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| Officer-in-charge of the Plant Pathology Unit, Michael James, (in lime green shirt) speaking with?? ministry staff and farmers during a field day at the Ministry of Agriculture’s headquarters at Graeme Hall, Christ Church. (A.Skeete/BGIS)?? |
Plants are a precious resource, whether as a source of beauty, nourishment or income, whether grown by a Barbadian householder or the largest farmer.
They are a cornerstone of the agricultural sector, with the trade in food crops a million dollar industry. However, the gains made by this vital sector could potentially be wiped out by the threat of plant diseases. Therefore, agricultural officials have had to remain vigilant to ensure local plant life is safe and secure from such hazards.
The Ministry of Agriculture’s Plant Pathology Unit is a vital cog in this regard as government continues to ensure Barbados’ agricultural plant diversity remains healthy. Plant Pathology refers to the scientific study of plant diseases and disorders caused by pathogens (disease causing organisms) and environmental conditions.
Officer-in-charge of the Unit, Michael James, explained that his department’s scope extended to all plant life, whether they are grown locally, entering Barbados or being exported from the island.??
He expounded on some of the problems which could have an impact on plant health in the island.
"Diseases in our field are caused by pathogens…These can range from fungi, bacteria, viruses to nematodes (roundworms) and mycoplasma-like organisms. Plants can also be affected by abiotic problems which are caused by things outside the remit of pathogens such as nutrition, temperature, wind, rain or the sun… They too can cause major damage to plants," he said.
In citing some of the major plant diseases which impacted Barbados over the years, Mr. James recalled a fungus problem with yams in the 1980s called Yam Anthracnose, and Bunchy Top which affected papaya.??
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| Plant Pathologist, Michael James, (in lime green shirt) inspecting some pigeon pea plants with ministry staff and farmers during a field day at the Ministry of Agriculture’s headquarters at Graeme Hall, Christ Church. (A.Skeete/BGIS)?? |
"You could not get yams to grow; not that Barbadians had lost the art of growing yams but the Anthracnose problem really decimated yam production. It looked as if some fields had been scorched. With papaya, again in the late 1980s, we had plantations growing acres of papayas and then we had a particular problem called Bunchy Top, which is caused by a fastidious bacterium and for which there is no ???cure’.?? That also decimated a lot of the papaya fields within Barbados. If you look around there are very few plantations which grow papaya in a large scale right now," the Plant Pathologist pointed out.
There have also been cases of solanaceous plants such as sweet and hot peppers affected by bacterial spot, sweet peppers and tomatoes having blossom end rot, onions suffering from onion blast (a bacterial disease and a nutritional and physiological disorder) and the palm family of plants also affected by a fungus.
The Department has sought to maintain a record of the most common diseases that affect particular crops throughout the island. Disease surveys and surveillance are conducted to ensure that data related to disease presence, spread and severity is captured, which in turn assists the unit in the control and management of any diseases. Among the crops monitored are sugar cane, cotton, onions, yams, sweet potato and cassava as well as citrus.
Once a disease is identified and confirmed, Mr. James explained that his section worked in tandem with other related departments to ensure Barbados’ plant diversity was protected and/or any disease is brought under control or managed.
The Plant Pathology Unit, along with Entomology, the Pesticide Control Board, and the Plant Quarantine Unit, form the Plant Protection, Department – a four-pronged, integrated approach in safeguarding the island’s agricultural crop resources.
"We would tell Plant Quarantine, for example, these particular diseases are not present in Barbados and we don’t want them here. So, you might have to restrict or put certain conditions on plants or other live agricultural products coming into Barbados, so you do not have these diseases entering. We also work with Entomology because there are some diseases which use vectors – insects such as aphids, whitefly and mealy bugs – that would take a disease to different plants. There are also some bacteria and fungi that are spread by vectors," he noted.
In terms of controlling and managing plant diseases, Mr. James said that process was broken down into three areas. "You try to keep it out, that is, exclude it. This function is primarily handled by Plant Quarantine. You try to eradicate it by destroying sources of inoculums (spread of the disease). Finally, we try to protect the crop or control the disease by resorting to other options such as using disease resistant or tolerant varieties, or in some cases, using pesticides," he explained.
Citing the example of pigeon peas, he said some five years ago they were affected by Fusarium Wilt, a soil borne disease which could severely hinder or halt pigeon pea growth or kill the entire plant.
According to the Plant Pathologist, this disease did not respond to chemicals and as such, sprays were ineffective, while exclusion was out of the question since it was already endemic in the island. So, agricultural officials had to explore other options.
"When we investigated we found out that in Africa, this particular disease had been present for a number of years. They have lived with it and had developed tolerant or resistant varieties… We were able to get about six varieties and we planted some last year and carried out our experiment on how well these varieties would stand up to Barbadian conditions.
"Of particular interest were the yields as well as the susceptibility of the plants to the pathogen here – they performed favourably. In fact, there were two varieties that performed extremely well, surpassing our own local variety. We will continue to work on these before we release these seeds because we want to see how they grow – how high, the peas per pod, the length of the pod and other agronomic data and if farmers like them," he said.
Noting that it was extremely difficult to eradicate a pathogen once it entered the island, Mr. James also had some advice for plant lovers, travellers and importers.
"Whenever persons may seek to import anything, from a pack of seeds to a caseload, let us know. Speak with the Plant Quarantine Division and let them know what you plan to do. When we say seed, it does not only mean that plant part but refers to anything that can be used to propagate a plant. It may mean a piece of a plant or tissue culture… If you are bringing in mangoes or oranges, it depends on where you are bringing them from. It’s not only plants but fruits and vegetables and how you bring them in as well…"
The Plant Pathologist observed that many Barbadians took the issue of plant diseases for granted, however, he urged them to call upon the expertise available in the department, if they had any queries about plant health and disease control. "It does not matter if you are a householder, with one plant in your house that you like or a farmer that has 50 or 60 acres in Barbados, no matter what, we are there to diagnose that problem," Mr. James maintained.
The Plant Pathology Unit of the Ministry of Agriculture is located at Graeme Hall, Christ Church and officers may be reached at 434-5000, or 434-5114, or persons may visit the website http://www.agriculture.gov.bb/ for further information.