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How to Control Black Sigatoka (Banana Leaf Spot)
| By Pinoy Farmer | April 30, 2009 | 
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Black Leaf Streak or Black Sigatoka was first recognized in Fiji in 1963. Since then, it has been found elsewhere and has steadily replaced yellow sigatoka in banana producing countries.
The disease is caused by a fungus, Mycosphaerrella fijiensis and is considered to be more virulent than yellow sigatoka.
When both diseases are present, black sigatoka predominates. Saba or Cardaba is resistant while Lakatan, Latundan, Bungulan, and Señorita are susceptible cultivars.
Transmission
When the conidia are released, they are disseminated by water while the ascopores are discharged during wet periods and dispersed by wind. The unfurling leaf and the first open are initially infected.
Under a crowded canopy and humid condition, the conidia can rapidly spread the disease on a susceptible variety.
Symptoms
• Initially, tiny brown streaks appear on the underside of the third and fourth leaves.
• After the streak stage, spots develop in a similar way as in yellow sigatoka.
• Streaks elongate into reddish-brown that later become dark brown or black.
• Dense aggregation of the black streaks may form and when these areas become water-soaked, the leaf turns black, dries up rapidly, and becomes brown.
Cultivar Reaction
All commercially grown varieties such as Cavendish, Grand Maine, Lakatan, Latundan, Bungulan, Saba or Cardaba, and Señorita are susceptible to this disease.
Control Measures
1. When planting bananas, you should consider the recommended population per unit area to avoid overlapping of leaf canopy that would create favorable microclimate for disease development.
2. Remove infected leaves to prevent faster spread of the disease. Cut the whole leaf when 75% of the entire leaf is spotted. If, infection is 50% or less, the leaf must be trimmed to remove spotted areas. However, deleafing should not be overdone.
3. Provide drainage canals to avoid waterlogging that triggers high humidity favorable for disease development.
4. Maintain proper plant nutrition.
5. Institute a planned chemical control program. For small farmers, apply fungicidal spray at the rate of 100 L/ha with either Dithane M-45 at 35 g/L, Daconil at 2 g/L, or Benlate at 1-2 g/L water at an interval of 14-21 days. Proper and adequate shaking of the spray solution must be maintained to avoid phytotoxicity on banana leaves and fruits.
Source: Open Academy for Philippine Agriculture
Topics: Crops & Vegetables, Farming Methods | 5 Comments »
September 17th, 2009 at 2:22 pm
Here in Davao Del Norte where export banana plantations are present, Benlate was discontinued for Sigatoka control. Moreover, spray intervals are shorter (7 days) for contact fungicides like Dithane and Daconil due to high inoculum and disease pressure as a result of monocopping.
September 23rd, 2009 at 12:29 pm
To control black sigatoka,a good ground support program like proper deleafing,on time fertilization,good weed control,good drainage and proper plant population density per hectare should be simultaneously applied to good Sigatoka chemical control program.
January 2nd, 2010 at 6:10 pm
I have a solution that works on sigatoka. Non toxic, organic. works wonders
June 28th, 2010 at 11:35 pm
A new organic fungicide has been developed locally and has been receiving favorable reviews from several research institutes. ANTICA is now available to the local market, and is cheaper compared to the chemical pesticides/fungicides available in the coutnry, a must try for banana growers.
August 5th, 2010 at 5:56 am
August 05, 2010
In controlling black sigatoka, a banana farmer must practice balance fertilization program using new method of applying liquid micronutrients that contain 16 vital essential elements being organically process or organic chelates. Active ingredients of dithane is MANCOZEB which is a composition of manganese, copper, zinc and boron. There are macro/micronutrients available in the market nowadays that composes of 3 primary nutrients 3 secondary nutrients and 10 micronutrients these are very essential in planting bananas of any kind variety. Due to climate change we need to have global awareness in nourishing farmlands through organic farming. We need to SAVE MOTHER EARTH. And when we will start, now is the time to act everyone has the role of saving our planet earth.How could we plant banana without an E because there is no more PLAN(E)T (E)ARTH.