A survey was conducted of nursery operators participating in workshops in west-central Florida. The purpose of the survey was to identify the irrigation best management practices (BMPs) adopted by container nurseries in west-central Florida and obtain information regarding emphasis of future extension educational programs. Workshops were conducted in Hillsborough County, Fla., and Manatee County, Fla., and participation was voluntary. Respondents were asked about BMPs used in the nurseries according to the irrigation system used and it was found that the majority of the nurseries relied on well water as the primary source for irrigation. While 69% of the nurseries monitored uniformity of microirrigation systems, only 35% monitored uniformity of overhead irrigation systems. Thirty-four percent of the nurseries collected irrigation or rain runoff and 9% knew the water holding capacity of their substrate. Most of the nurseries grouped plants by irrigation requirements (74%) and grouped container sizes by irrigation requirements (69%). The survey indicates that many BMPs are not widely adopted by nurseries in west-central Florida. The information from this survey can be used as a guide to focus the efforts of university extension educational programs to achieve greater adoption of BMPs.
Gisele Schoene, Thomas Yeager and Dorota Haman
Gisele Schoene, Thomas Yeager and Joe Ritchie
In crop models, it is important to determine the leaf area, because the amount of light interception by leaves influences two very important processes in the plant: photosynthesis and evaporation. Leaf area is dependent on leaf appearance and expansion rates. Leaf appearance rate is driven mainly by temperature. Although the influence of temperature on leaf area development is well known for several agronomic crops, there is no information for woody ornamentals. An experiment was conducted to study the relationship between temperature and leaf appearance of container-grown sweet viburnum. Plants were grown in field conditions in Gainesville, Fla., during two growing periods (Apr. to Aug. 2004 and Aug. 2004 to Jan. 2005). Daily maximum and minimum temperature and leaf appearance were recorded. Linear regression equations were fitted to data and maximum and minimum temperature and leaf appearance were recorded. Linear regression equations were fitted to data and base temperature was assumed to be 8 °C. Thermal time (°C d) was calculated as daily average maximum and minimum air temperature minus the base temperature and was regressed against leaf number. The sum of accumulated thermal time was found to be linearly correlated with leaf number. Phyllochron, which is the thermal time between the appearances of successive leaves, was estimated 51 °C per day. The information presented in this study will be useful in modeling water use of sweet viburnum in response to environmental conditions.