Abstract Leaf blast caused by Magnaporthe oryzae is among the major diseases that limit rice productivity in the world, and control of the disease occurs, basically, through the application of fungicides. Control methods such as the application of growth promoting rhizobacteria could be inserted in the integrated management of rice blast. The objective of this work was to evaluate the potential of four liquid formulations containing Pseudomonas fluorescens (BRM 32111) and Burkholderia pyrrocina (BRM 32113) to suppress leaf blast, under field conditions. The trials were conducted at Embrapa Rice and Beans, between December 2018 and April 2019. The experiments were performed in a randomized block containing 7 treatments, 4 replicates. The treatments consisted of microbiolized seeds and sprays at 14 and 21 days after planting with: Formulation 11 + BRM 32,113 (T1); Formulation 32 + BRM 32,113 (T2); Formulation 11 + BRM 32,111 (T3): Formulation 20 + BRM 32,111 (T4); BRM 32,111 (T5); BRM 32,113 (T6) and Absolute control (water – T7). Severity of leaf blast and panicle, gas exchange and grain yield were evaluated. Plants treated with P. fluorescens (T3, T4 and T5) or B. pyrrocinia (T1, T2 and T6) presented 49%, 39%, 60%, 15% increase in the assimilation rate of CO2 (A), transpiration (E), stomatal conductance (gs) and internal CO2 concentration (Ci), respectively. All treatments were efficient in suppressing leaf and panicle blast and in promoting biomass increase in 55%. The yields of T1, T4, T5 and T6 treatments increased 481, 424, 688 and 427 kg ha−1, respectively. Our results indicate that the formulated rhizobacteria have the potential to be included in the integrated management for blast control in rice fields.

中文翻译：

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荧光假单胞菌和吡咯伯克霍尔德菌防治旱稻稻瘟病免耕体系的制剂

摘要 由稻瘟病菌引起的叶瘟是世界上限制水稻产量的主要病害之一，对该病害的防治主要是通过施用杀菌剂。可在稻瘟病综合治理中插入应用促进生长的根际细菌等防治方法。这项工作的目的是评估含有荧光假单胞菌 (BRM 32111) 和伯克霍尔德菌 (BRM 32113) 的四种液体制剂在田间条件下抑制叶瘟的潜力。试验于 2018 年 12 月至 2019 年 4 月在 Embrapa Rice and Beans 进行。 试验在包含 7 个处理、4 个重复的随机区组中进行。处理包括微生物化种子和种植后 14 天和 21 天的喷雾剂：配方 11 + BRM 32,113 (T1)；配方 32 + BRM 32,113 (T2)；配方 11 + BRM 32,111 (T3)：配方 20 + BRM 32,111 (T4)；BRM 32,111（T5）；BRM 32,113 (T6) 和绝对控制（水 – T7）。评价叶瘟和穗的严重程度、气体交换和谷物产量。用 P. fluorescens (T3、T4 和 T5) 或 B. pyrrocinia (T1、T2 和 T6) 处理的植物在 CO2 (A)、蒸腾作用 (E) 的同化率方面分别增加了 49%、39%、60%、15% )、气孔导度 (gs) 和内部 CO2 浓度 (Ci)。所有处理均能有效抑制叶片和穗瘟，促进生物量增加55%。T1、T4、T5 和 T6 处理的产量分别增加了 481、424、688 和 427 kg ha-1。