防治长柔毛野豌豆生草果园杂草茎叶处理剂筛选

王恒智1,王立鹏1,孙瑞红2,金 涛3,彭学岗3,王金信1,刘伟堂1*

1山东农业大学植物保护学院·山东省农药毒理与应用技术重点实验室,山东 泰安 271018;2山东省果树研究所,山东 泰安 271018;3青岛清原化合物有限公司,山东 青岛 266000)

摘 要:【目的】筛选出有效防治果园长柔毛野豌豆生草田杂草的茎叶处理剂,为果园长柔毛野豌豆生草田杂草的化学防治提供参考。【方法】室内盆栽比较了8种除草剂对长柔毛野豌豆的安全性和常见杂草的生物活性,筛选药剂进行复配,进一步研究复配制剂的联合除草类型,测定其对长柔毛野豌豆的安全性及其在长柔毛野豌豆与杂草之间的选择性指数,并对复配制剂进行田间药效试验。【结果】灭草松、咪唑乙烟酸与精喹禾灵茎叶喷雾处理在2×田间推荐剂量下对长柔毛野豌豆安全。咪唑乙烟酸在长柔毛野豌豆与碎米莎草、马唐、牛筋草、狗尾草、播娘蒿、牛繁缕之间的选择性指数大于2.0;灭草松在长柔毛野豌豆与荠菜、播娘蒿、牛繁缕之间的选择性指数小于0.7,安全性差;精喹禾灵在长柔毛野豌豆与牛筋草、狗尾草、马唐之间的选择性指数大于8.8。联合作用测定结果表明咪唑乙烟酸与精喹禾灵按不同质量比复配后对马唐、牛筋草、看麦娘、牛繁缕、播娘蒿、荠菜的联合作用类型均为加成作用,其中以质量比2∶1复配后,选择性指数在2.4~8.9之间。田间试验结果显示:咪唑乙烟酸和精喹禾灵复配后在有效成分125~150 g·hm-2剂量下,于杂草2~3叶期、长柔毛野豌豆3~5复叶期茎叶喷雾处理,药后30 d对荠菜、播娘蒿和看麦娘的总体鲜质量防效在86%以上,同时对长柔毛野豌豆安全。【结论】咪唑乙烟酸和精喹禾灵复配可以作为果园长柔毛野豌豆生草田防除杂草候选药剂。

关键词:果园生草;长柔毛野豌豆;咪唑乙烟酸;精喹禾灵;除草活性;安全性

长柔毛野豌豆Vicia villosa,属一年生豆科植物,通常被用于果园生草或作为一种优质牧草和绿肥[1]。其广泛分布在欧洲,中亚,伊朗和美国东部。在中国,长柔毛野豌豆主要生长在黄河、淮河和海河流域[2],理想的播种时间在8 月下旬至9 月下旬,其种群的快速建立与种植方法、种植密度和种子发芽率有着密切的关系[3]。当温度达到15 ℃时,长柔毛野豌豆开始出现花蕾,在适当的环境条件下,单个植株可以产生800~1000粒种子[4]

迄今为止,许多研究[5-6]已经报道了在农业生产中应用长柔毛野豌豆,其用于果园生草不仅可以显著提高作物产量和果实含糖量,还可以在一定程度上控制病害。在中国,长柔毛野豌豆主要用于果园人工生草或者作为伴生植物[7],通过吸引昆虫来提高果实授粉率,同时可以减少土壤水分蒸发,增加土壤有机质含量和空隙度,改善表层土壤pH和土壤微生物活性[8-10]。此外,相较于杂草,长柔毛野豌豆对光照、生存空间、水分和养分等生活因子的竞争能力更强,同时会释放化感作用物质氰胺,可以有效抑制其他有害杂草的萌发、出苗和生长[11-12],如郭晓霞等[13]研究发现长柔毛野豌豆可以通过化感作用对稗草、早熟禾和波斯婆婆纳种子萌发和幼苗均有不同程度的抑制作用;同时在番茄田行间种植长柔毛野豌豆可有效抑制杂草生长并提高番茄产量[14]。孙瑞红等[15]研究发现,在果园人工种植长柔毛野豌豆后,对荠菜Capsella bursa-pastoris、播娘蒿Descurainia sophia 和糖芥Erysimum bungei 等杂草的总体株防效高达85.6%。

长柔毛野豌豆人工生草作为一种创新型的果园管理方式,在有效增加土壤肥力的同时,还可以抑制杂草的萌发、出苗和生长。然而,在生产实践中发现,生草前期由于其他杂草的竞争,长柔毛野豌豆不容易建立起种群。为了更好地对果园进行长柔毛野豌豆生草,前期有害杂草的化学防治显得尤为重要。一般来说,豆科植物对除草剂具有较高的敏感性,因此在选择除草剂时要有针对性,充分考虑到对作物的安全性和对杂草的防效[16]。目前已有防除牧草苜蓿(豆科植物)田杂草的药剂筛选报道[17];此外,赵远征等[18]研究发现,苗前土壤封闭剂是长柔毛野豌豆田较为适宜的除草剂,然而该研究却未筛选出适宜的苗后茎叶处理剂。目前,国内外鲜有关于苗后茎叶处理防除长柔毛野豌豆田杂草的报道。鉴于此,本研究首先采用温室盆栽法,测定了8种除草剂茎叶处理对长柔毛野豌豆的安全性,并进行杀草谱测定,筛选出除草剂进行复配,测定了复配制剂对马唐Digitaria sanguinalis、牛筋草Eleusine indica、看麦娘Alopecurus aequalis、牛繁缕Myosoton aquaticum、荠菜和播娘蒿的联合除草作用,筛选了合适的复配比例,并就复配制剂对长柔毛野豌豆和杂草之间的选择性进行了研究,最后进行了复配制剂的田间药效试验,旨在为果园长柔毛野豌豆生草田前期杂草的化学防控提供理论指导。

1 材料和方法

1.1 试验材料

1.1.1 供试药剂 所用除草剂见表1,均为目前市场中常见对豆科植物较为安全的茎叶处理剂。

表1 供试除草剂及室内生物测定剂量
Table 1 Herbicides and their doses used in the greenhouse experiments

注:剂量均表示有效成分剂量。
Note:The herbicide doses indicate the active ingredients.

