Low Irrigation Regimes Research Articles

Vegetative Growth Response of ‘Olympus’ Strawberry to Polyethylene Mulch and Drip Irrigation Regimes1

Abstract Two field plantings of strawberries [Fragaria × ananassa Duch. cv. Olympus] were grown with and without black polyethylene mulch at 3 levels of drip irrigation and differential irrigation was maintained after plant establishment for 1 month in 1977 and 2 months in 1978. During the driest portion of each year the soil water potential at 20 cm depth remained above −0.5 bars for the highest level of irrigation, and fell below −11 bars at the lowest level. Mulch conserved soil moisture at the 2 lower irrigation levels in 1977, but this effect was minor in 1978. Vegetative growth was increased by both irrigation and mulch. The number of leaves produced during the first growing season was 30% (1977) and 25% (1978) greater in the high than the low-irrigation regime. Mulching improved leaf production 27% (1977) and 14% (1978). Most of these vegetative differences between treatments were still apparent at fruit harvest the following July. During a second year of treatments on the 1977 planting, the number of leaves was further enhanced by mulch and high irrigation. At the subsequent fruit harvest, 2-year-old plants had more leaves than those 1 year old, but the leaf area per plant averaged 27% lower. Leaf and crown dry weights of either 1- or 2-year-old plants at fruit harvest were slightly greater due to irrigation and significantly higher due to mulch, whereas root dry weight was unaffected by either treatment. The amount of summer irrigation required to sustain vigorous vegetative growth in mulched plants was only one third that of unmulched strawberries.