西宁地区草坪阔叶杂草防除试验

于2001和2003年4-6月对西宁地区草坪阔叶杂草进行了除草剂药效试验。结果表明,5种药剂试验处理中,72%2,4-D丁酯与48%百草敌药效最好,防效分别为89.8%和87.9%,75%杜邦巨星药效较好,防效为85.2%,药效较差的是10%甲磺隆,防效为52.9%,25%氯磺隆药效最差,防效为37.6%。浓度筛选试验中,72%2,4-D丁酯400倍液与500倍液药效最好,防效分别为97.5%和96.7%,48%百草敌1 000倍液与1 300倍液防效分别为92.9%和92.3%,药效较好,75%杜邦巨星10 000倍液药效较差,防效为87.9%,其中以72%2,4-D丁酯500倍液的防除成本最低,其次是48%百草敌1 300倍液,防除成本最高的是75%杜邦巨星10 000倍液,从防除效果和成本2方面综合考虑,72%2,4-D丁酯为西宁地区防除草坪阔叶杂草较理想的除草剂,田间推荐剂量为500倍液。     

草坪阔叶杂草防除技术研究

在2000～2001年两年问,应用使它隆乳油、阔草克乳油、丁甲颗粒剂、杂8颗粒剂、2甲4氯钠盐、2,4-D丁酯六种选择性除草剂及其混剂对华中农业大学校园草坪杂草进行防除试验.结果表明使它隆、阔草克、72%2甲4氯、72%2,4-D乳油以及两种混剂对几种主要杂草防效比较好,30d的防效能达到100%,而且两种混剂有增效作用,扩大了除草剂的使用范围,比单独使用的防效有所提高.     

除草剂2,4-D丁酯对皮燕麦安全性和产量的影响及其残留动态分析

以陇燕3号为试验材料,喷施低、中和高3个剂量(450, 750和1050 mL·hm^-2)的2,4-D丁酯,在药后1,7,14,21,28 d以及开花期、灌浆期植株和收获后籽粒中测定2,4-D丁酯残留量,探讨不同剂量2,4-D丁酯处理对杂草防效、燕麦的安全性、株高和产量的影响。结果表明,2,4-D丁酯对燕麦安全性、产量及田间杂草防效影响显著。高剂量下燕麦出现顶端下垂、叶尖发红和药斑等药害现象。杂草防效随2,4-D丁酯施用剂量的增加而提高。高剂量除草剂喷施后45 d,株防效较药后30 d仍有小幅上升,鲜重防效达到90%以上。3个剂量均使株高有一定程度的降低,高剂量下燕麦株高较对照降低了10.49%。低剂量下干草产量有所降低,但与对照差异不显著(P>0.05),籽粒增产22.64%;中剂量下燕麦干草产量呈增加趋势,籽粒增产40.57%;高剂量下,燕麦干草产量下降了8.85%(P<0.05)。2,4-D丁酯及2,4-D在皮燕麦中的残留量随除草剂施用剂量的增加而上升。施药28 d后,高浓度下燕麦中2,4-D丁酯和2,4-D残留量最高,达0.168 和0.011 mg·kg^-1,显著(P<0.05)高于低浓度处理。综上所述,本试验条件下,750 mL·hm^-2为皮燕麦田2,4-D丁酯的最佳使用剂量。     

草坪阔叶杂草的防除技术研究

2001～2002年,应用百草敌、2,4-D丁酯乳油、2甲4氯丙酸及混合药剂对西宁郊区石头磊实验地草坪杂草进行防除实验.结果表明百草敌、2,4-D丁酯乳油及混合物药剂Ⅰ对几种主要杂草防除效果比较好,与对照相比较,30 d能达到100%,且两种混剂有增效作用,扩大了除草剂的使用范围.     

混配除草剂对燕麦田杂草的防效及燕麦产量的影响

为了筛选适宜燕麦(Avena sativa)田使用的安全、高效的混配除草剂组合,选用96%精异丙甲草胺乳油和10%苄嘧磺隆可湿性粉剂、57%2,4-D丁酯乳油和10%乙羧氟草醚乳油按照不同比例两两组合,混配后施于燕麦田,研究其对燕麦田杂草的防除效果以及对燕麦安全性和产量的影响。结果表明,不同除草剂处理对杂草的防效差异显著(P 0.05),混配处理的防效普遍高于各单剂处理。T5和T9对杂草的防效最好,但后者对燕麦有药害。综合安全性、除草效果及对燕麦的增产作用,筛选出综合效应最佳的混配组合,即57%2,4-D丁酯乳油438.5 mL·hm~(–2)+10%乙羧氟草醚乳油300 mL·hm~(–2)(T12);其药后30 d的鲜重防效达87.99%,燕麦干草产量为9 875.3 kg·hm~(–2),燕麦种子产量为4 314.3 kg·hm~(–2)。     

