苦瓜挥发油对美洲斑潜蝇的产卵忌避和拒食作用

经气相色谱-质谱联用仪（GC／MS）分析,从苦瓜（Momordica chrantia L．）挥发油中检测出20种化学成分。在已检出的成分中,乙酸的含量最高,占挥发油总量的21．579％,其次是甲酸和苯甲酸,分别占7．855％和7．494％,5-乙基-2-呋喃酮、3-羟基-2-丁酮、1-羟基-2-丙酮等也占有很高的比例。苦瓜挥发油对美洲斑潜蝇的产卵、取食具有忌避作用,采用四臂嗅觉仪对美洲斑潜蝇成虫的行为反应进行测定,结果表明,美洲斑潜蝇成虫对这种挥发油具有相同的行为趋向。     

水杉种子挥发物质的鉴定及其抗菌活性测定

采用气质联用仪(GC-MS)测定水杉种子挥发油的化学组成,并采用生长速率法测定水杉种子挥发油对梨黑斑病菌(Alternaria kikuchiana)、苹果霉心病菌(A.alternata)、大蒜叶枯病菌(Stemphylium botryosum)、莴苣灰霉病菌(Botrytis cinerea)、小麦赤霉病菌(Fusarium graminearum)、茶轮斑病菌(Pestalotiopsis theae)、构骨炭疽病菌(Colletotrichum sp.)和大葱紫斑病菌(A.porri)8种植物病原真菌生长的影响。结果表明:水杉种子挥发油的主要成分为1R-α-蒎烯(46.355%)、柠檬烯(13.663%)、(1S-内型)-1,7,7-三甲基-二环[2.2.1]庚-2-醇乙酸酯(6.941%)、石竹烯氧化物(6.924%)、β-蒎烯(4.902%)、(1S)-6,6-二甲基-2-亚甲基-二环[3.1.1]庚烷(4.807%)等。水杉种子挥发油对8种植物病原真菌均有一定的抑制作用,其中100μL·培养皿-1剂量对大蒜叶枯病菌、小麦赤霉病菌、茶轮斑病菌的抑菌率在60%以上。本研究表明,水杉种子挥发物质中含有多种活性成分,在医药化工等方面有着广阔的应用前景,在农业上有一定的开发价值。     

4种植物提取物对美洲斑潜蝇的控制作用研究

应用4种植物的不同溶剂提取液对美洲斑潜蝇成虫进行产卵和取食驱避作用研究。结果表明：华南毛蕨的甲醇提取液对美洲斑潜蝇的产卵驱避效果最好，其驱避率为83．020％，其次是海南红豆的甲醇提取液和潺槁树的石油醚提取液，其产卵驱避率分别为64．120％和61．380％；在拒食作用方面，潺槁树氯仿提取液的拒食效果最好，其拒食率为64．100％；各种植物的乙醚提取液对美洲斑潜蝇的产卵和取食均有引诱作用。     

珠光香青挥发油对赤拟谷盗的趋避和触杀作用

采用水蒸气蒸馏法从珠光香青中提取挥发油,采用GC-MS方法分析其化学组成,并进行珠光香青挥发油对赤拟谷盗触杀和趋避的生物活性的测试。珠光香青挥发油的主要化学成分有石竹烯氧化物(35.94%)、八氢1,7-二甲基-4-(甲基乙烯基)-1,4-桥亚甲基-1氢-茚(11.84%)、2-异丙基-5-甲基-9-亚甲基-双环[4.4.0]-1-癸烯(11.78%)、桉油烯醇(7.91%)、喇叭茶醇(7.88%)、α-毕橙茄醇(6.25%)。生物活性测试结果显示,珠光香青挥发油对赤拟谷盗触杀的LD50值为41.25 mg/头,同时珠光香青挥发油对赤拟谷盗具有很强的趋避活性。     

不同供氮水平对广藿香产量与品质的影响

为探讨不同供氮水平对广藿香产量和品质的影响,采用砂培试验,研究了广藿香在3、 6、 12、 18、 24 mmol/L 5种不同氮水平下（用N1、 N2、 N3、 N4、 N5表示）氮营养、 生长性状、 产量、 挥发油含量和品质的变化。结果表明,随着供氮水平的提高,广藿香生长性状参数、 氮营养、 植株鲜（干）重量、 挥发油含量增加,茎和叶的油分含量下降。在广藿香的茎挥发油中,N1和N2处理的12种成分含量均显著高于N4与N5。-广藿香烯、 -愈创木烯、 苦橙油醇、 -愈创木烯、 反式-丁香烯、 广藿香醇、 广藿香酮含量以N1处理最高。刺蕊草烯、 -广藿香烯、 -愈创木烯、 -榄香烯、 异石竹烯含量在N2处理最高。在广藿香叶挥发油所测定的成分中,除了-广藿香烯外, N1和N2 处理的其他成分含量均显著高于N4与N5。-广藿香烯、 -愈创木烯、 -愈创木烯、 -荜澄茄烯、 异石竹烯、 -愈创木烯、 反式-丁香烯、 广藿香醇、 广藿香酮含量在N1处理最高。刺蕊草烯、 -广藿香烯、 -榄香烯含量以N2处理最高。广藿香茎和叶挥发油所测定的12种有效成分N1与N2及N4与N5处理之间无显著差异。总之提高氮水平有利于增加挥发油含量,但油分含量降低。     

