In vitro evaluation of fungicides, biocontrol agents and botanicals for their bioefficacy against root rot of acid lime (Citrus aurantifolia Swingle) in northern Karnataka.
This paper presents the results of a study conducted in vitro to determine the effective fungicides, biological control agents (BCAs) and botanicals against the root rot (caused by Fusarium solani [Haematonectria haematococca]) of acid lime. Seven systemic fungicides, i.e. carbendazim, propiconazole, hexaconazole, thiophanate-methyl, carboxin+thiram, metalaxyl MZ and fosetyl-Al [fosetyl] (at 0.05, 0.1 and 0.15%), and 5 non-systemic fungicides, i.e. mancozeb, captan, copper oxychloride, Bordeaux mixture and chlorothalonil (at 0.1, 0.2 and 0.25%), were assayed following the poisoned food technique. Nine BCAs, namely Trichoderma harzianum, T. viride, T. virens, T. asperellum, T. harzianum (local), Paecilomyces lilacinus, Verticillium lecani [Lecanicillium lecanii], Pseudomonas fluorescens and Bacillus subtilis, were tested using the dual culture technique. The botanicals used at 5 and 10% were Allium cepa, A. sativum, Bougainvillea spectabilis, Pongamia pinnata, Tridax procumbens, Lantana camara, Duranta repens [D. erecta], Azadirachta indica, Parthenium hysterophorus and Capsicum annuum, using the poisoned food technique. The results indicated that carbendazim (96.83% inhibition) and chlorothalonil (50.41% inhibition) among the systemic and non-systemic fungicides, respectively, were significantly the most effective against the root rot pathogen. Also, T. harzianum and Allium sativum at 10% among the BCAs and botanicals, respectively, were significantly effective in inhibiting (60.37%) the mycelial growth of F. solani.