供试除草剂Herbicides 480 g·L-1灭草松水剂480 g·L-1 bentazone AS 80%唑嘧磺草胺水分散粒剂80%flumetsulam WDG 21.4%三氟羧草醚可溶液剂21.4%acifluorfen sodium SL 20%乙羧氟草醚乳油20%fluoroglycofen EC剂量Doses/(g·hm-2)561.6,1 123.2,2 246.4 18,36,72 129.4,258.8,517.7 37.5,75.0,150.0 250 g·L-1氟磺胺草醚水剂250 g·L-1 fomesafen AS 30%二氯吡啶酸可溶液剂30%clopyralid SL 10%咪唑乙烟酸水剂10%imazethapyr AS 10%精喹禾灵乳油10%quizalofop-p-ethyl EC生产或提供厂家Manufacturer or supplier山东先达农化股份有限公司Shandong Cynda(Chemical)Co.,Ltd.河南瀚斯作物保护有限公司Henan Hansi Crop Protection Co.,Ltd.山东先达农化股份有限公司Shandong Cynda(Chemical)Co.,Ltd.山东玥鸣生物科技有限公司Shandong Yueming Biotechnology Co.,Ltd.新乡中电除草剂有限公司Xinxiang Zhongdian Chucaoji Co.,Ltd.安徽丰乐农化有限责任公司Anhui Fengle Agrochemical Co.,Ltd.齐齐哈尔盛泽农药有限公司Qigihar Shengze Pesticide Co.,Ltd.山东先达农化股份有限公司Shandong Cynda(Chemical)Co.,Ltd.187.5,375.0,750.0 22.5,45.0,90.0 50.25,100.5,201.0 37.5,75.0,150.0

1.1.2 供试植物 杂草:苘麻Abutilon theophrasti、反枝苋Amaranthus retroflexus、碎米莎草Cyperus iria、马唐D.sanguinalis、牛筋草E.indica、狗尾草Setaria viridis、打碗花Calystegia hederacea、马齿苋Portulaca oleracea、荠菜C.bursa-pastoris、看麦娘A.aequalis、播娘蒿D.sophia 和牛繁缕M.aquaticum,均为我国果园常见夏熟和秋熟杂草,于2019年采自山东省泰安市及周边省市非耕地,成熟的杂草种子清理干净,室温晾干,25 ℃保存备用;长柔毛野豌豆V.villosa 由山东省果树研究所提供,种子千粒质量约25 g,25 ℃保存备用。目前,该品种在中国广泛应用于果园生草和作为一种绿肥植物。

1.1.3 主要仪器 BSA-224S型万分之一电子天平,赛多利斯科学仪器(北京)有限公司;SPX型智能光照培养箱,宁波江南仪器厂;ASS-4型自动控制农药喷洒系统(TEEJET-9503EVS 扇形喷头),国家农业信息化工程技术中心研制,北京盛恒天宝科技有限公司。

1.2 试验方法

温室试验参照《农药室内生物测定试验准则(NY/T 1155.8—2007;NY/T 1155.4—2007;NY/T 1155.7—2006)》进行。

1.2.1 药液配制 准确称取一定量制剂,用清水溶解配制成高浓度母液,再用清水稀释成所需浓度。以清水作为空白对照。

1.2.2 试材培养 取未使用过农药的表层风干土[壤土,pH=7.67,有机质含量(w,后同)为15.79 g·kg-1],过3.35 mm 孔径筛,装入塑料盆钵,备用。选取籽粒饱满的杂草或长柔毛野豌豆种子,置于铺有2层滤纸的培养皿中,添加8 mL去离子水润湿滤纸,于光照培养箱中(恒温25 ℃,光周期12 h,相对湿度75%)催芽。根据种子大小,将一定数量的露白种子均匀播种于塑料盆钵中,覆细土约0.5 cm,置于山东农业大学可控日光温室(自然光照,白天24~33 ℃,夜间18~24 ℃,相对湿度65%~79%)培养。待植株长至1~2 枚真叶时间苗,保留固定株数长势一致的幼苗。

1.2.3 施药方式 于长柔毛野豌豆3~5 复叶期、杂草2~4叶期,采用农药喷洒系统进行茎叶喷雾处理,喷雾压力0.275 MPa,喷液量450 L·hm-2,喷头与塑料盆钵之间的距离为50 cm。施药完成后在喷洒系统中静置2~3 min,待药液与茎叶接触稳定之后,置于上述日光温室中继续培养。

1.2.4 8种除草剂对长柔毛野豌豆安全性测定 选取目前市场中对豆科植物较为安全的8种茎叶处理剂,参考田间推荐剂量设置3个处理,分别是田间推荐剂量的1/2 倍、1 倍和2 倍(表1),并设置空白对照。每处理4次重复。于药后21 d剪去长柔毛野豌豆地上部分鲜质量,根据公式(1)计算鲜质量抑制率:

使用DPS v 13.5 对2 次试验结果进行ANOVA分析,若同一处理之间不存在差异显著性(p >0.05),则对2次结果进行合并处理。

1.2.5 杀草谱测定 根据8种除草剂对长柔毛野豌豆安全性测定结果,选择咪唑乙烟酸、灭草松和精喹禾灵对我国果园常见夏熟和秋熟杂草进行杀草谱测定,剂量设置见表1,并设空白对照。每处理4 次重复。于药后21 d 剪去杂草地上部分鲜质量,根据公式(1)计算鲜质量抑制率。数据统计同1.2.4节。

