Collar rot is one of the most destructive diseases affecting passion fruit farming. Characterised by a dark, water-soaked lesion around the base of the stem, collar rot can lead to plant wilting and eventual death if not managed early.
Experts warn that without proper control, farmers risk losing their entire gardens, especially during the rainy season.
Twaha Kakooza, a passion fruit farmer from Bubajjwe village in Kayunga district, says collar rot once devastated a quarter of his farm.
“The disease starts slowly, but within weeks, the plants begin to die off.
I later learned that it thrives in waterlogged soils,” he says.
Since then, Kakooza has adopted raised beds and improved drainage to reduce moisture accumulation around the roots.
Muhammad Kyazze, another farmer from Kamuli village in Kangulumira, says hygiene is also key in controlling the disease.
“I sanitise pruning tools and remove infected plants immediately. I also avoid working in the garden when it’s wet to prevent spreading the fungus,” Kyazze explains.
He now applies copper-based fungicides as a preventive measure.
Gideon Zakke, an agronomist, advises farmers to ensure good soil drainage and avoid deep planting.
“The fungus Phytophthora spp, which causes collar rot, thrives in wet and poorly aerated soils. Mulching should be done carefully, too much mulch near the stem increases moisture, encouraging infection,” he notes.
Zakke also recommends grafting purple passion fruit onto yellow passion fruit rootstocks, which are more tolerant to soil-borne diseases.
Regular monitoring, proper spacing, and applying fungicides like Ridomil or copper oxychloride can help manage the disease effectively.
Farmers should also avoid using contaminated manure and maintain clean fields.
With the right practices, collar rot can be managed, saving farmers from heavy losses and ensuring healthy, productive passion fruit vines.
