3种喷雾助剂对呋虫胺防治苹果黄蚜的增效作用

采用室内毒力测定、助剂润湿铺展性能和田间效果评价研究了3种功能助剂NF-100、GY-T1602和迈道对呋虫胺防治苹果黄蚜的减施增效作用。结果表明,NF-100、GY-T1602和迈道3种助剂均未能提高呋虫胺对苹果黄蚜的毒力;20%呋虫胺SG 1 110～5 000倍液中分别添加0.1%NF-100、0.5%GY-T1602和0.3%迈道,表面张力降低6.97～37.44 mN/m、静态接触角降低10.58°～48.67°、黏附张力增加2.32～21.71 mN/m; 20%呋虫胺SG(有效成分用量32 mg/kg)减量处理添加3种助剂药后3～15 d对苹果黄蚜田间防效达90.83%～99.33%,其中添加NF-100和GY-T1602药后15 d防效均显著高于添加迈道处理及20%呋虫胺SG(40 mg/kg)未减量处理。因此,喷雾助剂NF-100和GY-T1602可显著改善呋虫胺药液的润湿铺展性能,减少呋虫胺有效成分用量20%,对苹果黄蚜仍有较高防效、且持效期延长。     

天然胶乳凝固方法的研究进展

对多年来天然胶乳凝固方法及其研究进展进行综述并作比较分析,指出盐凝固将有望取代目前常用的酸凝固,满足制胶工业规模化生产。     

两种季铵盐阳离子表面活性剂对水生生物的毒性效应

为评价两种季铵盐阳离子表面活性剂对水生态的安全性,运用评价化学品对水生生物毒性的标准试验方法,测定了十二烷基二甲基苄基氯化铵(1227)和双八、十烷基季铵盐(C8-10)两种季铵盐阳离子表面活性剂对3种水生生物(斜生栅藻、大型溞和斑马鱼)的毒性。结果表明,在0.05~0.5 mg.L-1的浓度范围内,1227、C8-10对斜生栅藻的毒性表现出明显的剂量-效应关系,随处理浓度的增大抑制效应增强,0.5 mg.L-1C8-10对斜生栅藻具有杀灭作用;同时1227、C8-10与斜生栅藻还存在时间-效应关系,处理后抑制率随时间呈先升高后下降的趋势,72 h时抑制率最高。1227和C8-10对斜生栅藻96 h的EC50分别为0.109、0.103 mg.L-1,对大型溞的48 h LC50分别为1.56×10-2、1.45×10-2mg.L-1,对斑马鱼的96 h LC50分别为2.36、2.19 mg.L-1。C8-10对3种水生生物的毒性均高于1227,两种季铵盐阳离子表面活性剂对大型溞和斑马鱼的致死率(LC50)均随作用时间延长逐渐减小。     

Proper adjuvant selection to enhance the activity of triclopyr combined with metsulfuron on the control of Hedyotis verticillata

A study was conducted to evaluate the combined activity of a tank mixture of triclopyr plus metsulfuron with non-ionic surfactant (NIS), crop oil concentrate (COC), and organosilicon (OS) adjuvants on the control of Hedyotis verticillata under glasshouse and field conditions. The results of both the glasshouse and field experiments showed that 160 g ai ha⁻¹ triclopyr plus 0.2 g ai ha⁻¹ metsulfuron and 320 g ai ha⁻¹ triclopyr plus 0.4 g ai ha⁻¹ metsulfuron, with the addition of 0.25% NIS, 0.05% COC, or 0.05% OS, were effective in controlling H. verticillata . A comparison of the cost revealed that the most cost-effective combination for controlling H. verticillata is 160 g ai ha⁻¹ triclopyr plus 0.2 g ai ha⁻¹ metsulfuron combined with 0.25% NIS.     

十二烷基苯磺酸钠对乐果在水-气界面挥发动力学的影响研究

以有机磷农药乐果为研究对象,研究了不同浓度的阴离子型表面活性剂十二烷基苯磺酸钠（SDBS）存在时,乐果在水一气界面的挥发行为,以进一步认识农药的迁移转化规律,为复合污染水体中表面活性剂对有机物挥发的影响提供理论依据。研究结果表明：在试验条件下,乐果水溶液在水-气界面的恒温挥发过程符合一级动力学,并且其挥发行为受到表面活性剂的影响作用显著。不同浓度的表面活性剂对乐果挥发的影响不同,与未加入表面活性剂时乐果的挥发情况相比,当加入的SDBS浓度小于临界胶束浓度（CMC）时对乐果的挥发具有促进作用;当SDBS浓度超过CMC,乐果的挥发行为受到抑制,挥发速率开始变小。     

Effect of Salinity Stress and Surfactant Treatment on Physiological Traits and Nutrient Absorption of Fenugreek Plant

