复配表面活性剂在高浓度可分散油悬浮剂中流变性能的研究

应用复配表面活性剂协同增效理论及对流变性能的影响,对24%烟嘧·莠去津可分散油悬浮剂(OD)的乳化剂和分散剂进行筛选。结果表明:农乳500#与SR -08间具有强烈的协同增效作用。使用农乳500#与SR -08复配表面活性剂制备的24%烟嘧·莠去津可分散油悬浮剂黏度低,流动性好,触变性优良,各项指标均达到行业标准。较单一表面活性剂制备的24%烟嘧·莠去津可分散油悬浮剂产品性能有明显提高。复配表面活性剂的协同增效作用有利于提高24%烟嘧·莠去津可分散油悬浮剂的稳定性。     

烟嘧·莠去津防除玉米田杂草试验报告

23％烟嘧·莠去津SC1500～2250ml／hm^2能有效防除玉米田一年杂草,药后30d对马唐、狗尾草、藜、铁苋菜、异型莎草的株防效为92．9％～98．5％,鲜重防效为94．2％～99．3％。对玉米安全。     

杂草种类、叶龄及药后降水时间对烟嘧磺隆药效的影响

温室盆栽条件下研究了反枝苋Amaranthus retroflexus、马唐Digitaria sanguinalis、稗草Echinochloa crus-galli、牛筋草Eleusine indica和苘麻Abutilon theophrasti 5种杂草对烟嘧磺隆的敏感性。结果表明:反枝苋和稗草对该药剂最敏感,而苘麻对烟嘧磺隆的耐药性最高。药液中添加2.5 mL/L的有机硅助剂Silwet L-77提高了对除马唐以外的所有草种的防除效果,表明在作用于马唐时Silwet L-77与烟嘧磺隆之间存在拮抗作用。杂草叶龄对烟嘧磺隆的药效有明显的影响,3~5叶期施药,防效高达89.9%以上,而7叶期的防效只有75%。药后1.5 h和3.0 h降水3 mm降低了烟嘧磺隆的防效,但药后6.0 h降雨对药效无显著影响。烟嘧磺隆与Silwet L-77混用,可提高药剂对反枝苋的抗雨水冲刷能力,但对马唐的效果没有提高。     

不同助剂和喷头对烟嘧·莠去津的防效及安全性的影响

为了研究不同喷雾助剂和喷头对玉米田常用除草剂烟嘧·莠去津防除效果的影响,在自走式喷杆喷雾机施药过程中,选择不用型号喷头(XR11001、XR110015、XR11002)、不同助剂(2、3、4号喷雾助剂),调查药后14 d玉米田杂草株防效以及药后28 d玉米田杂草株防效和鲜重防效,并调查对玉米的安全性和玉米的产量。结果表明:自走式喷杆喷雾机施药过程中,选择喷头XR11001、4号助剂的杂草防效要优于其他处理组,且对玉米安全,不会影响玉米产量。自走式喷杆喷雾机施药的效果要优于人工喷雾。自走式喷杆喷雾机施药过程中,选择细喷头和合适的喷雾助剂,能有效提高药效。     

4种杀菌剂对紫皮石斛锈病的田间药效评价

针对紫皮石斛锈病。试验选用10%苯醚甲环唑WG,250 g/L嘧菌酯SC,29%吡萘·嘧菌酯SC,75%肟菌·戊唑醇WG 4种杀菌剂进行田间药效试验。结果表明:复配剂29%吡萘·嘧菌酯SC 600 mL/hm~2与75%肟菌·戊唑醇WG 300 g/hm~2,防效相当且显著高于其余两个施药处理,在第3次施药后7 d时达最高防效分别为87.70%和88.56%,鲜重折合产量比空白对照分别增产13.48%、13.22%,可在实际生产中交替使用。     

20%三氟苯嘧啶WG对稻飞虱的防治效果

试验分别使用植保无人机和背负式电动喷雾器喷施20%三氟苯嘧啶WG防治稻飞虱。结果表明,不同的施药器械对药效无明显影响; 20%三氟苯嘧啶WG对稻飞虱具有较好的速效性,药后3 d防效达83.59%;持效期长,14 d后防效达98.52%。     

几种除草剂及其组合对烟田杂草的防除效果

为了筛选高效安全烟田除草剂及除草剂组合,在广东烟区开展几种除草剂及除草剂组合对烟田杂草的防除效果试验。结果表明,芽前除草剂50%仲灵·异松乳油和72%异丙甲草胺乳油对烟田杂草防除效果较好,施药后60 d对杂草鲜质量防效分别为78.42%和71.62%;芽后除草剂25%砜嘧磺隆水分散粒剂和除草剂组合5%精喹禾灵乳油+48%灭草松水剂对烟田杂草的防效较好,施药后30 d对杂草鲜质量防效分别为78.72%和92.90%。     

