11种杀菌剂对柑桔褐腐疫霉的室内毒力测定

由疫霉菌引起的苗疫、褐腐病是柑桔苗期和结果期间的重要病害,为筛选出有效防治药剂,采用菌丝生长速率法测定了11种杀菌剂对柠檬褐腐病菌柑桔褐腐疫霉(Phytophthora citrophthora)的室内毒力。结果表明,杀菌剂毒力由强到弱依次为氟噻唑吡乙酮、双炔酰菌胺、烯酰吗啉、霜脲氰、氟菌?霜霉威、甲霜?锰锌、代森锰锌、百菌清、三乙膦酸铝、氢氧化铜和丁子香酚,EC50值分别为0.0017、0.0116、0.6264、0.6471、1.596、4.034、13.23、25.40、41.74、69.15和71.51 mg?L-1。     

7种杀菌剂对草坪草腐霉枯萎病菌的毒力测定与药效试验

采用生长速度法和孢子囊形成法测定了7种杀菌剂对草坪腐霉枯萎病菌的毒力作用,并进行了7种杀菌剂拌种的温室盆栽防治效果研究。室内毒力测定表明,不同杀菌剂对腐霉菌菌丝的生长和游动孢子囊的形成有显著的抑制作用（P<0.05）。对菌丝的生长有明显抑制效果的杀菌剂主要是霜脲锰锌、代森锰锌和霜霉威盐酸盐,前两种杀菌剂的半致死浓度（EC50）值均为1.28 mg·L-1,后者的EC50值为3.26 mg·L-1。对游动孢子囊的形成抑制效果明显的杀菌剂是吡唑醚菌酯、霜脲锰锌和代森锰锌,其EC50值分别是0.09 、0.21和0.46 mg·L-1。用7种杀菌剂分别拌种后,高羊茅(Festuca arundinacea)出苗率都有不同程度的提高,其中霜脲锰锌和代森锰锌对腐霉枯萎病的防治效果较好。根据杀菌剂的室内毒力测定和盆栽防效试验结果,霜脲锰锌和代森锰锌对腐霉枯萎病的防治效果优于其它5种杀菌剂。     

13种杀菌剂对芒果炭疽病菌的室内毒力测定及田间防效

近年来芒果炭疽病在贵州芒果园发生普遍、危害极重，通过本研究掌握芒果胶孢炭疽菌（Colletotrichum gloeosporioides Penz）对不同杀菌剂的毒力及田间防治效果，将为芒果炭疽病的防治提供理论依据。采用生长速率法测定13种杀菌剂对芒果胶孢炭疽菌的毒力，结果表明：13种杀菌剂中450g/L咪鲜胺EW对胶孢炭疽菌抑菌效果最好，EC50小于0.01mg/l，250克/升吡唑醚菌酯EC、50%氟啶胺SC、50%多菌灵WP和12.5%氟环唑SC的EC50均小于1 mg/L，对胶孢炭疽菌具有较好抑菌效果。芒果幼果期进行田间防治，结果表明：450g/L咪鲜胺EW1500倍液、250克/升吡唑醚菌酯EC1250倍液、50%多菌灵WP1000倍液、12.5%氟环唑SC2000倍液、250g/L嘧菌酯SC1250倍液、50%氟啶胺SC1500倍液和70%甲基硫菌灵WP1000倍液等7种药剂可相对有效地控制芒果炭疽病的发生，防效为57.57%~65.57%。该研究将为贵州芒果炭疽病的防治提供理论依据及技术支撑。     

枇杷拟盘多毛孢菌的室内及田间药剂筛选

【目的】筛选几种对重庆枇杷灰斑病致病菌有效的防治药剂。【方法】 选用11种杀菌剂采用生长速率法对致病病原菌进行抑菌活性测定并选取其中10种进行田间防效试验。【结果】室内药效试验表明，各药剂在不同浓度下对枇杷拟盘多毛孢菌的菌丝生长均有不同程度的抑制作用，且抑制率与浓度呈正相关。其中25%咪鲜胺EC抑制效果最好，EC50为0.0378mg/L。田间药效试验表明，25%咪鲜胺EC 833倍液防治效果最好，防效达83.08%。【结论】综合筛选出咪鲜胺、嘧菌酯及丙环唑效果较好可用于田间大面积防治重庆枇杷灰斑病。     

8种农药对柑桔拟茎点霉Phomopsis sp.毒力测定及田间防治试验

测定8种农药对柑桔拟茎点霉Phomopsis citri Fawcett的毒力测定及田间防效试验时，发现丙环唑对该菌抑制效果最好，苯醚甲环唑与其它药剂差异显著，其它药剂之间差异不显著。     

