When growing peppers, your biggest enemy may be the bacterial spot of pepper, an incredibly destructive disease that causes yellow and brown spots on all parts of your plants and fruit. This eventually leads to defoliation, loss of fruit yield and low quality crops. This disease is especially prevalent in areas with frequent rainfall and high temperatures during growing seasons.
Bacterial spot of pepper can be found on the leaves, stems and fruits of the pepper plant. On the leaves it usually beings as a yellow lesion, small in size. As these get bigger they spread to larger parts of the leaf and the center of the lesion becomes brown and dried, eventually breaking out entirely and leaving a hole. If a leaf or plant has a number of these lesions, they can join together and form long lines of holes or discolored areas. The tips and edge of the leaf then begins to dry and break off, followed by the rest of the leaf. When found on the fruit, these lesions are green and raised. They become brown with scabby centers. Lesions on the stems are darker, almost black, and long.
Bacterial spot of pepper is caused by a bacteria, called Xanthomonas campestris pv. vesicatoria. This bacteria can come from infected seeds, soil or crop residue. Dried seeds can carry this disease for 10 years, and infected soil for six months. Pepper plants can become infected if they suffer a puncture or wound. This can then be spread through water, cultivating techniques, hoeing and transplanting.
Prevention and Treatment
To prevent bacterial spot of pepper, keep your fields free of debris, and use pathogen-free transplants and seeds. Rotate your crops so that you are only growing peppers every three to four years. If you have a problem with bacterial spot of pepper, make sure to deep-plow your fields so that the infected debris is buried deep. There are some pesticides that may also be helpful to stop the spread of this bacteria.