六种杀菌剂对马铃薯粉痂病的盆栽防治效果

随着马铃薯产业的持续发展,马铃薯粉痂病已成为限制马铃薯种植的重要土传病害,为筛选能有效防控其发生危害的杀菌剂供生产应用,研究采用盆栽拌土和灌根的方法比较了6种杀菌剂对马铃薯粉痂病的防治效果。结果表明,3种杀菌剂对马铃薯粉痂病的防治效果显著,分别是50%嘧菌环胺水分散粒剂、325 g/L苯醚甲环唑·嘧菌酯悬浮剂、560 g/L百菌清·嘧菌酯悬浮剂,防效均达到60%以上,但325 g/L苯醚甲环唑·嘧菌酯悬浮剂对产量影响较大,减产高达84.4%。在生产上可采用50%嘧菌环胺水分散粒剂、560 g/L百菌清·嘧菌酯悬浮剂防治粉痂病,而不推荐使用325 g/L苯醚甲环唑·嘧菌酯悬浮剂。     

几种药剂对马铃薯早疫病的防治效果

马铃薯早疫病(Alternaria solani)是重庆早市菜用马铃薯上的最主要病害。本研究选取生产中应用较广泛的7种药剂,在地膜覆盖栽培模式下筛选具有较好防控效果的药剂。结果表明:500 g/L氟啶胺悬浮剂1200倍,250 g/L嘧菌酯悬浮剂1 000倍效果较好,第2次施药后10 d防效分别为83.41%,82.01%,明显高于当地常用药剂代森锰锌。因此,可以在大面积生产上使用。     

苯醚甲环唑和嘧菌酯在水稻中的残留消解动态及残留分析

本文建立了气质联用仪测定稻田环境中苯醚甲环唑和嘧菌酯的残留分析方法,对苯醚甲环唑和嘧菌酯在水稻、土壤和田水中的消解动态和残留规律进行了研究。苯醚甲环唑和嘧菌酯在糙米、稻壳、植株、土壤和田水中的最低检测浓度均为0.20 mg/kg,最小检出量为0.2 ng,在不同样品中的平均加标回收率为80.8%~109.5%,相对标准偏差在1.7%~19.7%之间。田间试验结果表明,苯醚甲环唑和嘧菌酯在水稻植株和田水中的残留消解动态规律均符合一级动力学反应模型,苯醚甲环唑在水稻植株和田水中的残留消解半衰期分别为6.3~11.6 d和1.4~11.6 d;嘧菌酯在水稻植株和田水中的残留消解半衰期分别为3.6~8.7 d和2.9~23.1 d。以推荐剂量600 g/hm2和1.5倍推荐剂量900 g/hm2,最多施药3次,距最后一次施药15 d时,苯醚甲环唑和嘧菌酯在糙米中的最高残留量分别为0.461 mg/kg和0.634 mg/kg,低于我国国家标准《食品中农药最大残留限量》(GB2763-2014)中规定的糙米中苯醚甲环唑最大残留限量0.5 mg/kg和欧盟、美国规定的糙米中嘧菌酯最大残留限量5.0 mg/kg。     

小麦中嘧菌酯残留及膳食摄入风险评估

为对嘧菌酯在小麦生产上应用的安全性进行评价,采用田间试验,使用QuEChERS方法进行样品前处理,气相色谱法电子捕获检测器进行定量分析,对嘧菌酯在小麦中的残留动态及最终残留量进行了研究,并对小麦籽粒中嘧菌酯残留量进行了膳食摄入风险评估。结果表明,在0.01~1.0mg·kg~(-1)添加水平范围内,嘧菌酯在植株、籽粒空白添加的平均回收率为87.9%~108.4%,相对标准偏差为1.1%~6.2%,其最小检出量为5×10~(-12)g,植株、籽粒中的最低检测浓度均为0.01mg·kg~(-1)。该检测方法准确度、灵敏度高,重复性好,可满足嘧菌酯在小麦植株及籽粒中的残留分析要求。消解动态研究表明,嘧菌酯在小麦植株中的消解半衰期为3.3~4.3d。最终残留试验表明,20%嘧菌酯可湿性粉剂按施药剂量180、270g a.i.·hm~(-2),连续喷药2~3次,施药间隔7d,药后7、14、21d,嘧菌酯在小麦籽粒中的最终残留量均≤0.354mg·kg~(-1)。普通人群嘧菌酯的国家估算每日摄入量是2.43mg,占日允许摄入量的19.0%左右,因此,按本试验方式进行施药,不会对一般人群健康产生不可接受的风险。     

