Table 2.

Inhibitory effect of Welsh onion-cultivated soil and root extracts on multiplication of Fusarium oxysporum f. sp. cucumerinum in liquid medium.

Experiment	Type of amendment in the liquid mediuma	Heat/Antibiotics treatment	Focu density (log spores ml−1)e
Experiment 1	Welsh onion-cultivated soilb	No treatment	5.76 ± 0.10 a
		40 °C	5.82 ± 0.09 a
		60 °C	6.13 ± 0.02 b
	Cucumber-cultivated soilb	No treatment	6.11 ± 0.04 b
	Non-cultivated soilb	No treatment	6.21 ± 0.05 b
	Control (SDW)	No treatment	6.58 ± 0.03 c
Experiment 2	Welsh onion-cultivated soilb	No treatment	5.78 ± 0.23 a
		Antibioticsd	6.30 ± 0.08 b
	Control (SDW)	No treatment	6.77 ± 0.09 b
		Antibiotics	6.63 ± 0.12 b
Experiment 3	Welsh onion-root extractc	No treatment	6.01 ± 0.37 a
		40 °C	6.78 ± 0.16 b
		60 °C	6.75 ± 0.16 b
	Cucumber-root extractc	No treatment	6.86 ± 0.09 b
	Control (SDW)	No treatment	6.81 ± 0.03 b

^aLiquid medium: potato sucrose broth including the spores of Fusarium oxysporum f. sp. cucumerinum.

^bWelsh onion-cultivated soil, cucumber-cultivated soil, or non-cultivated soil was 1000-fold diluted with sterile distilled water, and then a 0.3 ml of each 1000-fold dilution of soils was added into the liquid medium.

^cThe concentrations of Welsh onion- and cucumber-root extract were 50 mg root material per ml. A 1.5 ml of each root extract was added into the liquid medium.

^dAntibiotics means a mixture of antibacterial antibiotics comprising ampicillin (300 µg ml⁻¹), imipenem (300 µg ml⁻¹), and chloramphenicol (300 µg ml⁻¹).

^eMean ± SD shown (n = 3). For each experiment, figures followed by different letters indicate significant differences (P < 0.01, Tukey’s test).