Effect of night temperatures on the severity of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. on Euonymus fortunei (Turcz.) Hand.-Mazz. rooted cuttings of `Emerald Gaiety', `Canadale Gold', and `Emerald 'n Gold' was investigated. Uniform cuttings were exposed to day temperatures of 35.3 °C and night temperatures of 19.3 °C or 28.6 °C in growth chambers. Plants exposed to a 28.6 °C night temperature had higher disease ratings than those exposed to a 19.3 °C night temperature. `Emerald Gaiety' was damaged least by C. gloeosporioides compared to `Canadale Gold' and `Emerald 'n Gold'. Disease ratings on all cultivars increased linearly over the 6-week experimental period.
Stephanie S. Ningen, Janet C. Cole and Kenneth E. Conway
Stephanie S. Ningen, Janet C. Cole, Michael W. Smith, Diane E. Dunn and Kenneth E. Conway
The effectiveness of shade intensity and time of day in which irrigation was applied were tested for control of anthracnose symptoms caused by Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. on container-grown Euonymus fortunei (Turcz.) Hand.-Mazz. `Canadale Gold', `Emerald 'n Gold', and `Emerald Gaiety' during the 2002 and 2003 growing seasons. Rooted cuttings in 3.8 L containers were placed in 0% (full sun), 63%, 73%, or 80% shade at Park Hill, Okla., in 2002 and 2003 and at Stillwater, Okla., in 2002. Overhead irrigation was used to irrigate one-half of the plants in each cultivar and shade treatment in the morning and the other one-half during the afternoon. At both sites, disease damage ratings were inversely related to shade intensity throughout each growing season. Disease incidence was usually lower on afternoon irrigated plants than on morning irrigated plants. `Canadale Gold' typically had the most anthracnose symptoms followed by `Emerald 'n Gold'. `Emerald Gaiety' had the least symptoms regardless of shade intensity or irrigation time.