杀菌剂对猕猴桃溃疡病菌的室内毒力测定及田间防效

为明确不同杀菌剂对猕猴桃溃疡病的防治效果，采用平板菌落计数法对22种杀菌剂进行室内毒力测定。结果表明：0.2%纳米银溶液、0.3%四霉素水剂、3%噻霉酮水分散粒剂、20%溴硝醇可湿性粉剂、72%硫酸链霉素可溶粉剂、78%波尔?锰锌可湿性粉剂对溃疡病菌有很好的抑制作用，EC50分别为0.0865、0.0928、1.1044、2.2965、3.6714和5.228 mg/l；20%甲磺酰菌唑可湿性粉剂、99.8%硝酸银、3%中生菌素可湿性粉剂和80%乙蒜素乳油对病菌具有一定的抑菌作用，EC50分别为11.416、13.981、16.9523和20.1025mg/l。选用5种抑菌效果较好的药剂进行田间药效试验，试验结果表明0.3%四霉素水剂效果最好，平均防效为71.06%；其次为72%硫酸链霉素可溶粉剂、0.2%纳米银溶液、3%噻霉酮水分散粒剂，平均防效分别为70.39%、63.31%、53.78%；而20%溴硝醇可湿性粉剂的防效较差，平均防效为44.80%；此研究为修文猕猴桃溃疡病的科学防治提供了理论依据。     

不同杀菌剂对草坪草病原菌毒力的作用测定

采用生长速率法测定了不同杀菌剂对3种主要引起坪草病害的褐斑病菌、腐霉枯萎菌、夏季斑枯病菌的毒力。结果表明,烯唑醇、甲基硫菌灵、代森锰锌、咪鲜胺对立枯丝核菌的EC50值分别为0.078 3,5.968 4,7.181 2和11.386 8 mg/L,以烯唑醇对立枯丝核菌的毒力最高。烯唑醇、咪鲜胺、代森锰锌、甲基硫菌灵对夏季斑枯病菌的EC50值分别为0.016 2,0.554 4,6.035 3,1 218.497 8 mg/L,以烯唑醇抑菌效果显著优于其它3种杀菌剂。采用菌丝干重测定法测定了阿米西达、霜脲氰、霜克、咪鲜胺、代森锰锌对腐霉枯萎病菌的毒力,其EC50值依次为0.053 3,7.837 4,13.310 7,19.715 1,29.771 5 mg/L,以阿米西达的抑菌效果最好。     

蓝莓炭疽病的药剂防治试验

选8种绿A生产可用杀菌剂对蓝莓炭疽病病菌进行室内毒力测定，试验结果表明：对引起蓝莓炭疽病的两种主要病原菌均具有较好抑菌作用的杀菌剂为吡吡唑醚菌酯、氟环唑、丙环唑、咯菌腈；排除2种对两种病原菌抑制效果均差的药剂，将其余 6种药剂进行田间药效试验，结果表明：在试验条件下，250 g /L 吡唑醚菌酯 EC1800 倍液、125g/L氟环唑SC 1500倍液、25%丙环唑EC 1000倍液均对蓝莓炭疽病具有较好的防治效果     

八种杀菌剂对香蕉黑斑病的防治效果比较

比较250 g/L丙环唑乳油等八种常用杀菌剂对香蕉黑斑病的防治效果。结果表明，250 g/L丙环唑乳油750倍液的防效最好，施药3次后10天防效达83.68%，其次为125 g/L氟环唑悬浮剂900倍液和30%苯醚甲环唑悬浮剂3000倍液，防效分别为76.03%和74.58%。3种药剂在本试验浓度范围内未发现对香蕉产生药害，可推广使用。     

甘肃省黄芪霜霉病发病规律及防治经济阈值研究

为明确甘肃省黄芪霜霉病的发病规律、防治药剂、经济危害允许水平和防治经济阈值,采用田间定点定期系统调查的方法,对该病害的发病进程以及影响发病的气候因素等进行了研究,采用模型拟合的方法研究了霜霉病病情指数与黄芪产量损失率的最佳拟合模型,选用6种杀菌剂进行了田间药效试验。结果表明: 黄芪霜霉病在5月份显症,8月初至9月中旬为盛发期,一直延续到收获。黄芪霜霉病的病情指数随晚间平均相对湿度和病情基数的增加而增加,病情指数增长率随着白天平均温度的增加而增加。4种模型拟合结果表明,对数函数(y=33.81lnx-97.15)是拟合霜霉病病情指数(x)与黄芪产量损失率(y)的最好模型;选用60%百泰(5%吡唑醚菌酯·55%代森联)WG 800倍液进行霜霉病的防治时,经济危害允许水平和经济阈值分别为5.65%和17.73。药剂试验结果表明,52.5%抑快净WG 1500倍液、60%百泰WG 1000倍液是防治黄芪霜霉病良好的药剂;72%霜脲氰·锰锌WP 400倍液、75%百菌清WP 350倍液以及65%代森锌WP 200倍液对黄芪霜霉病亦有较好的防效,可选择在生产中使用。     

Scrapie in goats in Cyprus

Ovine scrapie was first recorded in Cyprus in 1985. Subsequently four dairy goats kept in two mixed flocks with affected sheep developed characteristic clinical signs similar to those seen in sheep. Fifteen goats from the two flocks were examined histologically and neurological lesions consistent with a diagnosis of scrapie were found in the four animals and in three others which had subsequently developed early neurological signs. These lesions were similar to those of naturally-affected sheep although neuronal degeneration and vacuolation were more severe in some cases.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.