Field performance of some selected fungicides in the control of Cercospora leaf spot disease of groundnut (Arachis hypagaca L.) in Ghana

Abstract

Five fungicides, Benomyl, Carbendazim, Metiram, Tridemorph and Triphenyltin hydroxide, were tested over 3 and 4 years in the field as weekly and forthnightly foliar sprays and as seed-dressing chemicals against Cercospora leaf spot disease of groundnut. For spraying, concentrations of 0.2 per cent (Benomyl, Carbendazim, Triphenyltin hydroxide) and 0.3 per cent (Metiram and Tridemorph) were used. For seed-dressing, the rates were 3.0 g aJ./kg of seed (Benomyl, Carbendazim and Triphenyltin hydroxide) and 4.8 g a.i/kg of seed, (Metiram and Tridemorph). Benomyl and Carbendazim significantly reduced leaf spot incidence more than Triphenyltin hydroxide which, in turn, significantly reduced the disease more than Tridemorph and Metiram when sprayed weekly and fortnightly. Weekly spraying gave significantly higher yields than forthnightly spraying. Foliar spraying with the fungicides was significantly more effective (P=0.01) in controlling the disease and inceasing yield than seed-dressing. It is recommended that fortnightly foliar application of 0.02 per cent Benomyl or Carbendazim should be used to control leaf spot disease of groundnut caused by Cercospora arachidicola and Cercosporidum personatum,