1.2.6 选择性指数测定 根据杀草谱结果,进一步进行3种除草剂在长柔毛野豌豆和不同杂草之间选择性指数的测定,参照预实验结果,剂量设置为咪唑乙烟酸9.375、18.750、37.500、75.000、150.000 g·hm-2(有效成分剂量,下同),灭草松144、288、576、1152、2304 g · hm- 2,精 喹 禾 灵9.375、18.750、37.500、75.000、150.000 g·hm-2,并设空白对照。每处理4次重复。处理后药后21 d 称取植株地上部分鲜质量,根据公式(1)计算鲜质量抑制率。数据统计同1.2.4节,同时用统计软件DPS v 13.5 进行数据分析,以鲜质量抑制率概率值(y)和剂量对数值(x)建立回归方程(y=a+bx),计算3 种除草剂对长柔毛野豌豆的GR10(Herbicide rate causing 10% growth reduction of plants)、对杂草的GR90(Herbicide rate causing 90%growth reduction of plants)值及95%置信限,并用公式(2)计算3 种除草剂在长柔毛野豌豆和不同杂草之间选择性指数[19]

1.2.7 咪唑乙烟酸和精喹禾灵复配的联合作用测定 根据3 种除草剂选择性指数测定结果,选择咪唑乙烟酸和精喹禾灵进行复配。咪唑乙烟酸剂量为37.5、60.0、75.0 g·hm- 2,精喹禾灵剂量为18.75、37.50、75.00 g·hm-2及2 种药剂复配,对马唐、牛筋草、看麦娘、牛繁缕、荠菜、播娘蒿进行茎叶喷雾处理,每处理4次重复,另设空白对照。于施药后21 d称取杂草植株地上部分鲜质量用公式(1)计算鲜质量防效(E)。按公式(3)计算理论鲜质量防效E0。当EE0=−10%~10%时为加成作用,当EE0>10%时为增效作用,当EE0<−10%时为拮抗作用。

式中:X 表示咪唑乙烟酸的实际鲜质量防效,%;Y 表示精喹禾灵的实际鲜质量防效,%。

1.2.8 咪唑乙烟酸和精喹禾灵复配的安全性测定将咪唑乙烟酸和精喹禾灵按质量比2:1 混配后,分别对杂草和长柔毛野豌豆进行茎叶处理,剂量分别为28.125、56.250、90.000、112.500、150.000 g·hm-2,90、120、240、300、450 g·hm-2,另设空白对照,并在药后21 d称取植株地上部分鲜质量,根据公式(1)计算鲜质量防效,统计方法同1.2.6 节,分别计算复配制剂对杂草的GR90值及对长柔毛野豌豆的GR10值。根据公式(2)计算复配制剂在长柔毛野豌豆和杂草之间的选择性指数。

1.3 田间药效试验

于2021 年春季杂草发生期在山东省泰安市泰山区圣元村桃园(36.13°N,117.20°E)进行田间药效试验,以明确咪唑乙烟酸和精喹禾灵复配对长柔毛野豌豆生草田杂草防除效果及对长柔毛野豌豆的安全性。桃园海拔143 m;累计降雨量60.4 mm;土质为砂姜黑土,有机质含量1.7%,pH7.1;桃树品种为中油4号(玉妃),树龄2 a,株距3 m,行距4 m。

于2020 年10 月16 日对长柔毛野豌豆进行撒播,每666.7 m2播种量为1.75 kg。施药时间为2021年2 月21 日(多云,10~19 ℃,微风),此时杂草处于2~4 叶期,长柔毛野豌豆3~5 复叶期。施药使用MATABI-16 型背负式喷雾器,扇形喷头,喷液量为450 L·hm-2。施药时田间杂草主要为播娘蒿(50~62株·m-2),荠菜(20~31株·m-2),看麦娘(10~24株·m-2)。试验采用随机区组设计,设置6个处理,分别为咪唑乙烟酸90 g·hm-2,精喹禾灵60 g·hm-2,咪唑乙烟酸+精喹禾灵(2∶1)100、125、150、250 g·hm-2,并设空白对照,每处理4次重复,共28个小区,小区采用长方形设计,面积20 m2(4 m×5 m)。

杂草防效调查:分别在药后15 d和30 d,在小区内随机选取4个取样点,每个样点0.33 m2,记录样点内存活的杂草种类及其株数,根据公式(4)计算株防效P(number)(%)。于药后30 d 同时测定杂草地上部分鲜质量,根据公式(4)计算鲜质量防效P(biomass)(%):

式中:PSC为4 个对照组每种杂草的株数或鲜质量之和,PT 为处理组植株数或鲜质量。采用最小二乘法(LSD)在p=0.05水平上对数据进行比较分析。

安全性评估:分别在药后3、5、10 和20 d,采用目测法观察长柔毛野豌豆生长情况。若有药害,则准确描述药害症状并记录受害程度。

2 结果与分析

2.1 9种除草剂对长柔毛野豌豆安全性测定

由表2 可以看出,唑嘧磺草胺、乙羧氟草醚、氟磺胺草醚、二氯吡啶酸在处理剂量下对长柔毛野豌豆的鲜质量抑制率均>90%,部分植株甚至死亡,安全性差;三氟羧草醚在129.4 g·hm-2处理剂量下对长柔毛野豌豆相对较安全,而在517.7 g·hm-2处理剂量下抑制率大于90%,安全性较差;咪唑乙烟酸、精喹禾灵和灭草松在试验剂量下对长柔毛野豌豆鲜质量抑制率<30%,安全性较高,因此,本研究选择这3种除草剂进行杀草谱研究。

表2 对长柔毛野豌豆安全的茎叶处理剂筛选
Table 2 Safety screening of herbicides for postemergence treatment of V.villosa

注:++++表示抑制率>90%;+表示抑制率30%~59%;-表示抑制率<30%。
Note: ++++ means inhibitory rate of fresh weight >90%; + means inhibitory rate of fresh weight between 30%and 59%;-means inhibitory rate of fresh weight <30%.