榆林市马铃薯早疫病病原分离鉴定与化学药剂室内毒力测定

马铃薯早疫病在榆林市发生普遍,生产中长期使用固定几种农药,使得病原产生抗药性,防治效果变差。为筛选有效防治马铃薯早疫病的药剂,试验采用组织分离法分离纯化马铃薯早疫病病原,通过柯赫法则确定病原,采用形态学和rDNA-ITS的分子系统学分析相结合的方法鉴定病原,利用菌丝生长速率法测定了9种杀菌剂对病原菌的室内抑制效果。结果表明,榆林市马铃薯早疫病病原菌为Alternaria alternata;9种杀菌剂毒力由大到小的顺序为噁酮·氟噻唑(SC)异菌·氟啶胺(SC)苯甲·百菌清(SC)烯酰·吡唑酯(WG)氟菌·霜霉威(SC) 72%霜脲·锰锌(WP) 69%烯酰·锰锌(WP) 75%代森锰锌(WG) 70%丙森锌(WP);噁酮·氟噻唑(SC)、异菌·氟啶胺(SC)、苯甲·百菌清(SC)、烯酰·吡唑酯(WG)和氟菌·霜霉威(SC)的EC_(50)值分别为3.601,7.493,21.113,27.555和51.874μg/mL,EC_(95)值分别为124.987,489.168,1 338.277,3 011.257和2 325.134μg/mL,表明以上5种药剂抑菌效果较好,可供进一步田间试验施用;70%丙森锌(WP)和75%代森锰锌(WG)对A. alternata室内抑菌效率较差,EC_(50)值分别为3 969.600和1 525.580μg/mL,可见A. alternata已对这2种杀菌剂产生抗药性。研究为马铃薯早疫病田间防治筛选低毒高效药剂奠定基础。     

250g/L嘧菌酯悬浮剂对不同地区马铃薯晚疫病的防治效果分析

杀菌剂防治马铃薯晚疫病是生产中采用的主要措施。通过施用250 g/L嘧菌酯悬浮剂对河北、甘肃、青海3个地区马铃薯晚疫病的防治效果进行分析。结果表明,250 g/L嘧菌酯悬浮剂对3个地区马铃薯晚疫病均具有较好的防治效果;在河北地区,250 g/L嘧菌酯悬浮剂的有效成分用量为75.00 g/hm2时,对马铃薯晚疫病的防效达到77.53%;在青海地区,各试验处理的防效达到71.26%~84.02%;在甘肃地区防治效果更好,防效均达到80%以上。该试验结果为250 g/L嘧菌酯悬浮剂在生产上的推广使用提供理论依据。     

甲氧基丙烯酸酯类杀菌剂防治马铃薯黑痣病的室内及田间试验

进行了4种甲氧基丙烯酸酯类杀菌剂对马铃薯黑痣病菌的室内毒力测定,防治马铃薯黑痣病的室内盆栽试验及田间药效试验。采用菌丝干重法测定4种甲氧基丙烯酸酯类杀菌剂室内毒力结果表明,烯肟菌胺、唑菌酯、唑胺菌酯及烯肟菌酯对马铃薯黑痣病菌毒力相当,与嘧菌酯无明显差异。室内盆栽试验结果表明,相对于其他测试药剂,烯肟菌胺与唑胺菌酯对马铃薯黑痣病防效相对更好,分别为74.3%和77.1%。田间药效试验结果表明,播种时,沟施烯肟菌胺或唑胺菌酯对马铃薯黑痣病有较好抑制作用,推荐剂量均为187.5 g/hm~2。     

