By Julius Odeke
An invasive parasitic plant that looks like a beautiful golden ornament is decimating wild and domestic trees and crops in Teso sub-region.
The golden dodder aka cuscuta has also been spotted in several urban centres countrywide, being dispersed by people who admire its yellow colour and birds that eat its seeds.
“This weed tends to attract a flock of small birds scavenging for insects on the dense, leafy weed that covers much of the tree,” Bernard Ouke, the Kalaki district forestry officer, says.
“Most of the trees in the district have been attacked by the weed.”
The creeping plant builds a blanket with its spaghetti-like filaments. The densely-packed filaments look like a well-decorated ornament where the small birds perch as they pick insects and suck juicy substances from the plant, Ouke says.
Introduced in Uganda around 1963 through imported food relief supplies, this weed is a native of the Americas, Ephrance Tumuboine, an assistant commissioner for crop protection in the Ministry of Agriculture, Animal Industry and Fisheries, says the parasitic plant has been spotted in Bombo, Busia, Mbale, Mbarara, Lyantonde and many other areas. It is also the cause of this death of life in the bushes and forests in Teso, Budaka and Mbale.
The weed is also decimating wild trees and those planted in compounds and gardens. It is already compromising the main source of income for the local population as it is affecting tea, coffee, mangoes and other crops.
The takeover of the green vegetation has been rapid and seemingly unstoppable. For the last four years, local media has reported an upsurge of the golden dodder in different parts of the country, including urban centres.
Reports and photos of the fast-spreading invasive weed have crept through from Busia, Butaleja, Pallisa, Luwero, Kampala and Kibuku districts, among others, where this mesh-like plant covers trees in the wild.
Although the Ministry of Agriculture, Animal Industry and Fisheries appears to know of this danger, it has taken a lukewarm, laissez-faire attitude.
Efforts to control the golden dodder, Tumuboine says, have been hard to come by as the Government has struggled to keep pace with the plant’s prolific growth.
Perhaps only Kampala Capital City Authority has cared enough to massively destroy this parasite that was easily seen as widespread on many roadside trees and flowers.
Christine Abuko, a 54-year-old farmer in Anyara sub-county with at least 10 acres colonised by the plant, says: “Dodder is a very dangerous weed that has suffocated and killed many fruit trees in the area and people are still awed at how to destroy it.”
“Some of the trees planted — like guavas, oranges and mangoes — have died due to that weed coiling around them.”
Little research
“Not much research has been done on the dodder despite having spent about 60 years in the country,” explains Prof. Patrick Mucunguzi, head of the Botany department at Makerere University.
“Makerere University, too, has done little on researching more about the golden dodder. Yes, we had tried but were limited by meagre resources. So, limited funds could not enable us to go further,” he adds.
Mucunguzi says Uganda has various categories of golden dodder, which include cuscuta epilinum, with five-part pale flowers in large heads of 10-15mm across and cuscuta approximata, also known as small-seed dodder, which has five-part flowers.
Cuscuta epithymum has reddish fi laments and flowers and Cuscuta australis is known as the leafless dodder.
“Golden dodder is one of the most sparsely studied weed species in Uganda,” Mucunguzi says.
However, he adds that the human factor is partly to blame for accelerating the spread of the invasive plant as people pick it as an ornament for decorative purposes.
For example, children pick their filaments as they play and run around with them. Thus, human activity is highly to blame for spreading the golden dodder in Uganda.
On why it is a parasite, Mucunguzi says: “The carpet formed by the invasive weed on tree surfaces prevents light from reaching the leaves. Therefore, it reduces photosynthesis, the process through which trees manufacture their food.”
“The absence of the parasitic golden dodder’s natural enemies in a foreign environment expedites its fast growth rate in the bush,” Herbert Elaju, an independent advocate of forestation, says.
‘Whole country in trouble’
“So, it’s not only in eastern and northern Uganda; the whole country is in trouble,” Mucunguzi said.
He adds that if the Government and other partners do not step up their efforts to curb this weed, many trees and crops will be killed.
The seeds of the field dodder are dispersed by wind, water, birds, and other animals, and by man’s activities.
The seeds can remain viable for three to 10 years – even after passing through the gut of an animal! Immature seeds are said to germinate faster than mature ones.
Though seeds are viable and germinate readily, cuscuta species can only survive the seedling stage if they get a host immediately after germination (before the food in the cotyledons is finished).
“The golden dodder attacks crops like sweet potatoes, cassava and yellow oleander – because they have milky substances in them,” Elaju says.
Yellow oleander is locally known as eligoi in Ateso. In Teso, children use its milky substance to glue torn books and paper money together.
Elaju expressed worry, saying: “Our organisation [based in Teso and Karamoja] is trying to save the indigenous trees, especially the edible fruits types, for the future. But now this deadly weed is ravaging both the natural and man-planted forests countrywide. Our efforts, therefore, may not yield any positive results if the Government does not come to fight it.”
“Dodder is mostly spread along the rivers, creeks, floodplains and areas that practice irrigations as water is the principal method of its spread and suitable host plants are concentrated along waterways.”
Medicinal value
Amazingly, golden dodder is said to have some medicinal value.
Jacob Okullo, a resident of Wera sub-county in Amuria district, says golden dodder is commonly used to treat various diseases.
Okullo’s assertions agree with an Internet search that New Vision made.
Golden dodder is used to treat urinary tract, spleen, psychiatric and hepatic disorders. It is also used for cancer, depression, eczema (atopic dermatitis) and other body pains.
For example, a 27-page article by five scientists, published in the Iranian Journal of Basic Medical Sciences, in November 2019, says various cultures have used the dodder in functional foods and traditional medicinal systems.
LEAD PHOTO CAPTION: Mbarara South division agriculture officer Vincent Mugabe showing how golden dodder has attacked plants in his area recently. Photo by Julius Odeke
