沼液处理对连作西瓜枯萎病发生、产量及品质的影响

利用沼液防治土传病害是实现沼液高值利用重要途径。以西瓜优佳018为材料,采用田间试验方式,研究等氮磷钾养分下,沼液结合覆膜、闷棚等综合防治措施,对西瓜连作土壤中尖孢镰刀菌数量的削减效果以及对西瓜产量及品质的影响。结果表明:水或沼液结合覆膜、闷棚等处理连作土壤20天,能有效降低土壤中尖孢镰刀菌的数量,其中沼液处理降低幅度更大。处理期间,沼液和水处理土壤温度、湿度显著高于对照。沼液处理减缓了西瓜枯萎病大面积发生的时间,前期(西瓜移栽后的45天内)西瓜枯萎病发病率和病情指数均显著低于水处理和对照,开花期之后发病率大幅提高,因而西瓜收获时沼液处理与对照发病率无显著差异,但病情指数显著低于对照。与对照和水处理相比,沼液处理西瓜产量、商品果产量、维生素C含量均显著提高,而硝酸盐含量降低,但沼液处理西瓜含糖量低于对照。以上表明,利用沼液处理西瓜连作土壤能有效增加西瓜产量,提升品质,并对枯萎病的发生有一定的延缓作用。

Effect of Biogas Slurry Application on Incidence of Fusarium wilt, Fruit Yield and Quality of Watermelon

Suppression of soil borne diseases by biogas slurry application is an important way to achieve high-value-use of the resource. A field experiment was conducted to study the effect of biogas slurry application combined with mulching and heat suffocation on the reduction of the density of Fusarium oxysporum in soil, and fruit yield and quality of watermelon. The obtained results showed that biogas slurry or water treatment combined with mulching and heat suffocation for continuously 20 d, could reduce the number of the pathogen significantly, and the increment of the reduction was more pronounced on the treatment of biogas slurry application. During the soil treatment, the soil temperature of biogas slurry or water treatment was significantly higher than that of the control. Biogas slurry treatment significantly slowed down fusarium wilt explosion in the field. The fusarium wilt disease incidence on the biogas slurry treatment was significantly lower than those in the water treatment and the control within 45 d after transplantation. After the blossom period, the incidence increased greatly in all treatments, and no significantly difference was found between the biogas slurry treatment and the control. However, the fusairum wilt disease index was significantly lower in biogas slurry treatment than those in control and water treatment. Compared with the water treatment and the control, the total fruit yield, merchantable fruit yield and vitamin C content in the fruit were greater in the biogas slurry treatment. The nitrate content and sugar content in the fruit was lower in biogas slurry treatment than those of the control. Above all, pretreatment of continuous watermelon cropping soil by biogas slurry could effectively promote fruit yield and quality and slow down fusarium wilt explosion in field.