When Pythium spp. shows up late in the crop cycle, there are few options for salvaging the crop. Once the fungus is managed, it takes time for roots to re-grow, and there may not be enough time for plants to recover prior to sale. Signs of infected plants are wilting and stunting. Roots are soft and decayed, sometimes extending up into the stem where it causes a canker. Looking closely, the rotted outer covering of the root slips from the central core. There are different species of of Pythium that can cause problems on poinsettias.
Photoperiodic lighting is used to create long days for flower induction of long-day (LD) plants or to delay the flowering of short-day plants. Generally, long-day plants will flower when the daylength is longer than 14-16 hours (night length of less than 10 hours). Therefore, long-day lighting should be used from around Sept. 1 to April 15. Note that the critical daylength is likely to be different for each species.
Controlling whiteflies on poinsettias has been challenging since sweetpotato whitefly, Bemisa tabaci, first appeared in Florida in 1986 and then began to appear in greenhouses soon after. It was found to be a new, more insecticide-resistant strain, termed ‘B-biotype,’ with a broader host range than the usual B. tabaci. In 2004 an even more resistant strain, the Q biotype, was found in the US on poinsettia. Initially, these two biotypes were thought to all belong to the same B.
Easter 2016 falls on an early date, March 27th. Bringing a lily crop in on time will be a special challenge and some time-saving choices will need to be made along the way.
During this recent summer drought, grasshoppers may have been moving into your container grown annuals such as ornamental millet or container grown perennials. In the fall, you will mainly see adults feeding. Hot dry summers and warm autumns tend to be favorable to grasshoppers.