Plamistość liści Crassula multicava i możliwości chemicznej ochrony

The aim of this work was to determine the cause of leaf spotting of Crassula multicava and potential methods of their control. The leaves of succulent Crassula multicava growing in greenhouse conditions showed disease symptoms, yellow and gradually browning spots, and the disease was caused by Pestalotiopsis guepinii . The strobilurin fungicides, azoxystrobin (Amistar 250 SC), kresoxim - methyl (Discus 500 WG) and chlorotalonil with addition of zinc (Gwarant 500 SC) greatly inhibited the growth of Pestalotiopsis guepinii . Total inhibition of the myce lium growth was observed when azoxystrobin at concentration of 6 μ g/cm³ was added. Kresoxim - methyl and chlorotalonil with addition of zinc at a concentration of 10 μ g/cm³ limited the mycelium growth in 98% and 80% respectively. The inhibitory effect was gr eater for azoxystrobin than kresoxim - methyl and chlorotalonil. Preventively and curatively used of synthetic analogs of strobilurins and Gwarant greatly limited the development of Pestalotiopsis guepinii.