We established an assessment system to rate the biological control
potential of all bacteria isolates based on in vitro activities of
their extracellular metabolites under two categories: Category
(A), consisted of 3 items (cellulase, glucanase and chitinase) which
accounted for (250, 148 and 44 antagonistic isolates) and Category
(B), comprised 2 items (siderophores and protease which
accounted for 124 and 91 antagonistic isolates. We adopted a
zero-to-three-point scale to score the isolates for enzyme activity,
0 meaning no hyaline zone present. For the isolates under category
(A), one, two, and three indicated the occurrence of hyaline zones
with widths of 0–5, 5-6, and >6 cm, respectively. One, two, and