Vol. 12, Issue 12 (2023)

Author(s):
P Mahalakshmi, M Ayyandurai and P Mareeswari

Abstract:
Studies were conducted to test the efficacy of liquid formulation of Pseudomonas fluorescens against fusarial wilt of carnation under in vitro and in vivo conditions. Thirty four isolates of P. fluorescens were screened against the mycelial growth of F. oxysporum f. sp. dianthi. Among the isolate tested, the isolate of Pf12 significantly inhibited the pathogen mycelial growth (2.70 cm) which accounted 70.0 percent reduction over control with 6.30 mm inhibition zone followed by Pf7 recorded 64.78 percent reduction of mycelial growth with 5.83mm of inhibition zone. The effective strain of Pf12 in different age old culture were tested their effect on the mycelial growth of the pathogen. The result showed that the cultures from 7 to 15 days recorded the least mycelial growth of 2.51 to 2.56 cm followed by the cultures from second and 30 days with the mycelial growth of 2.64 and 2.88 cm which was on par with each other. The poly house experiment revealed that among the treatments, Application of liquid formulation of Pf12 by soil drenching + seedling dip combined with basal application of Th2 recorded lowest mean percent disease index of 5.44 which was on par with chemical check which was recorded 5.34%. and also significantly increased the growth characters of plants which showed higher stalk length (66.35 cm), stalk girth (3.94 cm), number of branches (4.24/plant), number flowers per plant (3.56/plant) and flower diameter (4.57 cm).