The early symptoms of the citrus canker are brown spots on the leaves and fruit rind blemishing. But infections can cause defoliation, death of shoots and fruit drop.
While not harmful to humans, the disease affects the health of infected citrus trees and the marketability of infected fruit. There is no cure for citrus canker thus prevention is the best option.
Canker causes the citrus tree to continually decline in health and fruit production until the tree produces no fruit at all. Citrus canker is highly contagious and can be spread rapidly.
Tom Okello Anyii, a model farmer in Lira District has learned a hard lesson. The executive director of TAF Mixed Farm in Telela Village in Ngetta Sub County, whose orchard has about 1,400 plants, says citrus production has continuously declined largely due to the incurable citrus disease.
“This has caused several farmers to abandon their orchards. For the growers that remain in the business, they have to lick their wounds,” he says. The citrus canker just rubbed salt into an old wound as farmers in the neighbouring Soroti District are frustrated with the lack of market for their oranges that was driven by the opening of the Soroti Fruit Factory in Aloet village.
Against this bleak backdrop, solutions were needed. “We tried chemical compositions but they were not effective,” he says.
Recent studies have recommended the use of bark horning at the beginning of the dry season, followed by chemical sprays, as an effective measure for managing citrus canker disease.
The recommended measures of preventing citrus canker include regular inspection of the orchard and on-site burning of infected trees. Anyii prefers the latter alternative.
“When I pick out infected fruits, I make sure that I uproot and burn down the affected plants,” he explains.
But there are challenges of adoption rate by other farmers. He that field sanitation is limited among farmers who still think having disinfectants is expensive or unnecessary.
“Visitors to any particular farm need to be disinfected in order to prevent the movement of diseases from one farm to another,” he says. At his orchard, which is guarded by a dog, visitors step in limestone, a disinfectant. Hydrated limestone, produces a dry and alkaline environment in which bacteria do not readily multiply.
“I have come to appreciate that there is no silver bullet. It is going to take a lot of approaches, but having limestone is a practical solution,” he said.