草坪阔叶杂草的防除技术研究

2001￣2002年,应用百草敌、2,4-D丁酯乳油、2甲4氯丙酸及混合药剂对西宁郊区石头磊实验地草坪杂草进行防除实验。结果表明:百草敌、2,4-D丁酯乳油及混合物药剂I对几种主要杂草防除效果比较好,与对照相比较,30d能达到100%,且两种混剂有增效作用,扩大了除草剂的使用范围。     

草坪阔叶杂草防除技术研究

在2001～2002年两年间,应用百草敌、2,4-D丁酯乳油、2-甲-4-氯丙酸及混合药剂对青海大学农牧学院草业科学系试验地草坪杂草进行防除试验.结果表明百草敌、2,4-D丁酯乳油及混合药剂Ⅰ对几种主要杂草防除效果比较好,与对照相比30 d能达100%,而且两种混合药剂有增效作用,扩大了除草剂的使用范围.     

几种除草剂对肃南栽培草地主要杂草防除试验研究

为筛选出适合甘肃省肃南牧区栽培草地主要杂草防除的除草剂,以栽培草地播前和苗后2个时期为试验地,选择2,4-滴丁酯乳油,40%磺草-莠去津和30%草甘膦水剂3种除草剂,开展5个不同剂量处理下的杂草防除试验。结果表明：栽培草地播前,30%草甘膦有效成分剂量为1.65L/hm^2时,对赖草防除效果达到了94.68%,同时对栽培草地的发芽和出苗都没有影响,是比较理想的播前除草剂。苗后2,4-滴丁酯乳油有效成分剂量为3.60L/hm^2时对以大蓟、叶蒿和藜为优势杂草的栽培草地防效较好,防效分别达78.92%,85.08%和95.83%。     

3种除草剂对苗期刺萼龙葵的防除试验

采用3种化学除草剂[质量分数为72%2,4-D丁酯乳油、质量分数为20%的克草胺+20%的莠去津悬浮剂和质量分数为20%的百草枯水剂]、设9个剂量水平,对刺萼龙葵(Solanum rostratum)的苗前期、子叶期幼苗、一叶期幼苗、二叶期幼苗、三叶期幼苗、四叶期幼苗进行室内防除试验.结果表明,72%2,4-D丁酯乳油...     

草坪阔叶杂草防除技术研究

在 2 0 0 0～ 2 0 0 1年两年间 ,应用使它隆乳油、阔草克乳油、丁甲颗粒剂、杂 8颗粒剂、 2甲 4氯钠盐、 2 ,4-D丁酯六种选择性除草剂及其混剂对华中农业大学校园草坪杂草进行防除试验。结果表明 :使它隆、阔草克、 72 %2甲 4氯、 72 %2 ,4-D乳油以及两种混剂对几种主要杂草防效比较好 ,3 0d的防效能达到 1 0 0 %,而且两种混剂有增效作用 ,扩大了除草剂的使用范围 ,比单独使用的防效有所提高。     

Growth Regulator Herbicides Prevent Invasive Annual Grass Seed Production Under Field Conditions

Growth regulator herbicides, such as 2,4-D, dicamba, picloram, and aminopyralid, are commonly used to control broadleaf weeds in rangelands, noncroplands, and cereal crops. If applied to cereals at late growth stages, while the grasses are developing reproductive parts, the herbicides often reduce cereal seed production. We are researching methods for using this injury response to control invasive annual grasses in rangelands by depleting their short-lived seed banks. In a previous greenhouse study, we found picloram and dicamba reduced seed production of the invasive annual grass Japanese brome (Bromus japonicus Thunb.) by nearly 100%. However, this promising greenhouse finding needs to be corroborated in the field before growth regulators can be confidently recommended for invasive annual grass control. This research note describes a study conducted in eastern Montana suggesting growth regulators may provide excellent control of invasive annual grasses. Specifically, we found typical use rates of aminopyralid and picloram reduced Japanese brome seed production by more than 95% (based on sample means) when applied at three different plant growth stages. This promising result contributes to the accumulating body of evidence suggesting growth regulators may control invasive annual grasses.     