氯嘧磺隆对精禾草克、精稳杀得防除马唐、蟋蟀草的拮抗作用

在盆钵中以3叶的马唐、蟋蟀草测定了氯嘧磺隆与精禾草克、精稳杀得的相互影响。结果表明,氯嘧磺隆在混用时能明显降低精禾草克、精稳杀得对马唐、蟋蟀草的效果。处理后20天,氯嘧磺隆(12,18,24g ai/hm~2)使精禾草克(15～30g ai/hm~2)对马唐的防效分别降低6.01％～42.59％,23.96％～40.85％,19.63％～27.50％。相同剂量的氯嘧磺隆使精稳杀得对马唐的防效下降2.70％～58.91％,对蟋蟀草的防效下降2.67％～51.73％。对各试验的结果进行Colby法和等效线法分析,判定氯嘧磺隆与精禾草克、精稳杀得的相互影响为拮抗作用。     

烟嘧·甲基磺草酮36%油悬浮剂玉米田间药效试验

田间药效试验结果表明,烟嘧.甲基磺草酮36%油悬浮剂在春玉米田茎叶喷雾施药,防除春玉米田多种一年生单、双子叶杂草除草效果好,杀草谱广,速效性好,持效期长,药后30d,株防效均在90%以上,鲜重防效均在97%以上,80～200mL/667m2对玉米安全,从成本考虑,建推荐剂量为100～120mL/667m2。     

烟嘧·氯氟吡氧乙酸·莠去津30%油悬浮剂玉米田间药效试验

田间药效试验结果表明,烟嘧.氯氟吡氧乙酸.莠去津30%油悬浮剂在春玉米田茎叶喷雾施药,防除春玉米田多种一年生单、双子叶杂草除草效果好,杀草谱广,速效性好,持效期长,药后30d,株防效均在90%以上,鲜重防效均在97%以上,80~200mL/667m2对玉米安全,从成本考虑,建推荐剂量为100~120mL/667m2。     

烟嘧磺隆8%油悬浮剂防除玉米田杂草田间药效及安全性试验

田间试验表明烟嘧磺隆8%油悬浮剂48～72g/hm^2能有效防除玉米田一年生杂草,药后30d对马唐、狗尾草、藜、铁苋菜、异型莎草的株防效在94.7%～98.5%,鲜重防效在93.7～98.4%。在推荐剂量下,对玉米生长安全。     

Mesotrione control and pigment concentration of large crabgrass (Digitaria sanguinalis) under varying environmental conditions

BACKGROUND: Mesotrione is a carotenoid biosynthesis‐inhibiting herbicide currently labeled for crabgrass (Digitaria spp.) control. Mesotrione control of large crabgrass has been reported to vary with temperature and relative humidity; however, the effect of irradiance on mesotrione efficacy has not previously been reported. Likewise, little is known about pigment concentrations of Digitaria spp. The present research investigated the effects of mesotrione on large crabgrass, Digitaria sanguinalis (L.) Scop., control and pigment concentrations under varying irradiance at three temperatures. RESULTS: Mesotrione (0.28 kg ha^?1) control of large crabgrass did not differ between temperature levels (18, 26 and 32 °C). Control was similar at tested irradiance levels (600, 1100 and 1600 µmol m^?2 s^?1). Mesotrione reduced large crabgrass chlorophyll a, chlorophyll b and total carotenoid concentrations, as well as chlorophyll a to b ratios. Treated plant bleaching was highest 7 days after treatment (DAT) but decreased by 21 DAT. Treated plants were less than 10% necrotic 3 and 7 DAT but nearly 35% necrotic 21 DAT. Treated large crabgrass bleaching was highest and photochemical efficiency was lowest 7 DAT. These results indicate that some plant recovery occurs prior to 21 DAT. CONCLUSION: Although mesotrione efficacy has previously been reported to vary according to environmental factors, mesotrione control of large crabgrass did not vary with measured temperature and irradiance levels in this study. On account of crabgrass convalescence, secondary applications of mesotrione may control large crabgrass more effectively when applied prior to 21 DAT. Copyright © 2009 Society of Chemical Industry     

Effects of surfactants and simulated rainfall on the efficacy of the Engame formulation of glyphosate in johnsongrass, prickly sida and yellow nutsedge

