呋虫胺20%悬浮剂防治小麦蚜虫田间药效试验

为评价呋虫胺20%悬浮剂对小麦蚜虫的田间防效,分别于2013和2014年在河北省保定市开展了田间药效试验。两年的田间药效试验结果表明,呋虫胺20%悬浮剂对小麦蚜虫具有较好的防效,防效随施药剂量的增加而提高,其有效成分使用量60~90g/ha对小麦蚜虫速效性较好,施药后1d,防效均保持在79.2%~83.2%之间;持效期较长,施药后14d,防效仍然保持在90%以上,同时该药剂在试验剂量范围内未对小麦产生药害且对天敌也比较安全。因此,呋虫胺20%悬浮剂是防治小麦蚜虫较为理想的药剂,可在生产上大面积推广应用,推荐于小麦蚜虫始盛期施药1次,其有效成分使用量为60~90g/ha。关键词:呋虫胺20%悬浮剂;小麦蚜虫;田间药效     

几种常用杀菌剂对马铃薯晚疫病防治效果比较研究

试验表明50%烯酰吗啉等九种杀菌剂对马铃薯晚疫病发病初期均有好的防效,药后7d防效均在81.5%以上。在马铃薯晚疫病初期施药,各药剂防效差异明显。第2次用药后7d,50%烯酰吗啉水分散粒剂、70%丙森锌可湿性粉剂、60%吡唑醚菌酯/代森联水分散粒剂、72%霜脲·锰锌可湿性粉剂对马铃薯晚疫病防治效果在83%以上,且最后增产效果均在40%以上。而70%甲基硫茵灵可湿性粉剂等其它5种药剂的防病效果只在70%左右,增产幅度也低。各药剂对马铃薯安全,无药害表现。建议向农民首推50%烯酰吗啉水分散粒剂防治马铃薯晚疫病,其次是72%霜脲·锰锌可湿性粉剂、70%丙森锌可湿性粉剂和60%吡唑醚菌酯/代森联水分散粒剂。     

甲氨基阿维菌素0.5%微乳剂防治枇杷黄毛虫田间药效试验研究

试验结果表明。甲氨基阿维菌素0.5%微乳剂防治枇杷黄毛虫具有速效性快、持效期长的特点,药后14d的防效仍高达99.3%~100%。供试药剂在试验剂量范围内对作物安全,是防治枇杷黄毛虫较理想的药剂。     

噁嗪草酮与五氟磺草胺或双草醚混用对水稻机插秧田杂草的防效及水稻的安全性

通过田间试验测定了1%噁嗪草酮悬浮剂(SC)与25 g/L五氟磺草胺可分散油悬浮剂(OD)或10%双草醚悬浮剂(SC)桶混使用对机插秧稻田杂草的防效及水稻的安全性。结果表明:1%噁嗪草酮SC 250、300、350 m L/667 m~2与25 g/L五氟磺草胺OD 80 m L/667 m~2混用,1%噁嗪草酮SC 350 m L/667 m~2与10%双草醚SC 10 m L/667 m~2混用,在水稻移栽后7 d毒土撒施及移栽后13 d茎叶喷雾施用对稗属杂草、千金子、鸭舌草、耳叶水苋、异型莎草等杂草的防效均达91%以上,优于对照移栽前2 d 35%丙草胺·苄嘧磺隆可湿性粉剂(WP)80 g/667 m~2毒土撒施+移栽后7 d 50%苯噻酰草胺·苄嘧磺隆WP 75 g/667 m~2毒土撒施处理、移栽后20 d 60 g/L五氟磺草胺·氰氟草酯OD 100 m L/667 m~2茎叶喷雾处理,移栽后7 d施药处理对杂草的防效高于移栽后13 d施药处理。1%噁嗪草酮SC 250、300、350 m L/667 m~2与25 g/L五氟磺草胺OD 80 m L/667 m~2或10%双草醚SC 10 m L/667 m~2桶混在水稻移栽后7 d或13 d处理对机插秧水稻安全。     

7种杀虫剂防治荔枝蝽象的药效试验

为了寻找出对荔枝蝽象(Tessaratoma papillosa Drury)高效、持效、安全的杀虫剂,通过室内毒力试验和田间药效试验研究7种杀虫剂对荔枝蝽象的防治效果。结果表明,30%敌百虫乳油1000倍液和5%锐劲特悬浮剂2000倍液对荔枝蝽象成虫的杀虫效果最好、药效最稳定,室内施药后72 h时30%敌百虫乳油1000倍液对荔枝蝽象成虫的校正死亡率达到100%、5%锐劲特悬浮剂2000倍液对荔枝蝽象成虫的校正死亡率达到98.35%,田间施药后1、3和7天此2种杀虫剂对荔枝蝽象的虫口减退率和田间防治效果均在90%以上。其次10%吡虫啉可湿性粉剂1000倍液、52.25%农地乐乳油2000倍液和2.5%敌杀死乳油3000倍液也表现出对荔枝蝽象良好的防治效果,室内施药后72 h时10%吡虫啉可湿性粉剂1000倍液对荔枝蝽象成虫的校正死亡率为96.65%、52.25%农地乐乳油2000倍液对荔枝蝽象成虫的校正死亡率为95.00%、2.5%敌杀死乳油3000倍液对荔枝蝽象成虫的校正死亡率为93.35%;田间施药后3、7天此3种杀虫剂对荔枝蝽象的虫口减退率和防治效果均达到90%以上。     

