124 



Journal of the Kentucky Academy of Science 66(2) 



Table 5. Synergistic inhibition of CoUetotrichum graminicola spore germination in a liquid glucose-salts medium 

 amended with sodium salicylate (SA) and cupric chloride (Cu). Germination was assessed microscopically based on the 

 presence (germinated) or absence (ungerminated) of an appresorium. No germ tubes were observed in the absence of 

 appresoria. All spores in one microscopic field at 100 X total magnification (>120 spores per well) were evaluated. 

 Values presented are mean ± standard error for two replicate wells per treatment (n = 2). Other abbreviations: OPC, 

 observed percent of control; ADD, ANT, and SYN denote additive, antagonistic, and synergistic interactions, respec- 

 tively. No germination was observed in the presence of 1.0 or 2.0 mM SA, and these data are not presented in the 

 body of the table. 





Cu 0.0 mM 



Cu 0.2 mM 



Cu 0.35 mM 



Cu 0.5 mM 



SA 0.0 mM 



91.5 ± 1.1 



86.0 ± 2.4 



70.0 ± 2.1 



37.5 ± 2.5 



OPC 



100 



94 



77 



41 



SA 0.2 mM 



89.0 ± 0.0 



84.0 ± 2.8 



84.0 ± 2.8 



86.5 ± 1.1 



OPC 



97 



92 



92 



95 







ADD 



ANT 



ANT 



SA 0.5 mM 



96.5 ± 0.4 



96.0 ± 0.0 



91.5 ± 1.8 



89.5 ± 0.4 



OPC 



105 



105 



100 



98 







ANT 



ANT 



ANT 



SA 0.75 mM 



36.0 ± 7.1 



4.0 ± 0.0 



1.0 ± 0.0 



0.0 ± 0.0 



OPC 



39 



4 



1 



0 







SYN 



SYN 



SYN 



or BRCF alone. However, the combination of 

 SA with 100 or 200 |jl1 of BRCF prevented 

 EC growth in 2/3 and 3/3 wells, respectively. 

 Neither BRCF nor SA alone prevented PESP 

 growth at the doses employed. However, the 

 addition of SA prevented PESP growth in 2/3 

 wells that received 50 jjlI of BRCF, and in all 

 three wells that received 100 or 200 |jl1 of 

 BRCF. Only a slight effect of SA on inhibition 

 of BC by WCF was observed, whereas growth 

 of PESP was uniformly prevented in all com- 

 binations of SA and WCF. 



The Interactive Effects of SA and NM 



These effects varied with NM source [NM 

 concentrate (NMC) or ready-to-use (NMRTU) 



formulations], SA and NM doses employed, 

 timing of fungal inoculation following addition 

 of NMRTU to GS, and species of test fungus. 

 In trials with NMC, little or no inhibition of 

 BC mycelial growth was observed with NMC 

 alone or in combination with SA, although a 

 transient delay in pigmentation was commonly 

 observed in NMC-SA combinations (data not 

 presented). In an experiment in which 

 NMRTU was added to wells immediately pri- 

 or to inoculation with BC, only a slight inhi- 

 bition of BC by the highest dose of NMRTU 

 was observed in the absence of SA (Table 7). 

 Amendment with 2.0 mM SA only sUghtly en- 

 hanced inhibition by NMRTU dilutions of 

 1/10 X and 1/5 X (data not shown). However, 



Table 6. Synergistic inhibition of mycelial growth of Botrytis cinerea (BC) and Pestalotia sp. (PESP) in a liquid glucose- 

 salts medium amended with sodium salicylate (SA) and bacterial culture fluids (BCF). Single 24-well culture plates 

 were filled with 0.5 ml GS per wefl to which were added 0, 50, 100, or 200 |xl of BCF from the 18 d potato-dextrose 

 broth shake cultures of an unidentified mixed white bacterial culture (WCF) or an unidentified mixed brown culture 

 (BRCF). Fungal growth was assessed as present or absent for each of three replicate wells per treatment (one 24-well 

 culture plate per BCF-fungus combination). 



WCF (jjLl/well) 



BRCF (|xl/well 



0 



50 



100 



200 



0 



50 



100 



200 



Incidence of BC mycelial growth 















SA 0.0 mM 3/3 



3/3 



3/3 



2/3 



3/3 



3/3 



3/3 



3/3 



SA 2.0 mM 3/3 



2/3 



3/3 



1/3 



3/3 



3/3 



1/3 



0/3 



Incidence of PESP mycelia 



1 growth 















SA 0.0 mM 3/3 



3/3 



3/3 



2/3 



3/3 



3/3 



3/3 



3/3 



SA 2.0 mM 3/3 



0/3 



0/3 



0/3 



3/3 



1/3 



0/3 



0/3 