除草剂Herbicides灭草松Bentazone鲜质量分级Fresh weight classification---唑嘧磺草胺Flumetsulam++++++++++++三氟羧草醚Acifluorfen sodium-+乙羧氟草醚Fluoroglycofen氟磺胺草醚Fomesafen二氯吡啶酸Clopyralid++++++++++++++++++++++++++++++++++++++++咪唑乙烟酸Imazethapyr精喹禾灵Quizalofop-p-ethyl剂量Doses/(g·hm-2)561.6 1 123.2 2 246.4 18.0 36.0 72.0 129.4 258.8 517.7 37.5 75.0 150.0 187.5 375.0 750.0 22.5 45.0 90.0 50.25 100.5 201.0 37.5 75.0 150.0------

2.2 咪唑乙烟酸、灭草松、精喹禾灵杀草谱研究

由表3可知,咪唑乙烟酸在处理剂量为75 g·hm-2时,对9种杂草的鲜质量抑制率超过了80%,包括反枝苋、碎米莎草、马唐、牛筋草、狗尾草、马齿苋、荠菜、播娘蒿和牛繁缕。灭草松在处理剂量为576 g·hm-2时,对6 种杂草的鲜质量抑制率超过了70%,包括苘麻、碎米莎草、牛筋草、打碗花、荠菜、播娘蒿。精喹禾灵在处理剂量为37.5 g·hm-2时,对3 种杂草的鲜质量抑制率超过了90%,包括马唐、牛筋草、狗尾草。

表3 咪唑乙烟酸、灭草松、精喹禾灵对杂草的鲜质量抑制率分级
Table 3 Inhibition of fresh weight of weeds by imazethapyr,bentazone,quizalofop-p-ethyl

注:++++表示抑制率>90%;+++表示抑制率80%~90%;++表示抑制率60%~79%;+表示抑制率30%~59%;-表示抑制率<30%。
Note:++++means inhibitory rate of fresh weight >90%;+++means inhibitory rate of fresh weight between 80%and 90%;++means inhibitory rate of fresh weight between 60%and 79%;+means inhibitory rate of fresh weight between30%and 59%;-means inhibitory rate of fresh weight <30%.

供试杂草Trial weeds精喹禾灵Quizalofop-P-ethyl剂量Doses/(g·hm-2)9.375 18.750 37.500苘麻A.theophrasti反枝苋A.retroflexus碎米莎草C.iria马唐D.sanguinalis牛筋草E.indica狗尾草S.viridis打碗花C.hederacea马齿苋P.oleracea荠菜C.bursa-pastoris看麦娘A.aequalis播娘蒿D.sophia牛繁缕M.aquaticum咪唑乙烟酸Imazethapyr剂量Doses/(g·hm-2)18.75-++++++++++++-++++++++++++37.50++++++++++++++++-+++++++++++++75.00+++++++++++++++++++-++++++++++++++++灭草松Bentazone剂量Doses/(g·hm-2)144++-++288+++++++576+++++++++--+--+-----+--+---+++-+----++++++++++++++++++++++++++++-++++++++-+++---------+-----+--

2.3 咪唑乙烟酸、灭草松、精喹禾灵选择性指数研究

咪唑乙烟酸、灭草松和精喹禾灵对长柔毛野豌豆的GR10值、对供试杂草的GR90值以及3 种药剂在它们之间的选择性指数见表4。可以看出,当防除禾本科杂草马唐、狗尾草和牛筋草时,精喹禾灵对长柔毛野豌豆的安全性高,选择性指数在8.8~9.2 之间;当防除阔叶杂草荠菜、播娘蒿和牛繁缕时,灭草松对长柔毛野豌豆的安全性差,选择性指数低于2.0;咪唑乙烟酸对阔叶杂草播娘蒿和牛繁缕选择性指数高,但是对禾本科杂草的选择性指数低于精喹禾灵。因此,本研究选择咪唑乙烟酸和精喹禾灵复配,杀草谱互补,进行下一步研究。

表4 咪唑乙烟酸、灭草松和精喹禾灵在长柔毛野豌豆和杂草之间的选择性指数
Table 4 The selectivity index of imazethapyr,bentazone,quizalofop-p-ethyl between Vicia villosa and weeds

注:—表示未测定。下同。Note:—.Undeterminate.The same below.

除草剂Herbicides咪唑乙烟酸Imazethapyr GR10/(g·hm-2)——101.6(82.9~124.7)灭草松Bentazone— —1 379.7(1 022.0~1 862.6)精喹禾灵Quizalofop-p-ethyl试材Material马唐D.sanguinalis狗尾草S.viridis牛筋草E.indica碎米莎草C.iria荠菜C.bursa-pastoris看麦娘A.japonicus播娘蒿D.sophia牛繁缕M.aquaticum长柔毛野豌豆V.villosa碎米莎草C.iria荠菜D.sophia播娘蒿D.sophia牛繁缕M.aquaticum长柔毛野豌豆V.villosa马唐D.sanguinalis狗尾草S.viridis牛筋草E.indica看麦娘A.japonicus长柔毛野豌豆V.villosa— —111.0(83.1~148.2)GR90/(g·hm-2)38.1(34.8~41.6)28.6(26.4~30.9)50.00(41.1~60.8)20.5(20.0~21.1)115.3(77.8~170.7)1 416.5(738.2~2 717.7)32.8(27.5~39.0)17.0(15.3~188.0)—183.1(117.8~284.5)4 253.3(3 274.5~5 524.7)2 065.0(1 439.2~2 962.8)25 783.2(17 708.5~37 539.6)—12.0(7.9~18.2)12.6(9.4~29.8)12.4(7.1~22.3)601.3(365.4~990.0)—选择性指数Selectivity indexs 2.7 3.6 2.0 5.0 0.9 0.1 3.1 6.0—7.5 0.3 0.7 0.1—9.2 8.8 9.0 0.2—

