FUNGICIDAL CONTROL OF BROWN SPOT OF PASSION FRUIT IN UGANDA

Passion fruit (Passiflora edulis Sims.) is one of the plants introduced into Uganda for commercial production in 1960's in an attempt to diversify the country's economy. The farms were initially concentrated in Busoga and Buganda. Unfortunately the crop was severely affected by diseases especially Brown Spot caused by Alternaria passiflorae Simmonds. For example a trial at the University Farm at Kabanyolo, near Kampala, did very well in the first 18 months, after which it was devastated by Brown Spot; also the crop in trials elsewhere in Uganda rapidly declined mainly because of this disease.

The symptoms of Brown Spot observed in Uganda resemble those described by Ondieki and Kori (1970) in Kenya. In other parts of the world this disease is controlled by pruning at least once a year, spraying with different fungicides, surgery to remove new lesions and by avoiding overhead irrigation (Smith, 1939; Anon, 1942; Malaguti and Narango, 1955).

The work of Ondieki and Kori (1970) provides a basis for recommending a fungicide programme to control Brown Spot in Kenya. At Kabanyolo spraying with Dithane M45 at 14-day intervals as recommended by Ondieki and Kori (1970) was started after the outbreak of the Brown Spot epiphytotic. However, this programme failed to control the disease and the field was finally abandoned. We therefore decided to obtain some experimental basis for fungicidal spray treatments against the disease. Our work is summarised in this paper.