广州地区美洲斑潜蝇寄生蜂种类及植物提取物对寄生蜂的影响

研究了广州地区美洲斑潜蝇寄生性天敌的种类及发生动态,以及华南毛蕨、苦瓜、飞机草等植物提取物对寄生蜂的影响。研究结果表明,广州地区美洲斑潜蝇寄生蜂有姬小蜂科、茧蜂科11种。主要寄生蜂为姬小蜂科种类,其中底比斯釉姬小蜂Chry socharis p entheus(W a lker)为寄生美洲斑潜蝇的优势寄生蜂,其次是丽灿姬小蜂Chry sonotomy ia f orm osa(W estw ood)和冈崎灿姬小蜂Ch.okazak ii(K am ijo)。研究了植物提取物对底比斯釉姬小蜂的羽化率和寄生率的影响,结果表明,植物提取物对寄生蜂是相对安全的,已商品化的印楝素乳油制剂对其也同样是安全的。     

紫苏挥发油化学成分GC/MS分析及抑菌评价研究

采用水蒸汽蒸馏法分别提取紫苏叶和花中挥发油,运用毛细管气相色谱-质谱联用法结合计算机检索对其挥发油进行化学成分分析,采用面积归一法测定了挥发油中各种成分的相对质量分数,利用抑菌贴片法、MIC法和光电浊度法分别对枯草芽孢杆菌和大肠杆菌进行了抑菌性研究。结果显示,从紫苏叶和花水蒸汽蒸馏所得挥发油中分别检测出12种和10种化合物,其中叶中主要成分为紫苏醛（75.88%）、柠檬烯（3.82%）、石竹烯（9.87%）和法呢烯（3.21%）;花中主要成分为紫苏醛（49.23%）、石竹烯（18.53%）、法呢烯（8.99%）、芳樟醇（11.3%）和姜黄二酮（4.55%）。紫苏精油对两种细菌均有很强的抑制作用,但对枯草芽孢杆菌的抑制能力要明显强于对大肠杆菌的抑制能力。     

山黄皮果挥发油成分研究

运用水蒸气蒸馏法分别从山黄皮果全果、果核和果皮（含肉）中提取挥发油,通过GC- MS分析,对其化学成分进行分离鉴定并测定了相对含量.山黄皮果挥发油有24个主要成分,占挥发油总量的98.91％.含量较高的有(+)-4-蒈烯(43.14％),肉豆蔻醚(34.43％),异松油烯(8.29),(+)-柠檬烯(4.16％),β-...     

番木瓜花挥发油提取及GC-MS分析

为研究番木瓜花的化学成分,以番木瓜花为材料,采用水蒸气蒸馏萃取法、挥发油提取器蒸馏萃取两种方式分别提取番木瓜花的挥发油,并利用气相色谱-质谱联用仪对提取出的番木瓜花的挥发油化学成分进行分离和鉴定。结果表明,利用挥发油提取器提取率约是水蒸气蒸馏法提取率的20倍,说明挥发油提取器提取效果更佳;通过GC-MS对样品进行分析发现,番木瓜花挥发油中主要包括苯乙醛、芳樟醇、古巴烯、石竹烯等成分,共26种化合物,其中9种是烷烯烃,8种是醇,2种是醛,1种是酯,1种是腈,1种是酚,4种其他化合物。     

黄土高原温室黄瓜斑潜蝇发生规律研究

通过大田调查与室内试验相结合的方法,研究了黄土高原温室黄瓜斑潜蝇发生规律。结果表明,黄土高原温室黄瓜斑潜蝇有4种,美洲斑潜蝇(Liriomyza sativae)为优势种,在温室内年发生8～10代,10月中旬～11月下旬为第一个发生高峰期,3月下旬至5月中旬为第二个发生高峰即防治关键时期。以各种虫态在温室内取食为害度过冬天,不能在田间自然条件下越冬。斑潜蝇幼虫在黄瓜植株上的垂直分布具有明显的层次性,以中下部密度最大,占90％以上。温度超过45℃持续2h或土壤相对湿度达100％超过20h,蛹羽化率均为0。温室种植模式、栽培面积及天敌等是影响斑潜蝇种群数量的主要因素。     