2.4 咪唑乙烟酸和精喹禾灵复配

2.4.1 咪唑乙烟酸和精喹禾灵复配联合作用测定从表5和表6可知,咪唑乙烟酸和精喹禾灵混用后对马唐、牛筋草、看麦娘、牛繁缕、播娘蒿、荠菜的联合作用类型均为加成作用。各个组合的混用对6种杂草的鲜质量抑制率均大于80%。其中,精喹禾灵为18.75和37.50 g·hm-2的组合对马唐、荠菜、播娘蒿EE0 值较大;因此,咪唑乙烟酸和精喹禾灵以37.5~75.0+18.75~37.50 g·hm-2的组合混用较为适宜,即质量比为(4~1)∶1。

表5 咪唑乙烟酸、精喹禾灵混用对马唐、牛筋草和看麦娘的联合作用评价
Table 5 The evaluation of the joint effect of imidazolium mixed with quizalofop-p-ethyl against Digitaria sanguinalis,Eleusine indica and Alopecurus aequalis %

药剂Herbicides处理Treatments/(g·hm-2)37.5 60.0 75.0 18.75 37.50 75.00 37.5+18.75 37.5+37.50 37.5+75.00 60.0+18.75 60.0+37.5 60.0+75.00 75.0+18.75 75.0+37.5 75.0+75.00马唐D.sanguinalis实际鲜质量抑制率E 81.5 84.3 89.8 86.5 90.5 95.1 89.1 90.5 94.4 90.9 93.9 95.5 94.3 95.5 96.4理论鲜质量抑制率E0 E-E0理论鲜质量抑制率E0 E-E0理论鲜质量抑制率E0 E-E0咪唑乙烟酸Imazethapyr精喹禾灵Quizalofop-p-ethyl————————————咪唑乙烟酸+精喹禾灵Imazethapyr+quizalofop-p-ethyl 81.5 98.3 99.1 97.9 98.8 99.3 98.6 99.0 99.5-8.4-7.8-4.4-7.0-4.9-3.8-4.3-3.5-3.1牛筋草E.indica实际鲜质量抑制率E 75.5 81.3 88.7 86.8 92.4 95.2 96.7 97.3 97.5 96.8 97.0 97.5 96.0 97.5 99.0 97.6 98.7 99.1 98.2 98.9 99.4 99.4 99.6 99.8-0.9-1.4-1.6-1.4-1.9-1.9-3.4-2.1-0.8看麦娘A.aequalis实际鲜质量抑制率E 44.3 55.2 72.0 34.5 55.8 62.8 70.4 70.9 74.0 79.3 81.7 84.7 87.7 84.1 88.0 63.5 75.4 79.3 70.7 80.2 83.8 81.7 87.6 89.6 6.9-4.5-5.3 8.6 1.5 1.4 6.0-3.5-1.6

表6 咪唑乙烟酸、精喹禾灵混用对牛繁缕、荠菜和播娘蒿的联合作用评价
Table 6 The evaluation of the joint effect of imidazolium mixed with quizalofop-p-ethyl against Myosoton aquaticum,Capsella bursa-pastoris and Descurainia sophia %

药剂Herbicides处理Treatments/(g·hm-2)37.5 60.0 75.0 18.75 37.50 75.00 37.5+18.75 37.5+37.50 37.5+75.00 60.0+18.75 60.0+37.50 60.0+75.00 75.0+18.75 75.0+37.50 75.0+75.00牛繁缕M.aquaticum实际鲜质量抑制率E 93.9 95.2 96.9 1.1 3.1 6.1 93.1 95.1 97.0 93.9 95.7 96.6 94.6 96.0 97.3理论鲜质量抑制率E0 E-E0理论鲜质量抑制率E0 E-E0理论鲜质量抑制率E0 E-E0咪唑乙烟酸Imazethapyr精喹禾灵Quizalofop-p-ethyl————————————咪唑乙烟酸+精喹禾灵Imazethapyr+quizalofop-p-ethyl 94.0 94.1 94.3 95.3 95.3 95.5 96.9 96.9 97.1-0.9 1.0 1.7-1.4 0.4 1.1-2.3-0.9 0.2荠菜C.burss-pastoris实际鲜质量抑制率E 84.9 85.2 86.2 13.0 27.0 35.3 96.7 97.3 97.5 96.8 97.0 97.5 96.0 97.5 99.0 86.9 89.0 96.1 87.1 89.2 90.4 88.0 90.0 91.1 9.8 8.3 1.4 9.7 7.8 7.1 8.0 7.5 7.9播娘蒿D.sophia实际鲜质量抑制率E 87.0 92.0 93.5 0.1 2.1 8.7 83.1 85.9 86.8 84.4 86.8 87.7 87.7 89.4 91.1 94.0 94.1 94.3 95.3 95.3 95.5 96.9 96.9 97.1-3.9-1.4-1.3-7.6-5.4-5.0-5.8-4.2-3.0

