Table 4.

Results of bioassay testing for fungicide retention (indicated by inhibition of Raffaelea spp. growth) in redbay stem plugs and branch discs plated on spore-seeded, cycloheximide streptomycin malt agar (CSMA).

SampleTree injection treatmentMonths since fungicide injectionNo. of treesNo. of trees with samples exhibiting inhibitionPercentage of samples per tree exhibiting inhibitionzPercentage of samples per tree exhibiting inhibition zone in the agarz
Stem plugsPropiconazole7.5121184 a25–10027 a0–75
Propiconazole4.5  5  595 a75–10080 b50–100
NoneN/A  5  0N/AN/AN/AN/A
Branch discsPropiconazole7.512  533 a17–8300
Propiconazole4.5  5  429 a17–5000
NoneN/A  5  0N/AN/AN/AN/A
  • zMean and range are based only on data from trees in which inhibition of mycelial growth was exhibited. Within columns, means followed by the same letter are not significantly different (P > 0.05) as determined by a two-sample t-test. Four stem plugs and six branch samples were collected per tree.

  • N/A = not applicable.