4种除草剂对皮燕麦、裸燕麦不同生育时期光合特性的影响

为探讨除草剂对燕麦光合特性的影响,采用完全随机区组设计,测定4种除草剂48%仲丁灵、40%二甲.辛酰溴、72%2,4-D丁酯和75%苯磺隆处理下皮燕麦品种陇燕3号(Avena sativa cv.Longyan No.3)和裸燕麦品种燕2号(Baiyan No.2)的叶绿素相对含量(SPAD)值和净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)及蒸腾速率(Tr)等光合指标。结果表明:4种除草剂均降低了皮、裸燕麦的SPAD、Pn、Gs、Tr和气孔限制值(Ls);4种除草剂对皮、裸燕麦的影响不同,其中48%仲丁灵和40%二甲.辛酰溴对光合作用影响较小,72%2,4-D丁酯和75%苯磺隆危害较大;皮、裸燕麦间对除草剂的反应存在差异,皮燕麦对4种除草剂的敏感性大于裸燕麦。     

Quercetin protects spermatogonial cells from 2,4-d-induced oxidative damage in embryonic chickens

Quercetin, an antioxidant flavonoid, is considered beneficial to human and animal health. In this study, the protective effects of quercetin in relation to oxidative damage of testicular cells were studied by analysis of the intracellular antioxidant system after treatment of embryonic chickens with hypoxanthine-xanthine oxidase (HX-XO) or 2,4-dichlorophenoxyacetic acid (2,4-D). Testicular cells from Day 18 embryos were challenged with quercetin alone or in combinations with HX-XO or 2,4-D for 48 h in culture. The results showed that quercetin manifested no deleterious effects on spermatogonial cells at concentrations up to 1.0 microg/ml. Exposure to HX-XO or 2,4-D (50 microg/ml) induced condensed nuclei and vacuolated cytoplasm and a decrease in testicular cell viability and spermatogonial cell number. Membrane integrity was damaged by elevated lactate dehydrogenase leakage. Exposure to HX-XO or 2,4-D also elicited lipid peroxidation by elevation of thiobarbituric acid reactive substances and decreased glutathione content and superoxide dismutase activity. However, simultaneous supplementation with quercetin restored these parameters to the levels in the controls. Consequently, HX-XO and 2,4-D induced oxidative stress in spermatogonial cells; however, dietary quercetin may attenuate the negative effects of environmental toxicants and restore the antioxidant system in testicular cells.     

Studies on the Animal Metabolism of Phenoxyacetic Herbicides

Gel filtration on Sephadex was applied to the study of plasma protein binding af 2,4-dichlorophenoxyacetic acid (2,4-D). Equilibrated with horse plasma and eluted with buffer pH 7.4, 2,4-D was recovered to 2 % in the plasma protein fraction (K_D 0), free 2,4-D being eluted at a K_D value of 2.2. When 50 % plasma in buffer was used as the eluant the mobility of 2,4-D increased considerably (K_D decreasing to 0.95), thus confirming the existence of a 2,4-D-protein interaction.Hydrolysis experiments in conjunction with thin-layer chromatography revealed no conjugation of 2,4-D in plasma of pigs and rats given 2,4-D amine orally and only slight conjugation, not exceeding 20 %, in urine of pigs, given 2,4-D amine orally.2,4-D butyl ester administered orally to pigs and rats was shown to be rapidly hydrolyzed to 2,4-D acid, only trace amounts of ester being detectable in body fluids and tissues.     

Oral intubation of dogs with combinations of fertilizer, herbicide, and insecticide chemicals commonly used on lawns

Six Beagle dogs were orally intubated with mixtures of a urea-based fertilizer, 2,4-D, mecoprop (MCPP), dicamba, and either bensulide or chlorpyrifos. The mixtures were formulated as they are used in liquid application to lawns. The dogs were given volumes of 10 ml/kg of body weight, delivering the following quantities of each ingredient: urea--623 mg/kg, inorganic phosphorus (P2O5)--24 mg/kg, potassium (K2O)--66 mg/kg, 2,4-D--6.5 mg/kg, MCPP--3.26 mg/kg, dicamba--0.55 mg/kg, and either bensulide--60.93 mg/kg or chlorpyrifos--6.77 mg/kg. The dogs were given 3 consecutive daily doses of the mixture containing bensulide (round 1) or the mixture containing chlorpyrifos (round 2). The dogs did not exhibit any clinical signs of illness associated with the treatments. Effects on hematologic values or routine clinical chemical analyses did not occur with the round 2 mixture. Serum lactic dehydrogenase activity decreased by approximately 50% after a single dose of the round 1 mixture was given. Plasma cholinesterase decreased to approximately 50% of control values following either the round 1 or the round 2 mixture; this decrease was not accompanied by cholinergic signs of intoxication.     