生产上主要杀菌剂对稻瘟病的防效及施药时期研究

稻瘟病是最主要的世界性水稻病害,化学防治是目前最为有效的防控措施。通过室内生测和田间试验相结合的方法,测试了多个特效药剂和广谱药剂对稻瘟病的防治效果,探讨了稻瘟病的最优防治适期和穗颈瘟、稻曲病兼防的可能性。结果表明,三环唑仍然是预防穗颈瘟的特效杀菌剂,而嘧菌酯、肟菌酯·戊唑醇和嘧菌酯·苯醚甲环唑等广谱杀菌剂对叶瘟表现出更好的防控效果。始穗期是防治穗颈瘟的关键时期,在发病严重的情况下在齐穗期再施1次药是必要的。如果选用合适的药剂,破口前施药对穗颈瘟也有一定的防控作用。由于防治稻曲病的最佳施药时期是破口前,因此,一次施药兼防穗颈瘟和稻曲病是可行的。     

砜嘧磺隆25%可湿性粉剂在马铃薯中的残留动态

为了制定砜嘧磺隆在马铃薯生产中的安全使用标准,采用田间试验的方法,研究砜嘧磺隆在马铃薯中的残留动态,应用液相色谱法测定砜嘧磺隆在马铃薯中的残留量。试验结果表明:砜嘧磺隆在马铃薯植株和土壤中降解符合一级化学反应动力学方程C=C0e-kt,砜嘧磺隆在土壤中半衰期为(0.02～3.10 d),在植株中的半衰期为(0.93～2.90 d)。该药属易分解农药(T1/2<30 d)。在马铃薯4叶期时喷药1次,按推荐剂量90 g/hm2及1.5倍剂量135 g/hm2施用25%可湿性粉剂砜嘧磺隆。在收获期马铃薯植株和块茎均未检测出,在马铃薯上的砜嘧磺隆安全使用量推荐为90 g/hm2,建议马铃薯上砜嘧磺隆最大残留限量值MRL暂定为0.1 mg/kg。     

吡虫啉在海南豇豆及土壤中的消解动态研究

建立了豇豆、土壤中吡虫啉测定高效液相色谱法,并研究吡虫啉在海南豇豆和其种植土壤中的消解动态以及在豇豆中的最终残留。结果表明:方法回收率为78%~89%,在0.05~5μg/mL线性关系良好,相对标准偏差(RSD)7%,最低定量限0.01μg/mL,方法满足检测工作要求。吡虫啉在豇豆和土壤中的半衰期分别为2.9、5.1 d。以1.5倍推荐剂量一次喷施农药2.5 d后吡虫啉残留量小于0.5μg/g。吡虫啉在土壤中半衰期较短,属于易降解农药;分别以1.5、2倍推荐剂量3次施药,每次施药间隔2d,自然降解4、6d后残留量均低于0.5μg/g。     

不同杀菌剂对马铃薯晚疫病的防治效果

通过田间试验调查,研究了7种化学药剂对马铃薯植株和薯块晚疫病的防治效果。结果表明:7种药剂对马铃薯晚疫病均可达到显著防治效果。防治效果最好的4种药剂为25%瑞凡、50%福帅得、0.5%苦参碱和30%甲霜.嘧菌酯,防治效果均达到80%以上;其次为45%三苯乙酸锡和68.75%银法利,防治效果达到70%以上;较差为52.5%抑快净,防治效果达到65%。建议在生产上交替使用,避免产生抗药性。     

Evaluation of sprinkler application of fungicides for control of potato early blight in Colorado

Sprinkler application of four fungicides, Du-Ter 47.5% W.P. (0.70 kg/ha), Difolatan 4F (3.51 1/ha), Bravo W-75 (1.68 kg/ha) and Bravo 500 (1.17 1/ha, 1.761/ha and 2.341/ha) were evaluated in Colorado for control of potato early blight caused byAlternaria solani (Ellis & G. Martin) L.R. Jones and Grout and compared to the conventional method of airplane application. Fungicides applied through center pivot irrigation systems generally achieved disease control equal to airplane application. Application of fungicides through both center pivot sprinklers and by airplane effectively reduced early blight infection. Control of early blight by airplane or sprinkler application of fungicides significantly (P = 0.05) increased potato yields in 1978. In other years (1977, 1979 and 1980) fungicide applications which reduced disease severity generally increased tuber yields but the increases were not significant when compared to the control.     

