ARET, Annual Report 2001, p. 129-5.

Efficacy of Bion on the control of wildfire in tobacco nursery

ARET, Agricultural Research and Extension Trust, Lilongwe, Malawi
This trial was conducted at Mwimba Research station forest because there was inadequate space in the greenhouse. The objective of the trial was to evaluate Bion under controlled environmental conditions and determine the inoculum levels and using different tobacco types and cultivars. A split-split plot design with tobacco type as main plots, cultivars as subplots and Bion rates as sub-subplots with three replications was used. Each treatment occupied a 1 m by 1 m area of seedbed. The varieties used were the following:NDDF (MW86-57, LA18, LAI33) Burley (BA-1, MW94/6/5, M84-1052, KBM 33), flue-cured (KE-1, MTRA 88, ABL 34, FLS89-109). The rates of application of Bion were: a) 0.625g Bion/L applied at 40ml/m2 (0.0125g ai/m2); b) 1.25g Bion/L applied at 40m1/m2 (0.025g ai/m2); c) 2.5g Bion/L applied at 40m1/m2 (0.05g ai/m2); and d) Control (0g ai/m2). Bion was applied 7 WAG followed by inoculation of the seedlings with wild fire pathogen P. syringae pv tabaci using a hand sprayer after clipping at 7 days after the first spray of the chemical. Second spray of the chemical was done at 10 days after the first spray and third spray at 7 days after second spray. The results from this experiment showed that Bion induced resistance in tobacco and the severity of the disease reduced with increased level of Bion applied. In addition, different cultivars reacted differently to wildfire infection with BW94/6/5 showing almost same immunity to the disease. The trial will however be repeated to confirm the results.