白羊草成熟胚组织培养及植株再生体系的建立

以白羊草(Bothriochloa ischaemum(L.)Keng)成熟胚为外植体,研究不同激素及其不同配比对愈伤组织诱导发生与生长状态及其绿苗分化能力的影响。从而建立了白羊草植株再生体系,为开展生物技术育种提供参考。结果表明:在愈伤组织诱导培养基中添加2.0 mg/L 2,4-D诱导频率为86.7%,MSB和MS培养基对愈伤组织诱导效果相近;在其继代培养基中添加1.0 mg/L 2,4-D愈伤组织增殖快,且保持胚胎发生能力;适宜的分化培养基为6-BA 0.1 mg/L+NAA 0.05 mg/L,分化率达61.3%;愈伤组织在不添加任何生长调节剂的培养基上即可生根。     

两个高羊茅品种成熟种子再生体系的建立

以2个高羊茅品种(“Plantation”和“沪坪1号”)的成熟种子为外植体,在MS培养基上分别添加不同浓度的2种植物生长调节剂,探索其愈伤组织的诱导、继代和分化的最佳激素配比及其相互间的影响,以建立简便高效的再生体系。结果表明,完整高羊茅种子最佳的愈伤诱导培养基为MS+2,4-D 3 mg/L,诱导率为71%;而把成熟种子进行纵切后得到的半粒种子的较优的愈伤诱导培养基为MS+2,4-D 2.5 mg/L,诱导率占半粒种子外植体的60%,占完整种子(2个半粒种子)外植体的90%以上;在最优诱导培养基上产生的愈伤组织的最佳继代培养基为MS+2,4-D 3 mg/L,其胚性愈伤诱导率为70%,而添加6-BA则抑制2,4-D对胚性愈伤组织的诱导;不同品种的最优的分化培养基不同——“Plantation”的最优分化培养基为MS+2,4-D 1 mg/L+6-BA 1 mg/L,而“沪坪1号”的最佳组合是MS+2,4-D 2 mg/L+6-BA 1 mg/L,分化率分别达到50%和56%。生根培养基采用已报道的组合1/2MS+NAA 0.5 mg/L,生根率达100%。     

新疆野生黄花苜蓿愈伤诱导及分化的研究

以新疆野生黄花苜蓿(Medicago falcata L.)为材料,通过愈伤组织诱导及分化途径获得再生植株;从种子硬实、外植体、激素(2,4-D和KT)、培养基方面探讨野生黄花苜蓿组织培养的影响因素。结果表明:4℃低温处理与浓硫酸浸种结合是破除黄花苜蓿硬实的较优方法,发芽率达90%;下胚轴为诱导愈伤组织的最佳外植体;MS培养基比改良的SH培养基对愈伤组织的诱导更有效,MS诱导培养基为MS+2,4-D 0.5 mg·L^-1+KT 0.8 mg·L^-1+蔗糖30 g·L^-1+琼脂粉7 g·L^-1,出愈率达到80%;浅绿色和浅黄色的愈伤组织在MS+2,4-D 0.2 mg·L^-1+KT 0.4 mg·L^-1+CH 1 g·L^-1+蔗糖20 g·L^-1+琼脂粉7 g·L^-1的培养基上分化较好,分化率为30%。研究结果将为黄花苜蓿生物技术育种奠定一定的基础。     

2,4-D对匍匐翦股颖不同品种愈伤组织诱导和分化的影响

以匍匐翦股颖Penn A-1和Penn A-4为供试品种,就2,4-D不同浓度和作用时间对匍匐翦股颖愈伤组织诱导及分化的影响进行试验。结果表明,2mg/L的2,4-D对Penn A-1愈伤组织诱导效果最佳,出愈率为36.4%,4mg/L的2,4-D对Penn A-4的效果最佳,出愈率为82.4%;愈伤组织最佳分化时间为2,4-D作用0～30d时,Penn A-1和Penn A-4分化率分别保持在50%和83%;分化能力随2,4-D作用时间的增长而下降,而颗粒状、质地松散的愈伤组织最终将失去分化能力。