苦瓜提取物对美洲斑潜蝇产卵和取食行为的影响

对苦瓜藤叶提取物进行了萃取分离,并对所得5种萃取物和氯仿分离组分进行了选择性生物测定,结果表明,苦瓜的氯仿萃取物对美洲斑潜蝇的产卵驱避作用和拒食作用最强,其IIPC值和拒食率分别为0．11和77．67％。进一步对氯仿萃取物进行组分分离,并进行生物测定,发现萃取物各组分对美洲斑潜蝇的产卵驱避作用和拒食作用差别很大,2组分、3组分显示出较好的产卵驱避作用,其IIPC值均为0,其次是70％乙醇冲洗液。70％乙醇冲洗液表现出强烈的拒食作用,其拒食率为43．48％,其次是2组分,其拒食率为34．79％。     

The application of biochar on soil acidity and other physico‐chemical properties of soils in southern Ethiopia

The aim of this research was to investigate the effect of biochar amendment on soil acidity and other physico‐chemical properties of soil in Southern Ethiopia using a field experiment of three treatments: (1) biochar made of corn cobs, (2) biochar made of chopped Lantana camara stem, and (3) biochar made of Eucalyptus globulus feedstock and a control, in which neither of the biochar was used. Each treatment had three levels of 6, 12 and 18 t ha⁻¹. The experiment was setup with RCBD in a factorial arrangement with three replications. In this regard, a total of 36 plots (each 2 × 2 m size) were applied with three replications to the depth of 0–15cm. From these 36 plots, composite soil samples were collected to the depth of 0–30 cm and analyzed for bulk density, total porosity, pH, soil organic carbon, total nitrogen, available phosphorus, potassium, and exchangeable acidity using standard procedures before and after biochar application. Two‐way ANOVA was also used to analyze the impact of the biochars on soil acidity and other properties. For the treatments that had significant effects, a mean separation was made using Least Significance Difference (LSD) test. The results showed the application of biochar significantly reduced, soil bulk density and exchangeable acidity when compared with a control (p < 0.05). Moreover, the total soil porosity, soil pH, total nitrogen, soil organic carbon, available phosphorus, and potassium were significantly increased in the soil. From among applied biochar treatments, Lantana camara applied at the level of 18 t ha⁻¹ had a higher impact in changing soil physico‐chemical properties. In general, the study suggests that the soil acidity can be reduced by applying biochar as it can amend other soil physico‐chemical properties.     

日光温室番茄病虫害发生特点与生态控制技术研究

研究结果表明,在日光温室生产条件下,番茄病害有35种,害虫16种。主要病虫为灰霉病、叶霉病、早疫病、晚疫病、脐腐病、斑潜蝇和温室白粉虱,田间发生特点为种类多、危害期长、流行速度快、危害重和损失大。并提出以健康栽培、生态调控、棚室O3消毒、套袋保护、防虫网阻隔等措施为主,结合适时适度使用高效低毒化学农药的生态控制技术措施。田间应用实践证明,该方案有效阻止了病虫的扩散流行,成功控制了主要病虫危害,防治效果较为理想,并使产品达到安全优质标准。     

收获时气象因子对苏格兰型留兰香精油产量和品质的影响

通过对2001—2005年连续5a在西安市长安区种植苏格兰型留兰香小区试验及收获期气象资料分析，研究了收获时的降雨和温度对其精油产量和品质的影响。结果表明：收获时的降雨量和温度对苏格兰型留兰香精油产量有明显的影响。降雨量越大，出油率越低，精油产量越低，大雨之后可下降50％左右，一般雨后有连续3～5d晴天，出油率和精油产量可基本恢复到雨前水平；收获时温度越高，出油率越高，精油产量越高，日均温20℃以上，出油率和精油产量高。因此，苏格兰型留兰香应在连续3d以上晴天、日均温20℃以上收获为宜。     

Essential oils from Mediterranean lamiaceae as weed germination inhibitors

The essential oils obtained from rosemary (Rosmarinus officinalis L.), thyme (Thymus vulgaris L.), and savory (Satureja montana L.) and the four monoterpenes that are their major constituents have been analyzed by GC and GC-MS and tested for their allelopathic properties on the seeds of three different annual weeds (Chenopodium album, Portulaca oleracea, and Echinochloa crus-galli) and three crops (Raphanus sativus, Capsicum annuum, and Lactuca sativa), with the aim to evaluate in vitro their potential as germination inhibitors. The essential oil composition varied with the species, thymol being the main constituent (44%) of thyme and carvacrol (57%) that of savory oil. Differences in essential oil composition were observed within two different rosemary ecotypes, type A, with alpha-pinene (37%) and 1,8-cineole (23%), and type B, characterized by a 2-fold content of 1,8-cineole (47%). This latest essential oil inhibited completely the germination of weeds while concurrently displaying little effect on pepper. The other two oils showed less selective action. S. montana essential oil, with 57% carvacrol, is the most active compound, completely inhibiting germination both of crops and weeds. Borneol, one of the main constituents of the oil of rosemary type B, showed an activity comparable to that of the whole oil. Crop and weed seeds treated with 1,8-cineole showed germination values that were not significantly different from controls, even if a slowing of the germination process expressed in terms of a significant increase in mean germination time was observed. Monoterpene compounds also present in the essential oils mainly represented the volatile fraction released from the crops and their residues into the soil.     

