Mixtures between Beauveria bassiana and potassium silicate to manage thrips in tomato plants for industrial processing

ABSTRACT Thysanoptera species can transmit virus to Solanaceae family vegetables, including tomato plants for industrial processing, causing the disease known as Tomato Spotted Wilt Virus (TSWV). Thrips resistance to insecticides indicate the urgent need of techniques adequate for Integrate Pest Management practices. The objective was to evaluate the control efficiency (CE%) against Frankliniella schultzei (Thysanoptera: Thripidae) of the fungus Beauveria bassiana (Bb), the resistance inducer potassium silicate (KSil) and the chemical insecticide profenophos + cypermethrin (PC) isolated, or in binary mixtures. The treatments were foliar spraying on tomato plants with Bb (T1), KSil (T2) and PC (T3) isolated or in mixtures of Bb+KSil (T4), PC+KSil (T5) and Bb+PC (T6). Thrips were sampled with white plastic trays at 0, 1, 7, 14 and 21 days after application (daa). The CE% of each product (isolated or in mixtures) differed at all time intervals. The Bb+KSil treatment had highest CE% from 24 hours of application, until the end of the experiment, ranging from 95% (1 daa) to 41.5% (21 daa). The CE% decreased in all treatments with a quadratic curve behavior, throughout time. PC insecticide, isolated, showed a decreased CE% through a linear regression. Grouping analyzes indicated the Bb+KSil effect was more dissimilar than the other evaluated treatments. Synergism between Bb and KSil, in mixture, indicate its potential for Integrated Pest Management programs of F. schultzei in tomato plants for industrial processing.

摘要 蓟马目（Thysanoptera）昆虫可将病毒传播至茄科蔬菜，包括用于工业加工的番茄植株，引发番茄斑点萎蔫病毒（Tomato Spotted Wilt Virus, TSWV）病害。蓟马对杀虫剂产生抗药性的现状，凸显了适配有害生物综合治理（Integrated Pest Management, IPM）技术体系的迫切需求。本研究旨在评估球孢白僵菌（Beauveria bassiana, Bb）、抗病诱导剂硅酸钾（potassium silicate, KSil）以及化学杀虫剂丙溴磷+氯氰菊酯（profenophos + cypermethrin, PC）单独施用或二元复配时，对舒尔茨蓟马（Frankliniella schultzei，Thysanoptera: Thripidae）的防控效率（CE%）。试验设置6个处理组：单独喷施Bb（T1）、KSil（T2）、PC（T3），以及复配组Bb+KSil（T4）、PC+KSil（T5）、Bb+PC（T6），均采用叶面喷施方式施用于番茄植株。分别于施药后0、1、7、14、21天（days after application, daa）采用白色塑料托盘法取样调查蓟马种群。结果显示，各药剂（单独或复配）的防控效率在所有时间区间均存在显著差异。Bb+KSil复配组自施药后24小时起至试验结束，始终表现出最高的防控效率，其防控效率范围为95%（施药后1天）至41.5%（施药后21天）。所有处理组的防控效率随时间推移均呈二次曲线趋势下降；而单独施用的PC杀虫剂的防控效率则呈线性下降趋势。聚类分析结果表明，Bb+KSil复配组的防控效果与其余受试处理组差异最为显著。Bb与KSil复配后表现出协同增效作用，表明其在工业加工用番茄的舒尔茨蓟马有害生物综合治理方案中具备应用潜力。