Monthly Archives: May 2013

Disease: Yellow Sigatoka Leaf Spot

One of the most destructive banana plant diseases is the Yellow Sigatoka Leaf Spot. The disease begins with small, light yellow spots or streaks parallel to the side vein of the leaf. The disease can only infect young banana leaves. Ascospores are released after rain and are spread by wind and rain. The most important factors for disease development are moisture on young leaves, caused by dew, rain or overhead watering, together with high temperatures. Hot and humid weather encourages rapid disease development. There is an incubation period of at least a month between infection and the appearance of leaf spots. Later, as the disease progresses, the spots elongate and turn brown with light gray centers. The spots elongate more and the tissue around them turns yellow and dies. Adjacent spots coalesce to form large lesions. The pathogen survives in the infected banana leaves and spreads via the wind. The period between fungicide applications depends on the climate and the amount of yellow Sigatoka already present. In the wet season, apply a protectant fungicide every three to four weeks. Either mancozeb (Dithane) with mineral oil or  chlorothalonil (Bravp) can be used.  Only apply fungicides in amounts recommended on the label. Infected and dead leaves will produce fungal spores as long as they are left on the plant. Early removal of diseased leaves is essential. Avoid removing all diseased leaves during the hot dry season because of their beneficial shading effects.

Maintenance: Leaves

No matter how unattractive the leaves are, if they are green, they stay. Yellow, brown etc. you can cut off. Banana leaves may begin to look very tattered after heavy winds. This is perfectly normal. The banana leaves split into strips allowing wind to pass through more easily. If the leaf stayed in one large piece it would be easier for the plant to be knocked over or damaged.

When cutting the leaves, be sure to have a sharp set of gardening scissors. DO NOT pull or rip the rest of a leaf off if there is some left over. It will tear all the way down the stem and damage the plant.

Diagram of Banana Plant

Diagram of Banana PlantThese terms will be used throughout the blog, so it is a good idea to become comfortable with them or keep this photo handy.

Sucker or Pup: the baby banana plant that we will separate from the Pseudostem (mother plant) when it is ready. These “pups” we then use to plant in other areas. When transporting pups make sure they are very well watered both before, during and after transport.

Corm:  Corms serve as a storage organ of which the banana plant can use to survive adverse hot and cold weather conditions. Until there is no corm left behind, the banana plant is still alive! Banana plants are fighters. You can cut it down to the corm and replant it or even cut up the corn a few times to create more than one plant. When cutting the pup off from the mother plant please be sure to take its corm along with it.

Hand: Another word for the first bunch of bananas that grow on the banana plant.

Hardiness Zones: what types of plants for my area?

Hardiness Zone Maps help to show what type of plant will best survive in each area. Typically when purchasing a plant, they will provide you with a number. This number helps you to see how hardy the plant is and what location it will do the best in. For a precise number, refer to this link  and type in your zip code. (click for larger images)

Hardiness Zone Map-U.S.