Biological control agents applied post-harvest may provide an effective way to manage leak of potatoes by competing with Pythium ultimum. The objective of this paper was to test the efficacy of various biological control agents and conventional post-harvest fungicides to manage leak. Two studies were performed with a Pseudomonas fluorescens triculture including desiccation tolerant variants of strains S11P12, P22Y05, and S22T04 in three formulations (a “fresh” triculture, dried on Kenite 700, or dried on Attapulgite clay) applied at a rate of 3.5 mL kg⁻¹. A third study contained treatments of the P. fluorescens “fresh” triculture, triculture dried on Kenite, triculture dried on Kenite blended with a fungicide containing a three-way mixture of azoxystrobin, fludioxonil, and difenoconazole (Azo+Flu+Dfz, 0.033 mL kg⁻¹), and triculture dried on Kenite rehydrated with nutrient broth Medium 1 blended with the same fungicide. Other treatments included Pseudomonas syringae (3.5 mL kg⁻¹) in Studies 1 and 2, while hydrogen peroxide and peroxyacetic acid (0.042 mL kg⁻¹), phosphorous acid (4.2 mL kg⁻¹), and Azo+Flu+Dfz (0.033 mL kg⁻¹) were used in all three studies. The three studies were each repeated twice using unwashed tubers (cv. ‘Russet Burbank’) that were wounded and inoculated with P. ultimum. After inoculation, tubers were treated, then stored at 21 C for four days prior to disease evaluation. In Study 1, none of the formulations of P. fluorescens triculture significantly controlled leak compared to the inoculated control; however, the “fresh” triculture formulation significantly decreased leak incidence by 24% in Study 2. In all three studies the three-way fungicide mixture Azo+Flu+Dfz resulted in lower leak incidence (1, 7, and 24%, in studies 1, 2, and 3 respectively) compared with the inoculated control (12, 37, and 50% leak incidence, in studies 1, 2, and 3 respectively). Study 3 showed the formulations of P. fluorescens strains were not effective in leak control but when combined with Azo+Flu+Dfz leak incidence significantly decreased compared to the inoculated control. The lowest leak incidence was seen when the triculture component of the fungicide mix was rehydrated with Medium 1 in Study 3. The P. fluorescens triculture formulations mixed with Azo+Flu+Dfz and rehydrated with Medium 1 had slightly higher bacterial counts than the “fresh” triculture and the triculture dried on Kenite, potentially indicating a greater activity level afforded by cell revival in dilute culture medium. P. syringae, phosphorous acid and hydrogen peroxide-peroxyacetic acid were ineffective in controlling leak in all three studies. The efficacy of the Azo+Flu+Dfz mixture appears promising for the management of leak in storage. The efficacy of P. fluorescens tricultures used alone was inconsistent in limiting leak incidence (only significant in 1 of 3 studies), and additional research and development may be warranted to realize its potential as biological control agent.

收获后施用的生物防治剂可能通过与最终腐霉菌竞争而提供了一种有效的方法来管理马铃薯的渗漏。本文的目的是测试各种生物防治剂和常规收获后杀菌剂处理泄漏的功效。荧光假单胞菌三培养进行了两项研究，包括以三种制剂（“新鲜”三培养，在Kenite 700上干燥或在凹凸棒粘土上干燥）的三种配方的菌株S11P12，P22Y05和S22T04的耐干燥变体。^-1。第三项研究包含荧光假单胞菌的治疗“新鲜”三培养，在Kenite上干燥三培养，在Kenite上干燥三混有杀菌剂的混合物，该杀真菌剂含有三氧嘧菌酯，氟地西尼和二苯并呋喃唑（偶氮+氟+ Dfz，0.033 mL kg ^-1）的三效混合物，三养在Kenite上干燥用营养肉汤再水化将培养基1与相同的杀菌剂混合。其他治疗包括研究1和2中的丁香假单胞菌（3.5 mL kg ^-1），过氧化氢和过氧乙酸（0.042 mL kg ^-1），亚磷酸（4.2 mL kg ^-1）和Azo + Flu + Dfz（0.033）在所有三个研究中均使用了mL kg ^-1）。使用未清洗的块茎（cv。“ Russet Burbank”）将三项研究重复两次，将其缠绕并接种P.霉。接种后，对块茎进行处理，然后在进行疾病评估之前将其在21°C下保存4天。在研究1中，与接种的对照相比，荧光假单胞菌三培养的配方均未显着控制渗漏。但是，在研究2中，“新鲜”三培养制剂显着降低了24％的泄漏发生率。在所有三项研究中，三元杀菌剂混合物Azo + Flu + Dfz导致泄漏发生率更低（在研究中分别为1％，7％和24％） 1、2和3）与接种的对照（分别为12、37和50％泄漏发生率，分别在研究1、2和3中）相比。研究3显示了荧光假单胞菌的配方菌株在渗漏控制中无效，但与Azo + Flu + Dfz结合使用时，与接种的对照相比，渗漏率显着降低。在研究3中，将杀菌剂混合物的三培养组分与介质1再水合后，泄漏发生率最低。与Azo + Flu + Dfz混合并与介质1再水合的萤光假单胞菌三培养配方的细菌数比“新鲜”略高。 “三重培养法”和“三重培养法”在Kenite上干燥，这可能表明在稀薄培养基中细胞的再生可提供更高的活性。丁香假单胞菌在所有三项研究中，亚磷酸和过氧化氢-过氧乙酸在控制泄漏方面均无效。Azo + Flu + Dfz混合物的功效看来有望解决储存中的泄漏问题。单独使用荧光假单胞菌三培养物的功效在限制泄漏发生率方面不一致（仅在三项研究中的一项有效），并且可能有必要进行额外的研究和开发，以实现其作为生物防治剂的潜力。