2.4.2 咪唑乙烟酸和精喹禾灵复配对长柔毛野豌豆的安全性测定 由表4和表7可知,咪唑乙烟酸和精喹禾灵以质量比2∶1 复配后,在长柔毛野豌豆与禾本科杂草马唐和牛筋草选择性指数在4.4~15.6 之间,高于咪唑乙烟酸单剂(2.0~2.7),同时具有防除阔叶杂草播娘蒿和荠菜的能力,选择性指数在2.4~8.9之间,弥补了精喹禾灵杀草谱的缺陷。以上结果表明咪唑乙烟酸和精喹禾灵复配可以有效防除马唐、牛筋草、播娘蒿和荠菜这4 种杂草,同时对长柔毛野豌豆安全。

表7 咪唑乙烟酸和精喹禾灵复配(2∶1)对杂草和长柔毛野豌豆的生物活性及选择性指数
Table 7 The biological activities of imazethapyr mixed with quizalofop-p-ethyl(2∶1)against weeds and V.villosa,and their selectivity indexes between them

试材Material马唐D.sanguinalis牛筋草E.indica播娘蒿D.sophia荠菜C.burss-pastoris长柔毛野豌豆V.villosa——341.3(236.4~492.7)77.2(70.7~84.2)21.9(18.9~25.5)139.7(110.4~176.7)38.4(30.8~47.8)—4.4 15.6 2.4 8.9—GR10/(g·hm-2)GR90/(g·hm-2)选择性指数Selectivity index

2.5 田间药效试验

2.5.1 复配制剂防除桃园长柔毛野豌豆生草田杂草效果 表8表明,药后15 d,咪唑乙烟酸单剂在90 g·hm-2剂量下对播娘蒿和荠菜效果较好,对看麦娘效果差;精喹禾灵单剂在60 g·hm-2剂量下对播娘蒿和荠菜无效,同时对看麦娘效果较差。咪唑乙烟酸和精喹禾灵复配在100~125 g·hm-2剂量下对播娘蒿和荠菜防效较高(77.3%~87.4%),但对看麦娘防效较低(53.2%~67.5%);当剂量提升至150~250 g·hm-2时,复配制剂对播娘蒿、荠菜和看麦娘均表现出较高防效,药后30 d,随着后期杂草的出苗,防效有所降低,但对各杂草防效仍高于82%。以上结果说明咪唑乙烟酸和精喹禾灵以质量比2∶1复配,在125~150 g·hm-2剂量下能有效防除桃园长柔毛野豌豆生草田播娘蒿、荠菜和看麦娘。

表8 咪唑乙烟酸与精喹禾灵复配(2∶1)对桃园长柔毛野豌豆生草田杂草防除效果
Table 8 The plant control efficiency of imidazolium mixed with quizalofop-p-ethyl(2∶1)against weeds in hairy vetch fields in apeach orchard %

注:I=咪唑乙烟酸;Q=精喹禾灵。同一列中不同小写字母表示经Fisher’s protected LSD 检验在p <0.05 水平差异显著。
Note:I=imidazolium;Q=quizalofop-p-ethyl;DAT=days after treatments.Different letters at the same column indicate significant difference at the p <0.05 according to Fisher’s protected LSD test.

总体Total 74.8±1.7 d 82.8±1.2 c 90.9±0.8 b 95.5±1.0 a 79.9±1.3 c 12.9±0.8 e 71.9±2.1 d 79.9±1.5 c 88.2±1.6 b 93.4±1.1 a 77.7±1.3 cd 14.0±1.6 e 78.7±0.3 d 86.3±1.3 c 90.2±1.2 b 96.4±0.4 a 82.0±2.0 d 8.0±0.5 e药后15 d株防效Reduction in plant number at 15 days after treatment I+Q(2∶1)I Q药后30 d株防效Reduction in plant number at 30 days after treatment I+Q(2∶1)I Q药后30 d鲜质量防效Reduction in fresh weight at 30 days after treatment I+Q(2∶1)I Q 100 125 150 250 90 60 100 125 150 250 90 60 100 125 150 250 90 60 80.7±1.1 d 87.4±1.3 c 93.7±1.4 b 96.6±1.3 a 80.3±0.9 d—79.2±1.5 d 85.6±1.0 c 90.9±1.3 b 94.3±1.4 a 78.4±1.5 d—82.0±0.4 c 89.4±1.1 b 90.7±1.4 b 97.0±0.8 a 81.7±2.5 c—77.3±3.7 c 84.1±3.9 bc 89.8±6.0 ab 95.5±0.1 a 81.8±2.9 bc—74.5±3.7 c 82.4±2.1 bc 87.3±3.2 ab 93.1±1.6 a 79.4±2.4 c—80.0±2.5 c 85.6±2.2 bc 91.0±2.1 b 96.0±0.9 a 83.6±1.4 c—53.2±9.6 c 67.5±6.4 bc 83.1±2.7 ab 92.2±2.0 a 76.6±5.8 b 67.5±0.5 bc 50.5±4.8 d 62.4±5.0 cd 82.2±3.6 ab 91.1±1.9 a 74.3±1.3 bc 64.4±5.6 cd 56.5±3.2 d 69.3±3.8 c 85.9±2.3 b 92.9±1.8 a 81.8±2.2 b 69.8±4.1 c调查时间Sampling time/d药剂Herbicides剂量Doses/(g·hm-2)播娘蒿D.sophia荠菜C.bursa-pastoris看麦娘A.aequalis

2.5.2 复配制剂对长柔毛野豌豆的安全性 通过田间观察发现,咪唑乙烟酸与精喹禾灵复配用于桃园长柔毛野豌豆生草田后10 d,在最高剂量250 g·hm-2下,少部分长柔毛野豌豆出现黄化,但药后20 d症状消失,生长与对照无差异。其他药剂处理长柔毛野豌豆生长在整个试验期间均正常。以上结果说明咪唑乙烟酸和精喹禾灵以质量比2∶1 复配,在100~250 g·hm-2剂量下对长柔毛野豌豆安全。

