EFFICACY OF FUNGICIDES FOR CONTROL OF A DIFFICULT FUNGUS ERYSIpHp CICHORACEARUM POWDERY MILDEW ON GERBERA DAISY GERBERA JAMESONII

摘要

Powdery mildew, caused by the fungus Erysiphe cichoracearum is a serious disease of Gerbera Daisy, Gerbera jamesonii. In 2005-06, five products, including conventional and a reduced risk biological fungicide, were trialed for efficacy against Erysiphecichoracearum and Sphaerotheca fusca in a polyhouse at Kerry's Bromeliad Nursery. Six susceptible cul-tivars of Gerbera plants started from tissue cultured-liners were potted in 20.0 cm (8 inch) plastic pots. Natural infection was allowed to take placeprior to the first application of the chemicals. Fungicides were applied on a 14 day schedule and replicated four times per treatment. Compass (trifloxystrobin) at 85 g (3 oz) per 380 L (100 gallon) of water, Heritage (azoxy-strobin) at 85 g (3 oz) per 380 L (100 gallon) of water and Syst-hane (myclobutanil) at 142 g (5 oz) per 380 L (100 gallon) of water were significantly more effective in the control of powdery mildew than whole milk 480 ml (16 f I oz) per 380 L (100 gallon) of water.