As the suspected leaf spot disease Black Sigatoka continues to ravage banana and plantain farms across the country, the Ministry of Agriculture (MoA) has said that preliminary results of samples sent to the United Kingdom (UK) to be tested point to symptoms of the scourge.
However, additional tests are being undertaken by the Commonwealth Agricultural Bureau International (CABI) in the UK on samples from Guyana.
Farmers in several areas across the coastland told Stabroek News recently that the “dry leaf” disease has impacted on their farms and some have stopped cultivating plantain and banana suckers. This was reported in Stabroek News’ series on the Grow More Food Campaign.
Earlier this year, multiple reports of a disease resembling Black Sigatoka were said to have been responsible for the authorities in Suriname cutting off the ‘back-track’ crossing on the Corentyne River. The MoA’s MDMU unit was subsequently established.
Agriculture Minister Robert Persaud told Stabroek News recently that the National Agricultural Research Institute (NARI) received a report from UK-based agency recently and according to him the report stated that the morphological features observed on the samples were in agreement with description given by CABI for Mycosphaerella fijiensis, the causative agent of Black Sigatoka. He said that CABI also attempted to isolate the fungus into pure culture so that the unit can confirm the identification using molecular methods. However, the agency reported that this procedure is not straight forward for this species as it is slow-growing and easily overtaken by other leaf saprophytes.
He said NARI’s plant pathologist and Head of the Musa Disease Management Unit (MDMU) Rajendra Persaud as well as Food and Agriculture Organization (FAO) consultant Assim Dilbar both made similar discoveries as reported by CABI. Persaud noted that the plant specialists also stated that a number of techniques have been unable to isolate the causal agent of Black Sigatoka and they have extracted a number of fungal isolates and these are being examined, as work on analyzing the samples received by the unit is ongoing.
The disease has been identified as being in parts of regions 1, 2, 3, 4, and 7 as well as to a lesser extent in regions 5 and 6, Persaud noted. He said that the spread of the disease is curtailed through the Ministry, the MDMU, NARI staff and field officers using “their proactive approach in all the various regions of the country.” Persaud said that the field officers continue to monitor all the disease-affected areas and have been providing farmers with advice on disease management strategies currently available in treating the spread of the disease. The aforementioned is being carried out through the MoA’s sensitization programme, training and demonstration exercises with farmers and other key stakeholders as well as disease management strategies and spray programmes. The MoA is appealing to all farmers, householders and the general public to adhere to quarantine advice which is to restrict the movement of rhizomes, suckers and leaves that could be carrying Black Sigatoka from infested to clean areas.
Persaud said that there are a number of projects which will be undertaken by the MDMU in 2011 and these include production and distribution of disease-free planting materials through tissue culture, evaluation of new fungicide molecules, disease severity studies and nutritional studies. He said work will also begin on the preparation of a “Sigatoka Manual.’
The MoA has stated that good cultural practices which can be adopted to curtail the spread of the disease are: regular de-trashing or de-leafing to remove dead and infected portion of leaves as these would contribute to re-infection and high levels of spore inoculum (Sanitation); prevention of overcrowding of field by planting at the correct spacing (approx 2.4 m) as well as pruning mats at regular intervals; and establishment of an adequate/ efficient drainage systems as well as good weed management.
As regards chemical control, the Ministry stated that spraying with recommended fungicides in a well planned spray programme while alternating (rotating) fungicides with the prevailing environmental condition is vital for successful control. Among the recommended fungicides are: Bravo, Manzate, Benlate, Tilt, Carbendazim, Maximo, Bellis and Mancozeb.