3 讨 论

果园生草作为一种先进的果园栽培管理方式,对提高果树光合作用效率、促进果树生长、优化果树树势、提高果实品质和调节果园生态环境具有非常重要的作用,同时可以增加土壤营养物质含量、改善土壤微生物结构、抑制有害杂草的萌发和出苗[20-22]。然而,果园生草定植前期由于其他杂草的竞争,不容易建立种群,因此,研究果园生草定植前期杂草的化学防除,对于帮助果园生草种群的快速建立具有重要意义。赵远征等[18]研究发现,苗后土壤处理剂尤其是960 g·L-1精异丙甲草胺乳油是长柔毛野豌豆田较为适宜的除草剂,在1440 mL·hm-2的剂量下,药后45 d对反枝苋、苣荬菜、藜和禾本科杂草的株防效分别为95.2%、73.4%、84.1%和84.9%,效果较好,然而该研究却未筛选出适宜的茎叶处理剂,同时该研究是在土壤墒情较好的耕地中进行除草剂土壤封闭处理的,而果园土壤通常不平整,且质地、墒情较差,不适宜土壤处理剂充分发挥药效。因此,目前亟需筛选出可以安全防除果园长柔毛野豌豆生草田杂草的茎叶处理剂。

从室内药剂筛选结果可以看出,在田间推荐剂量下,咪唑乙烟酸、灭草松和精喹禾灵茎叶处理对长柔毛野豌豆安全,同时对果园的一些主要杂草具有较高防效。通常来说,咪唑乙烟酸对豆科植物较为安全,广泛应用于花生、大豆、苜蓿田及林地的杂草防除[23-24],灭草松和精喹禾灵是除草剂复配组合中的重要单剂,如高效氟吡甲禾灵和灭草松混用茎叶喷雾处理防除花生田阔叶杂草和莎草[25],溴苯腈与精喹禾灵混用可以用于防治亚麻田禾本科和阔叶杂草[26],三氟啶磺隆与精喹禾灵混用防除棉田禾本科杂草、阔叶杂草和莎草[27]。除草剂复配是杂草化学防除中一种普遍且重要的方式,其在延缓抗药性发生、降低除草剂用量、增加防治效果和扩大杀草谱等方面具有重要意义[28]。本研究通过室内选择性试验发现:灭草松在长柔毛野豌豆和阔叶杂草之间选择性低,安全性差。此外,在田间条件下,赵远征等[18]也发现灭草松茎叶处理对长柔毛野豌豆产生药害,导致叶片黄化、皱缩,且植株长势较弱,说明长柔毛野豌豆对灭草松较为敏感,要谨慎使用。因此,本研究选择咪唑乙烟酸和精喹禾灵进行复配,扩大杀草谱,且对长柔毛野豌豆安全;同时,2 种药剂作用机制不同,有助于延缓抗药性的发生[29]。单剂间的配比是除草剂科学复配的一个重要因素,会显著影响复配制剂对不同种类杂草之间防效的均衡性[30]。联合作用测定结果表明,咪唑乙烟酸和精喹禾灵复配对杂草均呈现加成作用;同时,当以质量比4~1∶1混配时,有助于提高对杂草的防效。一般认为,当除草剂在作物和杂草之间的选择性指数大于2 时,该除草剂即可在该作物田安全应用[19]。本研究发现,咪唑乙烟酸和精喹禾灵以质量比2∶1混配时在长柔毛野豌豆和供试杂草之间的选择性指数大于4,维持在一个较高水平,对长柔毛野豌豆安全。

通过田间试验结果可以看出,咪唑乙烟酸和精喹禾灵以质量比2∶1复配,在125~150 g·hm-2时对桃园长柔毛野豌豆生草田播娘蒿、荠菜、看麦娘均具有较高防效,同时对长柔毛野豌豆安全,有潜力应用到果园生草田前期杂草治理中。在实际生产中,可根据田间杂草的具体发生情况选择不同的药剂进行防治:如果田间杂草仅为禾本科或阔叶杂草,则可单独施用精喹禾灵或咪唑乙烟酸进行防治;如果田间为禾本科和阔叶杂草混合发生,则建议精喹禾灵和咪唑乙烟酸混合施用。然而,由于咪唑乙烟酸可能对桃树有一定程度的伤害,不建议在桃树生长期使用,施药时间应尽量选择在长柔毛野豌豆定植后的桃树休眠期(10 月到翌年3 月),同时在施药过程中应压低喷头或使用防护罩喷头进行定向喷雾,最大程度地减少对桃树伤害。

本研究田间试验只进行了1年1地的试验,而各地果园的气候类型、土壤类型、地形特点和果树种类等因素有所差异,故下一步需进行多年多点多果树类型的田间试验,以增加试验结果的科学性,为咪唑乙烟酸和精喹禾灵复配在果园长柔毛野豌豆生草田前期杂草治理提供理论依据。

4 结 论

咪唑乙烟酸和精喹禾灵茎叶喷雾处理可以有效防除多种果园主要杂草、杀草谱互补,同时对长柔毛野豌豆安全,两者以质量比2∶1 复配,施药剂量在125~150 g·hm-2时,有潜力应用到果园长柔毛野豌豆生草田前期杂草治理中。

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Screening of post-emergence herbicides to control weeds in Vicia villosa fields in orchards

WANG Hengzhi1,WANG Lipeng1,SUN Ruihong2,JIN Tao3,PENG Xuegang3,WANG Jinxin1,LIU Weitang1*
(1College of Plant Protection, Shandong Agricultural University/Key Laboratory of Pesticide Toxicology and Application Technology,Taian 271018,Shandong,China;2Shandong Institute of Pomology,Taian 271018,Shandong,China;3Qingdao Kingagroot Chemicals Co.,Ltd.,Qingdao 266000,Shandong,China)

