Our 6 1/2" pots of Prestige red top leaves are pointing upward. Started about 3 weeks ago. We have not had shade cloth on Since mid September. Our 8 inch prestige red are fine. No other reds or colors are showing signs in either size pot. Based on other discussions we feel we need to treat for early signs of root rot. The roots are mainly white. Growth and Breaks are good, Height 15-18 inch, beginning to color.

This message has been edited. Last edited by: Craig King,

Prestige can show some upward leaf curl when temperatures are warm in the greenhouse. If there are also signs of Pythium this could also exaggerate the leaf curl because the plant's ability to take up water is compromised, so especially during the warmer part of the day some signs of stress such as leaf curl or wilting could occur. It would also make sense that the smaller container sizes are showing more stress because of the smaller soil volume they are probably drying out faster than the 8". This is a tough situation to manage if Pythium is becoming a concern because to help prevent and suppress the Pythium you want the plants to dry out but if you let them dry out when temperatures are warm in the greenhouse the leaf curl could potentially get worse. The key here would be trying to still let the plants dry down but also managing environmental conditions and keeping temperatures down. If you know you will be facing a period of bright, sunny, warm days it may mean putting up some shade cloth. You should also think about a fungicide drench to get on top of the Pythium.