Coriander spice oil: effects of fruit crushing and distillation time on yield and composition

Crushing intensity and distillation time were evaluated for their effects on the oil yield and composition of steam-distilled essential oil from fruits of Coriandrum sativum var. microcarpum L. A comparison of oils produced by laboratory- and pilot-scale stills showed that the two still types gave comparable yields and oil composition. The laboratory still was then used to compare oil yields and compositions from fruits crushed at three different intensities, at intervals during a distillation period of 60 min. Both crushing intensity and distillation time had significant (P< 0.05) effects on the yield and composition of the oil. The maximum oil yield was less from the light-crushed fruits, but the rate of oil recovery was significantly P < 0.05) higher. From the light-crushed fruits, 95% of the maximum yield was extracted in 22.5 min compared with 32 and 39 min for the standard and heavy-crushed fruits, respectively. The effect of crushing intensity on oil composition was most pronounced on the low-boiling-point a-pinene and on the higher-boiling-point geranyl acetate. Crushing had little effect on linalool content, but distillation time could be manipulated to alter the linalool content of the oil.     

The effect of phosphorus and mulching on the efficiency of phosphorus use and productivity of wheat grown on a mountain Alfisol in the Western Himalayas

Abstract. A field experiment was conducted over two years in one of the mountain Alfisols of the Western Himalayas to study the effects of phosphorus and mulching on phosphorus use efficiency (PUE) and productivity of wheat (cv. S-308) at difference growth stages. The source of phosphorus was single superphosphate at 0, 26, 52 and 78 kg P/ha whereas the sources of mulching materials were pine needles ( Pinus longifolia ), lantana weed ( Lantana camara ) at 8 t/ha and transparent polyethylene sheet compared with no mulch.
The phosphorus use efficiency (PUE) at tillering, flowering and harvesting was greatest at the lowest dose of P and decreased as the P levels were increased. However, the increased levels of P up to 78 kg/ha, significantly improved the dry matter yield at tillering stage (30%) and flowering stage (93%) and also the grain yield (139%) and straw yield (148%) at the harvest stage. The application of mulching materials in general, and polyethylene in particular, significantly increased the phosphorus use efficiency and the productivity of wheat by 27% at tillering stage; 17% at flowering stage, and by 98 and 110% in the case of grain and straw yield at harvest stage.
Although the polyethylene mulch effect was physically superior to the other materials, the latter gave greater financial returns. Consequently, the economic optimum application of P in association with 8 t/ha of lantana mulch was found to be 53 kg/ha over two years, whereas, in the absence of mulching, it was 58 kg/ha.     

Influence of the addition of rosemary essential oil on the volatiles pattern of porcine frankfurters

The effect of the addition of increasing levels of rosemary essential oil (150, 300, and 600 mg/kg) on the generation of volatile compounds in frankfurters from Iberian and white pigs was analyzed using solid-phase microextraction coupled to gas chromatography and mass spectrometry (SPME-GC-MS). Lipid-derived volatiles such as aldehydes (hexanal, octanal, nonanal) and alcohols (pentan-1-ol, hexan-1-ol, oct-1-en-3-ol) were the most abundant compounds in the headspace (HS) of porcine frankfurters. Frankfurters from different pig breeds presented different volatile profiles due to their different oxidation susceptibilities as a likely result of their fatty acid composition and vitamin E content. Rosemary essential oil showed a different effect on the generation of volatiles depending on the type of frankfurter in which they were added. In frankfurters from Iberian pigs, the antioxidant effect of the essential oil improved with increasing levels, showing the highest activity at 600 mg/kg. In contrast, 150 mg/kg of the essential oil improved the oxidative stability of frankfurters from white pigs, whereas higher levels led to no effect or a prooxidant effect. The activity of the essential oil could have been affected by the different fatty acid compositions and vitamin E contents between types of frankfurters. SPME successfully allowed the isolation and analysis of volatile terpenes from frankfurters with added rosemary essential oil including alpha-pinene, beta-myrcene, l-limonene, (E)-caryophyllene, linalool, camphor, and 1,8-cineole, which might contribute to the aroma characteristics of frankfurters.