The effects of surfactants and simulated rain were investigated on the efficacy of Engame and Roundup Ultramax formulations of glyphosate on johnsongrass ( Sorghum halepense L.), prickly sida ( Sida spinosa L.) and yellow nutsedge ( Cyperus esculentus L.). Flame surfactant provided the greatest enhancement of Engame efficacy and the effect was species-dependent. Flame enhanced the activity of Engame on johnsongrass and yellow nutsedge but not on prickly sida. Engame and Engame plus Flame were more active than Roundup Ultramax on a glyphosate acid-equivalent basis on johnsongrass without rain, and on yellow nutsedge with or without rain. The Engame and Roundup Ultramax activities on johnsongrass were similar with rain, and rain occurring between five and 30 min after treatment diminished their activities to < 38% of the control. With the addition of Flame surfactant, Engame activity on johnsongrass increased, such that 50% and 80% of the control were realized, even with rain occurring between five and 15 min after treatment, respectively. Engame and Roundup Ultramax provided better control of prickly sida than of johnsongrass following a rain event. The addition of Flame surfactant to Engame did not enhance the activity on prickly sida. Yellow nutsedge control with Engame and Engame plus Flame was greater than with Roundup Ultramax and rain had little effect on control regardless of the length of the rain-free period. These results demonstrated that the activities of Engame, Engame plus Flame and Roundup Ultramax were species-dependent and surfactant-dependent.     

Foliar absorption and translocation of nicosulfuron and rimsulfuron in five annual weed species

Ambrosia artemisüfolia L. (common ragweed) and Digitaria ischaemum Schreb. (smooth crabgrass) are not controlled by nicosulfuron and rimsulfuron at the highest recommended application rates, whereas Panicum miliaceum L. (wild proso millet), Amaranthus retroflexus L. (redroot pigweed) and Avena fatua L. (wild oat) are susceptible. The foliar absorption and translocation of ¹⁴C-nicosulfuron and ¹⁴C-rimsulf uron were studied in these weed species up to 48 h after treatment (HAT). Differences in herbicide uptake and translocation were not correlated with the species susceptibility. By 48 HAT, more than 50% of both herbicides remained on the treated leaf surface. Foliar absorption of rimsulfuron was greater than that of nicosulfuron in A. retroflexus, P. miliaceum and A. artemisüfolia. Most of the absorbed herbicide remained in the treated leaf of each weed species. Export of ¹⁴C–nicosulfuron ranged from 28 to 54% of that absorbed, in contrast to 15 to 39% for ¹⁴C–rimsulfuron. The absorption and translocation rates of both herbicides were highest within the initial 6 HAT, and decreased thereafter. Both herbicides showed approximately the same distribution pattern within each weed species.     

4种除草剂与助剂安融乐协同防除紫花苜蓿田马唐的研究

为探究高效氟吡甲禾灵?精吡氟禾草灵?烯草酮?精喹禾灵对紫花苜蓿田老根马唐的防除效果及助剂安融乐对上述4种药剂的增效作用, 在室内测定马唐幼苗和成株对4种除草剂及添加助剂的敏感性, 并在田间验证上述4种除草剂与助剂混用对老根马唐的防效?室内结果表明, 成株马唐对高效氟吡甲禾灵?精吡氟禾草灵?烯草酮?精喹禾灵的耐药性增加明显, 其中精喹禾灵的耐药性增加最大; 高效氟吡甲禾灵?精吡氟禾草灵?烯草酮?精喹禾灵与安融乐混配后, 成株马唐的鲜重GR50(有效成分)较单用上述除草剂分别减少16.6%?31.0%?31.5%?6.2%, 其中烯草酮与安融乐混配增效作用最为明显?田间结果表明, 安融乐的加入能提高上述4种除草剂对老根马唐的防效, 其中烯草酮和安融乐混配对老根马唐的增效最优, 株防效和鲜重防效较单用分别增加10.39和8.58百分点, 并显著提高紫花苜蓿产量?     

Phaeosphaeria sp.HD-06菌株对马唐的致病性分析及初步鉴定

为了得到能够有效抑制马唐Digitaria sanguinalis生长的生防微生物,在农田采集马唐种子,进行萌发试验,观察种子的萌发状况,从发病的种子和马唐幼苗基部分离致病菌,通过形态学观察以及ITS序列分析对致病菌进行鉴定。结果从罹病的马唐幼苗基部分离得到一株致病菌HD-06,该菌株的发酵液用水稀释至60%浓度时,对马唐种子的萌发抑制率和幼苗发病率均达到100%,这说明菌株HD-06对马唐有较好的生物防治作用。根据其形态学特点及ITS序列分析结果,鉴定菌株HD-06为暗球腔菌属Phaeosphaeria的真菌。这些结果为深入研究其对马唐的防治作用奠定了基础。     