枯草芽胞杆菌NJ-18对油菜菌核病的防治效果及其定殖动态

 菌株NJ-18是从油菜田土壤中分离筛选到的一株具有抗真菌活性的枯草芽胞杆菌。试验结果表明菌株NJ-18与油菜菌核病菌对峙培养能形成3.4 cm的抑菌圈;能抑制油菜菌核病菌菌丝生长发育;强烈影响菌丝生长量,NJ-18发酵滤液稀释62.5倍时对菌丝生长量抑制率高达96.7 %,稀释1 000倍时抑制率16.7 %。油菜离体叶片试验表明,NJ-18发酵液原液对菌核病的防治效果高达100 %,原液稀释200倍后防效10 %。大田试验结果表明,NJ-18发酵液稀释500倍对油菜菌核病的防治效果高达57.4 %,明显高于用量为150 g a.i./hm²的醚菌酯48.1 %的防治效果。采用浸根法研究NJ-18在油菜上的定殖动态表明,菌株NJ-18能够在油菜体内定殖,并能从油菜的根部向叶子扩散。     

Use of Aqueous Extracts of Avocado Pear,Pyrus Communis,Leaf as Anaesthetic in Gonadectomy of African Catfish,Clarias gariepinus

This study was carried out to determine the efficacy and effective concentration of avocado pear (Pyrus communis) leaf extract as an anaesthetic in gonadectomy of Clarias gariepinus broodstocks. Fresh avocado leaves were harvested, water extracted, and applied at 0 (control), 100, 130, 160, and 190ml/l to C. gariepinus broodstocks. Onset of individual phases of anaesthesia and recovery rate was determined. Gonadectomy was then carried out on individual anaesthetized fish and the time taken was recorded. Aqueous extracts of avocado pear leaf at concentrations ranging from 130–190 ml/l induced general anaesthesia. The recovery rate was concentration-dependent but non-linear, with a significant threshold in efficacy between 130 and 190 ml/l. There was no mortality recorded during the experimental period. The effective concentration of avocado pear leaf extracts that best sustained the gonadectomy was 190 ml/l with a recovery time of 12 minutes.     

几种杀菌剂对小麦白粉病的防治效果

[目的]通过室内及田间试验,筛选对小麦白粉病防治效果较好的化学药剂及合理的使用方法.[方法]采取室内盆栽接菌试验及田间小区试验相结合的方式进行,在植株发病后喷雾防治,药后定期调查防治效果.[结果]药后10 d,250g/L丙环唑乳油112.5 g a.i/hm2处理在室内及田间试验对白粉病的防效分别为82.02;和74.02;,防治效果优于其它药剂处理的防效;其次是25;三唑酮可湿性粉剂135 g a.i/hm2处理,室内及田间试验防效分别为81.84;和67.24;;400 g/L氟硅唑乳油48 g a.i/hm2处理的室内及田间试验防效分别为69.25;和67.99;,对白粉病的防效也较好.25;乙嘧酚水悬浮剂187.5 g a.i/hm2处理、250 g/L已唑醇悬浮剂18.75 g a.i/hm2处理、10;苯醚菌酯悬浮剂12 g a.i/hm2处理在室内试验中对白粉病防治效果较好,但田间小区试验中防效略低.[结论]250g/L丙环唑乳油112.5 g a.i/hm2处理、25;三唑酮可湿性粉剂135 g a.i/hm2处理、400 g/L氟硅唑乳油48 g a.i/hm2处理可有效控制小麦白粉病的发生及危害,且对小麦生长安全,可在大田合理轮换使用.     

青枯菌无致病力菌株对烟草青枯病的控病作用初步研究

从茄子、番茄、辣椒、烟草青枯病株中分离出116株无致病力青枯菌,室内平板喷雾法拈抗试验结果表明,有21株菌在NA培养基上可明显抑制青枯菌TbRs的生长;烟草MSK326品种温室盆栽控病试验表明,Tnljdl-3和Aujd8—2—1两株菌具有较好控病效果,20d后的相对防效分别为58．4％和97％。     

Promoter Trapping in Microalgae Using the Antibiotic Paromomycin as Selective Agent

The lack of highly active endogenous promoters to drive the expression of transgenes is one of the main drawbacks to achieving efficient transformation of many microalgal species. Using the model chlorophyte Chlamydomonas reinhardtii and the paromomycin resistance APHVIII gene from Streptomyces rimosus as a marker, we have demonstrated that random insertion of the promoterless marker gene and subsequent isolation of the most robust transformants allows for the identification of novel strong promoter sequences in microalgae. Digestion of the genomic DNA with an enzyme that has a unique restriction site inside the marker gene and a high number of target sites in the genome of the microalga, followed by inverse PCR, allows for easy determination of the genomic region, which precedes the APHVIII marker gene. In most of the transformants analyzed, the marker gene is inserted in intragenic regions and its expression relies on its adequate insertion in frame with native genes. As an example, one of the new promoters identified was used to direct the expression of the APHVIII marker gene in C. reinhardtii, showing high transformation efficiencies.