Abstract:【Objective】Vicia villosa, an annual leguminous plant, is usually used as high-quality forage,green fertilizer or cover crop,and widely distributed in Europe,Central Asia,Iran and the eastern United States.In China,V.villosa is being widely grown as cover or companion crop in orchards,which can greatly improve pollination rate by attracting insects.At the same time,it can reduce soil water evaporation,increase soil organic matter content and porosity,and improve pH value in soil surface and microbial activity in soil.In addition, compared with weeds,V.villosa has stronger competitiveness to living factors such as light, living space, water and nutrients, which can effectively inhibit the germination,emergence and growth of other harmful weeds.However,it was found that V.villosa is not easy to establish population due to the competition of other harmful weeds in the early stage of cover crop growing,and the weed chemical control in the early stage of cover crop growing is particularly important.Thus,this study aimed to finding out appropriate post-emergence(POST)herbicides against harmful weeds inV.villosa fields in orchads.【Methods】Whole-plant dose response experiments were conducted in greenhouse to evaluate the safty to V.Villosa and efficacy against weeds of eight POST herbicides that are safe for legumes and screen out herbicides for mixing.The joint effect type,the safety to V.Villosa and the selectivity indexs (SIs) of the mixtures were futher evaluated in greenhouse.Weed control efficacy and response of V.Villosa to the mixtures were also investigated in field experiments.【Results】The results of greenhouse study showed that flumetsulam, fluoroglycofen-ethyl, fomesafen and clopyralid caused serious damage to V.Villosa, with fresh weight inhibition higher than 90% at 1×filed recommended rates, while bentazone, imazethapyr and quizalofop-P-ethyl were safe to V.villosa, with fresh weight inhibiton lower than 30% at 2×filed recommended rates.In weed control spectrum tests, imazethapyr POST application at 75 g active ingredient (a.i.) per hm2 caused more than 80% of fresh weight reduction against eight weed species including Amaranthus retroflexus, Cyperus iria, Digitaria sanguinalis, Eleusine indica, Setaria viridis, Portulaca oleracea, Capsella bursa-pastoris, Descurainia sophia and Myosoton aquaticum; bentazone POST application at 576 g a.i.per hm2 caused more than 70%of fresh weight reduction against Abutilon theophrasti,C.iria,E.indica,Calystegia hederacea,C.bursa-pastoris and D.sophia; quizalofop-P-ethyl POST application at 37.5 g a.i.per hm2 caused more than 70%of fresh weight reduction against D.sanguinalis,E.indica and S.viridis.The SIs of imazethapyr between V.villosa and C.iria, D.sanguinalis, E.indica, S.viridis, D.sophia as well as M.aquaticum were all above 2.0; the SIs of bentazone between V.villosa and C.bursa-pastoris, D.sophia as well as M.aquaticum were below 0.7,with poor safety;the SIs of quizalofop-P-ethyl between V.villosa and D.sanguinalis, E.indica, S.viridis were above 8.8.Imazethapyr showed high selectivity between V.villosa and broad-leaved weed(D sophia and M.aquaticum),but its selectivity between V.villosa and gramineous weeds is lower than that of quizalofop-p-ethyl.Therefore, the combination of imazethapyr and quizalofop-P-ethyl was conducted to complement the their weed control spectrums.The joint effect type was additive when imazethapyr was mixed with quizalofop-P-ethyl for the control of D.sanguinalis,E.indica,Alopecurus aequalis,M.aquaticum,D.sophia,C.bursa-pastoris,with fresh weight inhibition higher than 80%,and when the mass ratio was 2:1(imazethapyr:quizalofop-P-ethyl),the SIs of mixtures between V.villosa and the six weeds above ranged from 2.4-8.9.The results of the field experiments showed that the POST application of the mixtures of imazethapyr and quizalofop-P-ethyl at 125-150 g a.i.per hm2 showed at least 86% of reduction in total fresh weight, against C.bursa-pastoris, D.sophia and A.aequalis,and high safety to V.Villosa,while imazethapyr at 90 g·hm-2 and quizalofop-Pethyl at 60 g a.i.per hm2 possessed poor control efficacy to A.aequalis and broadleaf weeds,respectively.【Conclusion】The POST application of imazethapyr and quizalofop-P-ethyl can effectively control the main weeds in orchards and their weed control spectrums were complementary, and was safe for V.villosa.When the mass ratio was (1-4)∶1 (imazethapyr∶quizalofop-P-ethyl), it improved weed control efficacy and the safety to V.villosa of imazethapyr when controlling gramineous weeds.When the mass ratio was(1-4)∶1(imazethapyr∶quizalofop-P-ethyl)and the application rates were 125-150 g a.i.per hm2,the mixtures possessed high control efficacy against on D.sophia, C.bursa-pastoris and A.aequalis in in V.villosa fields in peach orchards.At the same time,it was safe for V.villosa and had the potential to be applied for weed control V.villosa cover crop field in orchards.This study provides a theoretical basis for the chemical control of weeds in the early stage of V.villosa fields in orchards and has important practical value for the rapid establishment of stable community of V.villosa in orchards.

Key words: Grass growing in orchards;Vicia villosa; Imazethapyr; Quizalofop-P-ethyl; Herbicidal activity;Safety

中图分类号:S66

文献标志码:A

文章编号:1009-9980(2022)04-0674-11

DOI:10.13925/j.cnki.gsxb.20210503

收稿日期:2021-10-19

接受日期:2022-01-03

基金项目:山东省重大科技创新工程项目(2018CXGC0213)

作者简介:王恒智,男,讲师,博士,主要从事除草剂毒理和应用技术研究。Tel:18763890560,E-mail:wanghz@sdau.edu.cn

*通信作者Author for correspondence.E-mail:liuwt@sdau.edu.cn