14种除草剂对野稷的活性测定及田间防效

参照除草剂室内生物测定和田间药效防治试验准则,在温室中测定了14种除草剂对野稷的生物活性,并进行了田间小区药效评价。生测结果表明,土壤处理药剂中,异噁唑草酮、氟噻草胺、乙草胺、精异丙甲草胺、异噁草松对野稷的活性较高,其ED₉₀分别为43.08、47.14、137.09、209.93、583.74 g/hm²(有效成分用量);茎叶处理药剂中,苯唑草酮、高效氟吡甲禾灵、烟嘧磺隆和苯唑氟草酮对野稷的活性较高,其ED₉₀分别为22.21、35.95、95.64、111.43 g/hm²。田间药效试验结果表明,野稷出苗前,土壤喷雾40%氟噻草胺SC (810 g/hm²)、900 g/L乙草胺EC (1 620 g/hm²)和960 g/L精异丙甲草胺EC (2 160 g/hm²)对野稷防效较高,药后40 d对野稷的株防效均在86.0%以上,鲜重防效在88.4%以上,其次是75%异噁唑草酮WG (90 g/hm²),防效...     

麦田布顿大麦草的化学防除药剂筛选

布顿大麦草为麦田入侵杂草, 为尽早建立对该杂草的化学防除技术, 本研究采用室内盆栽法测定了布顿大麦草对21种除草剂的敏感性?结果表明:土壤处理剂41%氟噻草胺悬浮剂对布顿大麦草具有良好的防除效果, 42%氟啶草酮悬浮剂?60%丁草胺乳油?40%砜吡草唑悬浮剂?960 g/L精异丙甲草胺乳油对布顿大麦草的防除效果一般, 50%扑草净可湿性粉剂?50%异丙隆可湿性粉剂?45%二甲戊灵微囊悬浮剂?50%吡氟酰草胺可湿性粉剂防除效果不理想; 茎叶处理剂7.5%啶磺草胺水分散粒剂?12.5%烯禾啶乳油?41%草甘膦异丙胺盐水剂对布顿大麦草防除效果好, 5%咪唑乙烟酸水剂?8%炔草酯水乳剂?30 g/L甲基二磺隆可分散油悬浮剂?8%烟嘧磺隆可分散油悬浮剂?7%双唑草腈颗粒剂?70%氟唑磺隆水分散粒剂对布顿大麦草的防除效果一般, 5%唑啉草酯乳油?7.5%双环磺草酮颗粒剂?69 g/L精噁唑禾草灵水乳剂防除效果不理想?氟噻草胺?在推荐剂量492 g/hm2下, 处理21 d后对布顿大麦草的鲜重抑制率为75.40%; 啶磺草胺?草甘膦异丙胺盐?烯禾啶在推荐剂量14?1 500?187.5 g/hm2下, 处理21 d后对布顿大麦草的鲜重抑制率分别为73.96%?60.60%?65.07%?综合本研究结果及除草剂使用特性, 麦田布顿大麦草可采用氟噻草胺土壤封闭或者啶磺草胺茎叶喷雾处理进行有效防除; 油菜田布顿大麦草可采用烯禾啶进行防除; 非耕地布顿大麦草可采用草甘膦异丙胺盐进行防除?     

烟嘧磺隆降解菌株DT-4的降解特性及对高粱药害的缓解作用

土壤中烟嘧磺隆残留可对后茬作物产生不同程度药害。为解决玉米地烟嘧磺隆残留对后茬作物高粱药害问题,使用前期筛选出的烟嘧磺隆高效降解菌株绿木霉Trichoderma virens DT-4,通过高效液相色谱-质谱法检测其降解率,利用室内盆栽生测结合田间小区试验方法,确定降解菌株对土壤中烟嘧磺隆降解效果,降低烟嘧磺隆残留对高粱的药害。结果显示,烟嘧磺隆残留浓度在0.0025～0.1 ug/mL范围内,标准曲线线性良好,符合农残分析要求;PDB液体培养基中烟嘧磺隆在DT-4降解菌处理100 h的降解率高达93.00%;菌株最佳降解条件为培养温度35 ℃、pH 5、最适接种量5%、烟嘧磺隆初始质量浓度200 mg/L。盆栽试验土壤中烟嘧磺隆残留浓度为0.075 mg/kg时,加入降解菌DT-4后能够明显缓解高粱的株高、根长、鲜重、叶绿素含量、根系活力和净光合速率等生长发育指标,对高粱生长有明显的促进作用。田间小区试验中,不同剂型降解菌剂处理,高粱抽穗期效果最为显著,降解菌能够将低于60 g a.i./hm²烟嘧磺隆污染土壤的高粱修复至无明显药害水平,且降解菌剂应用效果为粉剂＞菌液。本研究表明高效降解菌株绿木霉DT-4可有效缓解烟嘧磺隆残留对后茬作物高粱的毒害作用,为玉米高粱轮作体系下烟嘧磺隆残留污染土壤的微生物修复提供科学参考。