Chemical control of Cercospora leaf spot disease of cowpea (<i>Vigna unguiculata</i> (L.) Walp.)

Abstract

Three fungicides, benlate (methy'I -1- (butylcarbamoyl) - 2 - benzimidazole carbamate), dithane M -45 (zinc and magnesium ethylene bisdithiocarbamate) and difolatan (5 Cis - N - 1, l ,2,2 - tetrachloroethy 1) thio - .4 - cyclohexane - 1, 2 – di-carboximide) were tested in the field for Cercospora leaf spot control. The test fungicides were differentially effective in controlling Cercospora leaf spot in cowpea. Benlate controlled the disease more effectively than any of the other fungicides tested. Out of the three spraying intervals tested, weekly. fortnightly and triweekly spraying, weekly spraying commencing three weeks after planting with each of the test fungicides was the most effective. The level of disease control achievable was also affected by the time of application. Cowpea grain yield was significantly (P = 0.05) enhanced when spraying started three weeks after planting.