Articles
A REVIEW OF BACTERIAL LEAF SPOT OF PEPPERS (CAPSICUM ANNUUM L.) CAUSED BY XANTHOMONAS CAMPESTRIS PV. VESICATORIA (DOIGE) DYE AND SOME METHODS OF ITS CONTROL
Peppers were the first new world food item commercially used in Europe.
Bacterial leaf spot of peppers caused by Xanthomonas campestris pv. vesicatoria (Doige) Dye appear during the rainy seasons almost everywhere in most of the chilli growing areas of Ethiopia.
Phytopathogenic strains isolated from leaf spot diseases of tomato (Lycopersicum esculentum mill), pepper (Capsicum annuum L.), and raddish (Raphanus sativus L.) are generally referred to the species Xanthomonas vesicatoria (Doige) Dows.
However, in recent years it has been claimed that strains isolated from each of the aforementioned host plants are sufficiently distinct in their physiological and pathological properties.
After the harvest of chilli the bacterium may possibly survive in soil, infected plant debris, stray standing plants, collateral hosts or in seeds to provide inoculum for the succeeding chilli crop.
Seeds of pepper, capsicum annuum, artificially inoculated with Xanthomonas vesicatoria were disinfected by a 4.2% calcium hypochlorite solution or a 2.63% sodium hypochlorite solution for 15 minutes followed by a 15 minutes water rinse.
Since increasing levels of Mg++ decreases streptomycin inhibition of bacterial growth, it is advisable to avoid luxury plant nutrition with Mg++ and to exclude Mg++ from streptomycin spray applications for improved disease control.
In addition, varietal differences in resistance to bacterial leaf spot of peppers have been found by several workers.
It was also found that one bacterium and four actinomycetes are antagonistic to Xanthomonas vesicatoria.