EFFECTIVENESS AND COMPATIBILITY OF FUNGICIDES, INSECTICIDES, AND STARTER SOLUTIONS APPLIED JOINTLY TO CAULIFLOWER

Abstract

Insecticides alone or combined with fungicides and acidic or basic starter solutions were applied to cauliflower in the transplant water to determine their compatibility for control of Hylemya brassicae (Bouché), Plasmodiophora brassicae Wor. and Rhizoctonia solani Kuhn. Effects were assessed by periodic counts to determine phytotoxicity, by uprooting wilted plants to determine maggot damage or wire stem (R. solani), by counting marketable and unmarketable heads, and by uprooting the plants at harvest and grading the maggot damage and incidence by clubroot (P. brassicae). Maggot damage was severe in plots without insecticides. Mercuric chloride gave some protection from maggot damage but retarded early growth and was incompatible with the organophosphorus insecticides Birlane, Dasanic, diazînon and Zinophos. Clubroot was more severe in peat soil than in sandy loam, but was unevenly distributed. Many plants that had clubroot and were attacked by maggots still produced marketable heads if they survived for 6 weeks immediately after transplanting. Acidic starter solution with mercuric chloride reduced the percentage head production. Diazinon was the least effective insecticide. The organocarbamate, Furadan, had systemic properties.