马铃薯早疫病的杀菌剂田间药效试验

马铃薯早疫病近年来在各马铃薯主产区发生比较严重,为此我们进行了马铃薯早疫病杀菌剂药效筛选试验。结果表明:防治效果较好的是25%阿米西达1 000倍、60%氟吗啉.代森锰锌600倍、52.5%抑快净2 000倍,防效分别为87.71%、84.13%、81.26%。由于防治效果比较明显,所以建议在生产上使用。     

比利时马铃薯晚疫病监测预警模型在贵州省威宁县的应用

为提高马铃薯晚疫病监测预警水平和防控效果,2010年引进了比利时马铃薯晚疫病监测预警系统并在威宁县草海镇白岩村马铃薯种植基地应用。经过3年的实践,结果证明,该系统能较为准确的定位马铃薯生产基地晚疫病防治时间和防治次数,对马铃薯晚疫病的防治具有积极的指导意义。     

攀枝花市马铃薯优质新品种引进筛选试验

为筛选适宜攀枝花市高寒冷凉地区适宜发展的较优马铃薯品种(系),引进6个马铃薯新品种(系),试验测定马铃薯新品种(系)的丰产性、抗逆性和块茎品质等性状.结果表明,新品系'S04-921'对早、晚疫病抗性强;总淀粉、直链淀粉和蛋白质含量高,产量34536 kg/hm2,较对照'米拉'增产10074 kg/hm2,增幅41....     

不同杀菌剂防治马铃薯晚疫病田间药效试验

试验研究了7种杀菌剂对马铃薯晚疫病的防治作用。结果表明:68.75%银法利悬浮剂1125 g/hm2、53%金雷多米尔水分散颗粒剂1500g/hm2、60%氟吗啉.代森锰锌可湿性粉剂1225g/hm2、72%克露可湿性粉剂2000g/hm2对马铃薯晚疫病防效分别为88.38%、86.15%、84.55%、81.68%,是防治马铃薯晚疫病较理想的药剂,且增产效果明显,建议在生产上交替使用。     

Quantitative analysis of host resistance,fungicide and weather effects on potato early and late blight using computer simulation models

Models which simulate the development of potato early blight, potato late blight and fungicide dynamics were used to analyze the effects of host resistance, fungicide and weather on individual and combined epidemics of these diseases. Fungicide and host resistance effects were based on (and accurately reflected) products and cultivars available to commercial potato growers in northeastern USA. Moderate resistance to early blight had a 2-3 fold greater effect than did moderate resistance to late blight in suppressing early and late blight, respectively. Analysis of simulation experiments indicated that replacement of an early blight susceptible cultivar with a cultivar moderately resistant to the disease would permit a reduction in the fungicide application frequency from once every week to once every two weeks without loss of disease suppression. Fungicide effect in suppressing late blight was 2-3 fold greater than in suppressing early blight. Variation in seasonal weather (typical of northeastern USA) influenced late blight development more strongly than it affected early blight development, and it affected epidemics of individual diseases more than combined epidemics.     

Deposition and redistribution of fungicides applied by air and chemigation for control of late blight in commercial potato fields

