WATER REQUIREMENTS TRIALS
Ian Smith HortiCulture
Evaluation of the performance of landscape ornamental plants in
response to reduced irrigation - Greenhouse Trial
The objective was to determine the response of 6 ornamental plant
cultivars to reducing irrigation regimes.
Experimental groups were established in a heated greenhouse at Silvan,
Victoria, Australia, consisting of four 3.6 sq meter troughs providing four
irrigation treatments. Ten plants of 6 cultivars were planted into 125mm
pots in each irrigation treatment.
Each trough was flood irrigated with the same volume at each irrigation,
the frequency of irrigation was used to provide a range of treatments
designed to stress the plants and so determine the cultivars response to
reducing water availability.
The primary objective was to determine whether the protocol used was
an effective measure of plant water requirements
All plants will respond identically to various levels of irrigation.
Materials and Methods
The trial was conducted at Silvan, Victoria in a heated greenhouse.
Diurnal temperature range was 140C to 280C during the period of trial.
Environmental variables were measured during the duration of the trial.
The potting media used was selected to provide effective capillary uptake
from the flooded benches. Ten plants potted in 125mm pots were
randomly assigned to each treatment. Moisture sensors were used to
determine the appropriate irrigation frequency to ensure the potting media
was continually moist and to maximise growth rate. The range of irrigation
treatments were achieved by varying the frequency, three day interval
being the maximum irrigation rate, with further treatments of 6 day
interval, 9 day interval and 12 day interval.
Plants responded as expected to reducing irrigation treatments. The
protocol used is effective in determining plant water response.
Selected ornamental ground cover cultivars - response to reducing