The group I included about 11 isolates with circular colony and smooth margin, which were AcPb, AcNd, AcHl, AcBd, AcJl, AcYt, AcDl, AcBl, AcAm, AcNb and AcJg.
However, it was excellent (++++) in about eight isolates viz., AcNd, AcHl, AcAb, AcYt, AcWs, AcAn, AcBl and AcJg; good (+++) in seven isolates viz, AcPb, AcOs, AcBd, AcJl, AcAk, AcLt and AcNs and fair (++) in five isolates viz., AcSt, AcDl, AcAm, AcNb and AcSl.
However, maximum mycelial width was recorded in AcLt (6.46 [micro]m) isolate, followed by the isolates viz., AcAk (6.30 [micro]m), AcBd (6.10 [micro]m), AcSt (5.89 [micro]m), AcAb (5.70 [micro]m) and AcYt (5.40 [micro]m).
Among these isolates, highest average conidial size (length X breadth) was recorded in the isolate AcAk (50.32 X 15.02 [micro]m), followed by the isolates viz., AcLt (45.80 X 14.62 [micro]m), AcBd (41.45 X 16.06 pm), AcBl (40.35 X 13.06 [micro]m), AcAb (39.40 X 15.31 pm), AcAn (39.11 X 13.56 [micro]m) and AcPb (38.30 X 15.62 [micro]m).
However, it was highest in the isolate AcHl (16.43 [micro]m), followed by the isolates viz., AcLt (15.24 [micro]m), AcAk(14.65 [micro]m), AcBl (14.34 [micro]m), AcAn (13.45 [micro]m), AcBd (13.03 [micro]m), AcJg (12.96 [micro]m) and AcAb (12.04 [micro]m).
Accordingly, in group A the isolates (04) included were AcHl, AcAn, AcBl and AcJg; in group B the isolates (12) included were AcPb, AcNd, AcSt, AcOs, AcAb, AcWs, AcAk, AcLt, AcBd, AcJl, AcYt and AcSl and in group C the isolates (04) included were viz., AcAm, AcNb, AcDl and AcNs.
In group C of less virulent isolates, the leaf spot frequency was ranged from 5.00 (AcDl) to 13.33 (AcAb) per plant; however, it was significantly maximum with the isolate AcLt (12.50), followed by AcAk (11.00), AcOs (10.67), AcSt (10.50), AcBd (9.67) and AcYt (9.00).