The fungicides metiram, mancozeb, metiram + triphenyltin hydroxide, propamocarb hydrochloride + chlorothalonil, dimethomorph + mancozeb, cymoxanil + mancozeb, and chlorothalonil were applied by aircraft and through center-pivot irrigation systems (chemigation) to replicated plots in commercial fields of ‘Russet Burbank’ potato. Fungicide deposition and redistribution were indirectly determined by inoculation of excised leaves withPhytophthora infestans and directly by chlorothalonil residue analysis from upper, middle, and lower crop canopies. The effectiveness of two surfactants added with fungicide and applied by aircraft, an increased water volume rate used by aircraft, and a reduced water volume used with chemigation was also determined. The addition of synthetic latex and siliconepolyether surfactants did not increase efficacy of metiram or mancozeb in controlling late blight when applied by aircraft. The protectant fungicides metiram, mancozeb, and chlorothalonil were not significantly different from dimethomorph + mancozeb, cymoxanil + mancozeb, and propamocarb hydrochloride + chlorothalonil in late blight control when applied by aircraft. However, cymoxanil + mancozeb had limited efficacy when applied by chemigation. Fungicide deposition through the canopy differed when air applications were made before or after canopy closure (row closure). Fungicides applied by aircraft prior to row closure protected the entire canopy; whereas, fungicide application after row closure initially protected the top and middle canopies, and subsequent applications and redistribution of the fungicides were needed for adequate protection throughout the canopy. The fungicides and fungicide mixtures tested were evenly deposited throughout the potato canopy with each chemigation application. Severity of late blight did not differ on leaves treated with mancozeb or chlorothalonil applied by aircraft at water volumes of 47 L/ha and 94 I/ha and then inoculated withP. infestans, nor did severity of late blight differ on inoculated leaves previously treated with chlorothalonil by chemigation at water volumes of 15,145 and 50, 571 L/ha.     

Interactive effects of fungicide programs and nitrogen management on potato yield and quality

The use of azoxystrobin (Quadris) for early blight control often results in potato vines remaining greener later in the growing season. This observation has lead to the suggestion that nitrogen (N) fertilizer could be applied at lower rates when azoxystrobin is used in a fungicide program since high N rates are sometimes used to help manage early blight. The objectives of this study were to evaluate the effectiveness of azoxystrobin for control of early blight under various N fertility management regimes and to determine if azoxystrobin affected plant N fertilizer requirements. Plots were established in 1999 and 2000 at Becker, MN, on a Hubbard loamy sand as a complete factorial, split-plot arrangement using a randomized complete block design with four replications. Fungicide treatments were used as the whole plot factor and included an untreated control, chlorothalonil, and azoxystrobin rotated with chlorothalonil. Fertility treatments were used as the sub-plot factor and included N applied at three levels (170, 250, and 340 kg ha^?1) and two timings (all prehilling or pre- and post-hilling). Early blight was problematic in 1999 and both early and late blight were severe in 2000. Significant interactions were observed between fungicide and fertility treatments for disease control. Control of diseases with fungicides was generally more effective at higher N rates regardless of N application timing. When azoxystrobin was used in the fungicide program, N rate was not as critical in managing foliar disease. In 1999, an interaction was not observed between N rate and fungicide treatment for yield. Yields increased with increasing N rate regardless of fungicide program. However, a significant interaction did occur between N rate and fungicide treatment in 2000 where yields decreased linearly in the control with increasing N rate, increased linearly with N rate using chlorothalonil, and did not respond significantly to N rate using azoxystrobin/chlorothalonil. Results of this study indicate that interactions between the incidence of early/late blight disease and N requirement for potato may depend on the rate of vine death and conditions affecting tuber maturity. At equivalent N rates, post-hilling N tended to depress yield regardless of fungicide program, suggesting that under the conditions of this study late season N is not an effective practice for managing foliar diseases such as early or late blight.     

240g/L收乐通防除马铃薯田野燕麦及对马铃薯安全性评价

野燕麦是马铃薯田的主要杂草之一,人工除草工作量大。本研究的目的是明确240 g/L收乐通EC在青海省马铃薯田防除野燕麦药效、适宜剂量及对作物的安全性。在田间使用了240 g/L收乐通EC制剂量300,450,600 mL/hm2,以108 g/L高效盖草能EC制剂量375 mL/hm2为对照药,设空白对照处理,于马铃薯3~5叶期,野燕麦为3~6叶期兑水300 L/hm2喷雾处理。结果表明,240 g/L收乐通EC是马铃薯田防除野燕麦的优良除草剂,适宜剂量为450 mL/hm2,对野燕麦40 d株防效和鲜重效均达85%以上,对马铃薯安全,增产率达10%以上。