It is one of the major diseases of tomato known to occur in the wet tropics, subtropics and some temperate regions of the world.
The pathogen responsible for the disease is known as Ralstania solanacearum. The pathogen can also cause bacterial wilt in other crops including :
The disease is very prevalent during the rainy season but also thrives in excess moisture or humidity. The entry point for the pathogen into the plants is through wounds or cracks in the roots. Improper routine management practices such as careless treatment of seedlings during transplanting, cutting of roots when earthing up the plant and through insect or nematodes wound increase the rate of infection.
The first notable symptom of the wilt is drooping of leaves on the tomato plant during the hottest part of the day. This occurs after a period of 2-5 days from the day of the infection. The leaves lose turgor, wilt and become brown. In its early stages only one or half a leaflet may wilt and plants may appear to recover at night when the temperatures are cooler.
High temperatures and moisture offer good conditions for the pathogen. The disease spreads rapidly and the plant wilts entirely in a few days. Fruits usually develop watery spots which develop on upper half of fruit. Other symptoms to be noticed include stunted plants and necrosis of the leaf marginal. One way of identifying whether your plant is infected is by cutting a section of a clean stem and suspend it in a glass of water. If the plant is infected a stream of milky white bacterial cells will be observed flowing from the stem.
Control of the disease can be done through;
Crop rotation with crop of a different family from tomato
Use of pesticides. Pesticides available include; Mancozeb, Propineb, Chlorothalonil, Metalaxyl, Copper Oxychloride and Azoxystrobin.