Field Results b

Methods
�
The experimental design was a randomized complete block split plot design with 5 irrigation treatments and 5 replicates. The irrigation treatments consisted of 1.0, 0.75, 0.50, 0.25 evapotranspiration.

Each replicate consisted of one plant each of 37 varieties. The 96 square metre blocks were separated by 2 metre turf paths. Plants were randomly located in the blocks to minimise shading, root competition and edge effects. Plants were transplanted from containers in May and June 2005 to ensure they were well established prior to the need to irrigate over summer.

Irrigation scheduling was controlled by a Weathertrak Pro Controller, in response to ETo generated by the Penman-Monteith formula based on weather data supplied from the Australian Bureau of Meteorology. In this experimental operation, weather data relevant to the Silvan site was sent via FTP to the US control centre for the Weathertrak US service, where the ETo was calculated, sent via the internet to Telstra Australia and then forwarded through GPRS to the Controller located at Silvan. Based on the ETo, the scheduling engine (Fig 1) in the Weathertrak Pro controller determined irrigation frequency and quantity.

Weather parameters were recorded using a Davis Vantage Pro weather station. Moisture sensors connected to the Davis Weather station recorded moisture levels at 200 mm depth in all irrigation treatments (Fig. 5) and no irrigation control plus additional sensors at 100mm and 300mm were located in the .5 ET treatment.
�
Assessment

Monthly assessment based on plant size (height, width) (Fig 7) plus performance indicators including landscape performance and foliage and form as measures of aesthetic appearance. Statistical analysis was applied to late spring (29/12/05) and late summer (5/4/06).
�
Performance and Foliage and Form
�
Acceptable performance = good landscape performance
Scored out of maximum of 5

Crop-specific factors (ETc) allow evapotranspiration rates to be calculated more accurately by factoring in the different transpiration rates of different crops at different stages in the growth cycle. An ETc of 1.0 is based on well watered grass that completely covers the ground and is uniformly clipped to a few inches in height.
If a crop transpires more or less then average then the ETc is adjusted up or down. An ETc of 1.25 is used if the crop transpires 25% more than grass. An ETc of 0.80 is used if the crop transpires 20% less than grass.
The ETc in the trial was set to 1 since there was a mixture of plants and there was little specific transpiration information on the plant cultivars and varieties used in the trial. The adjust feature of the Weathertrak controller was used to set irrigation treatments i.e. 1.0, 0.75, 0.50, 0.25 evapotranspiration.