生物有机肥施用期对香蕉枯萎病及土壤微生物的影响

在大田条件下,采用完全随机区组试验方法研究生物有机肥施用期对香蕉枯萎病和土壤微生物的影响。结果表明,在基肥期(BOF1)和营养生长期(BOF2)施用生物有机肥对香蕉生长表现出明显的促进作用,移栽后第270 d,BOF1和BOF2处理的茎围、叶宽和产量均高于其他处理,BOF2处理小区平均产量高达288kg,显著高于其余各组处理。在香蕉营养生长期施用生物有机肥,可以延迟香蕉枯萎病的发病时间,显著降低香蕉植株的发病程度。移栽后第270 d,BOF2处理的病情指数比施化肥处理(CF)低54%,将CF处理防效指定为0,防病效果达到52.5%。施用生物有机肥可以提高土壤中细菌和放线菌的数量,降低真菌数量,其中以BOF2处理效果最为明显。从移栽后第90 d开始,BOF2处理的细菌数量为26.67×106 cfu·g-1,到第270 d时数量达到64×106 cfu·g-1,始终显著高于其他各处理;在移栽后第180 d时,BOF2处理的放线菌数量比施有机肥处理(OF)增加了95.6%,第270 d时BOF2放线菌数量最高,为23.15×103cfu·g-1。施用生物有机肥可不同程度地提高土壤过氧化氢酶、蔗糖酶、脲酶和酸性磷酸酶的活性。病情指数与土壤中细菌、放线菌含量呈显著负相关,与真菌呈显著正相关。在香蕉营养生长期施用生物有机肥更有利于改善土壤微生物结构,提高土壤酶活性,延缓和降低香蕉枯萎病的发生,提高香蕉产量。

Effects of Biological Fertilizer Applications on Banana Wilt Disease and Soil Microorganisms

Banana Fusarium Wilt, a soil borne diseases caused by a fungus, has severely affected banana production. Under field conditions, the effects of biological fertilizer on Banana Fusarium Wilt and soil microorganisms were studied using a completely randomized block design. At basal and vegetative stages, applying biological fertilizer combined with chemical fertilizer obviously promoted banana growth, leading to greater stem diameter, blade width and yields of banana after 270 d of transplanting than at other growth stages. When processed in BOF2, the average output of banana per district was up to 288 kg, significantly higher than the rest treatments. Applying biological fertilizer during vegetative period significantly reduced the occurrence of banana wilt and delayed the onset of banana wilt. Compared with the chemical fertilizer control, the disease index was decreased by 54% by biological fertilizer applied at vegetative growth stage. Application of biological fertilizer at the basal stage improved the population of soil bacteria and actinomycetes, but reduced that of fungi. Soil catalase, invertase, urease and acid phosphatase activities were all improved by biological fertilizer. The disease index was significantly negatively correlated with the number of both bacteria and actinomycetes in soil, but significantly positively with the number of fungi in soil. The findings suggest that application of biological fertilizer at banana vegetative period could improve soil microorganism structure, promote soil enzyme activities, and reduce and/or delay banana wilt disease occurrence.