Evaluation of biological control agents for Fusarium wilt in Hiemalis begonia

Figures & data

Table 1.  Description of the biocontrol products employed in this study

Name	Active ingredient	Formulation^a	Target pathogens/effects	Manufacturer/Producer	Registration No.	Year registered in Canada
Actinovate®	Streptomyces lydicus strain WYEC108, 1.0 × 10^7 cfu g^−1	WP	Botrytis fruit rot, powdery mildew on field and greenhouse strawberry, gerbera daisy, pepper, cucurbit and tomato	Natural Industries, Inc. Houston, USA	28672	2007
Mycostop®	Streptomyces griseoviridis strain K61, 1.0 × 10^8 cfu g^−1	WP	Fusarium, Alternaria, Pythium, Phytophthora and Rhizoctonia and Phomopsis seed and root rot in ornamentals, greenhouse vegetables	Verdera Oy, Helsinki, Finland	26265	2000
Prestop®	Gliocladium catenulatum strain J1446, 2.0 × 10^8 cfu g^−1	WP	Soil-borne and foliar disease on greenhouse vegetables, herbs and ornamentals	Verdera Oy, Helsinki, Finland	28820	2008
RootShield®	Trichoderma harzianum Rifai strain KRL-AG2, 1.0 × 10^7 cfu g^−1	WP	Greenhouse crops and outdoor nursery plants root disease (Pythium sp., Rhizoctonia sp., Fusarium sp.)	BioWorks Inc., Geneva, NY, USA	29890	2011
Serenade® ASO	Bacillus subtilis strain QST713, 1 × 10^9 cfu g^−1	AS	Botrytis grey mould, fruit and vegetable bacteria and fungi disease	AgraQuest Inc., Davis, California, USA	28626	2007
CB1	Bacillus subtilis strain CB1, 1 × 10^7 cfu g^−1	SS	Soil-borne disease
CGB	Bacillus subtilis strain CB1, 1 × 10^7 cfu g^−1	SS	Soil-borne disease
JHB1	Bacillus subtilis strain CB1, 1 × 10^7 cfu g^−1	SS	Soil-borne disease
SSB1	Bacillus subtilis strain CB1, 1 × 10^7 cfu g^−1	SS	Soil-borne disease
WW4	Bacillus subtilis strain CB1, 1 × 10^7 cfu g^−1	SS	Soil-borne disease
^aWP, wettable powder; AS, aqueous suspension; SS, spore suspension.

Table 2.  Inhibitory effect of B. subtilis strains on F. foetens mycelial growth after 7-day dual culturing on PDA

Treatment	Colony radius (mm)	% inhibition
CB1	21.0	53.3 b
CGB	31.0	31.1 c
JHB1	14.0	68.9 a
SSB1	11.0	75.6 a
WW4	42.3	5.9 d
CK	45.0	0.0 d
LSD		8.74
CK indicates plates inoculated with F. foetens alone. Data followed by the same letters are not significantly (P > 0.05) different from each other.

Table 3.  Days post-inoculation for the first observed Fusarium wilt symptom on Begonia × hiemalis treated by B. subtilis strains and commercial products under greenhouse conditions

	First symptoms observed (days)
Treatment	Spring trial	Summer trial
CB1	21	21
CGB	21	28
JHB1	21	21
SSB1	21	21
WW4	21	21
Actinovate®	28	42
Mycostop®	28	21
Prestop®	30	35
RootShield®	21	28
Serenade® ASO	28	28
Inoculated control	21	21

Fig. 1. Effect of biocontrol agents on the development of F. foetens inoculated to Begonia × hiemalis under greenhouse conditions. B. subtilis strains in spring trial (a), and summer trial (b); commercial biocontrol products in spring trial (c), and summer trial (d).

Fig. 2. Effect of biocontrol agents on the above-ground dry weight (g) of Begonia × hiemalis under greenhouse conditions. Bars bearing the same letter are not significantly different at 5% level.

Fig. 3. Effect of biocontrol agents on the chlorophyll content index (CCI) of Begonia × hiemalis under greenhouse conditions in the spring trial (a) and summer trial (b).