Salinity is considered as a major abiotic stress affecting crop production in arid and semi-arid regions in the world. Surfactants can improve water-use efficiency in saline soils and improve crop yield. This study was conducted to evaluate the effect of salinity stress and surfactant treatments on photosynthetic pigments and nutrition elements of fenugreek in the Crop and Soil Science greenhouse at the Pennsylvania State University (University Park, PA, USA) in 2013. The experiment was conducted using a 5 × 3 factorial randomized complete block design with three replications. Factor A consisted of five salinity levels [0, 4, 6, 8, and 10 ds m^–1 sodium chloride (NaCl)] while factor B consisted of three nonionic surfactant levels (0, 1, and 3 ppm). The results indicated a stepwise reduction in photosynthetic pigments of fenugreek as salt stress increased, however, Peroxidase and polyphenol oxidase activity increased in fenugreek leaves as salinity stress increased. Levels of surfactant application had different effects on nutrient uptake. Some nutrient elements such as sodium, phosphorus, copper, manganese, and zinc content increased while others decreased at high salinity conditions. Surfactant application rate of 3 ppm at moderate and high salinity levels and 1 ppm at lower salinity levels had a good performance in enhancing the total photosynthetic and carotenoid activities in fenugreek.     

Triton X-100对漆酶处理苯酚的影响

研究了Triton X-100对漆酶氧化去除水溶液中苯酚的作用.苯酚和漆酶浓度分别是50 mg/L和 0.05 mg/mL时，提高苯酚去除率的Triton X-100最佳浓度是155 μM．Triton X-100的浓度从31~930 μM时漆酶活性随之增长，在930 μM Triton X-100存在时有最大增值17%.苯酚的初始浓度分别为50, 100, 200, 400和600 mg/L 时，155 μM Triton X-100作用下6 h后，苯酚去除率分别是对照组的1.2, 1.6, 3.4, 4.5和5.7倍.结果表明Triton X-100可以作为水处理或修复过程的添加剂来提高由漆酶催化的苯酚去除率.     

Biocontrol efficacy of Colletotrichum truncatum for hemp sesbania (Sesbania exaltata) is enhanced with unrefined corn oil and surfactant

In greenhouse and field experiments, an oil-in-water emulsion of unrefined corn oil and Silwet L-77 increased the biological weed control efficacy of Colletotrichum truncatum (Schw.) Andrus et Moore for control of the weed, hemp sesbania ( Sesbania exaltata [Raf.] Rydb. ex A.W. Hill). The surfactant – corn oil emulsion stimulated germination and appressoria formation in vivo and in vitro and delayed the need for dew. We hypothesize that the corn oil protected the conidia from desiccation during the dew-free period and the surfactant stimulated spore germination and appressoria formation. In field experiments conducted over 3 years, a single application of a 50% (v/v) unrefined corn oil tank mixture containing 0.2% (v/v) Silwet L-77 surfactant controlled hemp sesbania in soybeans an average of 95%. Aqueous fungal suspensions or adjuvants alone did not visually affect or control hemp sesbania. The soybean yields were significantly higher in the plots where weeds were effectively controlled. These results suggest that formulating C. truncatum in unrefined corn oil and surfactant greatly increases its infectivity and the biocontrol potential of this pathogen.     

Nutritional composition,growth and enzymatic response of vetiver grass grown under crude oil contamination as influenced by gibberellic acid and surfactant

Abstract

Although crude oil contamination is a constraint for crop production, some plants can develop under crude oil contaminated conditions by utilizing crude oil as nutrients after decomposition. A greenhouse trial was conducted to investigate growth, nutritional composition and enzymatic response of vetiver grass in confronting with crude-oil contamination as affected by gibberellic acid (GA) and Tween 80. Application of GA or co-application of GA with Tween 80 significantly increased mean shoot dry weight. Application of Twee 80 alone or in combination with GA significantly increased mean root dry weight as compared to control which was attributed to the effectiveness of Tween 80 alone or in combination with GA on the removal of total petroleum hydrocarbons from polluted soil. Application of crude oil diminished shoot phosphorus, iron, zinc and manganese uptakes. Application of GA and Tween 80, however, compensated the decrease in nutrient uptakes in vetiver grass resulted from crude-oil contamination. Application of crude oil at both 2 and 4% (W/W) levels increased catalase (CAT) activity and proline (PRO) content. Superoxide dismutase (SOD) activity increased only following the application of 2% crude oil level, while addition of all amendments decreased CAT activity. Addition of GA decreased activity of SOD. None of the studied amendments had a significant effect on PRO content. Application of a combination of GA and Tween 80 under crude oil contamination are recommendable since such treatments not only inhibited adverse effect of crude oil on nutrients uptake but also caused that vetiver grass tolerated high level of crude oil contamination.