Bull. Spec. CORESTA Congress, Brighton, 1998, p. 119, P05

Chemical control of brown spot disease of tobacco caused by Alternaria alternata

NAGARAJAN K.; SHENOI M.M.
Central Tobacco Research Institute (CTRI), Rajahmundry (A.P.) India
Among the diseases affecting leaf of tobacco, brown spot caused by Alternaria alternata is assuming importance in recent years on FVC tobacco in Karnataka light soils and Northern light soils of Andhra Pradesh. Recent studies indicated that the loss due to this disease varies from 15 to 26 percent under favourable weather conditions. Germplasm screening indicated that there are no resistant varieties of N. tabacum while resistant donor is available in wild Nicotiana Spp. In vitro and in vivo evaluation of chemical fungicides showed that Baycor, Bayleton, Beam, Score and Tilt fungicides are found promising in the control of this disease @ 0.2 to 0.4 percent concentration. Among the 12 botanicals tested, leaf extract of Lawsonia inermis and Azadirachta indica showed high mycotoxic properties against the pathogen.