Spraying for the control of black spot in Citrus
Farming in South Africa 25: 292, 226-228
Black spot (Phoma citricarpa) continues to menace citrus crops in South Africa. In a recent greenhouse experiment at Durban dead leaves from trees which had shown no visible symptoms of the disease were suspended in a wire net above young lemon trees. and were sprayed for 10 minutes every two hours during the daytime for six days. Ten months later typical spots developed on the young lemon leaves.