By Spy Uganda
Also known as Panama disease, fusarium wilt of banana is difficult to control and severe infections are often deadly. The disease has decimated crops and has threatened an estimated 80 percent of the world’s banana crop. Read on to learn more about banana fusarium wilt disease, including management and control.
Banana Fusarium Wilt Symptoms Fusarium is a soil-borne fungus that enters the banana plant through the roots. As the disease progresses upward through the plant, it clogs the vessels and blocks the flow of water and nutrients.
The first visible banana fusarium wilt symptoms are stunted growth, leaf distortion, and yellowing, and wilt along the edges of mature, lower leaves. The leaves gradually collapse and droop from the plant, eventually drying up completely.
The leaf symptoms of Fusarium wilt can be confused with those of the bacterial disease Xanthomonas wilt. In plants affected by Fusarium, yellowing and wilting of the leaves typically progresses from the older to the younger leaves. The wilted leaves may also snap at the petiole and hang down the pseudostem. In plants affected by Xanthomonas, the wilting can begin with any leaf and the infected leaves tend to snap along the leaf blade.
In countries with Moko disease, which is caused by Ralstonia solanacearum race 2, and also causes vascular discoloration, it is possible to confuse the two diseases. Unlike Moko, Fusarium wil does not cause wilting and blackening of young suckers or a dry rot in the fruit. The first symptoms of Moko on rapidly growing plants are the chlorosis, yellowing and collapse of the three youngest leaves, not the older leaves as with Fusarium wilt. Finally, with Moko the vascular discoloration is concentrated near the centre of the pseudostem and not peripherally, which is common with Fusarium wilt.
Modes Of Transmission
The fungus is commonly spread through infected planting material, infested soil and water.
Symptomless but infected suckers or rhizomes can transmit the disease when planted in a new area. Infected planting material is often responsible for the local, national and international spread of the disease. Certified tissue-culture plantlets should be free of the fungus and would not contribute to the spread of the disease.
Staff and visitors to a banana plantation have the potential of moving the fungus in or out through infested soil attached to vehicles, tools and shoes. Untreated soil used as a potting medium can transmit the fungus and animals can also move around fungal spores present in soil.
The fungus cannot be controlled using fungicides and cannot be eradicated from soil using fumigants. Drainage, environmental conditions and soil type influence host-pathogen interactions. Soils that suppress the disease have been reported in Central America, the Canary Islands, Australia and South Africa. However, the chemical, biological and physical factors responsible for this phenomenon are not well understood.
The solution best adapted to the continued production of bananas in infested soils is replacing susceptible cultivars with resistant ones.