treatment. The effects of CO₂ concentration on aphid population were, however, not significantly correlated with soil water level. Adult fecundity increased with CO₂ concentration, the highest fecundity being achieved under 60% FWC treatments. The nymphal period was not affected by CO₂ concentration. The shortest period occurred under 60% FWC. Atmospheric CO₂ and soil water had significant effects on the chemical composition of the wheat leaves. Aphid population size was positively correlated with leaf water content, concentrations of soluble proteins, soluble carbohydrates and starch, and negatively correlated with DIMBOA and tannins concentrations. http://www.phytoparasitica.org posting Oct. 20, 2003.     

有机肥部分替代化肥对春暖式大棚西兰花产量和品质的影响

为实现春暖式大棚西兰花优质高产高效生产,在等氮条件下研究有机肥不同比例（0、15%、30%、45%、60%）替代化肥对春暖式大棚西兰花产量、效益、品质以及土壤养分的影响。结果表明:春暖式大棚有机肥部分替代化肥处理西兰花产量都有所提高,土壤有机质、全氮、有效磷和速效钾含量均有增加趋势。与CK相比较,30%比例替代处理每667 m²增效115.88元;45%和60%比例替代处理的西兰花蛋白质和可溶性糖含量均增加,硝酸盐含量均下降。综合春暖式大棚西兰花产量、效益、品质和土壤养分等因素,有机肥部分替代化肥（氮）以30%为最佳。     

等养分含量有机肥替代化肥对辣椒生产的影响

摘要：为有效减少辣椒生产中的化肥施用量,以卓椒8号为试验材料,研究了常规施肥、等养分商品有机肥分别代替100%、1/2、2/3化肥对辣椒生物学性状、经济性状、抗病性、抗逆性和产量的影响。结果表明：与常规施肥相比,等养分有机肥适宜比例替代化肥可改善辣椒商品性状,提高产量,替代比例为1/2时最有利于延长辣椒生育期,株高、茎粗、果长、果肉厚度和产量分别增加了20.34 cm、0.37 cm、2.5 cm、0.047 mm和67.05%,建议在实际生产中推广使用。     

不同有机废弃物组合肥对灰棕荒漠土理化性质和玉米产量及经济效益的影响

系统研究了4种不同有机废弃物组合肥对灰棕荒漠土理化性质和玉米产量及经济效益的影响,结果表明:有机废弃物糠醛渣、羊粪、玉米秸秆、菜籽饼按0.50∶0.25∶0.20∶0.05容积比,经高温发酵处理,施用量为45.00 t/hm2对灰棕荒漠土理化性质和玉米产量及经济效益有良好的影响,与不施有机废弃物(对照)比较,土壤总孔隙度、团粒结构、贮水量分别增加8.69%、8.73%、91.36 m3/hm2;土壤有机质、碱解N、速效P、速效K、CEC分别增加5.86 g/kg 、21.42 mg/kg 、7.47 mg/kg 、42.67 mg/kg 、13.07 cmol/kg;玉米产量、产值、利润分别增加2.03 t/hm2、0.19×104 元/hm2、0.08×104 元/hm2;土壤容重降低0.28 g/cm3.灰棕荒漠土上施用生活垃圾,重金属离子有富集的趋势,而长期施用糠醛渣、蘑菇渣、锯末则无此效应.     

咯菌腈羧酸衍生物内吸传导性及对香蕉枯萎病的防效测定

为研发用于防治香蕉枯萎病的维管组织导向杀菌剂,基于植物韧皮部“离子井”效应对非内吸杀菌剂咯菌腈进行弱酸化结构修饰,在蓖麻模型上完成韧皮部输导性筛选和机制验证,通过盆栽试验研究咯菌腈羧酸衍生物在香蕉植株上的输导分布,并测定衍生物对香蕉枯萎病的防效。结果表明：羧酸基团引入使咯菌腈衍生物在蓖麻幼苗上表现出韧皮部输导性,证明存在pH依赖的“离子井”效应机制;盆栽试验结果显示,衍生物1a在被叶片吸收后能向下传递到香蕉植株球茎和根部,并能够降解释放出咯菌腈,对香蕉枯萎病的防效为54.5%,显著高于咯菌腈原药处理组的防效6.5%。表明基于韧皮部“离子井”效应的结构修饰是香蕉维管组织导向杀菌剂研发的有效途径。