Prevalence and management of root and collar rot of teak (Tectona grandis Linn.f.) seedlings in nurseries

Collar and root rot of teak seedlings caused by Fusarium oxysporum and Rhizoctonia bataticola was a serious disease during August to October in 10 nurseries of Akola district. Precent disease incid~nce was (5.15–15.17%) and (7.52–21.67%) due to R. bataticola and F. oxysporum in teak nurseries respectively. Incidence was more in August compared to October. In vitro study of the efficacy of eight different systemic and non-systemic fungicides by poison food technique revealed that carbendazim, penconazole, thiram, thiophanate methyl, carbendazim + thiram were effective in inhibiting the growth of R. bataticola, followed by dithane M-45 and tridemorph. Copper oxychloride did not cause any inhibition. against F. oxysporum A combination of thiram + carbendazim and carbendazim alone were highly efficient followed by thiophanate methyl, penconazole, tridemorph and copper oxychloride, in reducing the mycelial growth.

Antagonistic effect of Trichoderma longibrachiatum-7 recorded highest zone of inhibition against R. bataticola followed by T.harzianum -2. F. oxysporum, was inhibited by T.harzianum-2.