The Plant Protection and Quarantine services in the Division of Agriculture have discovered a new fungus called Goplana dioscoreae affecting yams in Dominica.
It produces yellow to light-orange pustules on the leaf which are more obvious on the upper surface, and sometimes present on the leaf stalks and stems.
The disease could cause reduction in tuberization and yield.
Acting head of the plant protection and quarantine services, Nelson Laville said this pest was identified in white and ladies yams (the main yams cultivated in Dominica) three weeks ago though a laboratory diagnosis.
He said a survey was conducted last week which was able to identify the fungus in a number of locations, namely the central agricultural region, the north east and north agricultural region and the East agricultural region.
Laville said advice will be given to famers and exporters on how to manage this disease to avoid spreading.
“What is important to us now is basically to advise our farmers and exporters on how to deal with it. Traditionally, we grow, weed, fertilize and harvest yams but currently, because of this problem and its potential risk to reduce our yields and to even kill all plants, then we have to begin certain treatments and management practices,” he added.
According to the quarantine officer, within the next couple of days, the division will be having an outreach to extension officers, local farmers and exporters on what the disease looks like, what can be done to manage it and how to prevent it from getting into export markets.
Laville also encouraged farmers to refrain from moving planting material from farms to anywhere else.
“Some areas are more intense than others but we are aware that the yams are now planted year-round and farmers are actively pursuing planting yams. We are advising currently, do not move any planting material, we will come to you to show you how you can manage and treat your plants before you move them, ” he cautioned.
Although in some in areas, the presence of the fungus is very low, Laville said it has the potential of spreading and as such, Plant Protection and The Ministry of Agriculture are working very hard to ensure that the Goplana dioscoreae disease does not get out of hand.
To prevent the spread of the disease, the division has instructed famers to ensure that fields are clean, to remove and burn debris and fallen infected leaves, to use clean planting material and to treat the plants with a copper-based fungicide. The farmers are being advised that in previously highly infected areas, they should apply copper-based fungicide every 15 days for the first 3 months after planting and in previously low infected areas, they should apply y bacillus subtillis based fungicide every 10 days for two months.
If the disease has already infected a field, persons are advised to spray one cycle of tech oil and five days later, commence a fungicide cycle with Mancozeb every ten days for 3 months.
Another disease . No one asks where they suddenly come about in the nature island. We need to stop importing pesticide and weedicide. Then we need to continue as our fire forefathers did and respect the natural ways of agriculture. Some of us go to study overseas and return with all the taught ideas of new technology and cloned plant types but only see short term profit and not long term sustainability.
So from citrus to banana to yam…. We need to stick to the old ways.