不同熏蒸处理与生物有机肥联用对西瓜枯萎病的防控效果

使用生石灰+碳铵、棉隆、辣根素3种土壤熏蒸剂和"馕播王"生物有机肥联用对5 a连作西瓜土壤进行消毒处理,比较不同处理方式对连作西瓜枯萎病的防控效果,同时分析土壤pH值与尖孢镰刀菌西瓜专化型数量之间的相关性。结果表明:不同熏蒸处理对西瓜枯萎病的防控效果差异显著,其中棉隆处理定植45 d时,枯萎病发病率最低,为25.38%,相对防效为73.14%;随着处理时间的延长,各处理土壤中尖孢镰刀菌西瓜专化型的数量逐渐降低,也以棉隆处理的土壤病菌数量最少,定植45 d时与其他处理的病原菌数量差异达到10倍数量级;土壤熏蒸处理后,pH值均有所上升,但随着枯萎病的发生,pH值又有所下降。由此得出,3种熏蒸剂对西瓜枯萎病均有一定防效,但是棉隆与生物有机肥联用的效果最优,既能减少枯萎病致病菌的数量,还能提升土壤pH值。因此,该措施可作为我国南方地区设施西瓜早春栽培枯萎病的综合防控措施之一。

Control Effect of Different Soil Fumigants and Bio-Organic Fertilizer on Watermelon Fusarium wilt by Continuously Cropping

Lime + ammonium bicarbonate and bio-organic fertilizer (M1), Dazomet and bio-organic fertilizer (M2), allylisothiocyanate and bio-organic fertilizer (M3) were respectively applied in 5-year watermelon replanted soil, control effects of different treatments on Fusarium wilt in continuous cropping watermelon were compared, and the quantity correlation of rhizosphere soil pH and Fusarium oxysporum f. sp. niveum was analyzed in this study. The results showed that the control effect of different soil fumigation treatments on watermelon wilt was of significant difference, the Fusarium wilt incidence of M2 was the lowest at 25.38%, the relative control efficiency of M2 was 73.14%, 45 d after field planting, and the difference between the number of pathogenic bacteria and other treatments reached 10 times. After soil fumigation treatment, the pH value increased, but decreased with the occurrence of Fusarium wilt. Therefore, the M1, M2 and M3 had certain control effects on Fusarium wilt, with the M2 as the optimal, and the M2 could decrease the number of Fusarium oxysporum f. sp. niveum and increase the soil pH value, which could be used to control the replanting disease of watermelon under early spring facility cultivation in southern China.