{"title":"The Influence of Inducing Agents Applied by Soil Drenches on Disease Severity of Apple and Pear Scab","authors":"G. Percival","doi":"10.48044/jauf.2020.026","DOIUrl":null,"url":null,"abstract":"Apple and pear scab are foliar diseases of ornamental and fruiting apple and pear trees. Unmanaged, yield and aesthetic losses can be severe. Overreliance on synthetic fungicides means novel means of disease management are required. Field trials were conducted using apple (Malus cv. Crown Gold) and pear (Pyrus communis ‘Williams Bon Chrétien’) to assess the efficacy of a range of commercially available inducing resistance (IR) agents (harpin protein, potassium phosphite, salicylic acid derivative, and chitosan) as root drenches against both scab diseases. A synthetic fungicide (penconazole) spray program used within the UK for apple and pear scab control was included for comparison. Each IR agent was applied four times, (i) before the visible appearance of scab (April through June, i.e., preventatively) or (ii) after symptoms of scab were visibly observed (June through August, i.e., curatively). Limited efficacy as scab protectants was demonstrated when IR agents were applied curatively. Likewise, limited efficacy was recorded when IR agents were applied once or twice as a preventative measure. However, when IR agents were applied as root drenches greater or equal to three times, efficacy as scab protectants was confirmed (increased leaf chlorophyll content, increased fruit yield, reduced leaf and fruit scab severity). A synthetic fungicide penconazole spray program provided the greatest protection against apple and pear scab in all trials when sprayed preventatively rather than curatively. Results suggest application of at least three root drenches from April through June with an appropriate IR agent provides a useful addition to existing methods of apple and pear scab management under field conditions.","PeriodicalId":39043,"journal":{"name":"Arboriculture and Urban Forestry","volume":"13 2 1","pages":"358-370"},"PeriodicalIF":0.0000,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Arboriculture and Urban Forestry","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.48044/jauf.2020.026","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Agricultural and Biological Sciences","Score":null,"Total":0}
引用次数: 0
Abstract
Apple and pear scab are foliar diseases of ornamental and fruiting apple and pear trees. Unmanaged, yield and aesthetic losses can be severe. Overreliance on synthetic fungicides means novel means of disease management are required. Field trials were conducted using apple (Malus cv. Crown Gold) and pear (Pyrus communis ‘Williams Bon Chrétien’) to assess the efficacy of a range of commercially available inducing resistance (IR) agents (harpin protein, potassium phosphite, salicylic acid derivative, and chitosan) as root drenches against both scab diseases. A synthetic fungicide (penconazole) spray program used within the UK for apple and pear scab control was included for comparison. Each IR agent was applied four times, (i) before the visible appearance of scab (April through June, i.e., preventatively) or (ii) after symptoms of scab were visibly observed (June through August, i.e., curatively). Limited efficacy as scab protectants was demonstrated when IR agents were applied curatively. Likewise, limited efficacy was recorded when IR agents were applied once or twice as a preventative measure. However, when IR agents were applied as root drenches greater or equal to three times, efficacy as scab protectants was confirmed (increased leaf chlorophyll content, increased fruit yield, reduced leaf and fruit scab severity). A synthetic fungicide penconazole spray program provided the greatest protection against apple and pear scab in all trials when sprayed preventatively rather than curatively. Results suggest application of at least three root drenches from April through June with an appropriate IR agent provides a useful addition to existing methods of apple and pear scab management under field conditions.
苹果和梨痂病是观赏果树和果树的叶面病害。如果管理不善,产量和美观的损失可能会很严重。过度依赖合成杀菌剂意味着需要新的疾病管理手段。田间试验采用苹果(Malus cv.;以Crown Gold)和梨(Pyrus communis ' Williams Bon chracritien ')为研究材料,评估一系列市上可获得的诱导抗性(IR)剂(harpin蛋白、亚磷酸钾、水杨酸衍生物和壳聚糖)作为根淋剂防治两种结痂病的功效。在英国用于控制苹果和梨结痂的合成杀菌剂(戊康唑)喷雾程序被纳入比较。每种IR剂应用四次,(i)在可见痂出现之前(4月至6月,即预防性)或(ii)在明显观察到痂症状之后(6月至8月,即治疗性)。当IR剂用于治疗时,证明其作为痂保护剂的功效有限。同样,当使用一次或两次IR剂作为预防措施时,记录的疗效有限。然而,当IR剂作为根淋施用大于或等于三次时,作为痂保护剂的功效得到证实(增加叶片叶绿素含量,提高果实产量,降低叶片和果实痂严重程度)。在所有试验中,一种合成杀菌剂戊康唑喷雾程序在预防性而非治疗性喷洒时,对苹果和梨结痂提供了最大的保护。结果表明,在4月至6月期间,施用适当的IR剂,至少进行三次根部浇水,是对田间条件下苹果和梨结痂管理现有方法的有益补充。